Τρίτη, 24 Απριλίου 2018

Occurrence and associated factors of carotid artery calcification detected by digital panoramic radiography in chronic kidney disease patients undergoing hemodialysis

To investigate the occurrence and associated factors of carotid artery calcification (CAC) in chronic kidney disease (CKD) patients undergoing hemodialysis.

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Automatic quantification of calcifications in the coronary arteries and thoracic aorta on radiotherapy planning CT scans of Western and Asian breast cancer patients

This study automatically quantified calcifications in coronary arteries (CAC) and thoracic aorta (TAC) on breast planning computed tomography (CT) scans and assessed its reproducibility compared to manual scoring.

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Heart volume reduction during radiotherapy involving the thoracic region in children: An unexplained phenomenon

Radiotherapy involving the thoracic region is associated with cardiotoxicity in long-term childhood cancer survivors. We quantified heart volume changes during radiotherapy in children (<18 years) and investigated correlations with patient and treatment related characteristics.

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Improving the modelling of irradiation-induced brain activation for in vivo PET verification of proton therapy

A reliable Monte Carlo prediction of proton-induced brain tissue activation used for comparison to particle therapy positron-emission-tomography (PT-PET) measurements is crucial for in vivo treatment verification. Major limitations of current approaches to overcome include the CT-based patient model and the description of activity washout due to tissue perfusion.

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A long-awaited guideline for the delineation of primary tumor in head and neck cancer, and a few concerns about it

We read the article entitled 'Delineation of the primary tumour Clinical Target Volumes (CTV-P) in laryngeal, hypopharyngeal, oropharyngeal and oral cavity squamous cell carcinoma: AIRO, CACA, DAHANCA, EORTC, GEORCC, GORTEC, HKNPCSG, HNCIG, IAG-KHT, LPRHHT, NCIC CTG, NCRI, NRG Oncology, PHNS, SBRT, SOMERA, SRO, SSHNO, TROG consensus guidelines' with great interest [1]. There was a lack of a guideline for the delineation of the primary tumor in head and neck cancer. This paper might shed light on the accurate delineation the clinical target volume (CTV).

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Efficacy of thoracic radiotherapy in patients with stage IIIB–IV epidermal growth factor receptor-mutant lung adenocarcinomas who received and responded to tyrosine kinase inhibitor treatment

Large-scale, prospective, randomized studies of the efficacy of thoracic radiotherapy (RT) in patients with unresectable stage IIIB–IV epidermal growth factor receptor (EGFR)-mutant lung adenocarcinomas who received and responded to EGFR tyrosine kinase inhibitor (TKI) treatment are not currently available. Therefore, we designed a propensity score-matched, nationwide, population-based, cohort study for estimating the effects of thoracic RT on patients with EGFR-mutant lung adenocarcinomas.

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Overview of research and therapy facilities for radiobiological experimental work in particle therapy. Report from the European Particle Therapy Network radiobiology group

Particle therapy (PT) as cancer treatment, using protons or heavier ions, can provide a more favorable dose distribution compared to X-rays. While the physical characteristics of particle radiation have been the aim of intense research, less focus has been placed on the actual biological responses arising from particle irradiation.One of the biggest challenges for proton radiobiology is the RBE, with an increasing concern that the clinically-applied generic RBE-value of 1.1 is an approximation, as RBE is a complex quantity, depending on both biological and physical parameters, such as dose, LET, cellular and tissue radiobiological characteristics, as well as the endpoints being studied.

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Preoperative Digital Subtraction Angiography in Incidental Unruptured Intracranial Aneurysms

Abstract

Purpose

Digital subtraction angiography (DSA) is deemed necessary to precisely visualize intracranial aneurysms and define individual treatment strategies. In patients with unruptured intracranial aneurysms (UIA) who were diagnosed by MRI, a four-vessel DSA is usually performed to detect additional aneurysms. This study aimed to evaluate whether the evaluation of all vessels beyond the aneurysm-harboring artery is really necessary.

Material and methods

Patients with an UIA that was detected on MRA (TOF/ceMRA) were prospectively included. All patients underwent a four-vessel DSA (including 3D-DSA) and two experienced neuroradiologists independently analyzed the MRI sequences before DSA. The number of aneurysms, size and anatomic localization were documented and correlated with the angiographic findings.

Results

The DSA revealed a total of 134 aneurysms in 106 patients. Overall sensitivity and negative predictive value of MRA were 95.6% and 95.6%, respectively. In patients with multiple (≥2) aneurysms, 4 very small aneurysms <3 mm in the A2 segment, posterior communicating artery (PcomA), extradural internal carotid artery (ICA) were missed with MRI alone. In one patient with an ICA aneurysm, an additional small MCA bifurcation aneurysm was overlooked by MRA but detected by DSA. The periprocedural complication rate was 0.9%.

Conclusion

The rate of aneurysms that were detected by DSA but not by MRA was very low, thus potentially justifying visualization of the vessel harboring aneurysm alone; however, the four-vessel angiography detected further small aneurysms in patients with multiple aneurysms and therefore seems to be indicated in this specific subgroup. This approach has the potential to reduce the risk of complications, the intervention time and thus radiation exposure.



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American Thyroid Association Scientific Statement on the Use of Potassium Iodide Ingestion in a Nuclear Emergency.

Related Articles

American Thyroid Association Scientific Statement on the Use of Potassium Iodide Ingestion in a Nuclear Emergency.

Thyroid. 2017 Jul;27(7):865-877

Authors: Leung AM, Bauer AJ, Benvenga S, Brenner AV, Hennessey JV, Hurley JR, Milan SA, Schneider AB, Sundaram K, Toft DJ

Abstract
This document serves to summarize the issues and the American Thyroid Association (ATA) position regarding the use of potassium iodide as a thyroid blocking agent in the event of a nuclear accident. The purpose is to provide a review and updated position statement regarding the advanced distribution, stockpiling, and availability of potassium iodide in the event of nuclear radiation emergencies in the United States.

PMID: 28537500 [PubMed - indexed for MEDLINE]



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Micro-CT study of the human cochlear aqueduct.

Related Articles

Micro-CT study of the human cochlear aqueduct.

Surg Radiol Anat. 2018 Apr 21;:

Authors: Li Z, Shi D, Li H, Tan S, Liu Y, Qi C, Tang A

Abstract
OBJECTIVE: The anatomic structure of the cochlear aqueduct (CA) in human temporal bone specimens was observed using micro-computed tomography (CT).
MATERIALS AND METHODS: Micro-CT scanning of 18-µm-thick slices was performed on 30 slides of human temporal bone specimens to observe the CA structure and its relationship with its surroundings. The length, internal and external apertures, and the narrowest width of the CA were measured. The differences in CAs were compared between high jugular bulb (HJB) specimens and normal specimens.
RESULTS: A large number of CA images were acquired using Micro-CT scanning, which clearly displayed the basic anatomic structures, stereotactic localizations, and adjacent relationships of the CAs. The whole course of a CA was 12.31 ± 3.60 mm, the diameter of the internal aperture was 465 ± 242 µm, the diameter of the external aperture was 2.88 ± 1.06 mm, the narrowest diameter was 601 ± 335 µm, the diameter of the opening of inferior cochlear vein (ICV) was 151 ± 50 µm, the distance between the internal aperture and ICV was 270 ± 197 µm, and the distance between the inferior margin of the internal acoustic meatus (IAM) and the top most part of the external aperture of the CA was 6.783 ± 2.15 mm. No bony obstruction of the CA or CA enlargement was observed in the specimens. A total of 28 CAs had one accompanying bony canal in the surroundings. The length and travelling of the CA were not affected by the level of the jugular bulb (JB). The variation of the travelling of the ICV was larger than that of the CA.
CONCLUSION: Micro-CT adequately displayed the bony CA canal and provided a new method for anatomical studies of the CA and a basis for functional studies.

PMID: 29680956 [PubMed - as supplied by publisher]



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A first-in-man PET study of [ 18 F]PSS232, a fluorinated ABP688 derivative for imaging metabotropic glutamate receptor subtype 5

Abstract

Purpose

Non-invasive imaging of metabotropic glutamate receptor 5 (mGlu5) in the brain using PET is of interest in e.g., anxiety, depression, and Parkinson's disease. Widespread application of the most widely used mGlu5 tracer, [11C]ABP688, is limited by the short physical half-life of carbon-11. [18F]PSS232 is a fluorinated analog with promising preclinical properties and high selectivity and specificity for mGlu5. In this first-in-man study, we evaluated the brain uptake pattern and kinetics of [18F]PSS232 in healthy volunteers.

Methods

[18F]PSS232 PET was performed with ten healthy male volunteers aged 20–40 years. Seven of the subjects received a bolus injection and the remainder a bolus/infusion protocol. Cerebral blood flow was determined in seven subjects using [15O]water PET. Arterial blood activity was measured using an online blood counter. Tracer kinetics were evaluated by compartment modeling and parametric maps were generated for both tracers.

Results

At 90 min post-injection, 59.2 ± 11.1% of total radioactivity in plasma corresponded to intact tracer. The regional first pass extraction fraction of [18F]PSS232 ranged from 0.41 ± 0.06 to 0.55 ± 0.03 and brain distribution pattern matched that of [11C]ABP688. Uptake kinetics followed a simple two-tissue compartment model. The volume of distribution of total tracer (V T, ml/cm3) ranged from 1.18 ± 0.20 for white matter to 2.91 ± 0.51 for putamen. The respective mean distribution volume ratios (DVR) with cerebellum as the reference tissue were 0.88 ± 0.06 and 2.12 ± 0.10, respectively. The tissue/cerebellum ratios of a bolus/infusion protocol (30/70 dose ratio) were close to the DVR values.

Conclusions

Brain uptake of [18F]PSS232 matched the distribution of mGlu5 and followed a two-tissue compartment model. The well-defined kinetics and the possibility to use reference tissue models, obviating the need for arterial blood sampling, make [18F]PSS232 a promising fluorine-18 labeled radioligand for measuring mGlu5 density in humans.



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Extraction, selection and comparison of features for an effective automated computer-aided diagnosis of Parkinson’s disease based on [ 123 I]FP-CIT SPECT images

Abstract

Purpose

This work aimed to assess the potential of a set of features extracted from [123I]FP-CIT SPECT brain images to be used in the computer-aided "in vivo" confirmation of dopaminergic degeneration and therefore to assist clinical decision to diagnose Parkinson's disease.

Methods

Seven features were computed from each brain hemisphere: five standard features related to uptake ratios on the striatum and two features related to the estimated volume and length of the striatal region with normal uptake. The features were tested on a dataset of 652 [123I]FP-CIT SPECT brain images from the Parkinson's Progression Markers Initiative. The discrimination capacities of each feature individually and groups of features were assessed using three different machine learning techniques: support vector machines (SVM), k-nearest neighbors and logistic regression.

Results

Cross-validation results based on SVM have shown that, individually, the features that generated the highest accuracies were the length of the striatal region (96.5%), the putaminal binding potential (95.4%) and the striatal binding potential (93.9%) with no statistically significant differences among them. The highest classification accuracy was obtained using all features simultaneously (accuracy 97.9%, sensitivity 98% and specificity 97.6%). Generally, slightly better results were obtained using the SVM with no statistically significant difference to the other classifiers for most of the features.

Conclusions

The length of the striatal region uptake is clinically useful and highly valuable to confirm dopaminergic degeneration "in vivo" as an aid to the diagnosis of Parkinson's disease. It compares fairly well to the standard uptake ratio-based features, reaching, at least, similar accuracies and is easier to obtain automatically. Thus, we propose its day to day clinical use, jointly with the uptake ratio-based features, in the computer-aided diagnosis of dopaminergic degeneration in Parkinson's disease.



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Correction to: Biological tumour volumes of gliomas in early and standard 20–40 min 18 F-FET PET images differ according to IDH mutation status

Abstract

The name of M. Unterrainer was inadvertently presented as M. Unterrrainer in the original article.



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PSA-stratified detection rates for [ 68 Ga]THP-PSMA, a novel probe for rapid kit-based 68 Ga-labeling and PET imaging, in patients with biochemical recurrence after primary therapy for prostate cancer

Abstract

Purpose

[68Ga]Tris(hydroxypyridinone)(THP)-PSMA is a novel radiopharmaceutical for one-step kit-based radiolabelling, based on direct chelation of 68Ga3+ at low concentration, room temperature and over a wide pH range, using direct elution from a 68Ge/68Ga-generator. We evaluated the clinical detection rates of [68Ga]THP-PSMA PET/CT in patients with biochemically recurrent prostate cancer after prostatectomy.

Methods

Consecutive patients (n=99) referred for evaluation of biochemical relapse of prostate cancer by [68Ga]THP-PSMA PET/CT were analyzed retrospectively. Patients underwent a standard whole-body PET/CT (1 h p.i.), followed by delayed (3 h p.i.) imaging of the abdomen. PSA-stratified cohorts of positive PET/CT results, standardized uptake values (SUVs) and target-to-background ratios (TBRs) were analyzed, and compared between standard and delayed imaging.

Results

At least one lesion suggestive of recurrent or metastatic prostate cancer was identified on PET images in 52 patients (52.5%). Detection rates of [68Ga]THP-PSMA PET/CT increased with increasing PSA level: 94.1% for a PSA value of ≥10 ng/mL, 77.3% for a PSA value of 2 to <10 ng/mL, 54.5% for a PSA value of 1 to <2 ng/mL, 14.3% for a PSA value of 0.5 to <1 ng/mL, 20.0% for a PSA value of >0.2 to <0.5, and 22.2% for a PSA value of 0.01 to 0.2 ng/mL. [68Ga]THP-PSMA uptake (SUVs) in metastases decreased over time, whereas TBRs improved. Delayed imaging at 3 h p.i. exclusively identified pathologic findings in 2% of [68Ga]THP-PSMA PET/CT scans. Detection rate was higher in patients with a Gleason score ≥8 (P=0.02) and in patients receiving androgen deprivation therapy (P=0.003).

Conclusions

In this study, [68Ga]THP-PSMA PET/CT showed suitable detection rates in patients with biochemical recurrence of prostate cancer and PSA levels ≥ 2 ng /mL. Detections rates were lower than in previous studies evaluating other PSMA ligands, though prospective direct radiotracer comparison studies are mandatory particularly in patients with low PSA levels to evaluate the relative performance of different PSMA ligands.



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11 C–acetate PET/CT: a potential alternative of transcranial biopsy for grading cerebral gliomas



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Hybrid MR-PET of brain tumours using amino acid PET and chemical exchange saturation transfer MRI

Abstract

Purpose

PET using radiolabelled amino acids has become a promising tool in the diagnostics of gliomas and brain metastasis. Current research is focused on the evaluation of amide proton transfer (APT) chemical exchange saturation transfer (CEST) MR imaging for brain tumour imaging. In this hybrid MR-PET study, brain tumours were compared using 3D data derived from APT-CEST MRI and amino acid PET using O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET).

Methods

Eight patients with gliomas were investigated simultaneously with 18F-FET PET and APT-CEST MRI using a 3-T MR-BrainPET scanner. CEST imaging was based on a steady-state approach using a B1 average power of 1μT. B0 field inhomogeneities were corrected a Prametric images of magnetisation transfer ratio asymmetry (MTRasym) and differences to the extrapolated semi-solid magnetisation transfer reference method, APT# and nuclear Overhauser effect (NOE#), were calculated. Statistical analysis of the tumour-to-brain ratio of the CEST data was performed against PET data using the non-parametric Wilcoxon test.

Results

A tumour-to-brain ratio derived from APT# and 18F-FET presented no significant differences, and no correlation was found between APT# and 18F-FET PET data. The distance between local hot spot APT# and 18F-FET were different (average 20 ± 13 mm, range 4–45 mm).

Conclusion

For the first time, CEST images were compared with 18F-FET in a simultaneous MR-PET measurement. Imaging findings derived from18F-FET PET and APT CEST MRI seem to provide different biological information. The validation of these imaging findings by histological confirmation is necessary, ideally using stereotactic biopsy.



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Investigation of receptor radionuclide therapy with 177 Lu-DOTATATE in patients with GEP-NEN and a high Ki-67 proliferation index

Abstract

Purpose

In the 2010 WHO classification, a Ki-67 proliferation index of 20% is the cut-off between intermediate-grade and high-grade gastroenteropancreatic neuroendocrine neoplasia (GEP-NEN). However, in clinical practice, tumours with a Ki-67 index of >15% are often considered high grade and treated with chemotherapy. In 40–70% of high-grade NENs, somatostatin receptors are overexpressed, enabling peptide receptor radionuclide therapy (PRRT) to be performed. We investigated the role of PRRT with 177Lu-DOTATATE in patients with GEP-NEN and a high Ki-67 proliferation index.

Methods

A total of 33 patients with advanced GEP-NENs, positive somatostatin receptor imaging (SRI+) and a Ki-67 proliferation index ranging from 15% to 70% were treated with Lu-PRRT. A cumulative activity of 18.5 GBq or 27.8 GBq of 177Lu-DOTATATE was administered in four or five cycles. Receiver operating characteristic (ROC) curve analysis was used to determine the best threshold of Ki-67 expression to predict disease progression.

Results

All patients completed the intended treatment. The median follow-up was 43 months (range 3–69 months). Two patients (6%) achieved a partial response and 21 (64%) showed stable disease, giving a disease control rate (DCR) of 70%. The median progression-free survival (PFS) was 23 months (95% CI 14.9–31.0 months) and the median overall survival was 52.9 months (95% CI 17.1–68.9 months). ROC curve analysis at 23 months revealed that the best Ki-67 index cut-off was 35%. In 23 patients (70%) the Ki-67 index was ≤35% and in 10 patients (30%) the Ki-67 index was in the range 36–70%. The DCR in the former group was 87% and 30% in the latter. The median PFS was 26.3 months (95% CI 18.4–37.7 months) and 6.8 months (95% CI 2.1–27 months), respectively (p = 0.005).

Conclusions

Lu-PRRT showed antitumour activity in SRI+ GEP-NENs of intermediate and high-grade. DCR and PFS were significantly better in patients with a Ki-67 index of ≤35% than in those with a Ki-67 index of >35%. On the basis of these results, PRRT should be considered as a therapeutic option in patients with high-grade SRI+ GEP-NENs, in particular those with a Ki-67 proliferation index of ≤35%.



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Combined model-based and patient-specific dosimetry for 18 F-DCFPyL, a PSMA-targeted PET agent

Abstract

Purpose

Prostate-specific membrane antigen (PSMA), a type-II integral membrane protein highly expressed in prostate cancer, has been extensively used as a target for imaging and therapy. Among the available PET radiotracers, the low molecular weight agents that bind to PSMA are proving particularly effective. We present the dosimetry results for 18F-DCFPyL in nine patients with metastatic prostate cancer.

Methods

Nine patients were imaged using sequential PET/CT scans at approximately 1, 12, 35 and 70 min, and a final PET/CT scan at approximately 120 min after intravenous administration of 321 ± 8 MBq (8.7 ± 0.2 mCi) of18F-DCFPyL. Time-integrated-activity coefficients were calculated and used as input in OLINDA/EXM software to obtain dose estimates for the majority of the major organs. The absorbed doses (AD) to the eye lens and lacrimal glands were calculated using Monte-Carlo models based on idealized anatomy combined with patient-specific volumes and activity from the PET/CT scans. Monte-Carlo based models were also developed for calculation of the dose to two major salivary glands (parotid and submandibular) using CT-based patient-specific gland volumes.

Results

The highest calculated mean AD per unit administered activity of 18F was found in the lacrimal glands, followed by the submandibular glands, kidneys, urinary bladder wall, and parotid glands. The S-values for the lacrimal glands to the eye lens (0.42 mGy/MBq h), the tear film to the eye lens (1.78 mGy/MBq h) and the lacrimal gland self-dose (574.10 mGy/MBq h) were calculated. Average S-values for the salivary glands were 3.58 mGy/MBq h for the parotid self-dose and 6.78 mGy/MBq h for the submandibular self-dose. The resultant mean effective dose of 18F-DCFPyL was 0.017 ± 0.002 mSv/MBq.

Conclusions

18F-DCFPyL dosimetry in nine patients was obtained using novel models for the lacrimal and salivary glands, two organs with potentially dose-limiting uptake for therapy and diagnosis which lacked pre-existing models.



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The roles of 11 C-acetate PET/CT in predicting tumor differentiation and survival in patients with cerebral glioma

Abstract

Purpose

This prospective study aimed to evaluate the clinical values of 11C–acetate positron emission tomography/computed tomography (PET/CT) in predicting histologic grades and survival in patients with cerebral glioma.

Methods

Seventy-three patients with surgically confirmed cerebral gliomas (19 grade II, 21 grade III, and 33 grade IV) who underwent 11C–acetate PET/CT before surgery were included. Tumor-to-choroid plexus ratio (TCR), which was defined as the maximum standardized uptake value (SUV) of tumors to the mean SUV of choroid plexus, was compared between three World Health Organization (WHO) grade groups. Moreover, metabolic tumor volumes (MTV) were calculated. Progression-free survival (PFS) and overall survival (OS) curves were plotted using the Kaplan–Meier method, and differences in survival between groups were assessed using the log-rank test.

Results

Median TCR was 1.20 (interquartile range [IQR], 1.14 to 1.4) in grade II, 1.65 (IQR, 1.26 to 1.79) in grade III, and 2.53 (IQR, 1.93 to 3.30) in grade IV gliomas. Significant differences in TCR were seen among the three WHO grade groups (P < 0.001). In Cox regression analysis including TCR, MTV, molecular markers, and other clinical factors, TCR was prognostic for PFS (P = 0.016) and TCR and MTV were prognostic for OS (P = 0.024 [TCR], P = 0.030 [MTV]). PFS and OS were significantly shorter in patients with a TCR ≥ 1.6 than in those with a TCR < 1.6. OS were significantly shorter in patients with a MTV ≥ 1 than in those with a TCR < 1.

Conclusions

TCR on 11C–acetate PET/CT significantly differed between low- and high-grade cerebral gliomas, and it showed the capability to further differentiate grade III from grade IV tumors. TCR and MTV were independent prognostic factors and predicted survival better than did the WHO grade.



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Advantage of 18 F-PSMA-1007 over 68 Ga-PSMA-11 PET imaging for differentiation of local recurrence vs. urinary tracer excretion



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68 Ga-PSMA PET/CT in the evaluation of bone metastases in prostate cancer

Abstract

Purpose

The aims of this retrospective analysis were to compare 68Ga-PSMA PET findings and low-dose CT findings (120 kV, 30 mA), and to obtain semiquantitative and quantitative 68Ga-PSMA PET data in patients with prostate cancer (PC) bone metastases.

Methods

In total, 152 PET/CT scans from 140 patients were evaluated. Of these patients, 30 had previously untreated primary PC, and 110 had biochemical relapse after treatment of primary PC. All patients underwent dynamic PET/CT scanning of the pelvis and lower abdomen as well as whole-body PET/CT with 68Ga-PSMA-11. The PET/CT scans were analysed qualitatively (visually), semiquantitatively (SUV), and quantitatively based on a two-tissue compartment model and a noncompartmental approach leading to the extraction of the fractal dimension. Differences were considered significant for p values <0.05.

Results

In total, 168 68Ga-PSMA-positive and 113 CT-positive skeletal lesions were detected in 37 patients (8 with primary PC, 29 with biochemical recurrence). Of these 168 lesions, 103 were both 68Ga-PSMA PET-positive and CT-positive, 65 were only 68Ga-PSMA-positive, and 10 were only CT-positive. The Yang test showed that there were significantly more 68Ga-PSMA PET-positive lesions than CT-positive lesions. Association analysis showed that PSA plasma levels were significantly correlated with several 68Ga-PSMA-11-associated parameters in bone metastases, including the degree of tracer uptake (SUVaverage and SUVmax), its transport rate from plasma to the interstitial/intracellular compartment (K1), its rate of binding to the PSMA receptor and its internalization (k3), its influx rate (Ki), and its distribution heterogeneity.

Conclusion

68Ga-PSMA PET/CT is a useful diagnostic tool in the detection of bone metastases in PC. 68Ga-PSMA PET visualizes more bone metastases than low-dose CT. PSA plasma levels are significantly correlated with several 68Ga-PSMA PET parameters.



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Amyloid and tau signatures of brain metabolic decline in preclinical Alzheimer’s disease

Abstract

Purpose

We aimed to determine the amyloid (Aβ) and tau biomarker levels associated with imminent Alzheimer's disease (AD) - related metabolic decline in cognitively normal individuals.

Methods

A threshold analysis was performed in 120 cognitively normal elderly individuals by modelling 2-year declines in brain glucose metabolism measured with [18F]fluorodeoxyglucose ([18F]FDG) as a function of [18F]florbetapir Aβ positron emission tomography (PET) and cerebrospinal fluid phosphorylated tau biomarker thresholds. Additionally, using a novel voxel-wise analytical framework, we determined the sample sizes needed to test an estimated 25% drugeffect with 80% of power on changes in FDG uptake over 2 years at every brain voxel.

Results

The combination of [18F]florbetapir standardized uptake value ratios and phosphorylated-tau levels more than one standard deviation higher than their respective thresholds for biomarker abnormality was the best predictor of metabolic decline in individuals with preclinical AD. We also found that a clinical trial using these thresholds would require as few as 100 individuals to test a 25% drug effect on AD-related metabolic decline over 2 years.

Conclusions

These results highlight the new concept that combined Aβ and tau thresholds can predict imminent neurodegeneration as an alternative framework with a high statistical power for testing the effect of disease-modifying therapies on [18F]FDG uptake decline over a typical 2-year clinical trial period in individuals with preclinical AD.



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Imaging α v β 3 integrin expression in skeletal metastases with 99m Tc-maraciclatide single-photon emission computed tomography: detection and therapy response assessment

Abstract

Purpose

Osteoclast activity is an important factor in the pathogenesis of skeletal metastases and is a potential therapeutic target. This study aimed to determine if selective uptake of 99mTc-maraciclatide, a radiopharmaceutical targeting αvβ3 integrin, occurs in prostate cancer (PCa) bone metastases and to observe the changes following systemic therapy.

Methods

The study group comprised 17 men with bone-predominant metastatic PCa who underwent whole-body planar and single-photon emission computed tomography/computed tomography (SPECT/CT) imaging with 99mTc-maraciclatide before (n = 17) and 12 weeks after (n = 11) starting treatment with abiraterone. Tumour to normal bone (T:N) ratios, tumour to muscle (T:M) ratios and CT Hounsfield units (HU) were measured in up to five target metastases in each subject. An oncologist blinded to study scans assessed clinical responses up to 24 weeks using conventional criteria.

Results

Before treatment, metastases showed specific 99mTc-maraciclatide accumulation (mean planar T:N and T:M ratios 1.43 and 3.06; SPECT T:N and T:M ratios 3.1 and 5.19, respectively). Baseline sclerotic lesions (389–740 HU) showed lower T:M ratios (4.22 vs. 7.04, p = 0.02) than less sclerotic/lytic lesions (46–381 HU). Patients with progressive disease (PD; n = 5) showed increased planar T:N and T:M ratios (0.29 and 12.1%, respectively) and SPECT T:N and T:M ratios (11.9 and 20.2%, respectively). Patients without progression showed decreased planar T:N and T:M ratios (0.27 and −8.0%, p = 1.0 and 0.044, respectively) and SPECT T:N and T:M ratios (−21.9, and −27.2%, p = 0.3 and 0.036, respectively). The percentage change in CT HU was inversely correlated with the percentage change in SPECT T:M ratios (r = −0.59, p = 0.006).

Conclusions

99mTc-maraciclatide accumulates in PCa bone metastases in keeping with increased αvβ3 integrin expression. Greater activity in metastases with lower CT density suggests that uptake is related to osteoclast activity. Changes in planar and SPECT T:M ratios after 12 weeks of treatment differed between patients with and without PD and 99mTc-maraciclatide imaging may be a potential method for assessing early response.



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Prospective observational study of 177 Lu-DOTA-octreotate therapy in 200 patients with advanced metastasized neuroendocrine tumours (NETs): feasibility and impact of a dosimetry-guided study protocol on outcome and toxicity

Abstract

Purpose

Peptide receptor radionuclide therapy in patients with neuroendocrine tumours has yielded promising results. This prospective study investigated the feasibility of dosimetry of the kidneys and bone marrow during therapy and its impact on efficacy and outcome.

Methods

The study group comprised 200 consecutive patients with metastasized somatostatin receptor-positive neuroendocrine tumours progressing on standard therapy or not suitable for other therapeutic options. A treatment cycle consisted of 7.4 GBq 177Lu-DOTA-octreotate with co-infusion of a mixed amino acid solution, and cycles were repeated until the absorbed dose to the kidneys reached 23 Gy or there were other reasons for stopping therapy. The Ki-67 index was ≤2% in 47 patients (23.5%), 3–20% in 121 (60.5%) and >20% in 16 (8%).

Results

In 123 patients (61.5%) the absorbed dose to the kidneys reached 23 Gy with three to nine cycles during first-line therapy; in no patient was a dose to the bone marrow of 2 Gy reached. The best responses (according to RECIST 1.1) were a complete response (CR) in 1 patient (0.5%), a partial response (PR) in 47 (23.5%), stable disease (SD) in 135 (67.5%) and progressive disease (PD) in 7 (3.5%). Median progression-free survival was 27 months (95% CI 22–30 months) in all patients, 33 months in those in whom the absorbed dose to the kidneys reached 23 Gy and 15 months in those in whom it did not. Median overall survival (OS) was 43 months (95% CI 39–53 months) in all patients, 54 months in those in whom the absorbed dose to the kidneys reached 23 Gy and 25 months in those in whom it did not. Median OS was 60 months in patients with a best response of PR or CR, 42 months in those with SD and 16 months in those with PD. Three patients (1.5%) developed acute leukaemia, 1 patient (0.5%) chronic leukaemia (unconfirmed) and 30 patients (15%) grade 3 or 4 bone marrow toxicity. Eight patients (4%) developed grade 2 kidney toxicity and one patient (0.5%) grade 4 kidney toxicity.

Conclusions

Dosimetry-based therapy with 177Lu-DOTA-octreotate is feasible. Patients in whom the absorbed dose to the kidneys reached 23 Gy had a longer OS than those in whom it did not. Patients with CR/PR had a longer OS than those with SD. Bone marrow dosimetry did not predict toxicity.



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Cancer metastasizes to the bone marrow and not to the bone: time for a paradigm shift!



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Antitumor effects of radionuclide treatment using α-emitting meta - 211 At-astato-benzylguanidine in a PC12 pheochromocytoma model

Abstract

Purpose

Therapeutic options for patients with malignant pheochromocytoma are currently limited, and therefore new treatment approaches are being sought. Targeted radionuclide therapy provides tumor-specific systemic treatments. The β-emitting radiopharmaceutical meta-131I-iodo-benzylguanidine (131I-MIBG) provides limited survival benefits and has adverse effects. A new generation of radionuclides for therapy using α-particles including meta-211At-astato-benzylguanidine (211At-MABG) are expected to have strong therapeutic effects with minimal side effects. However, this possibility has not been evaluated in an animal model of pheochromocytoma. We aimed to evaluate the therapeutic effects of the α-emitter 211At-MABG in a pheochromocytoma model.

Methods

We evaluated tumor volume-reducing effects of 211At-MABG using rat pheochromocytoma cell line PC12 tumor-bearing mice. PC12 tumor-bearing mice received intravenous injections of 211At-MABG (0.28, 0.56, 1.11, 1.85, 3.70 and 5.55 MBq; five mice per group). Tumor volumes were evaluated for 8 weeks after 211At-MABG administration. The control group of ten mice received phosphate-buffered saline.

Results

The 211At-MABG-treated mice showed significantly lower relative tumor growth during the first 38 days than the control mice. The relative tumor volumes on day 21 were 509.2% ± 169.1% in the control mice and 9.6% ± 5.5% in the mice receiving 0.56 MBq (p < 0.01). In addition, the mice treated with 0.28, 0.56 and 1.11 MBq of 211At-MABG showed only a temporary weight reduction, with recovery in weight by day 10.

Conclusion

211At-MABG exhibited a strong tumor volume-reducing effect in a mouse model of pheochromocytoma without weight reduction. Therefore, 211At-MABG might be an effective therapeutic agent for the treatment of malignant pheochromocytoma.



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The relationship between local recurrences and distant metastases in prostate cancer: can 11 C-choline PET/CT contribute to understand the link?

Abstract

Purpose

Previous studies in prostate cancer (PCa) patients tried to correlate the onset of local recurrence (LR) with the development of distant metastases and formulated, based on theoretical and experimental data, hypotheses linking the two events. We aimed to address this issue with 11C-choline positron emission tomography/computed tomography (PET/CT).

Methods

This retrospective study included 491 PCa patients previously treated with radical prostatectomy who had undergone 11C-choline PET/CT owing to biochemical failure. Further inclusion criteria were availability of clinical and pathological variables for survival analysis. Statistical significance was taken at P < 0.05.

Results

Seventy-two patients (14.7%) had evidence of LR at 11C-choline PET/CT. The frequency of LR increased from 13.8% in the interval 0–4 years after prostatectomy, to 23.9% in the 12–16-year interval (P = 0.080). On the contrary, the frequency of lymph node metastases (overall rate in the 0–16 years interval after prostatectomy: 26.3%) and of bone metastases (overall rate: 13.8%) decreased significantly over time. Kaplan-Meier curves showed no significant group difference in the rates of lymph node or bone metastases between patients with LR and patients without LR. LR significantly predicted PCa-specific survival at univariate analysis, but the statistical significance was lost at multivariate analysis.

Conclusion

We found no differences in the rates of lymph node and bone metastases between patients with and without LR. An inverse time-dependent trend was observed in the frequency of LR on one side and of lymph node and bone metastases on the other side. These findings were discussed in relation to previous theories linking LR to distant metastases and our study design.



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FDG-PET/CT for treatment response assessment in head and neck squamous cell carcinoma: a systematic review and meta-analysis of diagnostic performance

Abstract

Purpose

18-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is increasingly used to evaluate treatment response in head and neck squamous cell carcinoma (HNSCC). This analysis assessed the diagnostic value of FDG-PET/CT in detecting nodal disease within 6 months after treatment, considering patient and disease characteristics.

Methods

A systematic review was performed using the MEDLINE and Web of Knowledge databases. The results were pooled using a bivariate random effects model of the sensitivity and specificity.

Results

Out of 22 identified studies, a meta-analysis of 20 studies (1293 patients) was performed. The pooled estimates of sensitivity, specificity and diagnostic odds ratio (with 95% CI) were 85% (76–91%), 93% (89–96%) and 76 (35–165), respectively. With the prevalence set at 10%, the positive and negative predictive values were 58% and 98%. There was significant heterogeneity between the trials (p < 0.001). HPV positive tumors were associated with lower sensitivity (75% vs 89%; p = 0.01) and specificity (87% vs 95%; p < 0.005).

Conclusion

FDG-PET/CT within 6 months after (chemo)radiotherapy in HNSCC patients is a reliable method for ruling out residual/recurrent nodal disease and obviates the need for therapeutic intervention. However, FDG-PET/CT may be less reliable in HPV positive tumors and the optimal surveillance strategy remains to be determined.



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Is it time to change our vision of tumor metabolism prior to immunotherapy?



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Repeatability of quantitative 18 F-FLT uptake measurements in solid tumors: an individual patient data multi-center meta-analysis

Abstract

Introduction

3′-deoxy-3′-[18F]fluorothymidine (18F–FLT) positron emission tomography (PET) provides a non-invasive method to assess cellular proliferation and response to antitumor therapy. Quantitative 18F–FLT uptake metrics are being used for evaluation of proliferative response in investigational setting, however multi-center repeatability needs to be established. The aim of this study was to determine the repeatability of 18F–FLT tumor uptake metrics by re-analyzing individual patient data from previously published reports using the same tumor segmentation method and repeatability metrics across cohorts.

Methods

A systematic search in PubMed, EMBASE.com and the Cochrane Library from inception-October 2016 yielded five 18F–FLT repeatability cohorts in solid tumors. 18F–FLT avid lesions were delineated using a 50% isocontour adapted for local background on test and retest scans. SUVmax, SUVmean, SUVpeak, proliferative volume and total lesion uptake (TLU) were calculated. Repeatability was assessed using the repeatability coefficient (RC = 1.96 × SD of test–retest differences), linear regression analysis, and the intra-class correlation coefficient (ICC). The impact of different lesion selection criteria was also evaluated.

Results

Images from four cohorts containing 30 patients with 52 lesions were obtained and analyzed (ten in breast cancer, nine in head and neck squamous cell carcinoma, and 33 in non-small cell lung cancer patients). A good correlation was found between test–retest data for all 18F–FLT uptake metrics (R2 ≥ 0.93; ICC ≥ 0.96). Best repeatability was found for SUVpeak (RC: 23.1%), without significant differences in RC between different SUV metrics. Repeatability of proliferative volume (RC: 36.0%) and TLU (RC: 36.4%) was worse than SUV. Lesion selection methods based on SUVmax ≥ 4.0 improved the repeatability of volumetric metrics (RC: 26–28%), but did not affect the repeatability of SUV metrics.

Conclusions

In multi-center studies, differences ≥ 25% in 18F–FLT SUV metrics likely represent a true change in tumor uptake. Larger differences are required for FLT metrics comprising volume estimates when no lesion selection criteria are applied.



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Aggressive curettage of a chondroblastoma-like osteosarcoma of the proximal end of the tibia. A case report with seven-year follow-up

Abstract

A chondroblastoma-like osteosarcoma (CLO) in the proximal epiphysis and metaphysis of the tibia in a 30-year-old male is presented. With a wrong diagnosis of chondroblastoma, an aggressive curettage was performed. Later, the patient refused en-bloc resection. Seven years after surgery, there has been no local recurrence, and the patient is living an ordinary and active life. CLO is a very uncommon and controversial histologic subtype of osteosarcoma that can be misdiagnosed as chondroblastoma and therefore incorrectly treated. However, aggressive curettage with its functional advantages could be a reasonable option in selected cases.



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Mosaic-pattern dedifferentiation in liposarcoma and chondrosarcoma: imaging features of an uncommon form of dedifferentiation

Abstract

The term "dedifferentiation" was classically used in sarcoma pathology to refer to tumors in which a high-grade, undifferentiated sarcoma, or a high-grade sarcoma showing heterologous differentiation, arises from a pre-existing neoplasm of borderline or low-grade malignancy. The best recognized examples of this include dedifferentiated liposarcoma, arising from atypical lipomatous tumor/well-differentiated liposarcoma, and dedifferentiated chondrosarcoma, arising from grade 1 hyaline chondrosarcoma of bone. In the overwhelming majority of cases, this dedifferentiated, high-grade sarcoma presents as a macroscopically visible mass, adjacent to and clearly distinct from the pre-existing low-grade lesion. It is less well appreciated that dedifferentiation may also occur in a so-called "mosaic pattern,' in which the high-grade component is intimately admixed with elements of the precursor lesion, forming only microscopically apparent foci. This mosaic or co-mingling pattern of dedifferentiation is also reflected in the MR imaging appearance. In contrast to the classic pattern of dedifferentiation in which there are two distinct juxtaposed masses with different signal intensities and enhancement patterns, such changes are not seen in mosaic dedifferentiation. The imaging features of this pattern of dedifferentiation have not been described. In this report we describe the imaging features of two patients with mosaic pattern dedifferentiation, one with liposarcoma and one with chondrosarcoma. In both cases the precursor lesion was correctly diagnosed by pre-biopsy imaging, but the presence of high-grade sarcoma was not recognized.



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Clavicle pain



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Effect of sarcopenia on clinical and surgical outcome in elderly patients with proximal femur fractures

Abstract

Purpose

To investigate the relationship between sarcopenia with short-term surgical outcome in elderly patients with proximal femur fractures.

Methods and materials

Following Institutional Review Board approval, a database of patients receiving a pelvis CT scan for acute trauma between January 2000–August 2016 was screened for an isolated proximal femur fracture. Patients were excluded if they were: < 50 years old, had conditions predisposing to sarcopenia (renal failure, congestive heart failure, muscular dystrophies), had undergone no surgical treatment, had other major traumatic injuries, or had a pathologic femur fracture. The paraspinal muscle density (PSD) at the L4 level was measured in Hounsfield units. The skeletal muscle index (SMI) was measured as the total skeletal muscle area at L4 divided by patient height.2 PSD and SMI were tested for association with surgical outcome measures: length of hospital stay, perioperative mortality, medical complications, in-hospital blood transfusion volume, and 90-day readmission rate, using multiple variable regression analysis. Pearson correlation of PSD and SMI was performed.

Results

Controlling for age, gender, body mass index (BMI), and fracture type, low PSD and SMI were both independently associated with longer length of hospitalization (p = 0.008 and p = 0.032, respectively). Low PSD was associated with a higher amount of blood transfusion volume during the perioperative period (p = 0.004). Pearson correlation revealed moderate positive correlation between the SMI and PSD (r = 0.579, p < 0.001).

Conclusion

In proximal femur fractures, elderly patients with sarcopenia are more likely to have prolonged hospitalization following surgery and require more blood transfusion volume during the perioperative period.



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Adaptive statistical iterative reconstruction use for radiation dose reduction in pediatric lower-extremity CT: impact on diagnostic image quality

Abstract

Background

For the past several years, increased levels of imaging radiation and cumulative radiation to children has been a significant concern. Although several measures have been taken to reduce radiation dose during computed tomography (CT) scan, the newer dose reduction software adaptive statistical iterative reconstruction (ASIR) has been an effective technique in reducing radiation dose. To our knowledge, no studies are published that assess the effect of ASIR on extremity CT scans in children.

Objective

To compare radiation dose, image noise, and subjective image quality in pediatric lower extremity CT scans acquired with and without ASIR.

Materials and methods

The study group consisted of 53 patients imaged on a CT scanner equipped with ASIR software. The control group consisted of 37 patients whose CT images were acquired without ASIR. Image noise, Computed Tomography Dose Index (CTDI) and dose length product (DLP) were measured. Two pediatric radiologists rated the studies in subjective categories: image sharpness, noise, diagnostic acceptability, and artifacts.

Results

The CTDI (p value = 0.0184) and DLP (p value <0.0002) were significantly decreased with the use of ASIR compared with non-ASIR studies. However, the subjective ratings for sharpness (p < 0.0001) and diagnostic acceptability of the ASIR images (p < 0.0128) were decreased compared with standard, non-ASIR CT studies.

Conclusion

Adaptive statistical iterative reconstruction reduces radiation dose for lower extremity CTs in children, but at the expense of diagnostic imaging quality. Further studies are warranted to determine the specific utility of ASIR for pediatric musculoskeletal CT imaging.



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Hairline fractures following volar plating of the distal radius: a recently recognized hardware-related complication

Abstract

Objectives

Intraoperative hairline longitudinal fractures were recently reported in association with distal radius volar plating. Our aim was to further analyze this newly described complication.

Methods

A retrospective radiographic and chart review was performed on 225 patients who underwent distal radius plating between June 2013 and June 2015. The Acu-Loc/Acu-Loc2© plating system (Acumed, Hillsboro, OR, USA) was used in 208 cases, and the VariAx© plating system (Stryker, Kalamazoo, MI, USA) was used in 17 cases. Three independent reviewers performed a blind evaluation of all relevant radiographs for the occurrence of longitudinal fractures around the plate, and validity was considered only when there was agreement among all three of them.

Results

Hairline longitudinal fractures were identified in 57 cases (25%), 55 with the Acu-Loc/Acu-Loc2© system and 2 with the VariAx© system. All fractures occurred with volar plating. Fracture occurrence was associated with age over 59 years, female gender, extra-articular fractures, and the use of Hexalobe screws (Acu-Loc/Acu-Loc2© system).

Conclusions

We believe that the source of fracture occurrence lies within the screw design and that better screw design and possibly tapping in patients at risk may reduce the occurrence of intraoperative hairline longitudinal fractures. Further clinical and biomechanical research is needed to better understand this newly reported complication.



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Reproducibility of shear wave elastography measuresof the Achilles tendon

Abstract

Objective

To assess the reproducibility of shear wave elastography (SWE) measures in the Achilles tendon (AT) in vivo.

Materials and methods

Shear wave velocity (SWV) of 14 healthy volunteers [7 males, 7 females; mean age 26.5 ± 3.8 years, mean height 171.6 ± 10.9 cm, mean Victorian Institute of Sports Assessment Achilles questionnaire (VISA-A) score 99.4 ± 1.2] was measured with the foot relaxed and fixed at 90°. Data were collected over five consecutive measures and 5 consecutive days.

Results

Mean SWV values ranged from 7.91 m/s–9.56 m/s ± 0.27–0.50 m/s. Coefficient of variation (CV), correlations and intra-class correlation coefficient (ICC) scores ranged from 2.9%–6.3%, 0.4–0.7 and 0.54–0.85 respectively. No significant differences were noted for longitudinal or transverse data with respect to protocol or time and no significant differences were noted for foot position in transverse data. Significant differences in SWV values were noted between foot positions for longitudinal scanning (p = <0.05), with a relaxed foot position providing SWV values on average 0.47 m/s faster than a fixed position. Increased reproducibility was obtained with the foot relaxed. ICC between operators was 0.70 for transverse and 0.80 for longitudinal scanning.

Conclusions

Reproducible SWE measures were obtained over a 1-h period as well as a period of 5 consecutive days with more reliable measures obtained from a longitudinal plane using a relaxed foot position. SWE also has a high level of agreement between operators making SWE a reproducible technique for quantitatively assessing the mechanical properties of the human AT in vivo.



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The association of the medial joint vacuum phenomenon with ulnar collateral ligament injury in symptomatic elbows of younger athletes

Abstract

Objective

To determine the prevalence of intra-articular gas (IAG) on elbow radiography and evaluate variables, including IAG, as predictors of UCL injury.

Materials and methods

This IRB-approved retrospective study consisted of 241 consecutive elbow radiographic studies containing AP radiographs with valgus stress of both symptomatic and asymptomatic sides in 234 patients. The IAG, medial joint space (MJS), and MJS difference between the symptomatic and asymptomatic elbow (MJSD) were evaluated by two readers, as well as patient age, gender, sport played, and handedness. Primary outcomes included IAG on valgus stress radiographs and UCL injury, which was determined by intraoperative findings as the reference standard or MRI if surgery was not performed. Univariate analysis with Student's t, Fisher's exact, and chi-square tests were performed.

Results

IAG only manifested with valgus stress and was demonstrated in 30/482 (6.2%) valgus stress radiographs in 27/234 (11.5%) patients. Overall, 21/241 (8.7%) valgus stress radiographs of the symptomatic elbow demonstrated IAG in 21 patients. A total of 128/241 (53.1%) elbow studies had evidence of UCL injury. MJS IAG (p = 0.0147) and increased MJSD (p = 0.0088) were significantly associated with UCL injury. Patient gender, age, handedness, laterality, sport played, and absolute MJS were not associated with UCL injury. MJS IAG with valgus stress demonstrates a sensitivity of 11.7% and specificity of 98.3% in detecting UCL injury for the symptomatic elbow.

Conclusions

MJS IAG infrequently manifests on valgus stress radiographs, but is specific for UCL injury in the symptomatic elbow of overhead throwing athletes. MJS IAG and increased MJSD are significantly associated with UCL injury.



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MR arthrography of the hip: diagnostic performance and image quality of 3D-steady state free precession versus 2D turbo spin echo sequences

Abstract

Objective

To retrospectively compare the diagnostic performance of isotropic 3D steady-state free precession (3D-SSFP) sequences with 2D turbo spin-echo proton density-weighted fat-saturated (2D-TSE-PD fs) images in hip magnetic resonance arthrography; arthroscopy was a standard of reference.

Methods

Eighty-one patients with suspected labral tears who underwent hip MR arthrography (3-T scanner) were included. 2D-TSE-PD fs sequences were acquired in three planes and a singular sagittal 3D-SSFP. Labral tears, cartilage pathology and bone marrow were independently assessed by two blinded radiologists using a 5-point Likert scale. Accuracy was determined in 39 patients using invasive arthroscopy.

Results

Diagnostic confidence of labral and cartilaginous pathologies based on image quality was rated higher for 3D-SSFP (4.5 ± 0.8; 4.35 ± 0.7; p < 0.0001), but inferior for bone marrow pathology (3.9 ± 0.7; 4.0 ± 0.7; p < 0.0001). In the arthroscopy patients, similar sensitivity (85.9%) but higher specificity (74.4vs.42.9%) and higher positive and negative predictive values were found in 3D-SSFP of labral and cartilage pathologies.

Conclusions

3D-SSFP in hip magnetic resonance arthrography offers increased accuracy in detecting labral and cartilage pathologies compared with 2D–TSE-PD, while reducing the acquisition time. A drawback of 3D-SSFP was the inferior diagnostic confidence for bone marrow evaluation; thus, 3D-SSFP should be combined with conventional 2D-TSE sequences.



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Correction to: Triple elastofibromas located in the supra- and infrascapular regions—a case report

Abstract

The original version of this article unfortunately contained mistakes. The authornames of Matías de Albert, Manuel Perez, and Rosa Dominguez Oronoz as well as the affiliation of Dr. Perez are now corrected in this article.



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Case report: vertebral foreign body granuloma mimicking a skeletal metastasis

Abstract

Intraosseous foreign body granuloma formation related to migrated surgical material is a rarely reported condition with variable imaging appearance. In this case report, we describe a foreign body granuloma that occurred in a lumbar vertebral body one level above a prior surgical fusion. The lytic appearance mimicked a skeletal metastasis in a 65-year-old patient with recently diagnosed renal cell carcinoma. To the best of our knowledge, this is the first reported case of a lumbar vertebral foreign body granuloma occurring distant from the site of surgery, indistinguishable from skeletal metastasis on radiologic examination.



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Magnetic resonance imaging follow-up of chondroid tumors: regression vs. progression

Abstract

Objective

To present magnetic resonance imaging (MRI) evidence of the regression or progression of chondroid tumors and to investigate whether MRI can be used to predict the evolution of chondroid tumors.

Materials and methods

Twenty-one patients with enchondromas or atypical cartilaginous tumors who had undergone extremity MRI at least twice with a minimum 12-month interval between the MRIs were enrolled in this study. The diagnosis was based on the radiography and MRI findings. We classified the tumors into the following three groups according to changes between the MRIs: no change (NC), progression (P), and regression (R). We assessed the initial MRI features, including anatomical location, size, endosteal scalloping, peritumoral edema, fat entrapment, and direction of progression or regression. Nineteen of the 21 patients had contrast-enhanced images, and we analyzed the presence of atypical lobular enhancement against typical peripheral or septal enhancement.

Results

The R group comprised 11 cases (52%), the P group comprised five cases (24%), and the NC group comprised five cases (24%). None of the MRI features showed statistically significant differences among the groups. Atypical lobular enhancement was observed in the R (6 of 10, 60%) and NC (2 of 5, 40%) groups but not in the P group (0 of 4, 0%), although these differences were not statistically significant.

Conclusions

Chondroid tumors can either regress or progress in the MRI follow-up. Atypical lobular enhancement was seen only in stable or regressing tumors.



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Gemelli-obturator complex in the deep gluteal space: an anatomic and dynamic study

Abstract

Objective

To investigate the behavior of the sciatic nerve during hip rotation at subgluteal space.

Materials and methods

Sonographic examination (high-resolution ultrasound machine at 5.0–14 MHZ) of the gemelli-obturator internus complex following two approaches: (1) a study on cadavers and (2) a study on healthy volunteers. The cadavers were examined in pronation, pelvis-fixed position by forcing internal and external rotations of the hip with the knee in 90° flexion. Healthy volunteers were examined during passive internal and external hip rotation (prone position; lumbar and pelvic regions fixed). Subjects with a history of major trauma, surgery or pathologies affecting the examined regions were excluded.

Results

The analysis included eight hemipelvis from six fresh cadavers and 31 healthy volunteers. The anatomical study revealed the presence of connective tissue attaching the sciatic nerve to the structures of the gemellus-obturator system at deep subgluteal space. The amplitude of the nerve curvature during rotating position was significantly greater than during resting position. During passive internal rotation, the sciatic nerve of both cadavers and healthy volunteers transformed from a straight structure to a curved structure tethered at two points as the tendon of the obturator internus contracted downwards. Conversely, external hip rotation caused the nerve to relax.

Conclusion

Anatomically, the sciatic nerve is closely related to the gemelli-obturator internus complex. This relationship results in a reproducible dynamic behavior of the sciatic nerve during passive hip rotation, which may contribute to explain the pathological mechanisms of the obturator internal gemellus syndrome.



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Quantification of osteoblastic activity in epiphyseal growth plates by quantitative bone SPECT/CT

Abstract

Objective

Quantifying the function of the epiphyseal plate is worthwhile for the management of children with growth disorders. The aim of this retrospective study was to quantify the osteoblastic activity at the epiphyseal plate using the quantitative bone SPECT/CT.

Materials and methods

We enrolled patients under the age of 20 years who received Tc-99m hydroxymethylene diphosphonate bone scintigraphy acquired by a quantitative SPECT/CT scanner. The images were reconstructed by ordered subset conjugate-gradient minimizer, and the uptake on the distal margin of the femur was quantified by peak standardized uptake value (SUVpeak). A public database of standard body height was used to calculate growth velocities (cm/year).

Results

Fifteen patients (6.9–19.7 years, 9 female, 6 male) were enrolled and a total of 25 legs were analyzed. SUVpeak in the epiphyseal plate was 18.9 ± 2.4 (average ± standard deviation) in the subjects under 15 years and decreased gradually by aging. The SUVpeak correlated significantly with the age- and sex-matched growth velocity obtained from the database (R2 = 0.83, p < 0.0001).

Conclusion

The SUV measured by quantitative bone SPECT/CT was increased at the epiphyseal plates of children under the age of 15 years in comparison with the older group, corresponding to higher osteoblastic activity. Moreover, this study suggested a correlation between growth velocity and the SUV. Although this is a small retrospective pilot study, the objective and quantitative values measured by the quantitative bone SPECT/CT has the potential to improve the management of children with growth disorder.



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Clavicle pain



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Browser’s Notes



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A posterior labral cyst associated with an anterior labral tear of the hip

Abstract

Paralabral cysts are often associated with labral and other intraarticular hip pathology; MRI as well as diagnostic ultrasound can assist in diagnosis. Although often considered a coincidental finding, paralabral cysts can be a separate pain generator about the hip through compression of surrounding anatomy. They can also be initially mistaken for malignancy or other pathology by providers unfamiliar with their appearance. We present the case of an active 33-year-old female with right hip pain secondary to a large symptomatic posterior acetabular paralabral cyst with concomitant anterior labral tear. Following diagnosis on MRI, treatment included ultrasound-guided aspiration of the cyst, followed by arthroscopic anterior labral repair and separate cyst decompression from a posterior portal. The patient had complete resolution of her symptoms.



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Gouty involvement of the patella and extensor mechanism of the knee mimicking aggressive neoplasm. A case series

Abstract

Gout is a common inflammatory crystal deposition disease that occurs in many joints throughout the body. Active gout is most often associated with painful synovitis causing searing joint pains, but gout can also produce large masses of space-occupying deposits called tophi. Tophi are most frequently seen in juxta-articular locations with or without bony erosion and are often misdiagnosed as degenerative joint disease. Soft tissue deposits and tendon involvement are also known manifestations of gout, but can present with indeterminate and alarming findings on imaging. We present three cases of tophaceous gout mimicking aggressive neoplasms in the extensor mechanism of the knee. All cases presented as extensor tendon masses eroding into the patella, with imaging findings initially concerning for primary musculoskeletal malignancy.



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Infiltrating angiolipoma of the foot: magnetic resonance imaging features and review of the literature

Abstract

Angiolipoma is a benign soft tissue tumor with two subtypes: non-infiltrating and infiltrating. Although histologically benign, infiltrating angiolipoma can invade surrounding structures. The foot is a very rare location for angiolipoma, with only four cases reported in the English literature, including one infiltrating type. Here, we report a very rare case of infiltrating angiolipoma of the foot with magnetic resonance imaging (MRI) and ultrasonography (US) findings. A 7-year-old boy presented with a slowly growing foot mass. MRI showed an unencapsulated mass involving the third web space extending to the foot dorsum and sole. The mass was isointense to subcutaneous fat and was mixed with internal T1 low-signal-intensity enhancing areas. On US, we observed a heterogeneously hypoechoic mass with internal vascularity. Imaging and clinical features of angiolipoma and the radiologic differential diagnoses of a fat-containing mass in the pediatric foot are reviewed here. When there is an ill-defined foot mass with a fat component and variable enhancing portions in a child, infiltrating angiolipoma should be included in the differential diagnosis along with other fat-containing tumors.



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Exploring metal artifact reduction using dual-energy CT with pre-metal and post-metal implant cadaver comparison: are implant specific protocols needed?

Abstract

Objective

To quantify and optimize metal artifact reduction using virtual monochromatic dual-energy CT for different metal implants compared to non-metal reference scans.

Methods

Dual-energy CT scans of a pair of human cadaver limbs were acquired before and after implanting a titanium tibia plate, a stainless-steel tibia plate and a titanium intramedullary nail respectively. Virtual monochromatic images were analyzed from 70 to 190 keV. Region-of-interest (ROI), used to determine fluctuations and inaccuracies in CT numbers of soft tissues and bone, were placed in muscle, fat, cortical bone and intramedullary tibia canal.

Results

The stainless-steel implant resulted in more pronounced metal artifacts compared to both titanium implants. CT number inaccuracies in 70 keV reference images were minimized at 130, 180 and 190 keV for the titanium tibia plate, stainless-steel tibia plate and titanium intramedullary nail respectively. Noise, measured as the standard deviation of pixels within a ROI, was minimized at 130, 150 and 140 keV for the titanium tibia plate, stainless-steel tibia plate and titanium intramedullary nail respectively.

Conclusion

Tailoring dual-energy CT protocols using implant specific virtual monochromatic images minimizes fluctuations and inaccuracies in CT numbers in bone and soft tissues compared to non-metal reference scans.



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