Imaging cellularity in benign and malignant peripheral nerve sheath tumors: Utility of the “target sign” by Diffusion Weighted Imaging

Publication date: Available online 16 March 2018
Source:European Journal of Radiology
Author(s): Shivani Ahlawat, Laura M. Fayad
ObjectiveTo determine the utility of "target sign" on diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping for peripheral nerve sheath tumor (PNST) characterization.Materials and MethodsThis IRB–approved, HIPAA–compliant study retrospectively reviewed the MR imaging (comprised of T2- FS, DWI (b-values 50, 400, 800 s/mm²and ADC mapping), and static contrast-enhanced (CE) T1-W imaging of 42 patients (mean age: 40 years (range 8–68 years), 48% (20/42) females) with 15 malignant PNSTs (MPNSTs) and 33 benign PNSTs (BPNSTs). MPNSTs were histologically confirmed while BPNSTs were histologically-proven or with stable clinical and imaging appearance for at least 12 months. Two radiologists assessed imaging characteristics (size, signal intensity, heterogeneity, perilesional edema or enhancement) and the presence or absence of "target sign," on each sequence. A "target sign" was defined as a biphasic pattern of peripheral hyperintensity and homogeneous central hypointensity. Descriptive statistics are reported. Cohen's κ statistic or interclass correlation coefficient (ICC) were used to evaluate interobserver agreement between two observers. Univariate and multiple logistic regression analysis were performed to identify MRI features with predictive values.ResultsMPNSTs were larger than BPNSTs (6.3 ± 2.5 cm vs 3.5 ± −2.1 cm, p = 0.0002), had perilesional edema (87%(13/15) vs 18%(6/33), p < 0.0001), heterogeneous enhancement (71%(10/14) vs 13%(4/31), p = 0.0001) and perilesional enhancement (79%(11/14) vs 18%(6/31), p = 0.0001), respectively. The "target sign" was present in: 24%(8/33) BPNSTs vs 0/15 MPNST on T2-FS (p = 0.26); 39%(13/33) BPNSTs vs 20%(3/15) MPNST on DWI using b-value = 50 s/mm² (p = 0.5); 55%(18/33) BPNSTs vs 6%(1/15) MPNST on DWI using b-value = 400 s/mm² (p = 0.002); 48%(16/33) BPNSTs vs 6%(1/15) MPNST on DWI using b-value = 800 s/mm² (p = 0.005) and 64%(21/33) benign vs 0/15 MPNST on ADC mapping(p < 0.0001). By CE-T1 imaging, 32%(10/31) BPNSTs and 7%(1/14) MPNST had a target sign(p = 0.07). The odds of an MPNST in cases with minimum ADC ≤ 1.0 × 10(−3) mm(2)/s are 150 times higher than in cases with ADC > 1.0 × 10(−3).ConclusionIn this explorative study, a "target sign" suggests a benign PNST and is more often visible on DWI using high b-values and ADC maps compared with anatomic sequences.



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Role of PROPELLER-DWI of the prostate in reducing distortion and artefact from total hip replacement metalwork

Publication date: Available online 16 March 2018
Source:European Journal of Radiology
Author(s): Marcin Czarniecki, Iztok Caglic, James T. Grist, Andrew B. Gill, Kamil Lorenc, Rhys A. Slough, Andrew N. Priest, Tristan Barrett
ObjectiveTo compare image quality, artefact, and distortion in standard echo-planar imaging (EPI) with periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) for prostate magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) in patients with previous total hip replacement (THR).Methods21 male subjects with a clinical suspicion for, or known prostate cancer and previous THR were scanned at 1.5 tesla using a phased-array body coil. DWI was obtained using single-shot EPI and PROPELLER techniques using fat saturation (PROPELLER-DWI-FS), and without (PROPELLER-DWI-NFS). Image quality (the overall impression of diagnostic quality) was compared to T2-weighted (T2WI) imaging using a 5-point Likert scale, with diffusion sequences additionally scored for artefact and distortion according to a 4-point scale, with artefact defined as the amount of prostate affected and distortion as the degree of warping of the organ. The T2W and DW image volumes were compared to produce quantitative distortion maps. A two-sample Wilcoxon test compared the qualitative scores, with inter-reader variability calculated using Cohen's kappa.Results21 patients were included in the study, with an average age of 70.4 years and PSA 9.2 ng/mL. Hip metalwork was present bilaterally in 3 patients, left-sided in 9, and right-sided in 9.PROPELLER-DWI-FS significantly improved image quality (p < 0.01) and reduced distortion (p < 0.01) when compared to standard EP-DWI. Artefact was not shown to be significantly improved. The last 5 patients in the study were additionally imaged with PROPELLER-DWI-NFS, which resulted in a significant reduction in artefact compared to EP-DWI (p < 0.05). Quantitative distortion was significantly lower compared to EP-DWI for both PROPELLER with fat saturation (p < 0.01) and without fat saturation (p < 0.01).ConclusionPROPELLER-DWI demonstrates better image quality and decreases both artefact and distortion compared to conventional echo planar sequences in patients with hip metalwork.



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Editorial Board (Pantone 286 C)

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Table of Contents (Pantone 286 C)

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Society Page (Headings are Pantone 286 C; logos are 4/color)

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Information for Readers (Pantone 286 C)

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Letter to the Editor: "Decreasing use of radioactive iodine for low risk thyroid cancer in California, 1999-2015".

Letter to the Editor: "Decreasing use of radioactive iodine for low risk thyroid cancer in California, 1999-2015".

J Clin Endocrinol Metab. 2018 Mar 13;:

Authors: Wu D, Guan H

PMID: 29546403 [PubMed - as supplied by publisher]

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Radioactive seed localisation of non-palpable lymph nodes - A feasibility study.

Radioactive seed localisation of non-palpable lymph nodes - A feasibility study.

Eur J Surg Oncol. 2018 Mar 06;:

Authors: Hassing CMS, Tvedskov TF, Kroman N, Klausen TL, Drejøe JB, Tvedskov JF, Lambine TL, Kledal H, Lelkaitis G, Langhans L

Abstract
BACKGROUND: Radioactive seed localisation (RSL) is a preoperative localisation method using a small titanium seed containing iodine-125. The method is increasingly applied for localising non-palpable lesions in the treatment of breast cancer. We believe that RSL has the potential to be used in various surgical specialties. The aim of this feasibility study was to test RSL as a preoperative localisation of non-palpable lymph nodes.
METHODS: Between November 24, 2015 and October 26, 2016, 15 patients with suspicious lymph nodes on imaging were included in the study. The lymph nodes were located in the axillary region (n = 9), the head and neck region (n = 5) and the inguinal region (n = 1). The seeds were placed in the centre of the lymph node, in the capsule or just outside the capsule guided by ultrasound. During surgery, incision and localisation of the lymph nodes were performed based on the auditory signal of the gamma probe. After excision, lymph nodes including iodine seeds were sent for pathologic examination and the seeds were returned to the Department of Nuclear Medicine.
RESULTS: The non-palpable lymph nodes were all successfully marked using ultrasound. The lymph nodes were successfully localised and excised during surgery, and the procedure was performed without complications in the majority of the cases.
CONCLUSION: Localisation of suspicious non-palpable lymph nodes using RSL is feasible. RSL may ease the surgical procedure, minimise trauma to the surrounding tissue and ultimately benefit the patient. Future prospective studies are necessary to determine the further use of RSL within different surgical specialties.

PMID: 29545086 [PubMed - as supplied by publisher]

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Development of a vibration haptic simulator for shoulder arthroplasty

Abstract

Purpose

Glenoid reaming is a technically challenging step during shoulder arthroplasty that could possibly be learned during simulation training. Creation of a realistic simulation using vibration feedback in this context is innovative. Our study focused on the development and internal validation of a novel glenoid reaming simulator for potential use as a training tool.

Methods

Vibration and force profiles associated with glenoid reaming were quantified during a cadaveric experiment. Subsequently, a simulator was fabricated utilizing a haptic vibration transducer with high- and low-fidelity amplifiers; system calibration was performed matching vibration peak–peak values for both amplifiers. Eight experts performed simulated reaming trials. The experts were asked to identify isolated layer profiles produced by the simulator. Additionally, experts' efficiency to successfully perform a simulated glenoid ream based solely on vibration feedback was recorded.

Results

Cadaveric experimental cartilage reaming produced lower vibrations compared to subchondral and cancellous bones ( \(p\le 0.03\) ). Gain calibration of a lower-fidelity (3.5  \({g}_{\mathrm{pk-pk}}, 0.36\,{g}_{\mathrm{rms}})\) and higher-fidelity (3.4  \({g}_{\mathrm{pk-pk}}, 0.33\,{g}_{\mathrm{rms}})\) amplifier resulted in values similar to the cadaveric experimental benchmark (3.5  \({g}_{\mathrm{pk-pk}}, 0.30\,{g}_{\mathrm{rms}})\) . When identifying random tissue layer samples, experts were correct \(52\pm 9\%\) of the time and success rate varied with tissue type ( \(p=0.003\) ). During simulated reaming, the experts stopped at the targeted subchondral bone with a success rate of \(78\pm 24\%\) . The fidelity of the simulation did not have an effect on accuracy, applied force, or reaming time ( \(p>0.05\) ). However, the applied force tended to increase with trial number ( \(p=0.047\) ).

Conclusions

Development of the glenoid reaming simulator, coupled with expert evaluation furthered our understanding of the role of haptic vibration feedback during glenoid reaming. This study was the first to (1) propose, develop and examine simulated glenoid reaming, and (2) explore the use of haptic vibration feedback in the realm of shoulder arthroplasty.

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Endovascular Treatment of Very Large and Giant Intracranial Aneurysms: Comparison between Reconstructive and Deconstructive Techniques-A Meta-Analysis.

Endovascular Treatment of Very Large and Giant Intracranial Aneurysms: Comparison between Reconstructive and Deconstructive Techniques-A Meta-Analysis.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Cagnazzo F, Mantilla D, Rouchaud A, Brinjikji W, Lefevre PH, Dargazanli C, Gascou G, Riquelme C, Perrini P, di Carlo D, Bonafe A, Costalat V

Abstract
BACKGROUND: The safety and efficacy of reconstructive and deconstructive endovascular treatments of very large/giant intracranial aneurysms are not completely clear.
PURPOSE: Our aim was to compare treatment-related outcomes between these 2 techniques.
DATA SOURCES: A systematic search of 3 data bases was performed for studies published from 1990 to 2017.
STUDY SELECTION: We selected series of reconstructive and deconstructive treatments with >10 patients.
DATA ANALYSIS: Random-effects meta-analysis was used to analyze occlusion rates, complications, and neurologic outcomes.
DATA SYNTHESIS: Thirty-nine studies evaluating 894 very large/giant aneurysms were included. Long-term occlusion of unruptured aneurysms was 71% and 93% after reconstructive and deconstructive treatments, respectively (P = .003). Among unruptured aneurysms, complications were lower after parent artery occlusion (16% versus 30%, P = .05), whereas among ruptured lesions, complications were lower after reconstructive techniques (34% versus 38%). Parent artery occlusion in the posterior circulation had higher complications compared with in the anterior circulation (36% versus 15%, P = .001). Overall, coiling yielded lower complication and occlusion rates compared with flow diverters and stent-assisted coiling. Complication rates of flow diversion were lower in the anterior circulation (17% versus 41%, P < .01). Among unruptured lesions, early aneurysm rupture (within 30 days) was slightly higher after reconstructive treatment (5% versus 0%, P = .08) and after flow diversion alone compared with flow diversion plus coiling (7% versus 0%).
LIMITATIONS: Limitations were selection and publication biases.
CONCLUSIONS: Parent artery occlusion allowed high rates of occlusion with an acceptable rate of complications for unruptured, anterior circulation aneurysms. Coiling should be preferred for posterior circulation and ruptured lesions, whereas flow diversion is relatively safe and effective for unruptured anterior circulation aneurysms.

PMID: 29545248 [PubMed - as supplied by publisher]

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Anatomic Malformations of the Middle and Inner Ear in 22q11.2 Deletion Syndrome: Case Series and Literature Review.

Anatomic Malformations of the Middle and Inner Ear in 22q11.2 Deletion Syndrome: Case Series and Literature Review.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Verheij E, Elden L, Crowley TB, Pameijer FA, Zackai EH, McDonald-McGinn DM, Thomeer HGXM

Abstract
BACKGROUND AND PURPOSE: The 22q11.2 deletion syndrome is characterized by a heterogenic phenotype, including hearing loss. The underlying cause of hearing loss, especially sensorineural hearing loss, is not yet clear. Therefore, our objective was to describe anatomic malformations in the middle and inner ear in patients with 22q11.2 deletion syndrome.
MATERIALS AND METHODS: A retrospective case series was conducted in 2 tertiary referral centers. All patients with 22q11.2 deletion syndrome who had undergone CT or MR imaging of the temporal bones were included. Radiologic images were evaluated on predetermined parameters, including abnormalities of the ossicular chain, cochlea, semicircular canals, and vestibule.
RESULTS: There were 26 patients (52 ears) with a CT or MR imaging scan available. A dense stapes superstructure was found in 18 ears (36%), an incomplete partition type II was suspected in 12 cochleas (23%), the lateral semicircular canal was malformed with a small bony island in 17 ears (33%), and the lateral semicircular canal and vestibule were fused to a single cavity in 15 ears (29%).
CONCLUSIONS: Middle and inner ear abnormalities were frequently encountered in our cohort, including malformations of the lateral semicircular canal.

PMID: 29545254 [PubMed - as supplied by publisher]

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Randomized Assessment of the Safety and Efficacy of Intra-Arterial Infusion of Autologous Stem Cells in Subacute Ischemic Stroke.

Randomized Assessment of the Safety and Efficacy of Intra-Arterial Infusion of Autologous Stem Cells in Subacute Ischemic Stroke.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Bhatia V, Gupta V, Khurana D, Sharma RR, Khandelwal N

Abstract
BACKGROUND AND PURPOSE: Stroke is a debilitating illness for which treatment window is limited. Most patients present to the healthcare facility beyond that window. Autologous stem cells have shown some promise for this group of patients. This study was performed to evaluate the safety and the efficacy of intra-arterial infusion of bone marrow-derived mononuclear cells in patients with middle cerebral artery ischemic stroke.
MATERIALS AND METHODS: A prospective, randomized, open-label, blinded-end point study was performed from July 2015 to June 2016. Of 229 patients with acute stroke who presented to the hospital during this period, 20 patients who satisfied the inclusion/exclusion criteria were included and randomized into the control and intervention groups. Intra-arterial stem cell infusion into the ipsilateral MCA was performed in the patients in the intervention group at 8-15 days post-stroke ictus. Final analysis at 6 months was performed for primary (safety) and secondary outcomes (efficacy).
RESULTS: When we compared the primary end point of the study, no procedure-related mortality, complication, new infarct, or symptomatic intracranial hemorrhage was seen in the intervention group. When we compared the secondary end point of good clinical outcome, 8 (80%) patients in the intervention group showed good clinical outcome (modified Rankin Scale score < 2) with 4 (40%) patients in the control group achieving this (95% confidence interval for good outcome in patients with stem cell infusion, 49.03-94.3, and without stem cell infusion, 16.82-68.73; P = .068).
CONCLUSIONS: Intra-arterial infusion of stem cells can be carried out safely in the subacute stage of ischemic stroke. Improved clinical outcomes were observed with intra-arterial stem cell therapy; however, studies with larger cohorts are needed to validate the results.

PMID: 29545253 [PubMed - as supplied by publisher]

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European Multicenter Study for the Evaluation of a Dual-Layer Flow-Diverting Stent for Treatment of Wide-Neck Intracranial Aneurysms: The European Flow-Redirection Intraluminal Device Study.

European Multicenter Study for the Evaluation of a Dual-Layer Flow-Diverting Stent for Treatment of Wide-Neck Intracranial Aneurysms: The European Flow-Redirection Intraluminal Device Study.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Killer-Oberpfalzer M, Kocer N, Griessenauer CJ, Janssen H, Engelhorn T, Holtmannspötter M, Buhk JH, Finkenzeller T, Fesl G, Trenkler J, Reith W, Berlis A, Hausegger K, Augustin M, Islak C, Minnich B, Möhlenbruch M

Abstract
BACKGROUND AND PURPOSE: Endoluminal reconstruction with flow-diverting stents represents a widely accepted technique for the treatment of complex intracranial aneurysms. This European registry study analyzed the initial experience of 15 neurovascular centers with the Flow-Redirection Intraluminal Device (FRED) system.
MATERIALS AND METHODS: Consecutive patients with intracranial aneurysms treated with the FRED between February 2012 and March 2015 were retrospectively reviewed. Complications and adverse events, transient and permanent morbidity, mortality, and occlusion rates were evaluated.
RESULTS: During the defined study period, 579 aneurysms in 531 patients (median age, 54 years; range, 13-86 years) were treated with the FRED. Seven percent of patients were treated in the acute phase (≤3 days) of aneurysm rupture. The median aneurysm size was 7.6 mm (range, 1-36.6 mm), and the median neck size 4.5 mm (range, 1-30 mm). Angiographic follow-up of >3 months was available for 516 (89.1%) aneurysms. There was progressive occlusion witnessed with time, with complete occlusion in 18 (20%) aneurysms followed for up to 90 ± 14 days, 141 (82.5%) for 180 ± 20 days, 116 (91.3%) for 1 year ± 24 days, and 122 (95.3%) aneurysms followed for >1 year. Transient and permanent morbidity occurred in 3.2% and 0.8% of procedures, respectively. The overall mortality rate was 1.5%.
CONCLUSIONS: This retrospective study in real-world patients demonstrated the safety and efficacy of the FRED for the treatment of intracranial aneurysms. In most cases, treatment with a single FRED resulted in complete angiographic occlusion at 1 year.

PMID: 29545252 [PubMed - as supplied by publisher]

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Brain Diffusion Abnormalities in Children with Tension-Type and Migraine-Type Headaches.

Brain Diffusion Abnormalities in Children with Tension-Type and Migraine-Type Headaches.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Santoro JD, Forkert ND, Yang QZ, Pavitt S, MacEachern SJ, Moseley ME, Yeom KW

Abstract
BACKGROUND AND PURPOSE: Tension-type and migraine-type headaches are the most common chronic paroxysmal disorders of childhood. The goal of this study was to compare regional cerebral volumes and diffusion in tension-type and migraine-type headaches against published controls.
MATERIALS AND METHODS: Patients evaluated for tension-type or migraine-type headache without aura from May 2014 to July 2016 in a single center were retrospectively reviewed. Thirty-two patients with tension-type headache and 23 with migraine-type headache at an average of 4 months after diagnosis were enrolled. All patients underwent DWI at 3T before the start of pharmacotherapy. Using atlas-based DWI analysis, we determined regional volumetric and diffusion properties in the cerebral cortex, thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens, brain stem, and cerebral white matter. Multivariate analysis of covariance was used to test for differences between controls and patients with tension-type and migraine-type headaches.
RESULTS: There were no significant differences in regional brain volumes between the groups. Patients with tension-type and migraine-type headaches showed significantly increased ADC in the hippocampus and brain stem compared with controls. Additionally, only patients with migraine-type headache showed significantly increased ADC in the thalamus and a trend toward increased ADC in the amygdala compared with controls.
CONCLUSIONS: This study identifies early cerebral diffusion changes in patients with tension-type and migraine-type headaches compared with controls. The hypothesized mechanisms of nociception in migraine-type and tension-type headaches may explain the findings as a precursor to structural changes seen in adult patients with chronic headache.

PMID: 29545251 [PubMed - as supplied by publisher]

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The Importance of Flexion MRI in Hirayama Disease with Special Reference to Laminodural Space Measurements.

The Importance of Flexion MRI in Hirayama Disease with Special Reference to Laminodural Space Measurements.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Boruah DK, Prakash A, Gogoi BB, Yadav RR, Dhingani DD, Sarma B

Abstract
BACKGROUND AND PURPOSE: Hirayama disease is a benign focal amyotrophy of the distal upper limbs involving C7, C8, and T1 segmental myotomes with sparing of the brachioradialis and proximal muscles of the upper limb innervated by C5-6 myotomes. The objective of the present study was to study the utility of MR imaging in young patients presenting with weakness and wasting of the distal upper extremity and to evaluate the importance of the laminodural space during flexion cervical MR imaging.
MATERIALS AND METHODS: This was a prospective cross-sectional study conducted from January 2014 to July 2017 in a tertiary care center from Northeast India. Forty-five patients with clinically definite Hirayama disease underwent electrophysiologic evaluation followed by MR imaging of the cervical spine.
RESULTS: The mean age at recruitment was 22.8 ± 5.5 years. Forty patients (88.9%) had unilateral and 5 (11.1%) had bilateral upper extremity involvement. Cervical cord T2-weighted hyperintensities were demonstrated in 16 patients (35.6%), of which 15 (33.3%) had anterior horn cell hyperintensities. Flexion MR imaging showed loss of the posterior dural attachment, forward shifting of the posterior dural sac with postcontrast enhancement, and prominent posterior epidural venous plexus in all patients. The laminodural space at maximum forward shifting of the posterior dural sac ranged from 3 to 9.8 mm, with a mean distance of 5.99 mm (95% confidence interval, 5.42-6.57 mm).
CONCLUSIONS: Flexion cervical MR imaging is a very useful investigation in diagnosing Hirayama disease. The increase in the laminodural space and the presence of cervical cord flattening during flexion are essential for diagnosis.

PMID: 29545250 [PubMed - as supplied by publisher]

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Localized Marked Elongation of the Distal Internal Carotid Artery with or without PHACE Syndrome: Segmental Dolichoectasia of the Distal Internal Carotid Artery.

Localized Marked Elongation of the Distal Internal Carotid Artery with or without PHACE Syndrome: Segmental Dolichoectasia of the Distal Internal Carotid Artery.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Jia ZY, Zhao LB, Lee DH

Abstract
BACKGROUND AND PURPOSE: Segmental intracranial dolichoectasia of the distal ICA is a feature of PHACE syndrome or a sporadic phenomenon. We evaluated the relationship between intracranial dolichoectasia of the distal ICA and PHACE syndrome and illustrated the characteristic radiologic findings of the lesions.
MATERIALS AND METHODS: Intracranial dolichoectasia of the distal ICA was identified in 20 patients at our institution from 2005 to 2016 through a review of diagnostic cerebral angiography results. All radiologic images were reviewed to determine the vascular morphologic dispositions around the distal ICA, including dysplasia, mural calcification, vessel wall enhancement, lumen narrowing, and aneurysm formation. Medical records were reviewed to determine the symptoms of PHACE syndrome. Subsequently, the correlation between radiologic findings and PHACE syndrome was assessed.
RESULTS: In this cohort, which had a strong female predominance (male/female ratio= 2:18), intracranial dolichoectasia had a more ipsilateral vascular morphologic disposition. Mural calcification was detected more frequently in elderly patients, whereas vessel wall enhancement was detected more frequently in younger patients. Follow-up images showed a slow progression of the lesions. However, no significant differences in the vascular morphologic disposition and brain structural changes were observed between patients with (n = 11) and without (n = 9) PHACE syndrome.
CONCLUSIONS: The striking elongation and tortuosity of the distal ICA generally appeared to be a type of congenital lesion occurring early in embryogenesis as either a sporadic phenomenon or an arterial change associated with PHACE syndrome. Imaging findings revealed various mural abnormalities with a benign clinical course.

PMID: 29545249 [PubMed - as supplied by publisher]

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Evaluation of the Normal Cochlear Second Interscalar Ridge Angle and Depth on 3D T2-Weighted Images: A Tool for the Diagnosis of Scala Communis and Incomplete Partition Type II.

Evaluation of the Normal Cochlear Second Interscalar Ridge Angle and Depth on 3D T2-Weighted Images: A Tool for the Diagnosis of Scala Communis and Incomplete Partition Type II.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Booth TN, Wick C, Clarke R, Kutz JW, Medina M, Gorsage D, Xi Y, Isaacson B

Abstract
BACKGROUND AND PURPOSE: Cochlear malformations may be be subtle on imaging studies. The purpose of this study was to evaluate the angle and depth of the lateral second interscalar ridge or notch in ears without sensorineural hearing loss (normal ears) and compare them with ears that have a documented incomplete type II partition malformation.
MATERIALS AND METHODS: The second interscalar ridge notch angle and depth were measured on MR imaging in normal ears by a single experienced neuroradiologist. The images of normal and incomplete partition II malformation ears were then randomly mixed for 2 novice evaluators to measure both the second interscalar ridge notch angle and depth in a blinded manner. For the mixed group, interobserver agreement was calculated, normal and abnormal ear measurements were compared, and receiver operating characteristic curves were generated.
RESULTS: The 94 normal ears had a mean second interscalar ridge angle of 80.86° ± 11.4° and depth of 0.54 ± 0.14 mm with the 98th percentile for an angle of 101° and a depth of 0.3 mm. In the mixed group, agreement between the 2 readers was excellent, with significant differences for angle and depth found between normal and incomplete partition type II ears for angle and depth on average (P < .001). Receiver operating characteristic cutoffs for delineating normal from abnormal ears were similar for both readers (depth, 0.31/0.34 mm; angle, 114°/104°).
CONCLUSIONS: A measured angle of >114° and a depth of the second interscalar ridge notch of ≤0.31 mm suggest the diagnosis of incomplete partition type II malformation and scala communis. These measurements can be accurately made by novice readers.

PMID: 29545247 [PubMed - as supplied by publisher]

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MRI Characteristics of Primary Tumors and Metastatic Lesions in Molecular Subgroups of Pediatric Medulloblastoma: A Single-Center Study.

MRI Characteristics of Primary Tumors and Metastatic Lesions in Molecular Subgroups of Pediatric Medulloblastoma: A Single-Center Study.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Mata-Mbemba D, Zapotocky M, Laughlin S, Taylor MD, Ramaswamy V, Raybaud C

Abstract
BACKGROUND AND PURPOSE: Molecular grouping of medulloblastoma correlates with prognosis and supports the therapeutic strategy. We provide our experience with the imaging features of primary and metastatic disease in relation to the molecular groups.
MATERIALS AND METHODS: One hundred nineteen consecutive patients (mean age, 7.3 ± 3.8 years at diagnosis; male, 79 [66.4%]) with a confirmed diagnosis of medulloblastoma and interpretable pretreatment MRIs were retrieved from our data base from January 2000 to December 2016. Each patient was assigned to wingless, sonic hedgehog, group 3, or group 4 molecular groups. Then, we determined the imaging features of both primary and metastatic/recurrent disease predictive of molecular groups.
RESULTS: In addition to recently reported predictors based on primary tumor, including cerebellar peripheral location for sonic hedgehog (adjusted odds ratio = 9, P < .0001), minimal enhancement of primary group 4 tumor (adjusted odds ratio = 5.2, P < .0001), and cerebellopontine angle location for wingless (adjusted odds ratio = 1.4, P = .03), ependymal metastasis with diffusion restriction and minimal postcontrast enhancement ("mismatching pattern") (adjusted odds ratio = 2.8, P = .001) for group 4 and spinal metastasis for group 3 (adjusted odds ratio = 1.9, P = .01) also emerged as independent predictors of medulloblastoma molecular groups. Specifically, the presence of a metastasis in the third ventricular infundibular recess showing a mismatching pattern was significantly associated with group 4 (P = .02).
CONCLUSIONS: In addition to imaging features of primary tumors, some imaging patterns of metastatic dissemination in medulloblastoma seem characteristic, perhaps even specific to certain groups. This finding could further help in differentiating molecular groups, specifically groups 3 and 4, when the characteristics of the primary tumor overlap.

PMID: 29545246 [PubMed - as supplied by publisher]

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Arterial Spin-Labeling Improves Detection of Intracranial Dural Arteriovenous Fistulas with MRI.

Arterial Spin-Labeling Improves Detection of Intracranial Dural Arteriovenous Fistulas with MRI.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Amukotuwa SA, Marks MP, Zaharchuk G, Calamante F, Bammer R, Fischbein N

Abstract
BACKGROUND AND PURPOSE: Intracranial dural arteriovenous fistulas carry a risk of substantial neurologic complications but can be difficult to detect on structural MR imaging and TOF-MRA. The purpose of this study was to assess the accuracy and added value of 3D pseudocontinuous arterial spin-labeling MR imaging for the detection of these lesions.
MATERIALS AND METHODS: This retrospective study included 39 patients with a dural arteriovenous fistula and 117 controls who had undergone both DSA and MR imaging with pseudocontinuous arterial spin-labeling. Two neuroradiologists blinded to the DSA results independently assessed MR imaging with and without pseudocontinuous arterial spin-labeling. They recorded specific signs, including venous arterial spin-labeling signal, and the likelihood of a dural arteriovenous fistula using a 5-point Likert scale. Logistic regression and receiver operating characteristic analyses were performed to determine the accuracy of specific signs and the added value of pseudocontinuous arterial spin-labeling. Interobserver agreement was determined by using κ statistics.
RESULTS: Identification of the venous arterial spin-labeling signal had a high sensitivity (94%) and specificity (88%) for the presence a dural arteriovenous fistula. Receiver operating characteristic analysis showed significant improvement in diagnostic performance with the addition of pseudocontinuous arterial spin-labeling in comparison with structural MR imaging (Δarea under the receiver operating characteristic curve = 0.179) and a trend toward significant improvement in comparison with structural MR imaging with time-of-flight MRA (Δarea under the receiver operating characteristic curve = 0.043). Interobserver agreement for the presence of a dural arteriovenous fistula improved substantially and was almost perfect with the addition of pseudocontinuous arterial spin-labeling (κ = 0.92).
CONCLUSIONS: Venous arterial spin-labeling signal has high sensitivity and specificity for the presence of a dural arteriovenous fistula, and the addition of pseudocontinuous arterial spin-labeling increases confidence in the diagnosis of this entity on MR imaging.

PMID: 29545245 [PubMed - as supplied by publisher]

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Interaction Should Guide Management Decisions.

Interaction Should Guide Management Decisions.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Johansson E, Salzer J

PMID: 29545244 [PubMed - as supplied by publisher]

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Reply.

Reply.

AJNR Am J Neuroradiol. 2018 Mar 15;:

Authors: Jadhav AP, Menon BK, Goyal M

PMID: 29545243 [PubMed - as supplied by publisher]

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IMHOTEP: virtual reality framework for surgical applications

Abstract

Purpose

The data which is available to surgeons before, during and after surgery is steadily increasing in quantity as well as diversity. When planning a patient's treatment, this large amount of information can be difficult to interpret. To aid in processing the information, new methods need to be found to present multimodal patient data, ideally combining textual, imagery, temporal and 3D data in a holistic and context-aware system.

Methods

We present an open-source framework which allows handling of patient data in a virtual reality (VR) environment. By using VR technology, the workspace available to the surgeon is maximized and 3D patient data is rendered in stereo, which increases depth perception. The framework organizes the data into workspaces and contains tools which allow users to control, manipulate and enhance the data. Due to the framework's modular design, it can easily be adapted and extended for various clinical applications.

Results

The framework was evaluated by clinical personnel (77 participants). The majority of the group stated that a complex surgical situation is easier to comprehend by using the framework, and that it is very well suited for education. Furthermore, the application to various clinical scenarios—including the simulation of excitation propagation in the human atrium—demonstrated the framework's adaptability. As a feasibility study, the framework was used during the planning phase of the surgical removal of a large central carcinoma from a patient's liver.

Conclusion

The clinical evaluation showed a large potential and high acceptance for the VR environment in a medical context. The various applications confirmed that the framework is easily extended and can be used in real-time simulation as well as for the manipulation of complex anatomical structures.

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Osteonecrosis of the jaw unrelated to medication or radiotherapy.

Osteonecrosis of the jaw unrelated to medication or radiotherapy.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2017 Dec 28;:

Authors: Gadiwalla Y, Patel V

Abstract
Osteonecrosis of the jaw (ONJ) is an increasingly common condition primarily due to the rise of medication related osteonecrosis of the jaw (MRONJ) and osteoradionecrosis (ORN). Apart from MRONJ and ORN there remains a wide and varied range of rare causes and diseases that can lead to a clinical presentation of ONJ. This article aims to highlight alternatives causes of jaw necrosis following review of the literature to aid diagnosis and treatment planning for dental and head and neck specialities.

PMID: 29545079 [PubMed - as supplied by publisher]

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Gingival ulceration in a 63-year-old lung transplant recipient.

Gingival ulceration in a 63-year-old lung transplant recipient.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Feb 08;:

Authors: Will BM, Peters SM, Eisig SB, Grbic JT, McKenzie MA, Yoon AJ, Philipone EM

PMID: 29545078 [PubMed - as supplied by publisher]

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Corrective outcome and transverse stability after orthognathic surgery using a surgery-first approach in mandibular prognathism with and without facial asymmetry.

Corrective outcome and transverse stability after orthognathic surgery using a surgery-first approach in mandibular prognathism with and without facial asymmetry.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Feb 05;:

Authors: Guo J, Wang T, Han JJ, Jung S, Kook MS, Park HJ, Oh HK

Abstract
OBJECTIVES: The aim of this study was to evaluate corrective outcome and transverse stability after orthognathic surgery via a surgery-first approach (SFA) in mandibular prognathism with and without facial asymmetry using 3-dimensional analysis.
STUDY DESIGN: Twenty-nine patients who received mandibular setback surgery using SFA were divided into 2 groups according to the menton deviation (4 mm): symmetry group (n = 17) and asymmetry group (n = 12). Using computed tomography images obtained before (T0), immediately after (T1), and 6 months after (T2) surgery, time-dependent changes in variables related to facial asymmetry, including maxillary height, ramal length, frontal and lateral ramal inclination, mandibular body length, and mandibular body height, were evaluated.
RESULTS: Immediately after surgery, the asymmetry group showed significantly decreased discrepancies between the longer and non-longer sides for all variables (P < .05); there were no significant differences in discrepancies between the 2 groups. During the postoperative period, no significant changes in discrepancies were found in any variable in either group. Compared with T0, the asymmetry group showed significantly decreased discrepancies in ramal length, frontal and lateral ramal inclination, and mandibular body length at T2.
CONCLUSIONS: Variables related to facial asymmetry showed significant improvement after surgical-orthodontic treatment using SFA, and corrected outcomes showed good postoperative stability in both the symmetry and asymmetry groups.

PMID: 29545077 [PubMed - as supplied by publisher]

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Decision support system for the planning of minimally invasive aortic valve replacement surgery

Abstract

Purpose

Minimally invasive aortic valve replacement (MIAVR) procedures remain more complex and technically challenging compared to conventional full sternotomy surgery. This technique involves a restricted surgical field and a limited workspace, which is, at present, strictly reserved for the most experienced surgeons. The MIAVR clinical outcomes are strongly dependent on the appropriate choice of the thoracic incision. This work presents a decision support system to optimize, through an interactive visualization interface, the exposure of the target structure in a limited field of view.

Methods

Our approach is based on the computation of relevant anatomical measurements from preoperative CT images, and it takes into account the surgical guidelines in order to propose the surgical access that best fits the patient's morphology.

Results

The proposed planning system was applied and tested on 30 datasets from patients affected by severe aortic stenosis for validation purposes. We evaluated the accuracy of the automatic detections and the measurements calculated by the system with those chosen manually by the expert.

Conclusions

In 87% of thirty cases, the surgical strategy proposed by the decision support system was correct. For the remaining cases, the graphical user interface (GUI) allowed the user to manually adjust the anatomical features.

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Introducing First-Year Medical Students to Radiology

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Michael Kraft, Aaron Sayfie, Katherine Klein, Larry Gruppen, Leslie Quint
Rationale and ObjectivesThe aims of our study were (1) to describe a new educational intervention for first-year medical students that gave a substantial, early exposure to radiology and (2) to examine how this early exposure was received by the students.Materials and MethodsOur new curriculum incorporated a new 2-week course very early in the M1 year entitled Foundations of Diagnostics and Therapeutics. Among other topics, the course included a substantial introduction to radiology primarily through small-group seminars and online materials, administered using a flipped-classroom approach. The students were given pre- and postcourse surveys that assessed the degree to which they felt prepared to learn about radiology, as well as their interest in radiology. Results were analyzed using the Wilcoxon signed-rank test.ResultsSurvey responses were obtained from 170 students before the course and 65 students afterward. Upon completing the course, students showed significantly increased academic interest in radiology (P = .008) and a heightened perception of the effect of radiology on patient care (P = .04), without a significant change in interest in pursuing radiology as a career. Students showed an overwhelmingly positive response to the course, although some noted that previous anatomy training would have been helpful. Eighty percent agreed or strongly agreed that the flipped-classroom structure was an effective educational model.ConclusionsOur study demonstrated that students were very excited to gain exposure to radiology early in their medical school curriculum, and such exposure led to an improved perception of the field.



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Reproducibility of mRECIST in Measurement and Response Assessment for Hepatocellular Carcinoma Treated by Transarterial Chemoembolization

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Moon Hyung Choi, Ga Eun Park, Soon Nam Oh, Michael Yong Park, Sung Eun Rha, Young Joon Lee, Seung Eun Jung, Joon-Il Choi
Rationale and ObjectivesTo evaluate the reproducibility of Modified Response Evaluation Criteria in Solid Tumors (mRECIST) for hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) using multiphasic computed tomography.Materials and methodsThe institutional review board approved this retrospective study. We evaluated 97 patients who underwent TACE (60 conventional TACE [cTACE] and 37 drug-eluting bead TACE [DEB-TACE]) for HCC from 2010 to 2014. Four radiologists evaluated pairs of dynamic liver CTs scanned within 2 months before and after TACE based on mRECIST. Assessment of intra- or interobserver reproducibility for response categorization and sum of long diameter were evaluated using weighted kappa statistics (κ) and intraclass correlation coefficients, respectively. The relationship between concordance of target lesion selection and agreement of target lesion response was evaluated using Fisher exact test.ResultsIntraobserver reproducibility for overall response was moderate to excellent (κ = 0.525–0.865). Interobserver reproducibility was improved on the second review compared to the first review and it was good in both treatment groups (κ = 0.627 for cTACE and 0.602 for DEB-TACE). Between the two treatment methods, intra- or interobserver reproducibility was better after cTACE than DEB-TACE. Intraclass correlation coefficients for sum of long diameter measurement showed excellent intra- or interobserver reproducibility. The concordance rate of target lesion selection was significantly higher for patients with radiologists' agreement for target lesion response than patients with disagreed response (P = .003).ConclusionsThe intra- and interobserver reproducibility of mRECIST in patients with HCC after TACE was moderate to excellent, and the reproducibility was slightly better after cTACE than DEB-TACE.



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Honorary Authorship in Radiologic Research Articles

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Ronald L. Eisenberg, Long H. Ngo, Benedikt H. Heidinger, Alexander A. Bankier
Rationale and ObjectivesTo analyze the pattern and longitudinal evolution of honorary authorship in major radiology journals.Materials and MethodsIn this Institutional Review Board-approved study, an electronic survey was sent to first authors of original research articles published in the American Journal of Roentgenology, European Radiology, the Journal of Magnetic Resonance Imaging, and Radiology during 2 years (July 2014 through June 2016). Questions addressed the perception of honorary authorship and contributing factors, as well as demographic information. Univariate analysis was performed by using χ2 tests. Multivariable logistic regression models were used to assess independent factors associated with the perception of honorary authorship.ResultsOf 1839 first authors, 315 (17.3%) responded. Of these, 31.4% (97/309) perceived that at least one coauthor did not make sufficient contributions to merit authorship and 54.3% (159/293) stated that one or more coauthors performed only "nonauthor" tasks according to International Committee of Medical Journal Editors criteria. Of eight factors significantly associated with the perception of honorary authorship on univariate analysis, two were retained by the stepwise multivariate model: having someone suggest adding an author and a coauthor performing only a nonauthorship task.ConclusionThere has been little variation in the perception of honorary authorship among first authors of original research articles in radiology. The suggestion of adding an author and having coauthors performing only nonauthorship tasks are the two most important risk factors for honorary authorship. Our findings indicate that a prolonged course of transformation of current cultural norms is required to decrease honorary authorship.



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Burnout Education

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Morgan N. McLuckey, Richard B. Gunderman




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Social Media and Education in Radiology

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Reed A. Omary




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The Problems with the Kappa Statistic as a Metric of Interobserver Agreement on Lesion Detection Using a Third-reader Approach When Locations Are Not Prespecified

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Joanna H. Shih, Matthew D. Greer, Baris Turkbey
Rationale and ObjectivesTo point out the problems with Cohen kappa statistic and to explore alternative metrics to determine interobserver agreement on lesion detection when locations are not prespecified.Materials and MethodsUse of kappa and two alternative methods, namely index of specific agreement (ISA) and modified kappa, for measuring interobserver agreement on the location of detected lesions are presented. These indices of agreement are illustrated by application to a retrospective multireader study in which nine readers detected and scored prostate cancer lesions in 163 consecutive patients (n = 110 cases, n = 53 controls) using the guideline of Prostate Imaging Reporting and Data System version 2 on multiparametric magnetic resonance imaging.ResultsThe proposed modified kappa, which properly corrects for the amount of agreement by chance, is shown to be approximately equivalent to the ISA. In the prostate cancer data, average kappa, modified kappa, and ISA equaled 30%, 55%, and 57%, respectively, for all lesions and 20%, 87%, and 87%, respectively, for index lesions.ConclusionsThe application of kappa could result in a substantial downward bias in reader agreement on lesion detection when locations are not prespecified. ISA is recommended for assessment of reader agreement on lesion detection.



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Integration of a Zero-footprint Cloud-based Picture Archiving and Communication System with Customizable Forms for Radiology Research and Education

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Jason Hostetter, Nishanth Khanna, Jacob C. Mandell
Rationale and ObjectivesThe purpose of this study was to integrate web-based forms with a zero-footprint cloud-based Picture Archiving and Communication Systems (PACS) to create a tool of potential benefit to radiology research and education.Materials and MethodsWeb-based forms were created with a front-end and back-end architecture utilizing common programming languages including Vue.js, Node.js and MongoDB, and integrated into an existing zero-footprint cloud-based PACS.ResultsThe web-based forms application can be accessed in any modern internet browser on desktop or mobile devices and allows the creation of customizable forms consisting of a variety of questions types. Each form can be linked to an individual DICOM examination or a collection of DICOM examinations.ConclusionsSeveral uses are demonstrated through a series of case studies, including implementation of a research platform for multi-reader multi-case (MRMC) studies and other imaging research, and creation of an online Objective Structure Clinical Examination (OSCE) and an educational case file.



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Automated Breast Ultrasonography (ABUS) in the Screening and Diagnostic Setting

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Rossella Rella, Paolo Belli, Michela Giuliani, Enida Bufi, Giorgio Carlino, Pierluigi Rinaldi, Riccardo Manfredi
Automated breast ultrasonography (ABUS) is a new imaging technology for automatic breast scanning through ultrasound. It was first developed to overcome the limitation of operator dependency and lack of standardization and reproducibility of handheld ultrasound. ABUS provides a three-dimensional representation of breast tissue and allows images reformatting in three planes, and the generated coronal plane has been suggested to improve diagnostic accuracy.This technique has been first used in the screening setting to improve breast cancer detection, especially in mammographically dense breasts. In recent years, numerous studies also evaluated its use in the diagnostic setting: they showed its suitability for breast cancer staging, evaluation of tumor response to neoadjuvant chemotherapy, and second-look ultrasound after magnetic resonance imaging.The purpose of this article is to provide a comprehensive review of the current body of literature about the clinical performance of ABUS, summarize available evidence, and identify gaps in knowledge for future research.



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Survey Research

Publication date: Available online 16 March 2018
Source:Academic Radiology
Author(s): Prasad R. Shankar, Matthew S. Davenport, Sean A. Woolen, Ruth C. Carlos, Katerine E. Maturen
Survey research is appealing to many clinical researchers, including radiologists. Emerging interest in patient preferences and patient-centered outcomes related to imaging likely will stimulate additional use of questionnaires in our field. However, like other quantitative methods, survey-based research requires meticulous planning, execution, and analysis to generate reliable results and support meaningful conclusions. The purpose of this review is to provide a guideline for radiologists embarking on this type of research, with attention to questionnaire design, sampling, survey administration, and analysis.



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