What’s New in MSK Imaging? – July 2022

1 year ago

Evolving Role of Dual-Energy CT in the Clinical Workup of Gout: A Retrospective Study

Francis I. Baffour, MD, Andrea Ferrero, PhD, Gregory A. Aird, MD, Garret M. Powell, MD, Mark C. Adkins, MD, Delamo I. Bekele, MBBS, Matthew P. Johnson, MS, Joel G. Fletcher, MD and Katrina N. Glazebrook, MBChB


American Journal of Roentgenology




Background:  Dual-energy CT (DECT) allows noninvasive detection of monosodium urate (MSU) crystal deposits and has become incorporated into the routine clinical evaluation for gout at many institutions over the past decade.


Question: How did the  radiologists’ interpretations of DECT examinations performed for the evaluation of gout differ between the two time periods over the past decade (one beginning in March 2013 and one beginning in September 2019)?


Design: Retrospective study


Participants: 100 consecutive adult patients who underwent DECT to evaluate for gout in each of two periods (one beginning in March 2013 and one beginning in September 2019).


Methods:   Examinations performed in 2013 were conducted using a second-generation DECT scanner (80 kV [tube A] and 140 kV [tube B] with a 0.4-mm tin filter), and those performed in 2019 were conducted using a third-generation DECT scanner (80 kV [tube A] and 150 kV [tube B] with a 0.6-mm tin filter) that provides improved spectral separation. Original DECT reports were classified as positive, negative, or equivocal for MSU crystals indicative of gout. Joint aspirations occurring after the DECT examinations were recorded on the basis of findings from medical record review. A single radiologist performed a post hoc retrospective blinded image review, classifying examinations as positive, negative, or equivocal.


Main Results:

  1. Among DECT examinations performed for suspected gout, those performed in 2019 compared with 2013 had a significantly lower frequency of equivocal interpretations (16.0% vs 33.0%, p < .001)
  2. Joint aspiration was significantly less likely to be performed after negative DECT interpretations in 2019 than in 2013 (2.1% vs 17.4%, p = .02).



Conclusion:  When DECT examinations performed for gout in 2013 and 2019 were compared, the frequency of equivocal interpretations was significantly lower in 2019, possibly in relation to interval technologic improvements. Negative examinations were less frequently followed by joint aspirations in 2019, possibly reflecting increasing clinical acceptance of the DECT results.

Senior editor comments:

Great work! The results mirror our clinical practices with increasing trust by rheumatologists on DECT for gout detection despite normal serum uric acid levels and in avoiding unnecessary joint aspirations. Imaging, esp. DECT and MRI play a very important role in rheumatology practices for the initial diagnosis, confirmation, and exclusion of the suspected Gout. DECT is thus, a major advance for both Gout and bone marrow edema detection.


Resident take-home messages:

  • Dual-energy CT scan is an important technology, particularly in the evaluation of gout
  • The availability of dual-energy CT scanners has significantly increased.
  • The use of dual-energy CT scan in the evaluation of gout is now considered the gold standard. This study reinforces this concept.
  • Residents should familiarize themselves with concepts of dual-energy CT scanning and three-dimensional information maps produced by DECT.




Utility of Preoperative Shear-Wave Elastography of the Supraspinatus Muscle for Predicting Successful Rotator Cuff Repair: A Prospective Observational Study With MRI Correlation

Jeung Yeol Jeong, MD, Eun Kyung Khil, MD, A. Yeon Kim, MD, Seun Ah Lee, MD, PhD and Jung-Ah Choi, MD, PhD


American Journal of Roentgenology




Background: After rotator cuff tear, properties of the torn muscle predict failed surgical repair.


Question:  What is the utility of preoperative shear-wave elastography (SWE) of the supraspinatus muscle to predict successful rotator cuff repair?


Design: Prospective study


Participants: 74 patients (37 men, 37 women; mean age, 63.9 ± 10.0 [SD] years) who underwent rotator cuff repair between May 2019 and January 2021.


Exclusion criteria: If the patient had undergone prior ipsilateral rotator cuff repair, if the patient had undergone any other prior ipsilateral orthopedic surgery, if the rotator cuff tear was massive (> 5 cm) based on the greatest dimension of the tendon tear as measured at surgery, if the supraspinatus tendon was not identified as the primary pathology at the time of surgery (e.g., isolated infraspinatus or subscapularis tendon tear), or if the SWE examination of the supraspinatus muscle was nondiagnostic (e.g., severe artifacts in the elastogram).


Methods:  Patients underwent preoperative clinical shoulder MRI and investigational shoulder ultrasound including SWE using shear modulus. The mean elasticity values of the supraspinatus and trapezius muscles were measured, and the elasticity ratio (i.e., ratio of mean elasticity of supraspinatus muscle to mean elasticity of trapezius muscle) was calculated. The muscular fatty infiltration score (1–3 scale) was recorded on gray-scale ultrasound. On MRI, muscular fatty infiltration was assessed by Goutallier grade (0–4 scale), and muscular atrophy was assessed by the occupation ratio (ratio of cross-sectional areas of supraspinatus muscle and supraspinatus fossa) and by the muscle atrophy grade (0–3 scale). After rotator cuff repair, the surgeon classified procedures as achieving sufficient (n = 60) or insufficient (n = 14) repair.


Main Results:  Patients with insufficient repair, versus those with sufficient repair, more commonly exhibited a large (3–5 cm) tear. Patients with insufficient, versus sufficient, repair exhibited higher mean Goutallier grade, higher mean muscle atrophy grade, higher mean supraspinatus elasticity, higher mean elasticity ratio, and higher mean gray-scale fatty infiltration grade and showed lower mean occupation ratio.

At multivariable analysis including tear size, the three MRI measures, elasticity ratio, and gray-scale fatty infiltration grade, the only independent predictors of insufficient repair were muscle atrophy grade of 2–3 (odds ratio [OR] = 9.3) and elasticity ratio (OR = 15.7).


Conclusion: SWE-derived elasticity is higher in patients with insufficient rotator cuff repair; the elasticity ratio predicts insufficient repair independent of tear size and muscle characteristics.  Preoperative SWE may serve as a prognostic marker in patients with rotator cuff tear.


Senior editor comments:

Excellent work! It establishes used of SWE for pre-surgical assessment of RCT repair and future prognosis. Given similar accuracy of US and MRI for full-thickness tears of rotator cuff, US can help outline predictive modelling in a cost-effective way.


Resident take-home messages:

  • The success of rotator cuff surgery and the ability to predict the surgical outcome is key in the treatment of rotator cuff tears. Patients would choose surgical or non-surgical procedures if given a predictive outcome prior to surgery.
  • Important feature for successful results from surgical treatment of rotator cuff injuries includes muscle atrophy and muscle elasticity.
  • Shear wave elastography provides non-invasive criteria in conjunction with MRI to provide predictive analysis of the success of rotator cuff surgery.
  • Availability and knowledge of shear wave elastography are certainly becoming more common in daily practice.




Image Quality and Diagnostic Performance of Accelerated Shoulder MRI With Deep Learning–Based Reconstruction

Seok Hahn, MD, Jisook Yi, MD, Ho-Joon Lee, MD, Yedaun Lee, MD, Yun-Jung Lim, MD, Jin-Young Bang, MD, Hyunwoong Kim, MS and Joonsung Lee, PhD

American Journal of Roentgenology



Background:  Shoulder MRI using standard multiplanar sequences requires long scan times. Accelerated sequences have tradeoffs in noise and resolution. Deep learning–based reconstruction (DLR) may allow reduced scan time with preserved image quality.


Question: What is the impact of Deep learning-based reconstruction (DLR) on standard shoulder MRI sequences and accelerated sequences in terms of image quality and diagnostic performance?


Design: Retrospective study.


Participants: 105 patients (45 men, 60 women; mean age, 57.6 ± 10.9 [SD] years) who underwent a total of 110, 3-T shoulder MRI examinations.


Exclusion criteria: Patients with prior shoulder surgery (n = 57), shoulder infection (n = 6), glenohumeral joint trauma (n = 6), and bony metastasis in the shoulder (n = 1).


Methods: Examinations included standard sequences (scan time, 9 minutes 23 seconds) and accelerated sequences (3 minutes 5 seconds; 67% reduction), both including fast spin-echo sequences in three planes. Standard sequences were reconstructed using the conventional pipeline; accelerated sequences were reconstructed using both the conventional pipeline and a commercially available DLR pipeline. Two radiologists independently assessed three image sets (standard sequence, accelerated sequence without DLR, and accelerated sequence with DLR) for subjective image quality and artifacts using 4-point scales (4 = highest quality) and identified pathologies of the subscapularis tendon, supraspinatus-infraspinatus tendon, long head of the biceps brachii tendon, and glenoid labrum. In 27 patients who underwent arthroscopy, diagnostic performance was calculated using arthroscopic findings as a reference standard.


Main Results:  Mean subjective image quality scores for readers 1 and 2 were 10.6 ± 1.2 and 10.5 ± 1.4 for the standard sequence, 8.1 ± 1.3 and 7.2 ± 1.1 for the accelerated sequence without DLR, and 10.7 ± 1.2 and 10.5 ± 1.6 for the accelerated sequence with DLR. Mean artifact scores for readers 1 and 2 were 9.3 ± 1.2 and 10.0 ± 1.0 for the standard sequence, 7.3 ± 1.3 and 9.1 ± 0.8 for the accelerated sequence without DLR, and 9.4 ± 1.2 and 9.8 ± 0.8 for the accelerated sequence with DLR.


Conclusion:  Accelerated sequences with DLR provide 67% scan time reduction with similar subjective image quality, artifacts, and diagnostic performance to standard sequences.

Accelerated sequences with DLR may provide an alternative to standard sequences for clinical shoulder MRI.


Senior editor comments:

Thanks! This work again establishes that accelerated MR imaging should be used more and more in our practices given the continuous software and hardware improvements. It can not only improve patient comfort and imaging throughput but downstream, will significantly reduce costs to our ever-burgeoning healthcare system expenses.


Resident take-home messages:

  • Examination times on an MRI primarily affects patient safety, comfort, and outcomes.
  • Reducing time on MRI magnets also has direct implications for the economics of a center.
  • Advancements in deep learning algorithms to improve image quality have certainly made a significant impact on the practice of routine musculoskeletal imaging.
  • Multiple datasets samples and geographic and regional Deep learning algorithms will certainly improve the quality of “synthetic” images produced by DLR.




Examining the Bone Bruise Patterns in Multiligament Knee Injuries With Peroneal Nerve Injury

Jay Moran, BS, Christopher A. Schneble, MD, Lee D. Katz, MD, Andin Fosam, BS, Annie Wang, MD, Don T. Li, MD, PhD, Joseph B. Kahan, MD, William M. McLaughlin, MD, Peter Jokl, MD, Timothy E. Hewett, PhD, Robert F. LaPrade, MD, PhD, Michael J. Medvecky, MD


American Journal of Sports Medicine




Background: Tibiofemoral bone bruise patterns seen on magnetic resonance imaging (MRI) are associated with ligamentous injuries in the acutely injured knee. Bone bruise patterns in multiligament knee injuries (MLKIs) and particularly their association with common peroneal nerve (CPN) injuries are not well described.


As per Schenck classification, five patterns of major injuries are seen in knee dislocations (KD), each designated by a Roman numeral, from I to V.



Question: To analyse the tibiofemoral bone bruise patterns in MLKIs with and without peroneal nerve injury.


Design: Retrospective study , Case series; Level of evidence, 4.


Participants: 123 patients treated for an acute MLKI at a level 1 trauma centre between January 2001 and March 2021.


Inclusion criteria: (1) <30 days between the date of the reported injury and the date of the MRI; (2) T2-weighted fat-suppressed MR imaging sequences were available in both the coronal and sagittal planes; and (3) no documented history of any previous knee ligament tear.


Methods:  Patients were grouped into injury subtypes using the Schenck classification. Within this cohort, patients with clinically documented complete (motor and sensory loss) and/or partial CPN palsies on physical examination were identified. Imaging criteria required an MRI scan on a 1.5 or 3 Tesla scanner within 30 days of the initial MLKI. Images were retrospectively interpreted for bone bruising patterns by 2 board-certified musculoskeletal radiologists. The location of the bone bruises was mapped on fat-suppressed T2-weighted coronal and sagittal images. Bruise patterns were compared among patients with and without CPN injury.



(A) A coronal fat-suppressed T2-weighted MRI image example of a patient who sustained an MLKI with a complete peroneal nerve palsy on physical examination. The top arrow is pointing to a bone bruise on the medial femoral condyle that spanned the femoral-medial (M), femoral-medial central (C), femoral-medial notch (N), and femoral-medial trochlear (MT) zones. The bottom arrow points to a bone bruise on the medial tibial plateau that was localized to the medial tibia-medial (M), medial tibia-central (C), and medial tibia-subspine (MSs) zones with extension into the lateral tibia-subspine (LSs) and lateral tibia-central (C) zones.



Main Results: Of the 108 patients with a MLKI who met the a priori inclusion criteria, 26 (24.1%) were found to have a CPN injury (N = 20 complete; N = 6 partial) on physical examination. For CPN-injured patients, the most common mechanism of injury was high-energy trauma (N = 19 [73%]). The presence of a grade 3 posterolateral corner (PLC) injury (N = 25; odds ratio [OR], 23.81 [95% CI, 3.08-184.1]; P = .0024), anteromedial femoral condyle bone bruising (N = 24; OR, 21.9 [95% CI, 3.40-202.9]; P < .001), or a documented knee dislocation (N = 16; OR, 3.45 [95% CI, 1.38-8.62]; P = .007) was significantly associated with the presence of a CPN injury. Of the 26 patients with CPN injury, 24 (92.3%) had at least 1 anteromedial femoral condyle bone bruise. All 20 (100%) patients with complete CPN injury also had at least 1 anteromedial femoral condyle bone bruise on MRI. In our MLKI cohort, the presence of anteromedial femoral condyle bone bruising had a sensitivity of 92.3% and a specificity of 64.6% for the presence of CPN injury on physical examination.


Conclusion: In our MLKI cohort, the presence of a grade 3 PLC injury had the greatest association with CPN injury. Additionally, anteromedial femoral condyle bone bruising on MRI was a highly sensitive finding that was significantly correlated with CPN injury on physical examination. The high prevalence of grade 3 PLC injuries and anteromedial tibiofemoral bone bruising suggests that these MLKIs with CPN injuries most commonly occurred from a hyperextension-varus mechanism caused by a high-energy blow to the anteromedial knee.


Senior editor comments:

This is an expected result given the most common mechanism of CPN injury in the setting of multi-ligamentous knee injury. One quarter of patients with CPN injury is a very high number as reported. The patients must be assessed for CPN normalcy in all knee injury cases imaged with MRI regardless of bruise pattern, and the reader can also try to classify them with NS-RADS or Sunderland classification of nerve injuries to the best of their expertise and ability.


Resident take-home messages:

  • Bone bruise patterns are “beacons” for drawing the attention of the reviewers to local injury.
  • The presence of common peroneal nerve injuries should be evaluated in all PLC injuries, independent of the presence of bone bruising.
  • PLC Injuries are complex and evaluation of individual structures is a requirement.




Diffusion Tensor Imaging of the Knee to Predict Childhood Growth

Diego Jaramillo , Phuong Duong, Jie C. Nguyen, Sogol Mostoufi-Moab, Michael K. Nguyen, Andrew Moreau, Christian A. Barrera, Shijie Hong, José G. Raya






Background:  Accurate and precise methods to predict growth remain lacking. Diffusion tensor imaging (DTI) depicts the columnar structure of the physis and metaphyseal spongiosa and provides measures of tract volume and length that may help predict growth.


Questions:  Can physeal DTI metrics be used as predictors of height velocity (1-year height gain from time of MRI examination) and total height gain (height gain from time of MRI examination until growth stops) . How accurate is the prediction compared to bone age–based models?


Design: Retrospective study


Participants:  Femoral DTI studies (b values = 0 and 600 sec/mm2; directions = 20) of healthy children who underwent MRI of the knee between February 2012 and December 2016 were retrospectively analyzed.


Exclusion criteria: Partial physeal closure or physeal abnormalities at conventional MRI or poor quality of DTI scans (motion, susceptibility artifacts, or technical errors).



Methods:  Children with height measured at MRI and either 1 year later (height velocity) or after growth cessation (total height gain, mean = 34 months from MRI) were included. Physeal DTI tract volume and length were correlated with height velocity and total height gain. Multilinear regression was used to assess the potential of DTI metrics in the prediction of both parameters. Bland-Altman plots were used to compare root mean square error (RMSE) and bias in height prediction using DTI versus bone age methods.


Main Results:

  1. In a retrospective study of children who underwent diffusion tensor imaging of the knee, larger tract volumes correlated with greater height velocity in 89 children (height gain 1 year after imaging, r2 = 0.49) and total height gain in 70 children (r2 = 0.46) (P < .001).
  2. Compared with radiographic bone age–based methods, prediction using tract volume reduced root mean square error by 41% for predicting height velocity and by 64% for predicting total height gain.


Conclusion:  Models using tract volume derived from diffusion tensor imaging may perform better than bone age–based models in children for the prediction of height velocity and total height gain.


Senior editor comments:

Nice exploratory work showing the utility of functional imaging MRI technique for patient height prediction. However, there are other factors, which could lead to height variations. In addition, DTI may remain in research domain for the foreseeable future due to the inherent high variability of the technical parameters, its results with high standard deviations due to low SNR, and MRI platform capability issues.


Resident take-home messages:

  • Evaluation of the physeal plate is important for understanding skeletal maturity and rapidity of growth.
  • DTI use in the evaluation of physeal plate is in its infancy.




Improving Radiographic Fracture Recognition Performance and Efficiency Using Artificial Intelligence

Ali Guermazi , Chadi Tannoury, Andrew J. Kompel, Akira M. Murakami, Alexis Ducarouge, André Gillibert, Xinning Li, Antoine Tournier, Youmna Lahoud, Mohamed Jarraya, Elise Lacave, Hamza Rahimi, Aloïs Pourchot, Robert L. Parisien, Alexander C. Merritt, Douglas Comeau, Nor-Eddine Regnard, Daichi Hayashi






Background:  Missed fractures are a common cause of diagnostic discrepancy between initial radiographic interpretation and the final read by board-certified radiologists.


Question:  How effective is artificial intelligence (AI) in improving the diagnostic performances of physicians for fractures on radiographs?


Design: Retrospective study


Participants:  This study used the multi-reader, multi-case methodology based on an external multicenter data set of 480 examinations with at least 60 examinations per body region (foot and ankle, knee and leg, hip and pelvis, hand and wrist, elbow and arm, shoulder and clavicle, rib cage, and thoracolumbar spine) between July 2020 and January 2021.


Methods : Fracture prevalence was set at 50%. The ground truth was determined by two musculoskeletal radiologists, with discrepancies solved by a third. Twenty-four readers (radiologists, orthopedists, emergency physicians, physician assistants, rheumatologists, family physicians) were presented the whole validation data set (n = 480), with and without AI assistance, with a 1-month minimum washout period. The primary analysis had to demonstrate superiority of sensitivity per patient and the noninferiority of specificity per patient at –3% margin with AI aid. Stand-alone AI performance was also assessed using receiver operating characteristic curves.



■ In a retrospective study of 480 patients, artificial intelligence (AI)–assisted radiographic interpretation by six types of readers showed a 10.4% improvement of fracture detection sensitivity (75.2% vs 64.8%, superiority P < .001) without specificity reduction (5.0%, 95.6% vs 90.6%; P = .001 for noninferiority).

■ AI assistance shortened the radiograph reading time by 6.3 seconds per patient (P = .046).

■ The improvement in sensitivity was significant in all locations (delta mean, 8.0%–16.2%; P < .05) but shoulder and clavicle and thoracolumbar spine (delta mean, 4.2% and 2.6%; P = .12 and .52, respectively).

■ The stand-alone performance of the AI algorithm for fracture detection had an area under the receiver operating characteristic curve of 0.97 (P < .001)


Conclusion:  AI assistance improved the sensitivity and may even improve the specificity of fracture detection by radiologists and nonradiologists, without lengthening reading time.


Senior editor comments:

Excellent work! The results validate that the AI-algorithms will play a major role in both radiologist and clinician practices due to their high accuracy in repeated mundane tasks. With ever-increasing volumes of plain radiographs, it will help gain needed efficiencies in the healthcare systems.


Resident take-home messages:

  • AI can provide improved efficiency in workflow and in image interpretation.
  • Geographic, racial and regional variabilities can be improved with large datasets which cover these components in the development of AI-driven image interpretation.
  • multiple FDA-approved algorithms are currently available in routine image interpretation and workflow improvement and are set to increase over time.




Psoas muscle index is related to hip fracture in osteoporosis: a cross-sectional MRI study

Bilinc Dogruoz Karatekin & Zeynep Nilufer Tekin


Skeletal Radiology




Background: The aim of this study was to investigate the properties of psoas muscle in osteoporotic patients in lumbar magnetic resonance imaging (MRI) scan and their relationship with hip fracture.


Question: What is the relationship of psoas muscle with hip fracture in osteoporotic patients?


Design: Retrospective study


Participants: One hundred seventy-seven patients with osteoporosis (63.69 ± 9.677, 105 female) who had received lumbar spine MRI and dual-energy X-ray absorptiometry (DXA) examinations were retrospectively included.


Methods: Psoas muscle Thickness (PMT), cross-sectional areas (CSA), and psoas muscle index (PMI) values were measured for psoas muscle at L3 level and psoas muscle characteristics were compared between hip fracture and control groups.


Main Results:  PMT, CSA, and PMI values were statistically significantly different between hip fracture and control groups (respectively p < .001, p < .05, p < .01). The results showed that there was a significant association between being sarcopenic and having hip fracture (χ2 (1, n = 117) = 4.57, p < .05, phi = .20).


Conclusion:  PMT, CSA, and PMI might be associated with hip fracture in osteoporotic patients. However, this association is independent of bone mineral density (BMD). Psoas muscle features including PMT, CSA, and PMI should be used as significant predictors of falls and fractures in osteoporotic patients.

Senior editor comments:

It seems to be a chicken or egg phenomenon, whether the psoas muscle area is a predictor or simply reflects a disuse phenomenon as the latter can occur very quickly in the hip fracture patients. In addition, one level measurement is always questionable due to the muscle being variable in thickness and coursing obliquely. Nevertheless, this kind of work adds to the body of knowledge in the domain of opportunistic screening.


Resident take-home messages:

  • Psoas muscle bulk can impact patient mobility and outcomes.
  • Psoas Muscle bulk can also be linked to the possibility of hip fractures
  • Residents should include Psoas muscle bulk in their evaluation of hip injuries.




Percutaneous CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histocytosis: a three institution retrospective analysis

Connie Y. Chang, Julio Brandao Guimares, Gabby Joseph, Marcelo de Toledo Petrilli, Santiago Lozano-Calderon, Miriam A. Bredella & Thomas M. Link


Skeletal Radiology




Background:  The aim of this study is to evaluate the safety and effectiveness of CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histiocytosis (LCH) in a multi-institutional study.


Question: Can CT guided corticosteroid injection be used as an effective treatment for osseous LCH?


Design: Retrospective study


Participants: Forty corticosteroid injections performed in 36 patients (20 (56%) females, and 16 (44%) males, ages 12 ± 11 (2–57) years).



This IRB-approved study included patients from three institutions. The clinical, procedural, and imaging data for corticosteroid injections performed to treat osseous LCH were reviewed retrospectively. Location of the lesion, lesion maximum dimension and volume, corticosteroid type and dose, and time interval between injection and change in lesion size/volume and symptoms were recorded. Generalized estimating equations (accounting for multiple lesions per subject) were used to evaluate the association between predictors (dose, maximum lesion dimension, and lesion volume) and outcomes (time to partial and complete radiographic resolution, and time to pain control). This analysis was adjusted by anatomic site.


Results:  Forty corticosteroid injections were performed in 36 patients (20 (56%) females, and 16 (44%) males, ages 12 ± 11 (2–57) years). Mean lesion maximum dimension was 3.2 ± 1.7 cm, and volume was 10 ± 17 cm3. Imaging and clinical follow-up were available for 22/40 (55%) and 34/40 (85%) of injections, respectively. All lesions responded to corticosteroid injection. Times to partial and complete imaging resolution were 13 ± 9 and 32 ± 13 weeks, respectively, and time to pain resolution was 22 ± 14 weeks. There were no complications.


Conclusion: CT-guided corticosteroid injection is a safe and effective treatment for LCH. Pain resolution was achieved in all patients and imaging did not show progressive disease in any of the patients.


Senior editor comments:

Thanks for validating that simple percutaneous intra-lesional steroid injections are very useful for LCH like unicameral bone cysts and primary aneurysmal bone cysts. It however, remains to be seen if such treatments gain widespread acceptances in various oncology practices.


Resident take home messages:

  • It is important to have knowledge about newer techniques for treatment of osteolytic lesions of LCH.




Neuropathy Score Reporting and Data System: A Reporting Guideline for MRI of Peripheral Neuropathy With a Multicenter Validation Study

Avneesh Chhabra, MD, Swati D. Deshmukh, MD, Amelie M. Lutz, MD, Jan Fritz, MD, Gustav Andreisek, MD, Darryl B. Sneag, MD, Ty Subhawong, MD, Adam D. Singer, MD, Philip K. Wong, MD, Uma Thakur, MD, Tarun Pandey, MD, Majid Chalian, MD, Bayan N. Mogharrabi, BS, Mina Guirguis, BS, Yin Xi, PhD and Shivani Ahlawat, MD


American Journal of Roentgenology



Background : A standardized guideline and scoring system would improve evaluation and reporting of peripheral neuropathy (PN) on MRI. The objective of this study was to create and validate a neuropathy classification and grading system, which we named the Neuropathy Score Reporting and Data System (NS-RADS).


Question: Can NS-RADS be used as a standardized guideline for reporting PN?


Design: Retrospective study


Participants: Hundred patients with nerve imaging studies and known clinical diagnoses were included.


Methods:  Experts crafted NS-RADS using mutually agreed-on qualitative criteria for the classification and grading of PN. Different classes were created to account for the spectrum of underlying pathologies: unremarkable (U), injury (I), neoplasia (N), entrapment (E), diffuse neuropathy (D), not otherwise specified (NOS), and postintervention state (PI). Subclasses were established to describe the severity or extent of the lesions. Validation testing was performed by 11 readers from 10 institutions with experience levels ranging from 3 to 18 years after residency. After initial reader training, cases were presented to readers who were blinded to the final clinical diagnoses. Interobserver agreement was assessed using correlation coefficients and the Conger kappa, and accuracy testing was performed.



Neuropathy Score Reporting and Data System (NS-RADS) subclass N1 M3.

Coronal fat-suppressed T2-weighted (A), axial fat-suppressed T2-weighted (B), and coronal postcontrast fat-suppressed T1-weighted (C) images depict enhancing thickening of sciatic nerve with prominent fascicles (arrows) consistent with perineurioma (NS-RADS subclass N1)



Mai Result:  Final clinical diagnoses included normal (n = 5), nerve injury (n = 25), entrapment (n = 15), neoplasia (n = 33), diffuse neuropathy (n = 18), and persistent neuropathy after intervention (n = 4). The miscategorization rate for NS-RADS classes was 1.8%. Final diagnoses were correctly identified by readers in 71–88% of cases. Excellent inter-reader agreement was found on the NS-RADS pathology categorization (κ = 0.96; 95% CI, 0.93–0.98) as well as muscle pathology categorization (κ = 0.76; 95% CI, 0.68–0.82). The accuracy for determining milder versus more severe categories per radiologist ranged from 88% to 97% for nerve lesions and from 86% to 94% for muscle abnormalities.


Conclusion:  The proposed NS-RADS classification is accurate and reliable across different reader experience levels and a spectrum of PN conditions. NS-RADS can be used as a standardized guideline for reporting PN and improved multidisciplinary communications.


Resident take home message:


  • Residents should use NS-RADS while evaluating and reporting peripheral neuropathy on MRI.


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