Annual Scientific Meeting Abstracts of the

Skeletal Radiology (2018) 47:1315–1325 https://doi.org/10.1007/s00256-018-2994-5

ABSTRACTS

Annual Scientific Meeting Abstracts of the International Skeletal Society (ISS) 2018, Berlin, Germany

Special Scientific Session Program Monday, September 24, 2018 13:30–17:30 Ad Hoc Scientific Session Committee: Julie Fanburg-Smith, MD Alice S. Ha, MD Kenneth S. Lee, MD Thomas M. Link, MD, PhD Luca M. Sconfienza, MD, PhD Reto Sutter, MD Chair: Miriam A. Bredella, MD Session 1

83% for 2D and 3D iAUC; −10% for 3D kurtosis; −14% for 3D Kep; and 69% for fat fraction. There was no significant difference in baseline MR parameters between osteolytic and sclerotic metastases (P > .05). However, percent change between baseline and 3-week MR imaging of 2D Ktrans significantly greater in sclerotic than osteolytic metastases (83 vs 22%, P < .05), while those of 2D and 3D Kep were significantly lower in sclerotic than osteolytic metastases (−0.17 vs −0.29%; −7.48 vs −11%, respectively, P < .05). Conclusion: Multiparametric MR imaging may help predict the early response of bone metastases to target therapy in EGFR positive NSCLC patients at 3 T. 13:40. Do Contrast-Enhanced Sequences and Functional MRI Sequences Improve Diagnostic Accuracy in the Spectrum of Lipomatous Tumors?

Moderators: Miriam A. Bredella, USA; Luca M. Sconfienza, Italy 13:30. Bone Metastases in Non-Small Cell Lung Cancer: Assessment of Early Treatment Response to Target Therapy with 3T Multiparametric MR Imaging Jaejung Lim, Won-Hee Jee, Seul Ki Lee, Joon-Yong Jung, Ie-Ryung Yoo, Jun-Pyo Myong, Jin Hyoung Kang, Yohan Son, Mun Young Paek, Soojung Kim. Seoul, Republic of Korea. Purpose: To prospectively investigate the early response of bone metastases to target therapy with 3T multiparametric MR imaging in non-small cell lung cancer (NSCLC) patients with positive epidermal growth factor receptor (EGFR). Materials and Methods: The institutional review board approved this prospective study and written informed consent was obtained. Thirteen EGFR positive NSCLC patients underwent 3T MR imaging including standard MR imaging, intravoxel incoherent motion (IVIM) diffusionweighted MR imaging, multiecho Dixon imaging, and dynamic contrast-enhanced (DCE) MR imaging. MR imaging and 18F FDG PET/CT were performed at baseline and 20 weeks after target therapy. MR imaging alone was obtained at 3 weeks after target therapy. There were 24 bone metastases: osteolytic (n = 12) and sclerotic (n = 12) lesions. MR parameters were measured on a single-slice (2D) and volumetric (3D) analysis of whole tumor volume. Interval changes of MR parameters were calculated. In addition, MR parameters were compared between osteolytic and sclerotic metastases. Statistical analysis was performed with repeated measures analysis of variance (ANOVA), Wilcoxon signed-rank test, and Mann-Whitney test. Results: All bone metastases were classified as good responders based on final PET/CT. Between baseline and 3-week, significant time effects were found in interval increase of 2D and 3D apparent diffusion coefficient (ADC), 2D and 3D Ktrans, 2D Ve, 2D and 3D iAUC, and fat fraction, whereas interval decrease of 3D kurtosis and 3D Kep (P < .05). At 3week, percent changes were as follows: 33 and 14% for 2D and 3D ADC; 49 and 69% for 2D and 3D Ktrans; 141% for 2D Ve; 125 and

Brett A Shannon, Shivani Ahlawat, Carol D Morris, Adam S Levin, Laura M Fayad. Baltimore, MD, USA. Purpose: Distinguishing amongst lipomas, atypical lipomatous tumors (ALT), and dedifferentiated liposarcomas (DDLPS) can be challenging. We hypothesized that addition of dynamic contrast enhancement (DCE), diffusion weighted imaging (DWI), and chemical shift imaging (CSI) to the magnetic resonance imaging (MRI) protocol improves diagnostic accuracy for indeterminate lipomatous tumors. Materials and Methods: This is a retrospective study of 32 patients referred for biopsy or excision of a lipomatous tumor and pre-procedure MRI including fluid-sensitive, CSI, DWI (b values 50, 400, 800 s/mm2), pre- and post-contrast T1-weighted and DCE (7-second time resolution) sequences. MRI studies were reviewed for tumor septations, nodules, early arterial enhancement by DCE, apparent diffusion coefficient (ADC) values of the tumor and largest nodule, and CSI signal loss on opposed-phase compared with in-phase sequences. Radiologist diagnosis was recorded after review of imaging in 3 sessions: 1) T1/fluid-sensitive sequences, 2) with addition of post-contrast T1, and 3) with addition of DCE, DWI and CSI sequences. Histology was the diagnostic gold standard. Descriptive statistics were reported. Results: All tumors without thick septations were lipomas, and 12/13 tumors with nodules >1 cm were ALT or DDLPS. For lipomas, variants, ALT, and DDLPS, respectively: early arterial enhancement was present in 0/14 (0%), 1/4 (25%), 1/5 (20%), and 5/6 (83%); average tumor ADC values were 0.3, 0.9, 1.2, and 0.9; CSI signal loss >20% was present in 4/ 13 (31%), 3/4 (75%), 6/7 (86%), and 6/6 (100%). The radiologist’s interpretation accuracy using pre-contrast, post-contrast, and functional/CSI sequences, respectively, was 6/6 (100%), 6/6 (100%) and 6/6 (100%) for lipomas; 0/2 (0%), 0/1 (0%), and 0/2 (0%) for lipoma variants; 5/15 (33%), 5/16 (32%), and 5/15 (33%) for ALT; and 5/9 (56%), 5/9 (56%), and 5/9 (56%) for DDLPS. Conclusion: Diagnostic interpretation for indeterminate lipomatous tumors is not changed by the addition of contrast or functional imaging with DCE or DWI, as thick septations and large nodules are important to

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differentiating low grade (lipoma/variants) from higher grade lesions (ALT/DDLPS). However, DCE has the potential to distinguish DDLPS from ALT, potentially providing a means of triaging patients toward follow-up rather than biopsy in lesions with high grade features. 13:50. Accuracy of Magnetic Resonance Imaging for Diagnosis of Hallux Valgus Paulo Helito, Stephano Rocha, Renata Pereira, Renata Leão, Marcos Correa, Ceci Kurimori, Claudia Leite, Denise Amaral, Marcelo Bordalo-Rodrigues, Giovanni Cerri. São Paulo, Brazil. Purpose: Hallux valgus (HV) is a prevalent disease that deforms the forefoot. The diagnostic method of choice for HV is the measurement of the metatarsophalangeal angle (MPA) on weight-bearing radiographs. No diagnostic criteria exists for HV in magnetic resonance imaging (MRI). The study aims to assess the accuracy of MRI for the diagnosis of HV using plain radiography as the gold standard. Materials and Methods: Retrospective analysis of MRI scans of the forefoot accompanied by weight-bearing radiographs. Patients were divided in two groups according to measurement of the MPA on plain radiography: MPA ≥15° (hallux valgus) and MPA 90% for both readers regarding both sequences in the cervical and lumbar spine exams. Accuracy, sensitivity, and specificity of both sequences is also presented when compared to the reference gold standard radiographic evaluation. Conclusion: The inclusion of dynamic HASTE and radial GRE sequences is a rapid and easily performed addition to the standard protocol for kinematic cervical flexion-extension which could be used for assessment of dynamic canal stenosis, cord impingement, and spondylolisthesis and may be a valuable adjunct to radiographs. 16:50. Dynamic 4D CT of the Spine for Assessment of Cervical Instability Umme Sara Zishan, Safa Siddiqi, Nicola Lattimer, Laura Coventry, Joseph Papanikitas, Sarah Yanny, Richard Hughes, David Mckean. Stoke Mandeville, United Kingdom. Purpose: To evaluate the use of dynamic 4D CT of the cervical spine for assessment of spinal instability. Materials and Methods: We performed a retrospective search for patients who had dynamic 4D CT of the cervical spine in our institution over a period from January 2016 to June 2017. Referral criteria included patients with a history of cervical trauma with clinical suspicion of spinal instability. Our dynamic 4D CT study protocol involved a single spiral acquisition of the cervical spine with the patient moving from flexion to extension under the supervision of the Orthopaedic team. Agreed criteria for assessing the dynamic stability of cervical spine were defined and images reported by two experienced musculoskeletal radiologists. Data regarding clinical presentation, level and severity of injury were obtained. Diagnostic image quality was assessed on an ordinal scale (1 = non- interpretable; 2 = possibly interpretable with strong image artefacts, poor signal to noise ratio; 3 = interpretable with minimal image artefacts and sufficient signal to noise ratio; 4 = interpretable without image artefacts) by two experienced musculoskeletal radiologists. Total dose-length product (DLP) was recorded. Results: In total 10 patients had dynamic cervical CT from Jan 2016 to June 2017. The mean age was 52 (range 18–88) and 7 patients were male. Cervical spinal instability was excluded using dynamic 4D CT in 9 patients who did not require subsequent surgical fixation. 1 patient demonstrated previously undetected bilateral facet joint subluxation, which required spinal fixation. The mean image quality score for dynamic CT images was 3.7 (range 2 to 4). Average DLP of dynamic CT was 774.5 mGy.cm (range 427–1158). Conclusion: We present our initial experience of dynamic 4D CT for the investigation of cervical instability and describe the technical challenges we have encountered. Our results demonstrate that this technique can be a valuable problem-solving tool in specific cases of cervical trauma to exclude spinal instability.

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17:00. ESSR Award Paper 17:10. SSR Award Paper Pacinian Corpuscles: Bright Palmar Blind-Spots on MRI Nicholas Rhodes, Julia Lehman, Naveen Murthy, David Rubin. Rochester, MN, United States. Purpose: Pacinian corpuscles, the main touch receptors to pressure and vibration, are ubiquitous in the deep dermis and hypodermis of the fingers and palms. Sporadic reports of painful hyperplastic or hypertrophied Pacinian corpuscles have appeared in the pathology and dermatology literature. Nevertheless, their existence is largely unknown to most radiologists. We frequently noted hyperintense nodules in the palms of patients on water-sensitive MRI sequences, but were unable to explain their etiology. We hypothesize that the MRI finding of palmar hyperintense nodules (i.e., “palmar dots”) represents Pacinian corpuscles. Materials and Methods: We review the anatomy and distribution of Pacinian corpuscles and review the medical literature concerning them. We review our MR imaging of the hands and wrists and present a “typical” patient demonstrating T2/STIR hyperintense, nonenhancing palmar nodules. We present MRI correlation of two recently encountered patients who had Pacinian corpuscles identified at surgical exploration and pathologic analysis. Results: 1. “Palmar dots” vary in size, number, and density, but are present in all patients. 2. The appearance of a “palmar dot” on MRI (i.e., T2/STIR hyperintense focus without enhancement) is in keeping with the anatomy of the Pacinian corpuscle. 3. The distribution of “palmar dots” on MRI correlates with the known distribution of Pacinian corpuscles on anatomic dissection. 4. On pathologic evaluation of two cases of dissected Pacinian corpuscles, the pre-surgical MRIs demonstrated correlating “palmar dots”. Conclusion: Our observations support the hypothesis that “palmar dots”, ie T2/STIR hyperintense nodules within the palms, are Pacinian corpuscles. 17:20. AMS Award Paper ERAMRS: A New MR Scoring System for Early Rheumatoid Arthritis Fan Xiao, Ryan Lee, Lai-shan Tam, James Griffin. Hong Kong, Hong Kong. Purpose: To (a) introduce a new scoring system (ERAMRS) for measuring the degree of inflammation on MR in early rheumatoid arthritis (ERA) and (b) to see how well ERAMRS correlates with clinical scoring systems and serological parameters compared to currently used MR scoring systems. Materials and Methods: 106 patients (81 females, 25 males, age, 53 ± 12 years) with early (i.e. symptoms 1.1). On the contrary, 23% of the non-enhancing components showed mean ADC < 1.4. Conclusion: Soft tissue sarcomas are heterogeneous lesions with considerable intra-lesional ADC variability. Non-enhancing areas can both increase and decrease ADC measurements. DWI should be evaluated in conjunction with conventional MR imaging sequences including postcontrast imaging for accurate assessment of tumor cellularity. 12:48. An Open-Label, Prospective, Observational Study of the Efficacy of Bisphosphonate Therapy for Painful Osteoid Osteoma Valérie Bousson, Tifenn Leturcq, Hang-Korng Ea, Olivier Hauger, Nadia Mehsen-Cetre, Bassam Hamzé, Caroline Parlier-Cuau, Jean-Denis Laredo, Thierry Schaeverbeke, Philippe Orcel. Paris, France. Purpose: To assess the efficacy of bisphosphonate therapy on bone pain in patients with osteoid osteoma (OO) (main objective), and to describe bisphosphonate-induced changes in nidus mineralisation and regional bone-marrow oedema (BMO) (secondary objective). Materials and Methods: An open-label, prospective, observational study was conducted from 2011 to 2014. Patients with either risk factors for complications or a recurrence after percutaneous or surgical ablation were offered bisphosphonate treatment after receiving extensive information on the risks and advantages of the various treatment options. Those who accepted were included in the study after they provided informed consent. They received once monthly intravenous bisphosphonate treatment until significant pain alleviation was achieved. Results: We included 23 patients. The first two patients received pamidronate and the next 21 zoledronic acid (mean, 2.95 infusions per patient). Bisphosphonate therapy was successful in 19 patients (83%), whose mean pain visual analogue scale score decreased by 76.7%; this pain-relieving effect persisted in 17 patients (74%) with a mean follow-up time of 36 months. Computed tomography (CT) demonstrated a mean nidus density increase of 177.7% (p = 0.001). By magnetic resonance imaging (MRI), mean decreases were 38.4% for BMO surface area and 30.3% for signal intensity (p = 0.001 and p = 0.000, respectively). Conclusion: In 17/23 patients with painful OO managed conservatively with bisphosphonates, long-term final success was achieved. Bisphosphonates may accelerate the spontaneous healing of OO. 12:54. One-Button-Push 10-Min 3D MRI of the Knee: Preliminary Results of a Multi-Center Validation Study Filippo Del Grande, Marco Delcogliano, Esther Raithel, Steven E Stern, Derek F Papp, Christian Candrian, Jan Fritz. Lugano, Switzerland. Purpose: To test the hypothesis that an automated 10-min multi-contrast 3D MRI protocol of the knee is at least equivalent to a 20-min 2D TSE MRI standard-of-reference protocol for the diagnosis of internal derangement. Materials and Methods: We obtained prospective internal review board approval and written informed consent from all participants. Between 03/ 2017 and 05/2017, two centers enrolled 75 symptomatic subjects, of which 50 underwent 3 T MRI and 25 underwent 1.5 T MRI. The MRI study protocol consisted of 10-min 3D CAIPIRINHA SPACE TSE and 20-min standard-of-reference 2D TSE protocols that included non-fat-suppressed intermediate-weighted and fat-suppressed T2-weighted contrasts. Both protocols were acquired in during the same session in alternating success of equal proportions across the study. The corresponding 2D and 3D TSE datasets were separated, anonymized and randomized into individual studies. Two musculoskeletal radiologists assessed each study independently for structural abnormalities of the menisci, ligaments, cartilage, and bone. Descriptive statistics, inter-reader reliability, inter-method concordance,

Skeletal Radiol (2018) 47:1315–1325

diagnostic definitiveness, interchangeability comparison tests were applied. A p-value of