Paraneoplastic musculoskeletal disorders: review and update for radiologists.

Rheumatic paraneoplastic syndromes are rare syndromes that occur at distant sites from the underlying tumor and may involve the bones, joints, fasciae, muscles, or vessels. In the absence of a known tumor, early recognition of a rheumatic syndrome as paraneoplastic permits dedicated work-up for, and potentially early treatment of an occult malignancy. Although there is a continuously growing list of paraneoplastic rheumatic disorders, not all of these disorders have a well-established association with a neoplastic process. The goals of this article are to review the clinical characteristics, diagnostic work-up, and imaging findings of well-documented rheumatic paraneoplastic disorders.

Myeloma Response Assessment and Diagnosis System (MY-RADS): strategies for practice implementation.

Structured reporting systems have been developed for many organ systems and disease processes beginning with BI-RADS in 1993. Numerous reports indicate that referring health care providers prefer structured reports. Reducing variability of reports from one radiologist to another helps referring physician and patient confidence. Changing radiologists practice habits from completely free text to structured reports can be met with some resistance, but most radiologists quickly find that structured reports make their job easier. Whole-body MR studies are recommended as first-line imaging, by the International Myeloma Working Group (IMWG), for all patients with suspected diagnosis of asymptomatic myeloma and/or initial diagnosis of solitary plasmacytoma. Whole-body MR imaging (WBMRI) has been shown to have equal or greater sensitivity and specificity compared to PET/CT for detection of bone marrow involvement. Changing to WBMRI from other imaging modalities can be difficult for referring providers. Patient acceptance is high. MY-RADS is for myeloma patients who have WBMRI studies done. The intent of the system is to promote uniformity in MR imaging acquisition, diagnostic criteria, and response assessment and to diminish differences in the subsequent interpretation and reporting. A secondary benefit is a report template that provides a guide for interpretation for radiologists who may not have previously dictated these difficult studies. The characterization of bone marrow abnormalities in myeloma patients usually is fairly straightforward. To date, there is no standardized scoring or risk stratification of abnormalities nor is there an imaging atlas of abnormalities.

Society of Skeletal Radiology- white paper. Guidelines for the diagnostic management of incidental solitary bone lesions on CT and MRI in adults: bone reporting and data system (Bone-RADS).

The purpose of this article is to present algorithms for the diagnostic management of solitary bone lesions incidentally encountered on computed tomography (CT) and magnetic resonance (MRI) in adults. Based on review of the current literature and expert opinion, the Practice Guidelines and Technical Standards Committee of the Society of Skeletal Radiology (SSR) proposes a bone reporting and data system (Bone-RADS) for incidentally encountered solitary bone lesions on CT and MRI with four possible diagnostic management recommendations (Bone-RADS1, leave alone; Bone-RADS2, perform different imaging modality; Bone-RADS3, perform follow-up imaging; Bone-RADS4, biopsy and/or oncologic referral). Two algorithms for CT based on lesion density (lucent or sclerotic/mixed) and two for MRI allow the user to arrive at a specific Bone-RADS management recommendation. Representative cases are provided to illustrate the usability of the algorithms.

Updates and Ongoing Challenges in Imaging of Multiple Myeloma: AJR Expert Panel Narrative Review.

Advances in the understanding and treatment of multiple myeloma have led to the need for more sensitive and accurate imaging of intramedullary and extramedullary disease. This role of imaging is underscored by recently revised imaging recommendations of the International Myeloma Working Group (IMWG). This narrative review discusses these recommendations from the IMWG for different disease stages, focusing on advanced whole-body modalities, and addresses related challenges and controversies. In the recommendations, whole-body low-dose CT is central in initial patient assessment, replacing the conventional skeletal survey. Although the recommendations favor MRI for diagnosis because of its superior sensitivity and utility in identifying myeloma-defining events, FDG PET/CT is recommended as the modality of choice for assessing treatment response. Consensus opinions are offered regarding the role of imaging in multiple myeloma for characterization of disease distribution, determination of prognosis, and response evaluation.

Association of Patient Self-Reported Shoulder Scores to Quantitative and Semiquantitative MRI Measures of Rotator Cuff Intramuscular Fatty Infiltration: A Pilot Study.

OBJECTIVE. The purpose of this study was to determine the relationship of supraspinatus fat fraction and Goutallier grade to the American Shoulder and Elbow Surgeons (ASES) score in cohorts of older adults with painful full-thickness supraspinatus tendon (SST) tear and control subjects. SUBJECTS AND METHODS. Seventeen control subjects and 15 study participants with painful full-thickness SST tear were prospectively recruited (mean age ± SD, 63.0 ± 10.1 years and 62.6 ± 9.0 years, respectively). Study participants received shoulder MRI and completed ASES questionnaires at one time. Goutallier grade was assessed on T1-weighted MRI. Fat fraction was measured on 6-point Dixon MRI. Body mass index (BMI) was determined. Descriptive, correlation, reliability, and regression analyses were performed. RESULTS. The control and painful full-thickness SST tear cohorts differed in mean supraspinatus fat fraction (3.3% ± 1.4% and 7.3 ± 5.9%, respectively; p = 0.024) and Goutallier grade (0.4 ± 0.5 and 0.9 ± 0.7, respectively; p = 0.022). Fat fraction (p = 0.014) and Goutallier grade (p = 0.017) showed a significant inverse association with ASES score only in the SST tear cohort. The association of BMI to ASES score was significant only in the control group (p = 0.036). The correlation between BMI and fat fraction were different for the two groups (control cohort, r = 0.676 and p = 0.003; SST tear cohort, r = 0.124 and p = 0.687). Fat fraction showed strong interobserver reliability (intraclass correlation coefficient, 0.903); Goutallier grade showed poor interobserver reliability (κ = 0.178). CONCLUSION. The association of ASES score and supraspinatus fat fraction or Goutallier grade differs between patients with painful full-thickness SST tear and control subjects without symptoms. Although fat fraction shows strong reliability, Goutallier grade should be regarded cautiously because of suboptimal reproducibility. Our results also suggest that painful full-thickness SST tear alters the correlation between supraspinatus fat fraction and BMI as compared with control subjects.

The Ability of Dual-Energy Computed Tomography to Distinguish Normal Bone Marrow From Metastases Using Bone Marrow Color Maps.

OBJECTIVE: The objective of this study was to determine if dual-energy computed-tomography bone marrow color maps can improve sensitivity, specificity, accuracy, and confidence of detection of bone metastases. METHODS: Institutional review board approved this retrospective review of a consecutive series of cancer patients. Two radiologists first evaluated the fused 120 kV computed tomography images and recorded a number of suspicious lesions, confidence level, and Hounsfield units for each lesion. After a time gap, the studies were randomized for a second review with dual-energy computed-tomography bone marrow color maps. RESULTS: Eighteen patients and 1105 bones were reviewed. A total of 227 true metastatic lesions were present. With bone marrow color map review, sensitivity increased from 76.2% to 86.8%, for reader 1, and from 80.2% to 92.8%, for reader 2. Specificity and accuracy also increased. Confidence level increased for 12 lesions. CONCLUSIONS: Dual-energy computed-tomography bone marrow color map analysis of patients with metastatic cancers can improve the sensitivity, specificity, accuracy, and confidence level for the detection of bone metastases.

MRI of Traumatic Knee Dislocation: A Study to Evaluate Safety and Image Quality for Patients with Knee-Spanning Stabilization Devices.

This study evaluated safety and image quality of MRI exams performed for patients with traumatic knee dislocations in knee-spanning stabilization devices. It is an IRB-approved retrospective design with waived informed consent that included 63 patients with traumatic knee dislocation. 56 patients had metallic external fixators, and 7 patients had non-metallic knee immobilizers. 7 patients had bilateral dislocations yielding a total of 70 knee MRIs. 1.5 Tesla MRI exams were performed for all patients who were awake and alert at the time of imaging. All knee-spanning external fixators were considered "MR conditional" by the FDA. The electronic medical record was reviewed for notes from the technologist and nursing staff documenting any patient complaints or adverse events during the MRI exam as required by departmental protocol. Qualitative analysis of the six most frequently performed sequences were independently conducted by 2 musculoskeletal radiologists using a 5-point Likert scale. Overall image quality and select time intervals between the two groups were compared using an independent sample t test and the Mann-Whitney U test, respectively. No adverse events were reported for a 40-minute average estimated patient scan time with the stabilization devices in the MR gantry. Mean values of Likert scale scores were generated from two readers' data for comparison between the external fixation and the immobilizer groups. Most knee MRI exams with external fixators were within diagnostic quality despite artifacts (grade 3). MRI exams generally were of higher diagnostic quality in the immobilizer group than the external fixator group (p < 0.05). The external fixator models included DePuy Synthes, Smith and Nephew, Stryker Hoffman III, Zimmer FastFrame, and Zimmer XtraFix. MRI examinations in patients with external fixators for traumatic knee dislocations can be safely performed under certain conditions and provide diagnostic quality images.

Medication-induced periostitis in lung transplant patients: periostitis deformans revisited.

We report five cases of diffuse periostitis resembling hypertrophic osteoarthropathy and perostitis deformans in lung transplantation patients on chronic voriconazole, a fluoride-containing compound. Although drug-related periostitis has long been known, the association of lung transplant medication with periostitis was only recently introduced in the literature. To our knowledge, imaging findings have not been fully characterized in the radiology literature. Imaging features along with clinical history help to distinguish this benign condition from other disease entities. In this article, we review the current literature and illustrate the variety of imaging characteristics of this entity so that interpreting radiologists can make accurate diagnoses and avoid unnecessary work up.

Correlation of Quantitative Versus Semiquantitative Measures of Supraspinatus Intramuscular Fatty Infiltration to Shoulder Range of Motion and Strength: A Pilot Study.

PURPOSE: The relationship of magnetic resonance imaging (MRI) measures of rotator cuff intramuscular fatty infiltration (FI) to shoulder range of motion (ROM) and strength are not well understood. Our purpose was to determine if supraspinatus quantitative Dixon fat fraction has superior correlation to shoulder ROM and strength as compared to semiquantitative Goutallier grade. METHODS: Thirty-seven study subjects received shoulder MRI; and measurement of ipsilateral shoulder forward flexion ROM, abduction ROM and abduction strength. Supraspinatus Dixon fat fraction was measured on 6-point Dixon MRI by 2 diagnostic radiology residents. Supraspinatus Goutallier grade was assessed on T1-weighted MRI by 2 musculoskeletal radiologists. Questionnaires recorded demographics. Based on characteristics, study subjects were divided into 3 groups: Group 1, neither shoulder pain nor full-thickness supraspinatus tendon (SST) tear (n = 17; mean age, 63.0 ± 10.1 years); Group 2, positive complaint of shoulder pain but without full-thickness SST tear (n = 7; mean age, 57.4 ± 9.9 years); Group 3, positive complaint of shoulder pain and full-thickness SST tear (n = 13; mean age, 63.6 ± 8.1 years). One-way analysis of variance compared groups. Spearman (rho) rank order correlation was performed to determine correlation of supraspinatus Dixon fat fraction, or Goutallier grade, with measures of ROM and strength for the study population. Reliability analyses were performed for Dixon fat fraction and Goutallier grade. RESULTS: No significant differences were present among groups for age. Significant differences existed among groups for forward flexion ROM (P= 0.001), abduction ROM (P < 0.001), Dixon fat fraction (P = 0.004) and Goutallier grade (P = 0.012). Dixon fat fraction showed statistically significant inverse correlations with forward flexion ROM (rho = -0.47; P = 0.005), abduction ROM (rho = -0.35, P = 0.041), and abduction strength (rho = -0.42; P = 0.013). Goutallier grade demonstrated weak inverse correlation that lacked statistical significance (P > 0.05) for the same measures. Dixon fat fraction showed strong interobserver and intraobserver reliability with intraclass correlation coefficients of 0.956 and 0.999, respectively. Goutallier grade showed poor interobserver (kappa, 0.188) and moderate intraobserver (kappa, 0.608) reliability. CONCLUSION: Supraspinatus Dixon fat fraction has superior correlation to shoulder ROM and strength relative to Goutallier grade on MRI.

How to Diagnose Enchondroma, Bone Infarct, and Chondrosarcoma.

Enchondromas are among the most common benign tumors seen in the skeleton. They are encountered frequently in routine clinical practice. The purpose of this review is to help radiologists confidently diagnose enchondroma and distinguish it from other entities, such as bone infarct, bone graft, and low-grade chondrosarcoma.

CT-guided shoulder arthrography at the rotator cuff interval.

OBJECTIVE: The purpose of this study was to describe a CT-guided approach to the glenohumeral joint at the rotator cuff interval and to compare that approach to the more traditional approach, including technical considerations. CONCLUSION: CT-guided glenohumeral joint injections at the rotator cuff interval are faster and easier to perform than those performed using the more traditional approach.

Tunnel convergence in combined anterior cruciate ligament and posterolateral corner reconstruction.

PURPOSE: To examine the geometric relationship between tunnels created in the lateral femoral condyle in reconstruction of the anterior cruciate ligament (ACL) and the posterolateral structures. METHODS: The geometric relationship between a standard ACL tunnel and 11 lateral femoral tunnel variations in synthetic femur specimens was examined. Tunnel collision frequency and tunnel separation were measured radiographically. Subsequent evaluation was performed on 7 paired cadaveric specimens (14 knees) to access the efficacy of 2 configurations. RESULTS: Phase I-Tunnel collision frequency was 0% and 58% for 25-mm and 30-mm tunnel depths, respectively. Axial angles greater than 40 degrees and coronal angles > or =20 degrees resulted in unsafe configurations. The safest position for lateral tunnel placement was straight lateral approach (0 degrees in the coronal plane) with increased axial plane orientation (hand dropped toward the floor 40 degrees). The safe zone for lateral tunnel configuration was determined to be between [0,0] and [0,40] ([coronal, axial]). Phase II--Control group ([0,0]) collision frequencies were 43% and 86% for the 25-mm 30-mm tunnels, respectively. Experimental group ([0,40]) collision frequencies were 29% and 43% for the 25-mm and 30-mm tunnel, respectively. In femoral condyles measuring <35 mm, collision rates were 100% versus 0% in the control group ([0,0]) versus the experimental group ([0,40]). In specimens where no collision was seen, tunnel separation distance was 4.5 +/- 4.4 mm and 5.8 +/- 2.2 mm for the control and experimental groups, respectively (P = .39). CONCLUSIONS: Tunnel collision occurred often. Tunnel collision is dependent on femoral condyle geometry, tunnel depth, and tunnel configuration. To minimize the potential for tunnel collision, the surgeon should maintain a neutral alignment in the coronal plane, limit lateral tunnel depth to < or =25 mm, and direct the lateral tunnel anteriorly in the axial plane to a maximum of 40 degrees. CLINICAL RELEVANCE: This study describes guidelines for tunnel placement to prevent tunnel collision when performing combined ACL and posterolateral corner reconstruction.

Musculoskeletal and overgrowth syndromes associated with cutaneous abnormalities.

There are cutaneous abnormalities that are characteristic to certain peculiar musculoskeletal conditions. The understanding of associated imaging and clinical skin findings together in this context can play an important role for the dermatologist and radiologist in establishing the correct diagnoses. The scope of dermatological manifestations of many acquired diseases of the soft tissues, muscles or bone is broad. Therefore, the intent of this article is to review those entities that are genetic and/or inherited. The goal of this review is to develop a better understanding of the cases presented. In these cases, collaboration between dermatologists and radiologists may be paramount to generating a diagnosis and monitoring at-risk patients.

Osteochondroma-Related Pressure Erosions in Bony Rings Below the Waist.

This article investigates the clinical and radiological features of four cases of osteochondroma-related bony pressure erosion in adults. Rare imaging features of extrinsic pressure erosions on adjacent bones caused by solitary and familial forms of osteochondroma are presented. Although described to occur uncommonly in the paired bones of the lower leg, pressure erosion in the pelvic girdle is poorly understood. In this article, we discuss clinical contexts for management of osteochondroma-related bony pressure erosion in the mature skeleton.

Patient-centered care in diagnostic radiology: lessons learned from patient interviews prior to musculoskeletal magnetic resonance imaging.

BACKGROUND: Since most radiologists do not meet with patients, questionnaires often substitute for face-to-face interviews to collect patients' history. We report the effect of direct radiologist-patient interviews on the quality of patient history recorded for musculoskeletal magnetic resonance imaging. METHODS: Magnetic resonance imaging questionnaires completed by outpatients were separated into 2 cohorts: (1) imaging center (IC) forms with no radiologist interviews; (2) hospital (H) forms with radiologist-patient interviews. Three blinded radiologists independently scored each questionnaire for quality on a 5-point scale. A separate quantitative analysis was also performed. The unpaired t test, Fischer exact test, and χ² test were used to compare the cohorts. RESULTS: The mean score of the H cohort among reviewers was superior to the IC cohort: 3.79 (±0.98) versus 3.04 (±1.00), P < .0001. Each reviewer also independently found the H cohort to be of higher quality for patient history, P < .0001. For the IC cohort, 7.8% of questionnaires did not report a single symptom versus 0.0% in the H cohort, P = .0331. Also, the IC cohort recorded symptoms in 2 or less words more often than the H cohort, P < .0001. CONCLUSION: Brief radiologist-patient interviews are superior for obtaining a higher quality of patient history for musculoskeletal MRI than patient questionnaires alone.

Hematopoietic tumors and metastases involving bone.

This review explores in depth the most common malignant process involving the bone, namely metastatic disease, as well as some of the more common proliferative forms of hematopoietic disease of bone marrow. These are commonly encountered pathologic processes that often have vague nonspecific symptoms. Imaging findings are frequently subtle on initial radiographs; however, advanced imaging techniques, including CT, MR, and positron emission tomography, allow for accurate diagnosis, staging, and follow-up in most cases.

Central skeletal sarcoidosis mimicking metastatic disease.

Sarcoidosis is a systemic disease that histologically typically shows non-caseating granulomas. The most common radiologic finding is hilar and mediastinal adenopathy. Patients with widely disseminated disease may show involvement of the peripheral appendicular skeleton in 1-13% of such cases. A primary skeletal presentation without other manifestations typical of the disease is rare. We present a case of sarcoidosis in a middle-aged Caucasian man in whom the disease presented with widespread lytic lesions in the axial skeleton and long bones, mimicking metastatic disease. There was no involvement of the peripheral skeleton, skin or lungs.

Myeloma update.

Myeloma is the most common primary bone malignancy and one of the most common hematologic malignancies. Research on myeloma constantly produces new information on genetic factors, imaging techniques, and treatment complications among others that is of use to patients, referring physicians, and radiologists. This update emphasizes new developments regarding imaging techniques for diagnosis, staging, and follow-up of myeloma patients. Advances in whole body radiography, whole body computed tomography, whole body magnetic resonance imaging, and whole body nuclear techniques (including sestamibi and positron emission tomography) are discussed.