The use of routine non density calibrated clinical computed tomography data as a potentially useful screening tool for identifying patients with osteoporosis.

OBJECTIVES: To evaluate whether lumbar vertebral body density CT attenuation values measured in Hounsfield Units (HUs) on routine Computed Tomography (CT) examinations can be reliably measured with limited variability, and to evaluate for a correlation between HUs and bone mineral density as measured by dual energy X-ray absorptiometry (DXA) scan. METHODS: Retrospective review of a total of 249 routine MDCT examinations, performed to measure HUs at the first non-rib bearing lumbar vertebral body on axial images, cross-referenced to the lateral scout image. RESULTS: The overall ICC and RC for intra-reader variability on CT HU were 0.987 (95% CI 0.973 - 0.999) and 15.664 (95% CI 11.66-16.97). The overall ICC and RDC for inter-reader variability on CT HU were 0.952 (95% CI 0.892 - 0.999) and 30.20 (95% CI 23.73 - 34.48). The ICC and RC for interscanner variability were 0.98 (95% CI 0.95 - 0.99) and 16.67 (95% CI 13.13 - 22.85). The correlation between the L1 HUs and L1 BMD, L1 t-score, and overall t-score was 0.437, 0.392, and 0.400, respectively. CONCLUSIONS: CT attenuation values of the first lumbar vertebra can be measured on routine abdomen CTs with limited variability despite multiple readers and scanners. Correlation between HU and BMD as measured by DXA scan was only weakly positive, and by this method measuring the density of a lumbar vertebral body from a routine MDCT scan does not provide the sensitivity or specificity necessary for a screening test. However above a certain measured value (180 HU), patients have a low chance of osteoporosis and therefore may not need additional screening, potentially limiting radiation exposure and cost.

Radiographic scoring system to evaluate union of distal radius fractures.

PURPOSE: To evaluate the intra- and interobserver reliability of a scoring system for distal radius fracture union based on specific radiographic parameters obtainable from x-rays. METHODS: Two sets of 35 anteroposterior and lateral x-rays were obtained by retrospective review of consecutive patients with distal radius fractures (AO types A and C) treated by a single surgeon in 2009. One set was assembled for those patients treated nonsurgically and 1 set for those treated with open reduction and internal fixation (ORIF) with volar plating. Radius union scoring system (RUSS) scores were compiled from a 5-person review panel consisting of hand surgeons and musculoskeletal radiologists. Union of each of the 4 cortices was graded on a 3-point scale (0, fracture line visible with no callus; 1, callus formation but fracture line present; 2, cortical bridging without clear fracture line). Reviewers also recorded their overall impression of fracture union (united or not united). Each set of radiographs was reviewed twice by the 5 reviewers, 2 weeks apart. Inter- and intraobserver reliability were determined using intraclass correlation coefficients. RESULTS: For nonsurgically treated fractures, substantial agreement in union scores was found with regard to both intra- and interobserver reliability. For fractures treated with ORIF, substantial agreement was found in union scores with regard to intraobserver reliability and moderate agreement with regard to interobserver reliability. In addition, when using the reviewers' overall assessment of union as a reference standard, RUSS had a statistically significant predictive value in being able to differentiate between united and not united fractures. CONCLUSIONS: This radiographic union tool demonstrated substantial intra- and interobserver reliability for the determination of fracture union in the distal radius. The RUSS is a simple method for a standardized assessment of radiographic union of DRF treated nonsurgically or with ORIF. TYPE OF STUDY/LEVEL OF EVIDENCE: Economic/decision analysis IV.

Image guided core needle biopsy of musculoskeletal lesions: are nondiagnostic results clinically useful?

BACKGROUND: The clinical utility of nondiagnostic core needle biopsies is not fully understood. Understanding the clinical and radiologic factors associated with nondiagnostic core needle biopsies may help determine the utility of these nondiagnostic biopsies and guide clinical decision making. QUESTIONS/PURPOSES: We asked (1) whether benign or malignant bone and soft tissue lesions have a higher rate of nondiagnostic core needle biopsy results, and which diagnoses have the lowest diagnostic yield; (2) how often nondiagnostic results affected clinical decision-making; and (3) what clinical factors are associated with nondiagnostic but useful core needle biopsies. METHODS: A retrospective study was performed of 778 consecutive image-guided core needle biopsies of bone and soft tissue lesions referred to the musculoskeletal radiology department at a single institution. The reference standard was (1) the final diagnosis at surgery or (2) clinical followup. Diagnostic yield was calculated for the most common diagnoses. Clinical and imaging features related to each nondiagnostic core needle biopsy were assessed for their association with clinical usefulness. Useful nondiagnostic biopsies were defined as those that help guide treatment. Each lesion was assessed before biopsy by the orthopaedic oncologist as (1) "likely to be benign" or (2) "suspicious for malignancy." The overall diagnostic yield was 74%. RESULTS: Malignant lesions had higher diagnostic yield than benign lesions: 94% (323 of 345) versus 58% (252 of 433), yielding a relative risk (RR) of 1.61 and 95% CI of 1.48 to 1.75. Soft tissue lesions had a higher diagnostic yield than bone lesions: 82% (291 of 355) versus 67% (284 of 423); RR, 1.22; 95% CI, 1.22 (1.12-1.33). Ganglion cyst (36%, four of 11), myositis ossificans (40%, two of five), Langerhans cell histiocytosis (0%, 0 of four), and simple bone cyst 0%, 0 of six) had the lowest diagnostic yield. Of the nondiagnostic biopsies assessed for clinical usefulness by the orthopaedic oncologist, 60% (85 of 142) of the biopsies were useful in guiding clinical decision making. Useful nondiagnostic core needle biopsy results occurred more often in painless, nonaggressive lesions, assessed as "likely to be benign" before biopsy. CONCLUSIONS: Nondiagnostic core needle biopsy results in musculoskeletal lesions are not entirely useless. At times, they can be supportive of benign processes and can help avert unnecessary surgical procedures.

On-call musculoskeletal radiographs: discrepancy rates between radiology residents and musculoskeletal radiologists.

OBJECTIVE: The purpose of this study was to determine the rate of discrepancy between radiology residents and attending musculoskeletal radiologists in interpretation of on-call musculoskeletal radiographs. MATERIALS AND METHODS: We performed a retrospective review of 2219 consecutive musculoskeletal radiology reports on patients who visited the emergency department between January 2009 and December 2010. The images were initially interpreted overnight by on-call residents (postgraduate years 3-5), and a final interpretation was rendered the next morning by a musculoskeletal radiologist. The reports were evaluated for major discrepancies, such as missed fractures, osteomyelitis, foreign bodies, tumors, and acute arthritic conditions, which were defined as cases in which a change in clinical management was needed and required notification of the emergency care provider. RESULTS: The overall discrepancy rate was 1.8% (40/2219). Fractures accounted for 62.5% (25/40) of missed findings. Fractures involving the upper extremity, particularly the hand and wrist (2.2% [9/405]), were the most frequently missed. Radial fractures accounted for 50% (7/14) of the missed upper extremity fractures. Foreign bodies (10% [4/40]) and tumorlike lesions (7.5% [3/40]) accounted for the next most common misses. Finally, independent resident readings in the on-call setting had little adverse effect on patient care. CONCLUSION: In the on-call setting, the low discrepancy rate between interpretations of musculoskeletal radiographs by residents and by musculoskeletal attending radiologists is comparable to that reported for other body parts and modalities. Residents should be aware of the relatively high rate of missed pathologic findings in the upper extremity, especially the radius.

Pseudotear of the peroneus longus tendon on MRI, secondary to a fibrocartilaginous node.

OBJECTIVE: The purpose of this study was to identify the presence of a fibrocartilaginous node within the distal peroneus longus tendon (PLT) just proximal to the cubital tunnel and correlate this with MRI signal characteristics of the distal PLT, which could result in a pseudotear appearance on MRI. We correlated imaging characteristics with pathologic specimens. MATERIALS AND METHODS: Institutional review board approval was obtained. Retrospectively, 91 ankle MRIs utilizing a standard ankle protocol were reviewed by two musculoskeletal radiologists. Four cadaver ankles were imaged using a standard ankle MRI protocol and reviewed by the same radiologists. All the MRIs were examined for signal changes in the PLT. The cadaver ankles then underwent PLT dissection by an orthopaedic surgeon, and a pathologic review was undertaken by a pathologist with orthopaedic specialization, who looked for an os peroneum or proposed fibrocartilaginous node relating to the signal change found on the MRIs. RESULTS: In the 91 ankle MRI studies, the PLT demonstrated normal low and increased signals. On the fat-saturated T2-weighted sequence, 76 (83.5%) ankles demonstrated low signal and 15 (16.5%) demonstrated increased signal. Of the cadaver ankle MRIs, all four demonstrated increased signal within the PLT; three contained a fibrocartilaginous node and one contained an os peroneum in that same region. CONCLUSIONS: The MRI signal of the PLT can change with the presence of a fibrocartilaginous node, which may be due to the molecular and chemical content of the fibrocartilage. This node increases the MRI signal in the distal PLT and gives the appearance of a pseudotear.

A young patient with polyarthralgia and hearing loss: a case report of Muenke syndrome.

There are few reports of the typical radiographic findings in the hands and feet of patients with Muenke syndrome. We present a case report of a young girl with Muenke syndrome, whose diagnosis was made following the observation of coalitions and coned epiphyses on hand radiographs.