Prospective Multireader Evaluation of Photon-counting CT for Multiple Myeloma Screening.

Purpose To determine whether photon-counting CT (PCCT) acquisition of whole-body CT images provides similar quantitative image quality and reader satisfaction for multiple myeloma screening at lower radiation doses than does standard energy-integrating detector (EID) CT. Materials and Methods Patients with monoclonal gammopathy of undetermined significance prospectively underwent clinical noncontrast whole-body CT with EID and same-day PCCT (August-December 2021). Five axial scan locations were evaluated by seven radiologists, with 11% (eight of 70) of images including osteolytic lesions. Images were shown in randomized order, and each reader rated the following: discernibility of the osseous cortex and osseous trabeculae, perceived image noise level, and diagnostic confidence. Presence of lytic osseous lesions was indicated. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated. Comparisons were made using paired t tests and mixed linear effects models. Results Seven participants (four women) were included (mean age, 66 years ± 9 [SD]; body mass index, 30.1 kg/m2 ± 5.2). Mean cortical definition, trabecular definition, image noise, and image quality scores were 83, 67, 75, and 78 versus 84, 66, 74, and 76 for EID and PCCT, respectively (P = .65, .11, .26, and .11, respectively). PCCT helped identify more lesions (79% [22 of 28]) than did EID (64% [18 of 28]). CNRs and SNRs were similar between modalities. PCCT had lower radiation doses than EID (volume CT dose index: EID, 11.37 ± 2.8 vs PCCT, 1.8 ± 0.6 [P = .06]; dose-length product: EID, 1654.1 ± 409.6 vs PCCT, 253.4 ± 89.6 [P = .05]). Conclusion This pilot investigation suggests that PCCT affords similar quantitative and qualitative scores as EID at significantly lower radiation doses. Keywords: CT, CT-Spectral, Skeletal-Axial, Spine, Hematologic Diseases, Whole-Body Imaging, Comparative Studies Supplemental material is available for this article. © RSNA, 2022.

Comparison of the accuracy of telehealth examination versus clinical examination in the detection of shoulder pathology.

HYPOTHESIS/BACKGROUND: In 2017, the American Orthopaedic Association advocated for the increased use of telehealth as an assessment and treatment platform, and demand has significantly increased during the coronavirus disease 2019 pandemic. Diagnostic effectiveness (also called overall diagnostic accuracy) and reliability of a telehealth clinical examination vs. a traditional shoulder clinical examination (SCE) has not been established. Our objective is to compare the diagnostic effectiveness of a telehealth shoulder examination against an SCE for rotator cuff tear (RCT), using magnetic resonance imaging (MRI) as a reference standard; secondary objectives included assessing agreement between test platforms and validity of individualized tests. We hypothesize that tests provided in a telehealth platform would not have inferior diagnostic effectiveness to an SCE. METHODS: The study is a case-based, case-control design. Two clinicians selected movement, strength, and special tests for the SCE that are associated with the diagnosis of RCT and identified similar tests to replicate for a simulated telehealth-based examination (STE). Consecutive patients with no prior shoulder surgery or advanced imaging underwent both the SCE and STE in the same visit using 2 separate assessors. We randomized the order of the SCE or STE. A blinded reader assessed an MRI, to be used as a reference standard. We calculated diagnostic effectiveness, which provides values from 0% to 100% as well as agreement statistics (Kappa) between tests by an assessment platform, and sensitivity, specificity, and likelihood ratios for individual tests in both SCE and STE. We compared the diagnostic effectiveness (overall) of the SCE and STE with a Mann-Whitney U test. RESULTS: We included 62 consecutive patients with shoulder pain, aged 40 or older; 50 (81%) received an MRI as a reference standard. The diagnostic effectiveness of stand-alone tests was poor regardless of the group, with the exception of a few tests with high specificity. None had greater than 70% accuracy. There was no significant difference between the overall diagnostic effectiveness of the STE and SCE (P = .98). Overall agreement between the STE tests and the SCE tests ranged from poor to moderate (Kappa, 0.07-0.87). CONCLUSION: This study identified initial feasibility and noninferiority of the physician-guided, patient-performed STE when compared with an SCE in the detection of RCTs. Although these results are promising, larger studies are needed for further validation of an STE assessment platform.

Dose and Recovery Response of Patellofemoral Cartilage Deformations to Running.

BACKGROUND: Running is a common recreational activity that provides many health benefits. However, it remains unclear how patellofemoral cartilage is affected by varied running distances and how long it takes the cartilage to recover to its baseline state after exercise. HYPOTHESIS: We hypothesized that patellofemoral cartilage thickness would decrease immediately after exercise and return to its baseline thickness by the following morning in asymptomatic male runners. We further hypothesized that we would observe a significant distance-related dose response, with larger compressive strains (defined here as the mean change in cartilage thickness measured immediately after exercise, divided by the pre-exercise cartilage thickness) observed immediately after 10-mile runs compared with 3-mile runs. STUDY DESIGN: Descriptive laboratory study. METHODS: Eight asymptomatic male participants underwent magnetic resonance imaging of their dominant knee before, immediately after, and 24 hours after running 3 and 10 miles at a self-selected pace (on separate visits). RESULTS: Mean patellar cartilage thicknesses measured before exercise and after the 24-hour recovery period were significantly greater than the thicknesses measured immediately after both the 3- and 10-mile runs (P < .001). This relationship was not observed in trochlear cartilage. Mean patellar cartilage compressive strains were significantly greater after 10-mile runs compared with 3-mile runs (8% vs 5%; P = .01). CONCLUSION: Patellar cartilage thickness decreased immediately after running and returned to its baseline thickness within 24 hours of running up to 10 miles. Furthermore, patellar cartilage compressive strains were dose-dependent immediately after exercise. CLINICAL RELEVANCE: These findings provide critical baseline data for understanding patellofemoral cartilage biomechanics in asymptomatic male runners that may be used to optimize exercise protocols and investigations targeting those with running-induced patellofemoral pain.

Upper extremity exertional rhabdomyolysis: MR imaging findings in four cases.

While uncommon, exertional-induced rhabdomyolysis is an important diagnostic consideration when encountering hyperintensity within one or more muscles on fluid sensitive sequences in conjunction with signal abnormality in the overlying superficial fascia and subcutaneous fat. The clinical history of recent extreme exercise helps distinguish this disorder from other possible diagnoses, such as cellulitis, necrotizing fasciitis, compartment syndrome, inflammatory processes and diabetic myonecrosis. Patients diagnosed with severe exertional induced rhabdomyolysis often require hospital admission for intravenous hydration and serial laboratory monitoring due to the potential risk of acute renal failure. While contributory, magnetic resonance imaging findings can be nonspecific, and therefore the clinical history is often essential in making this diagnosis.

Quantifying the biochemical state of knee cartilage in response to running using T1rho magnetic resonance imaging.

Roughly 20% of Americans run annually, yet how this exercise influences knee cartilage health is poorly understood. To address this question, quantitative magnetic resonance imaging (MRI) can be used to infer the biochemical state of cartilage. Specifically, T1rho relaxation times are inversely related to the proteoglycan concentration in cartilage. In this study, T1rho MRI was performed on the dominant knee of eight asymptomatic, male runners before, immediately after, and 24 hours after running 3 and 10 miles. Overall, (mean ± SEM) patellar, tibial, and femoral cartilage T1rho relaxation times significantly decreased immediately after running 3 (65 ± 3 ms to 62 ± 3 ms; p = 0.04) and 10 (69 ± 4 ms to 62 ± 3 ms; p < 0.001) miles. No significant differences between pre-exercise and recovery T1rho values were observed for either distance (3 mile: p = 0.8; 10 mile: p = 0.08). Percent decreases in T1rho relaxation times were significantly larger following 10 mile runs as compared to 3 mile runs (11 ± 1% vs. 4 ± 1%; p = 0.02). This data suggests that alterations to the relative proteoglycan concentration of knee cartilage due to water flow are mitigated within 24 hours of running up to 10 miles. This information may inform safe exercise and recovery protocols in asymptomatic male runners by characterizing running-induced changes in knee cartilage composition.

Advanced Patellar Tendinopathy Is Associated With Increased Rates of Bone-Patellar Tendon-Bone Autograft Failure at Early Follow-up After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Revision anterior cruciate ligament (ACL) reconstruction can be potentially devastating for a patient. As such, it is important to identify prognostic factors that place patients at an increased risk for graft failure. There are no data on the effects of patellar tendinopathy on failure of ACL reconstruction when using a bone-patellar tendon-bone (BPTB) autograft. PURPOSE/HYPOTHESIS: The purpose of this study was to investigate the association of patellar tendinopathy with the risk of graft failure in primary ACL reconstruction when using a BPTB autograft. The hypothesis was that patellar tendinopathy would result in higher rates of graft failure when using a BPTB autograft for primary ACL reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients undergoing ACL reconstruction at a single institution from 2005 to 2015 were examined. A total of 168 patients undergoing primary ACL reconstruction with a BPTB autograft were identified. Patients' magnetic resonance imaging scans were reviewed for the presence and grade of patellar tendinopathy by 2 musculoskeletal fellowship-trained radiologists; both were blinded to the aim of the study, patient demographics, surgical details, and outcomes. Patients were divided into 2 groups: failure (defined as presence of symptomatic laxity or graft insufficiency) and success of the ACL graft. Statistical analyses were run to examine the association of patellar tendinopathy with failure of ACL reconstruction using a BPTB autograft. RESULTS: At a mean follow-up of 18 months, there were 7 (4.2%) patients with graft failure. Moderate or severe patellar tendinopathy was associated with ACL graft failure (P = .011). Age, sex, and side of reconstruction were not associated with the risk of graft failure, although the majority of patients who failed were younger than 20 years. The use of patellar tendons with moderate to severe tendinopathy was associated with a relative risk of ruptures of 6.1 (95% CI, 1.37-27.34) as compared with autograft tendons without tendinopathy. CONCLUSION: Moderate or severe patellar tendinopathy significantly increases the risk of graft failure when using a BPTB autograft for primary ACL reconstruction. Patellar tendinopathy should be considered when determining the optimal graft choice for patients undergoing primary ACL reconstruction with autograft tendons.

Hindfoot Arthritis Progression and Arthrodesis Risk After Total Ankle Replacement.

BACKGROUND: The purpose of this study was to assess the radiographic progression of subtalar and talonavicular degenerative joint disease in a series of patients who had undergone TAA (total ankle arthroplasty) with minimum follow-up of 5 years. METHODS: TAA patient radiographs from a single institution were analyzed for peritalar arthritic changes by extrapolating the modified Kellgren Lawrence (KL) grades of the knee to the subtalar and talonavicular joints. Patients were included if they had a minimum of 5 years of follow-up. Patients who had undergone prior arthrodesis of the talonavicular or subtalar joints were excluded. A total of 140 patients with average follow-up of 6.5 years (range, 5.0-8.9 years) were included. RESULTS: Overall, 27% of patients advanced 1 KL grade at the subtalar joint and 31% of patients increased 1 KL grade at the talonavicular joint. Furthermore, 60% and 66% of patients showed no progression in the subtalar and talonavicular joints, respectively. Two patients progressed greater than 2 KL subtalar arthritis grades and only 2 patients with talonavicular arthritis progressed to the same extent. Sixteen patients went on to require a subtalar arthrodesis compared to 2 requiring a talonavicular fusion ( P < .05). CONCLUSION: This study suggests a moderate but nominal radiographic increase in adjacent subtalar and talonavicular arthritis over a minimum of 5 years after TAA. Future studies require a comparative control group of ankle fusion, but these data may suggest the motion preserved with an arthroplasty diminishes the stresses and compensatory motion incurred during tibiotalar arthrodesis. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Magnetic resonance imaging and clinical features of glenoid labral flap tears.

OBJECTIVE: Displaced flaps of glenoid labral tissue are an uncommonly encountered finding on MRI of the shoulder, and are of unclear clinical significance. The purpose of this study is to describe the imaging characteristics of displaced glenoid labral flaps, evaluate for any common concomitant injuries, and identify the typical clinical presentation and management of patients with this lesion. MATERIALS AND METHODS: This retrospective, observational study was approved by the institutional review board. Nineteen patients with flap-type tears of the labrum on preoperative MRI were identified. Each examination was retrospectively reviewed by two radiologists for size, location, and signal intensity of the displaced flap of tissue, in addition to any co-existing labrum or cartilage pathological conditions and clinical information. RESULTS: All displaced flaps extended from the inferior margin of the glenoid into the axillary recess. The average size of the visualized flap was 10.9 by 6.0 by 2.6 mm. Seventy percent of the flaps had signal intensity isointense to labrum and hypointense to hyaline cartilage on T2-weighted images. All 19 patients had concomitant labral pathological conditions and 63% had cartilage defects, visualized on MRI. Clinical evidence of shoulder instability was seen in 83% of patients, and 67% were managed surgically. CONCLUSION: Glenoid labral flap tears have distinct imaging characteristics that may aid in their identification. Their presence should prompt careful evaluation of the glenoid articular cartilage. Recognition of a labral flap tear may have clinical importance, as 83% of patients with this finding demonstrated clinical evidence of shoulder instability, often requiring surgical intervention.

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.

Magnetic resonance imaging evaluation of meniscoid superior labrum: normal variant or superior labral tear.

OBJECTIVE: The objective of this study was to determine the incidence of a "meniscoid" superior labrum. MATERIALS AND METHODS: This was a retrospective analysis of 582 magnetic resonance imaging examinations of shoulders. Of those 582 examinations, 110 were excluded, for a variety of reasons, and the final analysis therefore included 472 cases. Consensus readings were performed by three musculoskeletal radiologists using specific criteria to diagnose meniscoid labra. RESULTS: A meniscoid superior labrum was identified in 48 (10.2%) of the 472 cases evaluated. Arthroscopic proof was available in 21 cases (43.8%). In 10 (47.6%) of those 21 cases, the operative report did not include the mention a superior labral tear, thus suggesting the presence of a meniscoid labrum. In only one of those cases were there specific comments about a mobile superior labrum (i.e., meniscoid labrum). In the remaining 11 (52.4%), surgical correlation demonstrated superior labral tears. CONCLUSION: A meniscoid superior labrum is not an infrequent finding. Depending upon assumptions and the requirement of surgical proof, the prevalence of a meniscoid superior labrum in this study was between 2.1% (surgically proven) and 4.8% (projected). However, superior labral tears are just as common and are often confused with meniscoid labra.

OBJETIVO: O objetivo deste estudo é determinar a incidência do lábio superior da glenoide com aspecto meniscoide. MATERIAIS E MÉTODOS: Foi feita análise retrospectiva de 582 exames de ressonância magnética do ombro. Foram excluídos 110 casos por motivos diversos, restando 472 casos para avaliação. A leitura foi feita em consenso por três médicos radiologistas musculoesqueléticos. RESULTADOS: Lábio superior meniscoide foi encontrado em 48 casos (10,2%). Resultados de artroscopia estavam disponíveis em 21 casos (43,8%). Em 10 destes casos (47,6%) não havia informação de lesão labral superior, sugerindo a presença de lábio meniscoide. Em apenas um caso havia comentário sobre um lábio superior hipermóvel, indicando um lábio meniscoide. Nos 11 casos restantes (52,4%) a correlação cirúrgica demonstrou lesão do lábio superior. CONCLUSÃO: Lábio superior de aspecto meniscoide não é um achado infrequente. Dependendo das hipóteses assumidas e da necessidade de prova cirúrgica, a prevalência de um lábio superior meniscoide varia entre 2,1% (comprovação cirúrgica) e 4,8% (projeção) nesta série. Entretanto, as lesões labrais superiores têm uma prevalência parecida e podem ser confundidas com o aspecto de um lábio meniscoide.

Magnetic resonance imaging evaluation of meniscoid superior labrum: normal variant or superior labral tear / Avaliação por ressonância magnética do lábio superior da glenoide de aspecto meniscoide: variante da normalidade ou lesão do lábio superior

Abstract Objective: The objective of this study was to determine the incidence of a "meniscoid" superior labrum. Materials and Methods: This was a retrospective analysis of 582 magnetic resonance imaging examinations of shoulders. Of those 582 examinations, 110 were excluded, for a variety of reasons, and the final analysis therefore included 472 cases. Consensus readings were performed by three musculoskeletal radiologists using specific criteria to diagnose meniscoid labra. Results: A meniscoid superior labrum was identified in 48 (10.2%) of the 472 cases evaluated. Arthroscopic proof was available in 21 cases (43.8%). In 10 (47.6%) of those 21 cases, the operative report did not include the mention a superior labral tear, thus suggesting the presence of a meniscoid labrum. In only one of those cases were there specific comments about a mobile superior labrum (i.e., meniscoid labrum). In the remaining 11 (52.4%), surgical correlation demonstrated superior labral tears. Conclusion: A meniscoid superior labrum is not an infrequent finding. Depending upon assumptions and the requirement of surgical proof, the prevalence of a meniscoid superior labrum in this study was between 2.1% (surgically proven) and 4.8% (projected). However, superior labral tears are just as common and are often confused with meniscoid labra.

Resumo Objetivo: O objetivo deste estudo é determinar a incidência do lábio superior da glenoide com aspecto meniscoide. Materiais e Métodos: Foi feita análise retrospectiva de 582 exames de ressonância magnética do ombro. Foram excluídos 110 casos por motivos diversos, restando 472 casos para avaliação. A leitura foi feita em consenso por três médicos radiologistas musculoesqueléticos. Resultados: Lábio superior meniscoide foi encontrado em 48 casos (10,2%). Resultados de artroscopia estavam disponíveis em 21 casos (43,8%). Em 10 destes casos (47,6%) não havia informação de lesão labral superior, sugerindo a presença de lábio meniscoide. Em apenas um caso havia comentário sobre um lábio superior hipermóvel, indicando um lábio meniscoide. Nos 11 casos restantes (52,4%) a correlação cirúrgica demonstrou lesão do lábio superior. Conclusão: Lábio superior de aspecto meniscoide não é um achado infrequente. Dependendo das hipóteses assumidas e da necessidade de prova cirúrgica, a prevalência de um lábio superior meniscoide varia entre 2,1% (comprovação cirúrgica) e 4,8% (projeção) nesta série. Entretanto, as lesões labrais superiores têm uma prevalência parecida e podem ser confundidas com o aspecto de um lábio meniscoide.

Angiomatoid fibrous histiocytoma: novel MR imaging findings.

OBJECTIVE: To describe novel MR imaging features, and clinical characteristics of soft tissue angiomatoid fibrous histiocytoma (AFH) at presentation, local recurrence, and metastases. MATERIALS AND METHODS: We described the MRI findings of six cases of histologically proven AFH. Pathologic findings, clinical presentation, and outcome were reviewed. RESULTS: Lesions were primarily cystic. At initial presentation, tumors were surrounded by low signal intensity fibrous pseudocapsule. High signal intensity consistent with the lymphoplasmacytic infiltrate was seen in T2-weighted and post-contrast images as a rim over the hypointense pseudocapsule (double rim sign). High signal intensity infiltrating tumoral cords extended into adjacent tissues, through pseudocapsular defects on T2-weighted and post-contrast images. The cystic component and tumor cell nodularity were demonstrated at post-contrast images. Clinically, lesions were often thought to be benign, underwent marginal resection, developed local recurrence, and one developed second recurrence consisting of metastases. Recurrent tumors appeared as multiple masses, misinterpreted as post-surgical changes. An intramuscular recurrence demonstrated double rim and infiltrating margin. CONCLUSIONS: A predominantly well-circumscribed, primarily cystic mass with double-rim and marginal infiltration on MRI suggests the possibility of AFH, in particular in child or young adult. Inclusion of these novel observations in AFH differential diagnosis may have a significant impact on treatment and prevention of recurrence.

Gemcitabine-induced radiation recall myositis.

Radiation recall is an uncommon phenomenon in which administration of a chemotherapeutic agent induces an acute inflammatory reaction in previously irradiated tissues, often weeks to years after completion of radiotherapy. This entity is well known to medical and radiation oncologists, however only three cases have been reported in radiology journals. We present a case of gemcitabine-induced radiation recall that manifested as myositis with associated dermatitis in the posterior thigh of a patient with remote history of localized radiotherapy for biopsy-proven breast cancer metastasis. We also present a brief literature review to update the topic of radiation recall in imaging, and emphasize the importance of knowledge of this phenomenon when considering the differential diagnosis of myositis/dermatitis in a patient who has received cancer treatment.

Bone marrow biopsy: RNA isolation with expression profiling in men with metastatic castration-resistant prostate cancer--factors affecting diagnostic success.

PURPOSE: To determine the rate at which computed tomographically guided pelvic percutaneous bone biopsy in men with metastatic castration-resistant prostate cancer (mCRPC) yields adequate tissue for genomic profiling and to identify issues likely to affect diagnostic yields. MATERIALS AND METHODS: This study was institutional review board approved, and written informed consent was obtained. In a phase II trial assessing response to everolimus, 31 men with mCRPC underwent 54 biopsy procedures (eight men before and 23 men both before and during treatment). Variables assessed were lesion location (iliac wing adjacent to sacroiliac joint, iliac wing anterior and/or superior to sacroiliac joint, sacrum, and remainder of pelvis), mean lesion attenuation, subjective lesion attenuation (purely sclerotic vs mixed), central versus peripheral lesion sampling, lesion size, core number, and use of zoledronic acid for more than 1 year. RESULTS: Of 54 biopsy procedures, 21 (39%) yielded adequate tissue for RNA isolation and genomic profiling. Three of four sacral biopsies were adequate. Biopsies of the ilium adjacent to the sacroiliac joints were more likely adequate than those from elsewhere in the ilium (48% vs 28%, respectively). All five biopsies performed in other pelvic locations yielded inadequate tissue for RNA isolation. Mean attenuation of lesions with inadequate tissue was 172 HU greater than those with adequate tissue (621.1 HU ± 166 vs 449 HU ± 221, respectively; P = .002). Use of zoledronic acid, peripheral sampling, core number, and lesion size affected yields, but the differences were not statistically significant. Histologic examination with hematoxylin-eosin staining showed that results of 36 (67%) biopsies were positive for cancer; only mean attenuation differences were significant (707 HU ± 144 vs 473 HU ± 191, negative vs positive, respectively; P < .001). CONCLUSION: In men with mCRPC, percutaneous sampling of osseous metastases for genomic profiling is possible, but use of zoledronic acid for more than 1 year may reduce the yield of adequate tissue for RNA isolation. Sampling large low-attenuating lesions at their periphery maximizes yield.

Tram-track appearance of the posterior cruciate ligament (PCL): correlations with mucoid degeneration, ligamentous stability, and differentiation from PCL tears.

OBJECTIVE: The purpose of our study was to describe the MRI findings in the posterior cruciate ligament (PCL) analogous to mucoid degeneration in the anterior cruciate ligament (ACL); to correlate MRI findings in the PCL with ligamentous stability; to differentiate the PCL tram-track appearance from the appearance of PCL tears; and to emphasize the coexistence of PCL and ACL mucoid degeneration, cruciate ganglia, and meniscal cysts. CONCLUSION: The tram-track PCL appearance commonly coexists with ACL mucoid degeneration; ganglia; and, less frequently, meniscal cysts. Both PCL tears and MRI findings suggestive of PCL mucoid degeneration show ligament thickening and increased PCL signal intensity. Tram-track PCLs are usually asymptomatic and typically have no ligamentous instability.

Elbow MR imaging findings in patients with synovial fringe syndrome.

OBJECTIVE: To describe imaging findings in patients with synovial fringe (SF) syndrome of the elbow and to compare with a control population. MATERIALS AND METHODS: Nine patients (5 men, 4 women) whose mean age was 35.7 years were diagnosed with SF syndrome and had undergone preoperative elbow MRI. The radiohumeral (RH) plica was assessed for thickness, cross-sectional area, coverage of one third or more of the radial head, blunting of the free edge, and T2 signal intensity abnormality. Other abnormalities of the RH joint were also assessed, including adjacent articular cartilage defects, subcortical bone marrow signal abnormality in the capitellum, and synovitis. Results were compared with 15 control patients who were asymptomatic laterally and posteriorly. RESULTS: Mean thickness and cross-sectional area of the RH plica were 1.8 mm and 19.4 mm(2) respectively in controls, compared with 2.5 mm and 21.9 mm(2) respectively in symptomatic patients. No statistically significant differences in the distribution of the mean thickness or cross-sectional area of the RH plica were found between the two groups. However, 67% of SF syndrome patients had a RH plica thickness greater than 2.6 mm compared with only 13% of controls (p = 0.021). Other abnormalities of the RH plica occurred more frequently in patients with SF syndrome compared with controls, but were not statistically significant. CONCLUSION: In patients presenting with posterolateral pain or mechanical symptoms in the elbow, RH plica thickness greater than 2.6 mm on elbow MRI examinations may help identify patients with SF syndrome.

MRI of selected abnormalities at the anterior superior aspect of the shoulder: potential pitfalls and subtle diagnoses.

OBJECTIVE: MRI has proven to be a helpful tool in the detection and description of pathologic changes of the rotator cuff, biceps tendon, and glenoid labrum and has thus become a mainstay in the evaluation of patients with shoulder pain. This review seeks to illustrate some of the more subtle abnormalities that can be detected on shoulder MRI and to highlight some normal anatomic variants that may mimic pathologic processes, concentrating on structures at the anterior superior aspect of the shoulder. CONCLUSION: Shoulder MRI can provide a very accurate evaluation of shoulder pathologic processes and can assist in elucidating abnormalities that can be difficult to diagnose clinically. Awareness of the known anatomic variants and the sometimes subtle potential pain generators at the anterior superior aspect of the shoulder will allow a more accurate interpretation and can therefore increase the diagnostic yield of shoulder MRI.

Magnetic resonance imaging features of osteochondral lesions of the talus.

BACKGROUND: Osteochondral lesions of the talus (OLT) traditionally have been thought to occur anterolaterally or posteromedially. Recent studies utilizing magnetic resonance imaging (MRI) have questioned this teaching. The purpose of this study was to use MRI to describe the location, frequency, and morphology of OLT and determine if any correlations exist between lesion location and other data points. METHODS: The location, frequency, and size of OLT based on a nine-zone grid were recorded on 77 MRI examinations. Lateral ligaments were inspected for evidence of injury. Stability of the lesions was assessed based on four MRI criteria: presence or absence of cartilage defects, edema-like signal abnormality, T2 bright rim, and/or subchondral cysts. Demographic data including patient age, injury mechanism, and chronicity were recorded. An ANOVA model was used to determine if statistical differences existed between lesion size and location. Pearson correlation coefficients were used to examine any association between lesion location and demographic data. RESULTS: Most of the lesions were located medially and centrally on the talar dome (54.5%), with the second highest frequency found laterally and centrally (31.2%). With the numbers available there was no statistical difference between the size of the lesions based on location. No strong correlations were found between lesion location and demographic data. CONCLUSION: This study refutes traditional teachings regarding the location of OLT and supports recent studies showing that most lesions are located medially and centrally on the talar dome.

Hemi-bucket-handle tears of the meniscus: appearance on MRI and potential surgical implications.

OBJECTIVES: To describe a type of meniscus flap tear resembling a bucket-handle tear, named a "hemi-bucket-handle" tear; to compare its imaging features with those of a typical bucket-handle tear; and to discuss the potential therapeutic implications of distinguishing these two types of tears. MATERIALS AND METHODS: Five knee MR examinations were encountered with a type of meniscus tear consisting of a flap of tissue from the undersurface of the meniscus displaced toward the intercondylar notch. A retrospective analysis of 100 MR examinations prospectively interpreted as having bucket-handle type tears yielded 10 additional cases with this type of tear. Cases of hemi-bucket-handle tears were reviewed for tear location and orientation, appearance of the superior articular surface of the meniscus, presence and location of displaced meniscal tissue, and presence of several classic signs of bucket-handle tears. RESULTS: A total of 15/15 tears involved the medial meniscus, had tissue displaced toward the notch, and were mainly horizontal in orientation. The superior surface was intact in 11/15 (73.3%). In 1/15 (6.7%) there was an absent-bow-tie sign; 6/15 (40%) had a double-PCL sign; 14/15 (93.3%) had a double-anterior horn sign. CONCLUSION: We describe a type of undersurface flap tear, named a hemi-bucket-handle tear, which resembles a bucket-handle tear. Surgeons at our institution feel this tear would likely not heal if repaired given its predominantly horizontal orientation, and additionally speculate the tear could be overlooked at arthroscopy. Thus, we feel it is important to distinguish this type of tear from the typical bucket-handle tear.

Imaging of recurrent intramuscular granulomatous masses induced by depot injection of leuprorelin.

Leuprorelin is a luteinizing hormone-releasing hormone (LH-RH) agonist that is used as an agent of androgen deprivation in some patients with prostate cancer. When administered in depot form, local granulomatous reactions may occur at the injection site, which may mimic masses and which are associated with treatment failure. We present a patient who, over a period of 5 years, developed multiple intramuscular gluteal masses while receiving leuprorelin therapy via intramuscular depot injections; biopsy of one of the masses showed the specific histologic features of leuprorelin granuloma. To our knowledge, this entity has not been described in the radiology literature. Awareness of this entity is necessary to suggest the correct diagnosis in patients with a history of leuprorelin depot injections.