Readability of extraspinal organs on scout images of lumbar spine MRI according to different protocols.

BACKGROUND: Scout images of lumbar spine MRI often include the extraspinal organs, which are barely included in routine MRI and can be a potential cause of lumbar pain. PURPOSE: To evaluate the readability of scout images for extraspinal organs in lumbar spine MRI according to different protocols. MATERIALS AND METHODS: A total of 150 patients who underwent 1.5 T or 3 T lumbar spine MRI from March to September 2015 at three hospitals with different scout image protocols, were selected. Two radiologists independently reviewed the scout images to investigate whether exclusive diagnosis of major diseases involving the femoral head, femoral neck, sacroiliac joint, and kidneys was possible. Readability levels were divided into four categories: definitely, possibly, limited, and non-evaluable. The readability of scout images according to the protocols was compared using Chi-square test. Interobserver agreement for the readability level of scout images was assessed using weighted κ statistics. RESULTS: Of 150 patients, "definitely evaluable" cases classified by two readers were 50-62 (33.3-41.3%) for femoral head (κ = 0.63-0.71), 37-66 (24.7-44.0%) for femoral neck (κ = 0.41-0.48), 72-93 (48.0-62.0%) for sacroiliac joint (κ = 0.35-0.37), and 63-73 (42.0-48.7%) for kidneys (κ = 0.45-0.47). More than 50% of femoral heads were classified as readable (definitely or possible evaluable) cases by two readers with excellent interobserver agreement. The readability level of scout images was significantly different according to image protocols including the MRI sequence, number of coronal plane slices, and intersection gap of coronal plane slices (p≤0.015). CONCLUSION: Scout images of lumbar spine MRI may be readable enough to rule out some major diseases of extraspinal organs. Standardization of the protocol will be needed to validate the potential role of scout images for screening extraspinal organs.

Radial head button holing: a cause of irreducible anterior radial head dislocation.

"Buttonholing" of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction.

An Osteochondral Lesion of the Distal Tibia and Fibula in Patients With an Osteochondral Lesion of the Talus on MRI: Prevalence, Location, and Concomitant Ligament and Tendon Injuries.

OBJECTIVE: The purpose of this study was to evaluate the prevalence and common location of a coexisting osteochondral lesion of the distal tibia and fibula and of associated abnormalities of the ankle ligaments and tendons on MRI in patients with an osteochondral lesion of the talus (OLT). MATERIALS AND METHODS: A search of a database of MRI studies performed between July 2003 and January 2014 yielded MRI examinations of 297 feet with OLTs. Two readers reviewed the MRI examinations independently for the presence of an osteochondral lesion of the distal tibia and fibula and for concomitant ligament and tendon injuries. If an osteochondral lesion of the distal tibia and fibula was present, the reviewers also recorded the location (zones 1-10) and stage. Interobserver and intraobserver reliabilities were assessed using kappa statistics. The associations between a coexisting osteochondral lesion of the distal tibia and fibula and an OLT or a concomitant ankle injury were evaluated using the chi-square test. RESULTS: Readers A and B identified 61 (20.5%) and 47 (15.8%) coexisting osteochondral lesions of the distal tibia and fibula, respectively, with good interobserver (κ = 0.73) and excellent intraobserver (κ = 0.97) reliabilities. The most common location of a coexisting osteochondral lesion of the distal tibia and fibula was zone 4 (29.5%) by reader A and zone 2 (21.3%) by reader B. Stage I and stage IIA were common (> 85%). The frequency of osteochondral lesions of the distal tibia and fibula was not significantly different according to the location or stage of OLT. Abnormalities in the tibialis posterior tendon and in the anterior and posterior talofibular, calcaneofibular, and deltoid ligaments were significantly more common in patients with a coexisting osteochondral lesion of the distal tibia and fibula than in those with an isolated OLT (p < 0.05). CONCLUSION: A coexisting osteochondral lesion of the distal tibia and fibula is not rare on MRI in patients with an OLT and is related to a higher frequency of concomitant ankle ligament and tendon injuries.

Value of T1/T2-weighted magnetic resonance imaging registration to reduce the postbiopsy hemorrhage effect for prostate cancer localization.

BACKGROUND: The aim of this study was to evaluate the value of T1/T2-weighted imaging (T1/T2WI) registration to reduce the postbiopsy hemorrhage effect for prostate cancer localization on prostate magnetic resonance imaging (MRI). METHODS: Twenty-one men with pathology-proven prostate cancer who underwent preoperative MRI in a single institution were selected. The zonal anatomy was divided into 16 sections. T2WI, T1/T2-weighted registered imaging (T1/T2RI), T2WI combined with diffusion-weighted imaging (T2WI + DWI), and T1/T2RI combined with DWI (T1/T2RI + DWI) were scored for the likelihood of cancer by two radiology faculty members and two trainees, and were compared with histology results. Areas under the receiver operating characteristics curve (AUCs) were used to assess diagnostic accuracy. RESULTS: For the trainees (Reader 3 and Reader 4), the AUC values were significantly higher (P < 0.05) for T1/T2RI (0.60 and 0.62, respectively) than for T2WI (0.54 and 0.56, respectively) in tumor detection, whereas no significant difference was observed for faculty members. There was no significant difference in AUC values between T1/T2RI and T2WI + DWI for all readers except for Reader 1. There was no additional diagnostic benefit for adding DWI with T1/T2RI for all readers. CONCLUSIONS: T1/T2WI registration is a feasible technique. For less experienced readers, T1/T2RI is better than T2WI in localization of prostate cancer.

MR Classification System Based on Axial Images for Cervical Compressive Myelopathy.

PURPOSE: To propose a new magnetic resonance (MR) classification system based on axial images for cervical compressive myelopathy (CCM) (Ax-CCM system), to assess the interobserver agreement with the Ax-CCM system, and to evaluate the relationship between Ax-CCM patterns and the baseline severity of CCM and the subsequent surgical outcome. MATERIALS AND METHODS: The institutional review board approved this retrospective study. A total of 202 patients (male-to-female ratio, 128:84; mean age ± standard deviation, 56.3 years ± 11.9; age range, 24-83 years) with CCM who underwent preoperative MR imaging and decompression surgery were retrospectively evaluated. The Ax-CCM pattern was based on the margin and extent of intramedullary hyperintensity on axial T2-weighted images, as follows; type 0 = normal, type 1 = diffuse, type 2 = fuzzy focal, and type 3 = discrete focal. Interobserver variability was analyzed by using the intraclass correlation coefficient across three readers. The modified Japanese Orthopedic Association (JOA) score and the postoperative improvement (good vs little improvement) were evaluated according to the Ax-CCM pattern by using one-way analysis of variance, the χ(2) test, and the Fisher exact test. RESULTS: The intraclass correlation coefficient for the Ax-CCM system was 0.83. The preoperative JOA score was significantly different according to Ax-CCM pattern across all readers (P < .05), with the type 2 pattern showing the worst preoperative JOA score (mean, 11.6 ± 3.1 for readers A and C and 11.7 ± 2.9 for reader B). The proportion of good improvement was significantly lower with the type 2 pattern (27 of 72 patients, 37%) than with the other patterns (64 of 123 patients, 52%) (P = .034). CONCLUSION: The Ax-CCM system showed good interobserver agreement, and the type 2 pattern was correlated with poor preoperative neurologic status and less postoperative improvement.

Clinical significance of incidentally detected aneurysms of the membranous ventricular septum in adults by multidetector computed tomography.

Although the clinical relevance of aneurysm of the membranous ventricular septum (AMVS) in adults is unclear, the frequency of AMVS detection has been increased because cardiac multidetector computed tomography has been widely adopted for the evaluation of coronary artery disease. Therefore, we aimed to assess the clinical significance of AMVS in a longitudinal study. In 30,120 adults with suspected coronary artery disease who underwent cardiac multidetector computed tomography in 3 hospitals, 52 patients with AMVS were retrospectively selected. We evaluated the clinical symptoms and electrocardiographic abnormalities (cross-sectional study) and the prevalence of embolic stroke (observational study) during a median 40-month (range 6 to 74 months) observation period. For the assessment of embolic stroke, we excluded 9 patients with other explainable embolic sources. Conduction abnormalities were noted in 13 of 52 adults (25%) with AMVS on electrocardiography and embolic stroke occurred in 6 of 43 patients (14%). The mean age and the prevalence of hypertension were significantly higher in the embolic stroke group than in the event-free group (p <0.05). Thrombi were detected in the 11.6% of AMVS, which was significantly related with embolic stroke (p <0.05). The size and morphology did not change in 15 patients with serial follow-up images. In conclusion, our study suggests that AMVS in adults should not be ignored because AMVS may be related to conduction abnormality or embolic stroke, and it does not spontaneously resolve or diminish in size.