Supratentorial Cystic Intracranial Lesions: MR Imaging Features

PURPOSE: To describe MR findings and differential points of supratentorial cystic intracranial lesions. MATERIALS AND METHODS: We retrospectively reviewed and analyzed the MR findings of 59 patients with supratentorial cystic intracranial lesions, and classified them as follows: tumor-associated cyst, infectious cyst, ex-vacuo type cyst, and congenital/developmental cyst. RESULTS: Among 59 patients, 47 tumor-associated cysts were seen in 17, 42 infectious cysts in 13, 17 ex-vacuo type cysts in 10, and 19 congenital/developmental cysts in 19. In 44 of 47 tumor-associated cysts, increased or inhomogeneous internal signal intensity was seen on T1-weighted image, 37 of 47 showed thick uneven walls ; 35 of 47 had enhancing solid components and there was variable perifocal edema and mass effect. Infectious cysts were multiple (11 of 13). In cases of brain abscess, increased internal signal intensity on T1-weighted image, low signal intensity of abscess wall on T2-weighted image, thick even enhancing wall, and marked perifocal edema(4 of 4) were seen in all four cases. Cysts in cysticercosis were variable in appearance depending on the stage, but were smaller than other cystic lesions. Ex vacuo type cysts were of uniform CSF signal intensity in all pulse sequences and there was no identifiable wall or enhancement associated with enlarged adjacent ventricle and encephalomalacia(17 of 17). Congenital/developmental cysts showed a single lesion(19 of 19), a signal intensity similar to CSF in all pulse sequences(15 of 19), no identifiable wall(16 of 19), no enhancement(17 of 19), and no perifocal edema(19 of 19). CONCLUSION: MR was used to categorize supratentorial cystic intracranial lesions into four groups on the basis of their number, size, internal homogeneity of signal intensity on T1-weighted image, enhancing pattern, perifocal edema and mass effect, thereby improving diagnostic specificity and patient management.

Frequency of Multiple Consecutive Rib Fracture after Blunt Chest Trauma

OBJECTIVE: to determine the frequency of the multiple consecutive rib fracture after blunt chest trauma. DESIGN, MATERIALS, AND METHODS: We retrospectively reviewed all the radiographs and medical charts of 87 patients with rib fractures after blunt chest trauma. Rib fractures were divided into single aud multiple. The multiple rib fractures were subclassified as consecutive, interrupted continuous, or random. RESULTS: Thirteen cases of single and 83 cases of multiple rib fractures were present. Among the 83 cases of multiple fractures, there were 73 cases (88%) of consecutive fractures, 5 cases (6%) of interrupted continuous fractures and 5 cases (6%) of random fractures. CONCLUSION: Among the multiple rib fractures consecutive rib fractrues are much more common than noncontiguous rib fractures. We recommend that if one find an apparently nonfractured rib between contiguously fractured upper and lower ribs, one should meticulously search for possible fracture of an apparently normal rib with high-index of suspicion.

MR Appearance of Synovial Plica in Patients with Plica Syndrome and Normal Plica

PURPOSE: To compare MRI appearance between plicae syndrome and normal plicae. MATERIALS AND METHODS: MR images of 60 cases of arthroscopically-confirmed plicae syndrome and 18 of arthroscopically-proven normal plicae were retrospectively analyzed. Sagittal T2-weighted MR images in all cases and MPGR(200) in 37 cases of plicae syndrome were obtained. Statistical analysis was performed using the chi-square test. RESULTS: On the basis of operatingresults, we observed 55 medial plicae, eight combined medial and suprapatellar plicae, four suprapatellar plicae,and one lateral plica. T2-weighted sagittal MR scans of the 60 cases demonstrated 37 medial plicae, 8 suprapatellar and one lateral plica. Joint effusion was found in 26 cases of 55 medial plicae. In T2-weighted sagittal MR scans, the identification of medial plicae was superior in the presence of joint effusion than its absence(plicae syndrome, p < 0.001 ; normal plicae group, p < 0.05). Medial plicae were well demonstrated onMPGR(200) axial images; on T2-weighted sagittal MR scans, they could be more frequently identified in the plicae syndrome group than in the normal control group(p < 0.001). Plicae syndrome-associated pathology included degenerative change of the articular cartilage of the medial femoral condyle in eight cases(14.5%), discoidmeniscus in nine(16.4%), lateral meniscus tear in 12(21.8%), medial meniscus tear in 21(38.1%), anterior cruciate ligament tear in three(5.5%), medial collateral ligament tear and osteochondritis dissecans in one case. CONCLUSION: The present study revealed that synovial plicae were well demonstrated in T2-weighted sagittal images, particularly on the presence of joint effusion. Medial plicae could be more frequently identified in the plicae syndrome group than in the normal control group, especially on T2-weighted sagittal MR scans.