MR Features of Myelofibrosis: Correlation with Bone Marrow Biopsy Findings

PURPOSE: To characterize the magnetic resonance (MR) imaging features of myelofibrosis and compare them with bone marrow biopsy findings. MATERIALS AND METHODS: The authors retrospectively reviewed sagittal T1-and T2 weighted and short tau inversion recovery (STIR) images of the thoracolumbar spine of six patients (five males and one female, mean age 46) with biopsy-proven myelofibrosis. Marrow signal intensity of the thoracolumbar spine was classified with respect to those of muscle and fat, based on the consensus of two radiologists after visual inspection. These MR features were compared with the degree of fibrosis and marrow cellularity, as determined by bone marrow biopsy. RESULTS: In all patients, marrow signal intensity of the thoracolumbar spine was reduced onT1 and T2 weighted images (invariably low on T1 weighted images, low (2/6) to intermediate (4/6) on T2 weighted images). On STIR images, marrow signal intensity was variable (high (3/6) or low (3/6)), and this correlated with degree of fibrosis, not with marrow cellularity. The signal intensity of marrow with mild to moderate fibrosis was high on STIR images, while that of marrow with marked fibrosis was low. CONCLUSION: MR imaging features of myelofibrosis were characterized as low on T1 weighted images and low to intermediate on T2 weighted images. In addition, the signal intensity of STIR imaging correlated with degree of fibrosis.

MR Features of Myelofibrosis: Correlation with Bone Marrow Biopsy Findings

PURPOSE: To characterize the magnetic resonance (MR) imaging features of myelofibrosis and compare them with bone marrow biopsy findings. MATERIALS AND METHODS: The authors retrospectively reviewed sagittal T1-and T2 weighted and short tau inversion recovery (STIR) images of the thoracolumbar spine of six patients (five males and one female, mean age 46) with biopsy-proven myelofibrosis. Marrow signal intensity of the thoracolumbar spine was classified with respect to those of muscle and fat, based on the consensus of two radiologists after visual inspection. These MR features were compared with the degree of fibrosis and marrow cellularity, as determined by bone marrow biopsy. RESULTS: In all patients, marrow signal intensity of the thoracolumbar spine was reduced onT1 and T2 weighted images (invariably low on T1 weighted images, low (2/6) to intermediate (4/6) on T2 weighted images). On STIR images, marrow signal intensity was variable (high (3/6) or low (3/6)), and this correlated with degree of fibrosis, not with marrow cellularity. The signal intensity of marrow with mild to moderate fibrosis was high on STIR images, while that of marrow with marked fibrosis was low. CONCLUSION: MR imaging features of myelofibrosis were characterized as low on T1 weighted images and low to intermediate on T2 weighted images. In addition, the signal intensity of STIR imaging correlated with degree of fibrosis.

CT Findings of Acute Pyelonephritis and Clinical Correlation

PURPOSE: To evaluate postcontrast CT findings of acute pyelonephritis and correlate these with clinical findings and severities. MATERIALS AND METHODS: We retrospectively reviewed the medical records and CT scans of 50 patients with abnormal CT findings among 52 patients of acute pyelonephritis whose postcontrast CT scans had been examined. Fifty cases of acute pyelonephritis were classified into three subgroups on the basis of postcontrast CT findings : Group I (n=20, 40%) wedge-shaped lesions; Group II (n=13, 26%) mass-like lesions; Group III (n=17, 34%) renal abscess formation. In each group, clinical findings and severity were analyzed and correlated with CT findings. The results were statistically analyzed. RESULTS: Although mean values of clinical parameters of group I were lower than those of group II and III with regard to all clinical parameters (including maximal temperature and duration of fever, flank pain, leukocytosis, and admission period), there was no statistically significant correlation among the three groups (p>0.05). All cases were successfully treated with antibiotics only, despite the high rate of abscess formation (34%). CONCLUSION: Acute pyelonephritis spans a continuum of CT findings of varying severity from wedge-shaped or mass-like lesions to multifocal abscesses ; postenhanced CT scan shows high sensitivity (96%) in the detection of acute pyelonephritis. Although the clinical course of groups of mass-like lesions and abscess formation was longer and more severe than that of wedge-shaped lesions, there was no statistically significant clinicoradiologic correlation among the three groups.

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.