[en] To assess the effect of the epidural steroid injection for patients suspected of having an internal disc disruption. Thirteen patients at the pain intervention clinic that received a lumbar interlaminar epidural steroid injection and were suspected of having an internal disc disruption were prospectively enrolled in this study. The treatment outcome was assessed using a 5-point patient satisfaction scale (no pain, much improved, slightly improved, no effects, aggravated) two weeks after injection. A successful outcome required a patient satisfaction scale of 'much improved' or 'no pain'. All patients received follow-up for two months. Two radiologists evaluated the presence of HIZ (high intensity zone), a dark disc by MR (n 10) and a diffuse bulging disc by CT (n = 3). Nine (69%) of the 13 patients achieved a successful outcome two weeks after injection. These nine patients showed no recurrence during the two months months follow-up. Of the 22 abnormal discs demonstrated by MRI and CT, MRI showed a dark disc in six patients and HIZ in 13 patients. CT showed diffuse bulging in three discs. Nine of 10 patients showed at least one HIZ. An lumbar interlaminar epidural steroid injection might be an effective tool for managing patients suspected of having an internal disc disruption

[en] Epidermal cysts are common benign subcutaneous lesions that occur in or on the skin. It is not very difficult to diagnose subcutaneous epidermal cysts using ultrasound imaging because they exhibit typical sonographic features. However, the differential diagnosis can be confused when epidermal cysts are found in unusual sites. The authors report a case involving a 4-year-old girl who presented with an intramuscular epidermal cyst in the gluteus maximus muscle. Magnetic resonance imaging revealed characteristic internal features of the epidermal cyst, despite being in an uncommon site, and was very useful in the preoperative diagnosis

[en] To assess the MR imaging features in differentiating a chondroblastoma (CB) from a giant cell tumor (GCT), with an emphasis on the accompanying peritumoral bone marrow edema. MR imaging findings in 20 patients with CB were compared with the imaging features of 22 patients with GCT. The location of the lesion, signal intensity, adjacent cortical change, degree of accompanying bone marrow edema, synovitis in the adjacent joint and cystic change were analyzed. The findings of CB and GCT were examined statistically with use of Fisher's exact test. The incidence ratios of MR imaging findings were as follows (CB:GCT). Metaphyseal dominant involvement (2:21), partial cortical disruption (2:14), extensive bone marrow edema surrounding the tumor (14:0) and synovitis in the adjacent joint (11:2) were statistically different in incidence between CB and GCT (ρ < 0.01). The inhomogeneous signal intensity (17:17) and cystic change (10:15) were not different in incidence between a CB and GCT. The presence of metaphyseal dominant involvement and cortical disruption favors a diagnosis of a GCT rather than a CB. In contrast, extensive bone marrow edema surrounding the tumor and synovitis in the adjacent joint are highly indicative of a CB

[en] To evaluate the usefulness of time-resolved contrast enhanced magnetic resonance angiography (4D MRA) after stent-assisted coil embolization by comparing it with time of flight (TOF)-MRA. TOF-MRA and 4D MRA were obtained by 3T MRI in 26 patients treated with stent-assisted coil embolization (Enterprise:Neuroform = 7:19). The qualities of the MRA were rated on a graded scale of 0 to 4. We classified completeness of endovascular treatment into three categories. The degree of quality of visualization of the stented artery was compared between TOF and 4D MRA by the Wilcoxon signed rank test. We used the Mann-Whitney U test for comparing the quality of the visualization of the stented artery according to the stent type in each MRA method. The quality in terms of the visualization of the stented arteries in 4D MRA was significantly superior to that in 3D TOF-MRA, regardless of type of the stent (p < 0.001). The quality of the arteries which were stented with Neuroform was superior to that of the arteries stented with Enterprise in 3D TOF (p < 0.001) and 4D MRA (p = 0.008), respectively. 4D MRA provides a higher quality view of the stented parent arteries when compared with TOF.

[en] A synovial cyst of the hip joint is a rare cause of unilateral leg edema, and it is usually associated with arthropathies such as rheumatoid arthritis and osteoarthritis. An asymptomatic synovial cyst of the hip joint that is not associated with an arthritic condition occurs infrequently. In this paper, we described the case of a 52-year-old woman who presented with unilateral right leg edema caused by a synovial cyst of the hip joint

[en] We describe a case of spontaneous total necrosis of hepatocellular carcinoma (HCC). Contrast-enhanced CT scanning revealed a hypoattenuating mass during both the hepatic arterial and portal venous phase. During the latter, subtle capsular enhancement was noted. Ultrasonography demonstrated the presence of a hypoechoic mass with a peripheral hyperechoic rim. The patient underwent tumorectomy, and a totally necrotic mass was found. Microscopic examination revealed necrotic tissue with HCC ghost cells, suggesting spontaneous total necrosis of HCC

[en] Charcoal can be used for preoperative localization of metastatic lymph nodes in the neck. Charcoal remains stable without causing foreign body reactions during as hort period. However, foreign body reactions may develop if charcoal is left in situ for more than 6 months. We reported a case of charcoal granuloma mimicking local recurrence on fluorodeoxyglucose-positron emission tomography/computed tomography and ultrasonography in a 47-year-old woman who had cervical lymph node dissection due to metastatic invasive ductal carcinoma of the breast.

[en] This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography. An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson's correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities. The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging. A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography

[en] Juvenile xanthogranuloma (JXG) is a benign, spontaneously regressing lesion that usually occurs during the first year of life, but may also occur in adulthood. Although the most common presentation of JXG is the cutaneous lesion, it can also manifest in various visceral organs. JXG of the external auditory canal is extremely rare, and there have been only a few reports of those cases in the English literature. In this study, we present a case of pathologically proven JXG that occurred in the external auditory canal with a symptomatic clinical presentation

[en] Background: To compare the MR findings of the ulnar collateral ligament (UCL) injury in baseball players between rehabilitation and reconstruction surgery. Materials and methods: Thirty nine baseball players with clinical evidence of a UCL injury based on medial elbow pain and valgus instability were included. All patients received the rehabilitation treatment for more than six weeks. The elbow MR images of 27 patients not responding to rehabilitation treatment were reviewed that consequently had reconstruction surgery; in addition to 12 patients with improved symptoms with only rehabilitation treatment. The MR imaging was compared between the two treatment groups using the Pearson's chi-square test, and linear-by-linear association for the following features: the degree, signal intensity and site of the UCL injury on fat suppressed T2-weighted images. Results: High-grade partial tears and complete tears were more commonly seen in the group that had surgery (14 out of 27 patients, 52%; 8 out of 27 patients, 30%), and low-grade partial tears and intact continuity were more common in the group that had rehabilitation only (5 out of 12 patients, 42%; 5 out of 12 patients, 42%) (p = 0.001). The injured UCL showed a fluid-like bright high or intermediate high signal intensity in the group that had surgery more frequently (14 out of 27 patients, 52%; 12 out of 27 patients, 44%), and intermediate high or low signal intensity was more frequent in the rehabilitation group (7 out of 12 patients, 58%; 3 out of 12 patients, 25%) (p = 0.013). The UCL injury at the origin site was most commonly seen in both groups (23 out of 27 patients, 85%; 11 out of 12 patients, 92%, respectively) (p = 0.496). Conclusion: Preoperative MR imaging is useful for predicting the rehabilitation outcome of UCL injuries in baseball players.