MR imaging and ultrasonography findings of early myositis ossificans: a case report.

Myositis ossificans (MO) is a benign soft tissue lesion with non-neoplastic heterotopic bone formation. MO in the intermediate and mature stages can be easily diagnosed if characteristic imaging findings such as a peripheral zonal pattern of ossification with variable thickness is observed. However, it is difficult to correctly diagnose early MO because it can mimic malignancy clinically, radiologically, and histopathologically. We report a case of early pseudosarcomatous phase of non-traumatic MO with atypical imaging findings. A 59-year-old woman presented with pain followed by a mass in the left thigh within a week. MR imaging and ultrasonography showed an intramuscular lesion with preserved muscle fascicles in the vastus lateralis muscle. Intralesional ossification or calcification was not seen on ultrasonography. A diagnosis of myositis ossificans was made by ultrasonographically guided biopsy.

Prevalence of Imaging Features on CT Thought to Be Associated With Femoroacetabular Impingement: A Retrospective Analysis of 473 Asymptomatic Adult Hip Joints.

OBJECTIVE: The objective of our study was to investigate the prevalence of imaging features on CT thought to be associated with femoroacetabular impingement (FAI) and the associations among them. MATERIALS AND METHODS: Of 430 consecutive adult patients (age range, 18-40 years) who underwent hip CT at our institution for hip symptoms or trauma surveillance, the asymptomatic hips were selected for the study, which resulted in the inclusion of 473 hip joints in the study group. Images were obtained using an MDCT scanner and were reformatted using a bone algorithm. The CT images were retrospectively evaluated by two radiologists for features indicative of FAI such as the alpha angle, femoral head-neck offset, acetabular version angle, and center-edge angle. The intraclass correlation coefficient was used to evaluate intra- and interobserver variabilities. Associations among these parameters were evaluated by calculating the odds ratio between each of the parameters separately. RESULTS: Of the 473 asymptomatic hip joints we studied, 190 (40%) joints showed at least one of the following features on CT: alpha angle greater than 55°, head-neck offset less than 8 mm, acetabular version angle less than 15°, or center-edge angle greater than 40°. At least one feature was found in the hips of male patients (43.2%), which is more frequently than in the hips of female patients (35.4%). There was a high degree of coexistence (odds ratio > 2) among these CT findings. CONCLUSION: Imaging features on CT that are known to be associated with FAI are common in asymptomatic adult hip joints, especially in men, with a high degree of coexistence among the findings.

Acupuncture-Induced Abscess in the Retroperitoneal Cavity and Thigh Muscle: A Case Report.

Acupuncture is increasingly being used in Asian countries and is generally considered a relatively safe procedure. However, adverse events have been reported consistently. Therefore, clinicians should be aware of the possibility of acupuncture-related complications and should actively treat serious cases. We report a case of an acupuncture-induced large abscess in the retroperitoneal cavity and thigh muscles treated with percutaneous catheter drainage, surgical incision, and drainage.

10-Year Clinical Follow-Up after Decompression of Lipofibromatous Hamartoma of the Median Nerve in a 3-Year-Old Patient: Case Report and Review of the Literature.

Lipofibromatous hamartoma, first reported in 1953, is a rare, slowly progressive soft tissue tumor, the characteristics of which include the enlargement of the affected nerve via the epineurial and perineurial proliferation of adipose and fibrous tissues. Out of 200 previously reported cases of lipofibromatous hamartoma of the median nerve, there have been approximately 25 pediatric cases under the age of 18. Herein, we report a case of lipofibromatous hamatoma of the median nerve in a 3-year-old female patient who was surgically decompressed via carpal tunnel release and epineurolysis. The patient was followed-up on an outpatient clinic basis annually with sonographic evaluations, and the postoperative 10th-year follow-up did not show recurrence or any deficits in motor and sensory functions.

[Comparison of True and Virtual Non-Contrast Images of Liver Obtained with Single-Source Twin Beam and Dual-Source Dual-Energy CT]. / 간의 ë‹¨ì¼ì„ ì› Twin Beamê³¼ ì´ì¤‘ì„ ì› 이중에너지 ì „ì‚°í™”ë‹¨ì¸µì´¬ì˜ì˜ 비조영증강 영상과 가상 비조영증강 영상의 비교 연구.

Purpose: To assess the magnitude of differences between attenuation values of the true non-contrast image (TNC) and virtual non-contrast image (VNC) derived from twin-beam dual-energy CT (tbDECT) and dual-source DECT (dsDECT). Materials and Methods: This retrospective study included 62 patients who underwent liver dynamic DECT with tbDECT (n = 32) or dsDECT (n = 30). Arterial VNC (AVNC), portal VNC (PVNC), and delayed VNC (DVNC) were reconstructed using multiphasic DECT. Attenuation values of multiple intra-abdominal organs (n = 11) on TNCs were subsequently compared to those on multiphasic VNCs. Further, we investigated the percentage of cases with an absolute difference between TNC and VNC of ≤ 10 Hounsfield units (HU). Results: For the mean attenuation values of TNC and VNC, 33 items for each DECT were compared according to the multiphasic VNCs and organs. More than half of the comparison items for each DECT showed significant differences (tbDECT 17/33; dsDECT 19/33; Bonferroni correction p < 0.0167). The percentage of cases with an absolute difference ≤ 10 HU was 56.7%, 69.2%, and 78.6% in AVNC, PVNC, and DVNC in tbDECT, respectively, and 70.5%, 78%, and 78% in dsDECT, respectively. Conclusion: VNCs derived from the two DECTs were insufficient to replace TNCs because of the considerable difference in attenuation values.

Renal Epithelioid Angiomyolipoma with Epithelial Cysts Mimicking Cystic Renal Cell Carcinoma: A Case Report of Combination of Two Rare Entities.

Renal angiomyolipomas (AMLs) are typically solid tumors, but there have been few reports of a rare cystic variant of AML. AML with epithelial cysts, where the epithelial cyst has a cuboidal epithelial lining, account for the majority of them. Next, epithelioid AML (EAML) with cystic changes due to hemorrhage and necrosis, which is composed of epithelioid cells with abundant eosinophilic cytoplasm, have also been reported. These rare cystic types of AML can be mistaken for other cystic tumors, such as cystic renal cell carcinoma, in preoperative imaging. We report the imaging findings of a rare case of EAML with epithelial cysts.

Solitary Spinal Epidural Metastasis from Prostatic Small Cell Carcinoma.

Solitary, spinal epidural metastasis (SEM) that is not related to vertebral metastasis is very rare. And solitary SEM from prostatic cancer is rarely found in previously published reports. However, it is clinically significant due to the possibility of neurologic dysfunction, and it can be assessed by MRI. In this report, we show a case of solitary SEM arising from prostatic small cell carcinoma detected by MRI.

New imaging strategies using a motion-resistant liver sequence in uncooperative patients.

MR imaging has unique benefits for evaluating the liver because of its high-resolution capability and ability to permit detailed assessment of anatomic lesions. In uncooperative patients, motion artifacts can impair the image quality and lead to the loss of diagnostic information. In this setting, the recent advances in motion-resistant liver MR techniques, including faster imaging protocols (e.g., dual-echo magnetization-prepared rapid-acquisition gradient echo (MP-RAGE), view-sharing technique), the data under-sampling (e.g., gradient recalled echo (GRE) with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), single-shot echo-train spin-echo (SS-ETSE)), and motion-artifact minimization method (e.g., radial GRE with/without k-space-weighted image contrast (KWIC)), can provide consistent, artifact-free images with adequate image quality and can lead to promising diagnostic performance. Understanding of the different motion-resistant options allows radiologists to adopt the most appropriate technique for their clinical practice and thereby significantly improve patient care.

Osteochondral lesion of the bilateral femoral heads in a young athletic patient.

Osteochondral lesions of the femoral head are uncommon and few studies have reported their imaging findings. Since joints are at risk of early degeneration after osteochondral damage, timely recognition is important. Osteochondral lesions of femoral head may often be necessary to differentiate from avascular necrosis. Here, we report a case of osteochondral lesions on bilateral femoral heads. This lesion manifested as subchondral cysts in initial radiographs, which led to further evaluation by computed tomography arthrography and magnetic resonance imaging, which revealed overlying cartilage defects.