Sung Gyu Moon

Time-Resolved 3D Contrast-Enhanced MRA on 3.0T: a Non-Invasive Follow-Up Technique after Stent-Assisted Coil Embolization of the Intracranial Aneurysm

Objective 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. Materials and Methods 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. Results 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. Conclusion 4D MRA provides a higher quality view of the stented parent arteries when compared with TOF.

MR imaging of ulnar collateral ligament injury in baseball players: Value for predicting rehabilitation outcome

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 Pearsons 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.

Atherosclerotic arterial wall change of non-stenotic intracracranial arteries on high-resolution MRI at 3.0T: Correlation with cerebrovascular risk factors and white matter hyperintensity.

OBJECTIVE Prior to detecting intracranial arterial stenosis, atherosclerotic wall change or plaque with positive remodeling can be evaluated with high-resolution MRI (HRMRI). We prospectively evaluate atherosclerotic arterial wall change in patients without intracranial stenosis using HRMRI at 3.0T and correlate the atherosclerotic change, cerebrovascular risk factors, and white matter hyperintensity (WMH). METHODS Patients were prospectively recruited for one year and underwent brain MRI, TOF-MRA and HRMRI using axial 3D T1 FSE of the intracranial arteries. After excluding patients with intracranial stenosis, two neuroradiologists graded the atherosclerotic change of the intracranial arterial wall on HRMRI and WMH using a 4-point scale. The relationship between atherosclerotic changes on HRMRI, cerebrovascular risk factors, and WMH were statistically evaluated. RESULTS Eighty-three patients without intracranial arterial stenosis were finally included. Older age (p=0.000), hypertension (p=0.002), and hyperlipidemia (p=0.007) were associated with severe atherosclerotic change on HRMRI. On multivariate analysis, older age (OR: 0.114; 95% CI: 0.033-0.397; p=0.001) and hypertension (OR: 0.178; 95% CI: 0.049-0.651; p=0.009) were significantly associated with severe atherosclerotic change on HRMRI. The presence of moderate and severe WMH was associated with older age, hypertension, and severe atherosclerotic change on HRMRI. On multivariate analysis, atherosclerotic change on HRMRI remained the only variable significantly associated with WMH (OR: 0.086; 95% CI: 0.016-0461; p=0.004). CONCLUSION Older age and hypertension are significantly associated with intracranial atherosclerotic change on HRMRI. Atherosclerotic change detected on HRMRI may be the strongest risk factor for WMH than any other cerebrovascular risk factor in patients without intracranial stenosis.

Charcoal-Induced Granuloma That Mimicked a Nodal Metastasis on Ultrasonography and FDG-PET/CT after Neck Dissection

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.

Detection of skeletal muscle metastasis: torso FDG PET-CT versus contrast-enhanced chest or abdomen CT:

Background Skeletal muscle metastasis (SMM) in cancer patients has not been sufficiently evaluated regarding prevalence and proper method of detection. Purpose To determine the prevalence of SMM and compare the diagnostic competencies for SMM of torso F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) and contrast-enhanced chest or abdomen CT. Material and Methods We investigated 18,225 PET-CT studies of 6359 cancer patients performed from 2005 to 2012. The PET-CT studies describing potential SMM were retrieved and the corresponding medical records were reviewed. The gold standard for SMM was histopathologically-proven SMM or imaging study-based disease progression. The detectability of SMM was compared between PET-CT and contrast-enhanced CT. Results Twenty-six patients had 84 SMM lesions, representing a SMM prevalence of 0.41%. Lung cancer was the most common SMM-associated malignancy (54%) and the gluteal/pelvic girdle muscle was the most frequently involved SMM site (37%). All 84 SMM lesions were visualized on PET-CT (100%). Of these PET-CT positive 84 SMM lesions, 51 lesions were in the CT field of view (FOV) (61%), whereas 33 lesions were out of the CT FOV (39%). Among these 51 lesions, 17 lesions showed rim-enhancing nodules/masses (33%), eight lesions showed homogeneously enhancing nodules (16%), three lesions showed heterogeneously enhancing nodules (6%), and 23 SMM lesions (45%) were non-diagnostic by CT. All 51 SMM lesions within CT FOV were detected on PET-CT (100%), whereas only 28 were visualized on CT (54.9%), resulting in a significant difference (P < 0.005). On average, 2.6 more organs with concomitant metastases were found when SMM was revealed by PET-CT. Conclusion The prevalence of SMM was as low as 0.41% in the current large cohort of cancer patients. Torso PET-CT was a more competent modality than contrast-enhanced CT in the detection of SMM.

Cervical epidural lymphangioma presenting as a hemorrhagic cyst: a case report.

Study Design. A case report. Objective. We report a case of epidural lymphangioma in the cervical spine, and it manifested as a hemorrhagic cyst. Summary of Background Data. Intraspinal lymphangioma is an uncommon tumor with only a few cases reported in the literature. Epidural lymphangioma presenting as a hemorrhagic cyst is extremely rare. Methods. The patient chosen was a 43-year-old woman with the chief complaint of neck pain and right upper extremity numbness of 2-month duration. Results. Cervical spine magnetic resonance (MR) imaging revealed an epidural cystic mass extending to the right C6–C7 neural foramen. The mass showed fluid-fluid levels on T2-weighted image and high-signal intensity on diffusion-weighted image. Surgical resection and histologic analysis confirmed the diagnosis of epidural lymphangioma with internal hemorrhage. Conclusion. Epidural lymphangioma is a rare benign tumor. However, it should be included in the differential diagnosis of hemorrhagic cystic mass in the epidural space, which presented with fluid-fluid levels on MR imaging and high-signal intensity on diffusion weighted imaging.