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Background and Purpose: The signal information per voxels of magnetic resonance imaging (MRI) for vessel wall could reflect the pathologic features of atherosclerotic vessels. The aim of this study is to evaluate the usefulness of magnetic resonance voxel-based histogram (VBH) of atherosclerotic basilar artery in patients with isolated pontine infarctions (PIs). Materials and Methods: Wall and lumen of basilar artery were segmented from high resolution MR of 42 patients with isolated PI and 10 normal volunteers. VBHs were obtained after normalization by dividing the intensity of segmented wall with the intensity of non-infarcted area of pons. The variables of VBH included area (A), mean signal intensity (SI), standard deviation (SD), kurtosis (K), and skewness (SK) and area stenosis [AS; Awall/(Awall + Alumen)] were compared according to the MRI-modified American Heart Association (AHA) atherosclerotic plaque schema, and between the subgroups of PI (lacunar: LPI and paramedian: PPI). Results: According to the MRI-modified AHA atherosclerotic plaque schema, Awall/T1 (mean area of wall on T1-weighted MRI), SIwall/T1, SDwall/T1, SKwall/T1, Kwall/T1, Alumen/T1, and AST1 showed statistical differences. AHA IV–VII showed higher Awall/T1, SIwall/T1, and AST1 than normal control. PPI showed statistical differences in Awall/T1, SIwall/T1, SK wall/T1, and Awall/T2 than those of normal control after post hoc test, whereas LPI in Awall/T1 and Awall/T2 (P < 0.05, Kruskal-Wallis test, Dunnett T3 procedure). Conclusions: VBH analysis can provide the quantitative information with regard to volume as well as composition of the atherosclerotic plaque in the basilar artery. The difference in patterns of VBH might be further useful in characterizing PIs with presumably different pathogenesis.

Study design Retrospective analysis of magnetic resonance imaging (MRI) for differentiating sacral insufficiency fractures from metastases of the sacrum. Objective To determine if a steady-state free precession (SSFP) diffusion-weighted MRI is useful for differentiating sacral insufficiency fractures from metastases of the sacrum. Summary of background data Conventional spin-echo sequence MRI is very sensitive for the detection of pathologic lesions in the sacrum, but the differential findings between sacral insufficiency fracture and metastasis are often not obvious because of the nonspecific changes of signal intensity. Another MR sequences for differentiation is needed. Methods Fourteen patients with sacral insufficiency fractures and 8 patients with metastasis at the sacrum were examined with MRI. Both the diffusion-weighted MRI and the spin-echo MRI were performed in all patients. Diffusion-weighted MRI sequences were based on a SSFP sequence. Results All the insufficiency fractures and metastasis at the sacrum revealed low signal intensity on T1-weighted MRI; low or high signal intensity was revealed on T2-weighted MRI. The contrast enhanced T1-weighted MRI showed strong enhancement at the sacrum in all cases of insufficiency fracture and metastasis. Diffusion-weighted MRI of the sacrum showed low signal intensity in all cases with sacral insufficiency fracture, but these images revealed high signal intensity in all cases with metastasis. Conclusion SSFP diffusion-weighted MRI is capable of differentiating benign sacral insufficiency fractures from metastatic tumors of the sacrum.

Objective We wished to report on the MRI findings of non-infectious ischiogluteal bursitis. Materials and methods The MRI findings of 17 confirmed cases of non-infectious ischiogluteal bursitis were analyzed: four out of the 17 cases were confirmed with surgery, and the remaining 13 cases were confirmed with MRI plus the clinical data. Results The enlarged bursae were located deep to the gluteus muscles and postero-inferior to the ischial tuberosity. The superior ends of the bursal sacs abutted to the infero-medial aspect of the ischial tuberosity. The signal intensity within the enlarged bursa on T1-weighted image (WI) was hypo-intense in three cases (3/17, 17.6%), iso-intense in 10 cases (10/17, 58.9%), and hyper-intense in four cases (4/17, 23.5%) in comparison to that of surrounding muscles. The bursal sac appeared homogeneous in 13 patients (13/17, 76.5%) and heterogeneous in the remaining four patients (4/17, 23.5%) on T1-WI. On T2-WI, the bursa was hyper-intense in all cases (17/17, 100%); it was heterogeneous in 10 cases and homogeneous in seven cases. The heterogeneity was variable depending on the degree of the blood-fluid levels and the septae within the bursae. With contrast enhancement, the inner wall of the bursae was smooth (5/17 cases), and irregular (12/17 cases) because of the synovial proliferation and septation. Conclusion Ischiogluteal bursitis can be diagnosed with MRI by its characteristic location and cystic appearance.

Study design Retrospective analysis of lumbosacral radiculography using 3-dimensional (3D) magnetic resonance (MR) rendering in patients with extraforaminal disc herniation. Objective To investigate the significance of lumbosacral radiculography as depicted by 3D MR rendering in the diagnosis of symptomatic extraforaminal disc herniation with or without foraminal extension. Summary of background data Given that accurate evaluation of the extraforaminal zones on routine axial and sagittal images is difficult, extraforaminal disc herniations tend to be sometimes overlooked. In addition, oblique coronal images along intervertebral foramina and MR myelography may not clearly demonstrate a detailed full view of nerve root changes. Furthermore, the detection of the morphologic changes of the nerve root is very important for the diagnosis of symptomatic extraforaminal disc herniation. Thus, a useful method for evaluating the nerve root in order to diagnose symptomatic extraforaminal disc herniation is required. Methods Twenty-four patients with extraforaminal and combined (extraforaminal with foraminal) lumbar disc herniations were included in this study. Conventional spin-echo sequence and 3D coronal fast-field echo sequences with selective water excitation by using the principles of the selective excitation technique (Proset imaging) were acquired. Indentation and swelling of the nerve roots and dorsal root ganglion (DRG) in the symptomatic sides and levels were evaluated on the basis of 3D MR rendering images of the lumbar spine. The tilting angle of the nerve root in the symptomatic side was compared with those in the asymptomatic contralateral side again on the basis of the 3D MR rendering images. Results Dorsal root ganglion indentation without swelling of the nerve roots was found in 7 patients whereas that with swelling of the nerve roots was observed in 6 patients. Swelling of the entire segment of the nerve from nerve root to spinal nerve (n = 9) or only the spinal nerve (n = 2) was observed in 11 patients. Compared with the contralateral nerve root, 7 patients exhibited a tilting angle abnormality of the ipsilateral nerve root. Conclusion Based on lumbosacral radiculography through 3D MR rendering, important findings related to the diagnosis of symptomatic extraforaminal disc herniation include swelling of DRG and/or nerve roots and DRG indentation. Ultimately, 3D MR lumbosacral radiculography is a very useful method in the diagnosis of the symptomatic extraforaminal disc herniation.

Posterior leukoencephalopathy syndrome is a rare complication of triple H therapy, which is the treatment for symptomatic vasospasm occurring following subarachnoid hemorrhage. This complication must be considered when neurological deterioration of a patient continues or worsens during triple H therapy. We report a patient diagnosed with posterior leukoencephalopathy syndrome during triple H therapy.

The aberrant pyramidal tract (APT) refers to the collateral pathway of the pyramidal tract through the medial lemniscus in the brainstem. We showed the presence of an APT in the normal human brain using diffusion tensor tractography. Diffusion tensor tractography showed that the motor tracts of the 28 hemispheres in 14 healthy normal individuals originated from the primary sensori-motor cortex and descended through the known pathway of the pyramidal tract. However, in five (17.9%) of the 28 hemispheres, we observed that the APT descended through the medial lemniscus from the midbrain to the pons, and then entered into the pyramidal tract at the upper medulla, after which it descended through the pyramidal tract to the lower medulla.

The purpose of this study was to evaluate the clinical features and the characteristics of MR images of patients with end-stage hepatic failure. We reviewed the MR findings and clinical features of 31 consecutive patients (20 men, 11 women=31, mean age 58.7 years) who had been diagnosed with clinical hepatic encephalopathy. Associations between the lesion locations on each MR sequence were analyzed using a binominal test. The clinical and MR findings were compared in relation to the etiology and clinical status. The most frequently involved site, seen as high signal intensity on T2-W images, was the corpus callosum (20 patients), followed by the dentate nucleus (16 patients) and the globus pallidus (13 patients). Significant associations were seen between the pallidus and the crus cerebri, between the crus cerebri and the red nucleus, between the crus cerebri and the dentate nucleus, and between the red nucleus and the dentate nucleus on the T2-W and DW images (P

Undifferentiated carcinoma with osteoclast-like giant cells is a rare neoplasm of exocrine pancreas. Till recently, some cases have been reported, however histogenesis of the tumors are controversial and their characteristic findings have not been described yet. Thirty five-year-old men and 75-year-old men were presented with upper abdominal pain and a palpable mass. On computed tomography, one case showed a well enhancing solid tumor with low density and the other was showed a mainly cystic tumor with peripheral enhancement in the body and tail of the pancreas. One case accompanied multiple metastatic liver masses with subhepatic lymph node enlargement. Tumor staining was seen on angiography. Biopsy and pancreatectomy were performed. Pathological findings revealed tumors composed of neoplastic spindle shaped or pleomorphic large cells with scattered non-neoplastic osteoclast-like giant cells. In one case, there were small foci of adenocarcinoma components in the periphery of the tumor. On immunohistochemical stain, neoplastic cells showed focal positivity for epithelial membrane antigen and vimentin. Tumors were diagnosed as undifferentiated carcinoma with osteoclast-like giant cells. We report these rare cases with a review of literature.

Tumors arising from ventricular wall are usually ependymomas, subependymomas, and subependymal giant cell astrocytomas. Intraventricular hemangioblastomas are very unusual, especially hemangioblastomas in the fourth ventricle. Here, we described a hemangioblastoma of the fourth ventricle which was completely excised.

A 78-year-old woman presented with weakness of the extremities, dysarthria, dizziness, and sensory impairment. Magnetic resonance imaging showed acute bilateral medial medullary infarction. Contrast enhanced magnetic resonance angiography demonstrated stenosis or occlusion of both intracranial vertebral arteries. We present a rare case of bilateral medullary infarction seen on diffusion-weighted imaging.

Purpose: We investigated the causes and mechanisms driving acute border zone infarctions using diffusion-weighted imaging (DWI). Materials and Methods: We analyzed DWI in 104 patients (male: 72 years, female: 32 years, age range: 44 to 84 years) with acute border zone infarction. The DWI patterns were classified as follows: pattern A- An acute border zone infarction combined with multiple small disseminated cortical infarctions, pattern B- An acute border zone infarction only. Results: The most common cause of acute border zone infarctions was extracranial internal carotid artery (ICA) stenosis (45 cases, 43%). Other causes included middle cerebral artery stenosis (22 cases, 21%), intracranial ICA stenosis (14 cases, 13%), unknown, (12 cases 12%), iatrogenic (6 cases, 6%) and cardiogenic (5 cases, 5%), respectively. The most common pattern for DWI was pattern A (83 cases, 80%). We performed a transcranial Doppler in 7 of 75 cases (11%), and found at least 1 embolic pulse. Conclusion: The most common pattern of DWI for acute border zone infarctions was pattern A. We propose that the mechanisms driving acute border zone infarctions are emboli coupled with hypoperfusion.

Purpose: The primary goal of this study was to evaluate the MR findings of systemic lupus erythematosus (SLE) patients with neuropsychiatric symptoms. Materials and Methods: The MR images of 38 patients with SLE were evaluated based on the presence of the following abnormal lesions: the locations of the abnormal signal intensity lesions in the white matter, infarctions, a small vessel vasculopathy, leukoencephalopathy, hemorrhage, abscess, and other lesions. Results: The MR images showed an abnormality in 22 of 38 (58%) episodes. Abnormal signal intensities were noted in the subcortical and periventricular white matter in six cases, acute territorial infarctions in five cases, multiple small acute embolic infarctions in four cases and a brain abscess in two cases. A reversible posterior leukoencephalopathy was found in one case. In addition, another patient had vasogenic edema with focal central cytotoxic edema at the pons. The entire cerebral and corpus callosum volumes were significantly smaller in four patients with SLE as compared to the volumes in healthy control subjects. Conclusion: SLE may induce variable MR imaging findings of the CNS. Recognition of the variable findings is helpful for easy diagnosis and prompt treatment.

The malignant transformation of an epidermoid cyst can be discovered at the same time as a pre-existing epidermoid cyst, or during a follow-up examination after an incomplete excision. We describe a rare case of malignant transformation of a cerebellopontine angle epidermoid cyst which extended into the middle cerebellar peduncle.

We report 2 patients with a traumatic carotid- jugular fistula. The first patient suffered a deep neck penetrating injury. The external carotid-jugular fistula was demonstrated by 3-dimension CT angiography (3D CTA) and digital subtraction angiography (DSA). The patient was treated with coil embolization. The second patient suffered a gun shot injury to the neck. 3D CTA and DSA revealed a common carotid-jugular fistula and a pseudoaneurysm. The common carotid-jugular fistula was treated with coil embolization in the fistula and the pseudoaneurysm was treated with stent assisted coil embolization .

Marchiafava-Bignami disease is a rare complication of chronic alcoholism and this malady typically manifests as callosal lesion. I report here on one patient with Marchiafava-Bignami disease (MBD) who has symmetric restricted diffusion in both lateral-frontal cortices, in addition to the callosal lesion.

Purpose: We attempted to evaluate the relationship between transarteiral chemoembolization (TACE) and injury to the peribiliary plexus by evaluating the number of microvessels in the peribiliary plexus of surgical specimen. Materials and Methods: Surgical specimens were obtained from 78 hepatocellular carcinoma patients and 22 patients with liver metastases. They were divided into 4 groups (Group 1; hepatocellular carcinoma without TACE [n=30], Group 2; hepatocellular carcinoma receiving preoperative TACE once [n=37], Group 3; hepatocellular carcinoma receiving preoperative TACE more than two times [n=11] and Group 4; metastatic carcinoma of the liver patients without a history of liver disease [n=22]). Immunohistochemical staining for factor VIII-related antigen was performed in all the specimens and the number of microvessels in the inner capillary layer and the outer venous layer of the bile duct (> 200 μm in diameter) was counted. Results: The mean numbers of microvessels in the inner capillary layer were 4.50, 4.08, 1.64 and 2.05, and those in the outer venous layer were 25.23, 20.00, 18.36 and 12.32 for the 4 groups, respectively. The number of microvessels in group 4 was statistically fewer than that of group 1 (p

Purpose: We wanted to evaluate the usefulness of MDCT for localizing a bleeding site and for helping make a decision on further management for acute intestinal bleeding. Materials and Methods: We conducted a retrospective review of 17 consecutive patients who presented with acute intestinal bleeding and who also underwent MDCT before angiography or surgery. The sensitivity of MDCT for detecting acute intestinal bleeding was assessed and compared with that of conventional angiography. Results: The sensitivity of MDCT for the detection of acute intestinal bleeding was 77% (13 of 17), whereas that of angiography was 46% (6 of 13). All the bleeding points that were subsequently detected on angiography were visualized on MDCT. In three cases, the bleeding focus was detected on MDCT and not on angiography. In four cases, both MDCT and angiogphy did not detect the bleeding focus; for one of these cases, CT during SMA angiography was performed and this detected the active bleeding site. Conclusion: In patients with acute intestinal bleeding, MDCT is a useful image modality to detect the bleeding site and to help decide on further management before performing angiography or surgery. When tumorous lesions are detected, invasive angiography can be omitted.

Prepancreatic postduodenal portal vein (PPPV) is a rare anomaly in which the portal vein runs between the pancreatic head and the duodenum. Understanding of this portal vein anomaly is important to avoid devastating complications, including portal vein ligation, resection or intraoperative hemorrhage. A 28-year-old female patient presented with right upper quadrant pain that she had suffered with for 2 days. Before performing laparoscopic cholecystectomy, we detected an abnormal shaped portal vein that ran in front of the pancreatic head and posterior to the duodenum on the CT scan. We report here on a rare case of prepancreatic postduodenal portal vein that was incidentally discovered on the CT axial images and coronally reformated images, in addition to observing it on the conventional portography.

Primary carcinoma of the male urethra are rare. Among the malignant tumors of the male urethra, squamous cell carcinoma is the most common. Transitional cell carcinoma is very rare, particularly in the distal urethra. We experienced a case of distal urethral transitional cell carcinoma, arising at the fossa navicularis of the penis, which we report here with a review of the literature. A 68-year-old male patient presented with bloody discharge from the prepuce for 1 month. Ultrasonography showed a poorly marginating, heterogeneous mass, invading the glans penis and the corpus spongiosum. The mass encircled the glandular urethra of the penis glans, and obstructed the glandular urethra and the fossa navicularis. A Doppler ultrasonogram revealed hypervascularity in this mass. The mass was isointense to the corpus carvernosum on the T1-weighted images and slightly hypointense to the corpus carvernosum on the T2-weighted images. Contrast-enhanced MR imaging showed a poorly enhancing mass in the glans penis. This mass was confirmed as a transitional cell carcinoma by histologic study and a partial penectomy was performed.

Purpose: To determine the magnetic resonance (MR) imaging findings of tuberculous arthritis, and the frequency-in such cases-with which tuberculoma occurs. Materials and Methods: MR images of 26 patients (M:F, 14:12; mean age, 46.2 years) with pathologically proven tuberculous arthritis were retrospectively reviewed. The presence of joint effusion, subchondral erosion, synovial proliferation and soft tissue abscess, and whether the inner wall of this abscess was smooth,were assessed. In particular, we determined whether a nodular lesion which showed low SI on T1WI, central low SI with peripheral high SI on T2WI, and rim enhancement on contrast study, was a tuberculoma. Results: The joints involved were those of the knee (n=7), hip (n=7), shoulder (n=4), sacroiliac region (n=3), elbow (n=3), and ankle (n=2). Joint effusion was noted in 15 cases (58%), and subchondral erosion in 24(92%). synovial proliferation was found in 23 cases (88%), and soft tissue abscess in 24 (92%). The inner wall of this abscess was irregular in 17 cases (71%). A tuberculoma was present in intra- or extra-articular soft tissue in 18 cases (69%). Conclusion: The MR findings of tuberculous arthritis were subchondral erosion, synovial proliferation, and soft tissue abscess. The presence of a tuberculoma in intra- or extra-articular soft tissue, a specific finding in tuberculous arthritis, was noted in 69% of our cases.

MR findings in nine patients(three female, six male) with neuro-Behcet's disease were retrospectively analyzed. NeuroBehcet's disease was diagnosed on the basis of typical clinical symptoms. Involved site, pattern, signal intensity, and contrast enhancement pattern on MRI were evaluated. In addition, follow up MR imaging was performed in four patients. The midbrain(7/9), internal capsule(7/9), pons(6/9), thalamus(6/9), basal ganglia (5/9), middle cerebella peduncle(4/9), medulla oblongata(2/9), and subcortical white matter(2/9) are involved on MRI. The size of lesions was 1cm to 3cm and their margin was ill-defined and patchy. Inhomogeneous high signal intensity on the T2-weighted images and low signal intensity on T1-weighted images was seen respectively. In four of nine cases, there was focal enhancement. On follow up MR imaging, improvement or recurrance of the lesions was found. Also in two cases of follow up cases, there was artophy in brainstem and(or) middle cerebellar peduncles. In conclusion, MR imaging with systemic clinical symptoms is useful for diagnosing neuro-Behcet's disease.