Proximal Coil Occlusion for Dissecting Aneurysm of the Proximal Posterior Inferior Cerebellar Artery

Here we report a case of ruptured dissecting aneurysm of the posterior inferior cerebellar artery(PICA) treated with proximal PICA coil occlusion using an endovascular technique. A 28-year-old man presented with acute severe headache and vomiting followed by seizure. At admission, he was drowsy, with diplopia and right ankle hypesthesia. Computed tomographic scans demonstrated a subarachnoid hemorrhage. Cerebral angiography demonstrated a dissecting aneurysm of the left proximal PICA. One day after the bleeding episode, he was undergone proximal PICA coil occlusion using an endovascular technique. The patient's postoperative course was uneventful. The decision that led to the choice of treatment is discussed.

Proximal Coil Occlusion for Dissecting Aneurysm of the Proximal Posterior Inferior Cerebellar Artery

Here we report a case of ruptured dissecting aneurysm of the posterior inferior cerebellar artery(PICA) treated with proximal PICA coil occlusion using an endovascular technique. A 28-year-old man presented with acute severe headache and vomiting followed by seizure. At admission, he was drowsy, with diplopia and right ankle hypesthesia. Computed tomographic scans demonstrated a subarachnoid hemorrhage. Cerebral angiography demonstrated a dissecting aneurysm of the left proximal PICA. One day after the bleeding episode, he was undergone proximal PICA coil occlusion using an endovascular technique. The patient's postoperative course was uneventful. The decision that led to the choice of treatment is discussed.

Bone Resorption Around Pedicle Screws After Pedicle Screw Plate Fixation

PURPOSE: To determine the frequency, level, distribution, onset, and pattern of progression of bone resorption that occurring around pedicle screws after pedicle screw plate fixation. MATERIALS AND METHODS: Bone resorption around 902 pedicle screws was analyzed in post-operative, and follow-up radiographs obtained from 156 patients who underwent pedicle screw plate fixation. To determine the resorption degree, categorized arbitrarily as grade 1 (less than 1 mm), grade 2 (1 mm or more, but less than 2 mm), or grade 3 (2 mm or more), the width of radiolucent zones was measured. In 39 patients in whom resorption was graded 1, 2, or 3, the pattern of progression of 78 screws was evaluated. RESUTLS: Resorption occurred around 78 (8.6%) screws in 39 (25%) patients, 26 of whom had more than one lesion. For 99% of screws, there was evidance of resorption within 12 weeks of pedicle screw plate fixation. During follow-up, 61.5% of screws (48/78) remained stable, while 38.5% (30 screws) showed progression to higher grades. The possibility of progression to a higher grade is less when the initial grade is lower. CONCLUSION: An understanding of the radiographic patterns of bone resorption is useful for monitoring a patient after pedicle screw plate fixation.

Pigmented Villonodular Synovitis of the Spine: A Case Report

Pigmented villonodular synovitis(PVNS) is a synovial lesion of joints or tendon sheaths, characterized by villous and nodular overgrowth of the synovial membrane. It commonly occurs in synovial joints of the appendicular skeleton, particularly those of the knee and hip, but rarely affecting those of the spine. We report a case of PVNS of the lumbar spine mimicking epidural mass.

MR Findings of Neuro-Behcet's Disease: Initial and Follow-up Changes

PURPOSE: To evaluate the MR findings of neuro-Behcet's disease, and changes occurring during follow up. MATERIALS AND METHODS: Brain MR imaging was performed in 19 patients in whom neuro-Behcet's disease had been clinically diagnosed. After treatment with corticosteroids and immunosuppressive agents, 23 follow-up MR images were obtained in 12 patients, and a total of 42 MR images were retrospectively reviewed by two radiologists. RESULTS: Of the 19 patients, 17 (89%) had parenchymal lesions, and the other two had dural venous sinus thrombosis. Among the 17 patients with parenchymal lesions, three showed leptomeningeal enhancement. A total of 72 parenchymal lesions were detected on initial MR images; 55 (76%) were patchy or nodular in shape and the lesion of the internal capsule appeared linear. Seventeen lesions (24%) in 12 patients were confluent. In order of frequency, the involved sites were the pons, midbrain, thalamus, basal ganglia, internal capsule, and frontal lobe. Thirteen lesions of 39 lesions detected on postcontrast images were enhanced, and a mass effect was seen in the area of 16 parenchymal lesions. Associated findings were microhemorrhage of the brain in two patients and spinal cord involvement in one. On short-term follow-up images obtained 1 week to 2 months after intensive treatment during the acute stage of the illness, the leptomeningeal enhancement seen in three patients had decreased and most parenchymal lesions showed improvement. Long-term follow-up images obtained 3 months to 3 years later showed that parenchymal lesions had relapsed in five patients, and brainstem atrophy had developed or progressed in five others. CONCLUSION: The most characteristic MR finding of neuro-Behcet 's disease is multiple non-hemorrhagic lesions involving the brainstem. Leptomeningeal enhancement and dural venous sinus thrombosis may also be noted. On follow-up MR, the lesions may show either improvement or aggravation, and brainstem atrophy is not uncommon.

Imaging Findings of Arteriovenous Malformations Involving Lung and Liver in Hereditary Hemorrhagic Telangiectasia (Osler-Weber- Rendu Disease): Two Cases Report

Hereditary hemorrhagic telangiectasia (HHT) or Osler-Weber-Rendu disease is an autosomal dominant disorder characterized by repeated episodes of bleeding. Multiple telangiectases consisting of thin-walled, dilated vascular channels with arteriovenous communication may involve, for example, mucocutaneous tissue, the gastrointestinal tract, and the liver, lung, and brain. We report the imaging findings of two cases of HHT involving arteriovenous malformation of both the lungs and liver, a rare condition. Chest radiography revealed a round mass, while helical CT showed a feeding artery and draining vein with arteriovenous malformation in the lung. Color Doppler sonography revealed an enlarged and tortuous hepatic artery with high systolic velocity. CT demonstrated an enlarged hepatic artery, arteriovenous shunt, and early draining hepatic vein in the liver. Celiac angiography showed arteriovenous malformation.

fMRI of the Motor Speech Center Using EPI

PURPOSE: To evaluate the feasibility of functional MR imaging(fMRI) using the echo-planar imaging (EPI)technique to map the motor speech center and to provide the basic data for motor speech fMRI during internal wordgeneration. MATERIALS AND METHODS: This study involved ten young, healthy, right-handed volunteers (M:F=8:2 ;Age: 21-27) ; a 1.5 T whole body scanner with multislice EPI was used. Brain activation was mapped using gradientecho single shot EPI(TR/TE of 3000/40, slice numbers 6, slice thickeness 10 mm, no interslice gap, matrix numbers128x128, and FOV 30x30). The paradigm consisted of a series of alternating rest and activation tasks, repeatedeight times. During the rest task, each of ten Korean nouns composed of two to four syllables was showncontinuously every 3 seconds. The subjects were required to see the words but not to generate speech, whereasduring the activation task, they were asked to internally generate as many words as possible from each of tennon-concrete one-syllabled Korean letters shown on the screen every 3 seconds. During an eight-minute period, atotal of 960 axial images were acquired in each subject. Data were analyzed using the Z-score(p<0.05), andfollowing color processing, the activated signals were overlapped on T1-weighted images. The location of theactivated area, mean activated signal intensity change (%), mean activated pixel numbers, and the presence ofcyclic change in signal intensity were evaluated. RESULTS: In seven subjects, activation was observed in the leftBroca's area and its adjacent areas(Brodmann areas 44, 45, 46, 6 and 10) ; in three of the seven, activation inBroca's areas was bilateral. In two of the remaining three subjects, the medial portion of the frontal lobe wasactivated, while in the other, there was no significant signal change in any area. Mean activated signal changewas 2.6+/-1.3% in the left Broca's area and 1.2+/-1.7% in the right, while the mean number of activated pixels was67+/-46 in the left area and 23+/-33 in the right. Periodic cyclic signal change according to rest and activationwas seen in the left Broca's area in four subjects, in the bilateral Broca's area in two, and in the medialportion of the frontal lobe in two. CONCLUSION: The results of this study indicate that in most subjects, fMRIusing EPI can effectively map the motor speech center. The data obtained may be useful for the clinicalapplication of fMRI.

In Vivo H-1 MR Slpectroscopy of Intracranial Solid Tumors

No abstract available.

Comparison of Turbo Spin Echo and HASTE Pulse Sequence in Brain MRI

PURPOSE: The purpose of this study was to evaluate the utility of Half-Fourier Acquisition Single Shot Turbo Spin Echo (HASTE) imaging of the brain, and to compare the results with those of the Turbo Spin Echo (TSE) technique. MATERIALS AND METHODS: TSE and HASTE sequences were retrospectively compared in 31 patients (19 men and 12 women) with cerebral lesions seen on TSE MR images. The related diagnoses were neoplasm (n=4), hematoma (n=5), cerebromalacia (n=4), infarct or ischemia (n=17), and granuloma (n=1). Qualitative analysis involved the independent review by two radiologists of TSE and HASTE images with regard to overall image quality, conspicuity of the lesion, delineation of the gray-white matter, conspicuity of the basal ganglia, degree of flow and ghost artifacts. All parameters were graded 1-4 (1=poor, 4=excellent), and for quantitative analysis, lesion-white matter, gray-white matter, and putamen-white matter contrast to noise ratios (CNR) were measured. RESULTS: During qualitative analysis, all lesions seen on a TSE image were detected on the corresponding HASTE image, but with regard to overall image quality, conspicuity of the lesion, delineation of gray-white matter, and conspicuity of the basal ganglia, HASTE imaging was inferior to that of TSE ; on TSE, these parameters were scored 4.0, 4.0, 3.7, and 3.7 respectively, and on HASTE, the corresponding figures were 2.9, 3.0, 1.5, and 1.9 (p0.05). Quantitative assessment showed that lesion-white matter CNR was not significantly different between the two techniques (p>0.05). Gray-white matter and putamen-white matter CNRs were 100.4+/-81.8 and 92.6+/-84.6 on TSE and 45.8+/-39.2 and 42.7+/-40.6 on HASTE, respectively (p<0.05). CONCLUSION: With regard to image quality, delineation of lesion and anatomic details, HASTE imaging is inferior to that of TSE, and this indicates that for routine brain imaging, HASTE cannot replace TSE. In view of its fast acquisition time, however, HASTE might sometimes be a useful alternative to TSE.

Endometrial Carcinoma Occuring from Polycystic Ovary Disease: A Case Report

Endometrial carcinoma usually occurs in postmenopausal women ; less than 5% occurs in women under the age of40. Up to one quarter of endometrial carcinoma patients below this age have PCO(polycystic ovary disease, Stein-Leventhal syndrome). The increased incidence of endometrial carcinoma in patients with PCO is related to chronic estrogenic stimulation. We report MR imaging in one case of endometrial carcinoma occuring in a 23 yearold woman with PCO and had complained of hypermenorrhea for about three years. On T2-weighted MR image the endometrial cavity was seen to be distended with protruded endometrial masses of intermediate signal intensity, and the junctional zone was disrupted beneath the masses. Both ovaries were best seen on T2-weighted MR imagingand showed multiple small peripheral cysts and low signal-intensity central stroma.

MRI Findings of Cortical Laminar Necrosis

PURPOSE: To evaluate the characteristic sequential MRI findings of cortical laminar necrosis. MATERIALS AND METHODS: We retrospectively reviewed the MRI findings of 11 patients with clinical signs of hypoxic brain damage who showed findings of cortical laminar necrosis with definite time of onset. Three were men and eight were women; they were aged between 27 and 74 (mean 59.3)years. All patients underwent imaging with a 1.0-T MagnetomImpact(Siemens) ; follow-up MR examinations were performed in five. RESULTS: The watershed zones in the parietooccipital, frontoparietal and temporoparietal cortex were involved in eight cases, whereas the other areas involved were the frontal lobe in two cases and the temporal lobe in one. In one case, MRI obtained two days latershowed brain swelling demonstrating obliteration of cortical sulci and high signal intensity of subcortical whitematter on T2WI. In five cases, MRI obtained between two and three weeks later showed gyriform high signalintensity along the cortex on T1WI, cortical high and subcortical low signal intensities on T2WI in four cases,and gyriform enhancement on gadolinium-enhanced scans in three cases. MRI obtained between three and four weeks later in three cases showed subcortical high signal intensity on T2WI in two cases and gyriform cortical highsignal intensities on T1WI and gyral enhancement in all cases. MRI obtained after 50 days in four cases includingtwo of follow-up MR, showed cortical gyriform high signal intensity on T1WI in all cases and subcortical high signal intensity on T2WI and mild gyriform enhancement on gadolinium-enhanced scans in three cases. In twofollow-up studies, the lesions had become more discrete and larger. CONCLUSION: Cortical laminar necrosis due tohypoxic brain damage shows relatively characteristic MR findings according to the stage. Therefore, MR imaging seems to be useful diagnostic tool for the evaluation of cortical laminar necrosis due to hypoxic brain damage.

Postoperative CT Findings of Aortic Aneurysm and Dissection

PURPOSE: To assess the postoperative CT findings of aortic aneurysms or dissections treared by resection- and-graft replacement or continuous-suture graft-inclusion technique MATERIALS AND METHODS: We reviewed postoperative follow-up CT findings of 14 patients, 19 cases. There were 8 patients(10 cases) of aortic aneurysm and 6 patients(9 cases) of aortic dissecton which involved the thoracic aorta in 9 patients(13 cases) and abdominal aorta in 5 patients(6 cases). The interval of follow-up after operation was from 9 days to 2 year 9 months. On CT scans, we analyzed the appearance of graft materials, differences of CT findings between two surgical techniques, and normal or abnormal postoperative CT findings. RESULTS: Most of grafts appeared as hyperdense ring on precontrast scan, and all of them were not seperated from aortic lumen on postcontrast scan. On CT findings of patients who were operated by continuous-suture graft-inclusion technique, perigraft thrombus was concentrically located with sharp demarcation by native aortic wall and its density was homogeneous, but in cases of those operated by resection-and-graft replacement, perigraft hematoma was eccentrically located with indistinct margin and its density was heterogeneous and native aortic wall could not be delineated. In patients without complication, perigraft thrombus or hematoma(15 cases), perigraft calcification(11 cases), residual intimal flap(6 cases), graft deformity(4 cases), perigraft air(2 cases) and reconstructed vessels(1 case) were noted. And in one patient with complication, perigraft flow was noted with more increased perigraft hemaroma. CONCLUSION: Precise knowledge of the differences of CT findings between two surgical techniques and nor- mal postoperative CT findings is crucial to evaluate the postoperative CT findings in aortic aneurysm and dissection.

CT Findings of Gallbladder Perforation

PURPOSE: To evaluate the usefulness in diagnosing the gallbladder perforation MATERIALS AND METHODS: CT scans of surgically proved 11 cases of gallbladder perforation were retrospectively reviewed. CT findings analyzed were iuminal diameter of GB, GB wall thickness and configuration, presence or absence of fluid collection in the pericholecystic or intraperitoneal space, and observation of pericholecystic anatomic structures. All patients underwent cholecystectomy, and surgical findings were also compared. RESULTS: The GB was distended in 6 cases(55% with a range of 4.0-7.5cm, mean :5.2cm). GB wall was thickened in most cases(9/11,82%) with homogeneous(n=7) or inhomogeneous(n=2) enhancement. At the sites of perforation, focal defect or contour bulging was seen in the GB wall in 3 cases. in 2 cases with gangrene, GB wall showed loss of normal contour with mottled contrast enhancement. Pericholecystic or intraperitoneal fluid co11ection was noted in 9 cases(82%), especially in the region of perforation. In all cases, there was evidence of diffuse infiltration in the pericholecystic space, omenturn or mesentery. Other findings included cholecy-stoenteric fistula in 1 case, and intrahepatic or intraperitoneal abscess formation in 2 cases. CONCLUSION: CT is useful in correct diagnosis of gallbladder perforation.