Acute Obstructive Cholangitis after Transarterial Chemoembolization: the Effect of Percutaneous Transhepatic Removal of Tumor Fragment

Acute obstructive cholangitis due to the migration of necrotized tumor fragment is a rare complication occurring after a transarterial chemoembolization. The percutaneous tumor removal procedure following percutaneous transhepatic biliary drainage is an appropriate treatment over endoscopic removal for the relief of acute cholangitis in this case. Following this serial management, no invasive hepatocellular carcinoma of the bile duct recurred after two years of follow-up.

Congenital External Auditory Canal Atresia and Stenosis: Temporal Bone CT Findings

PURPOSE: To determine the computed tomographic (CT) findings of atresia and stenosis of the external auditory canal (EAC), and to describe associated abnormalities in surrounding structures. MATERIALS AND METHODS: We retrospectively reviewed the axial and coronal CT images of the temporal bone in 15 patients (M:F=8:7; mean age, 15.8 years) with 16 cases of EAC atresia (unilateral n=11, bilateral n=1) and EAC stenosis (unilateral n=3). Associated abnormalities of the EAC, tympanic cavity, ossicles, mastoid air cells, eustachian tube, facial nerve course, mandibular condyle and condylar fossa, sigmoid sinus and jugular bulb, and the base of the middle cranial fossa were evaluated. RESULTS: Thirteen cases of bony EAC atresia (one bilateral), with an atretic bony plate, were noted, and one case of unilateral membranous atresia, in which a soft tissue the EAC. A unilateral lesion occurred more frequently on the right temporal bone (n=8, 73%). Associated abnormalities included a small tympanic cavity (n=8, 62%), decreased mastoid pneumatization (n=8, 62%), displacement of the mandibular condyle and the posterior wall of the condylar fossa (n=7, 54%), dilatation of the Eustachian tube (n=7, 54%), and inferior displacement of the temporal fossa base (n=8, 62%). Abnormalities of ossicles were noted in the malleolus (n=12, 92%), incus (n=10, 77%) and stapes (n=6, 46%). The course of the facial nerve was abnormal in four cases, and abnormality of the auditory canal was noted in one. Among three cases of EAC stenosis, ossicular aplasia was observed in one, and in another the location of the mandibular condyle and condylar fossa was abnormal. In the remaining case there was no associated abnormality. CONCLUSION: Atresia of the EAC is frequently accompanied by abnormalities of the middle ear cavity, ossicles, and adjacent structures other than the inner ear. For patients with atresia and stenosis of this canal, CT of the temporal bone is essentially helpful in evaluating these associated abnormalities.

A Case of Vacuolar Myelopathy in Patient with Acquired Immunodeficiency Syndrome / 감염

The spinal cord is a commonly affected site in human immunodeficiency virus (HIV) infection. Even though the most common disease of the spinal cord is vacuolar myelopathy, there is no case report yet in Korea. We experienced a case of suspicious vacuolar myelopathy in a 33 year-old male patient with acquired immunodeficiency syndrome. The patient presented with progressive paraparesis, gait disturbance, urinary difficulty, and the loss of sensation below thoracic spine 6~7 dermatome. Cerebrospinal fluid showed mild pleocytosis, increased protein level, and normal glucose content. The spine MRI showed extensive ill defined areas of increased signal intensity through the visualized lower cervical and thoracic spinal cord. Steroid therapy with antiretroviral drugs appeared to be ineffective to improve the symptoms of the patient.

Unusual Acute Encephalitis Involving the Thalamus: Imaging Features

OBJECTIVE: To describe the brain CT and MR imaging findings of unusual acute encephalitis involving the thalamus. MATERIALS AND METHODS: We retrospectively reviewed the medical records and CT and/or MR imaging findings of six patients with acute encephalitis involving the thalamus. CT (n=6) and MR imaging (n=6) were performed during the acute and/or convalescent stage of the illness. RESULTS: Brain CT showed brain swelling (n=2), low attenuation of both thalami (n=1) or normal findings (n=3). Initial MR imaging indicated that in all patients the thalamus was involved either bilaterally (n=5) or unilaterally (n=1). Lesions were also present in the midbrain (n=5), medial temporal lobe (n=4), pons (n=3), both hippocampi (n=3) the insular cortex (n=2), medulla (n=2), lateral temporal lobe cortex (n=1), both cingulate gyri (n=1), both basal ganglia (n=1), and the left hemispheric cortex (n=1). CONCLUSION: These CT or MR imaging findings of acute encephalitis of unknown etiology were similar to a combination of those of Japanese encephalitis and herpes simplex encephalitis. In order to document the specific causative agents which lead to the appearance of these imaging features, further investigation is required.

MR Imaging of Acute Necrotizing Encephalopathy:A Report of Two Cases

Acute necrotizing encephalopathy is the term used to describe acute encephalopathy with bilateral thalam-otegmental involvement that occurs in infants and children after febrile viral illness. We report the MR findings of two cases of this condition.

Acute Spontaneous Subdural Hemorrhage by Cerebral Aneurysmal Rupture: Report of Two Cases

Two cases of acute spontaneous subdural hemorrhage caused by cerebral aneurysmal rupture are presented. The patients’ chief complaints were sudden bursting headache and comatose mentality. There was no history of trauma or proclivity for spontaneous bleeding, and CT scans of the brain indicated subdural hemorrhage without remarkable subarachnoid hemorrhage. In case 1, an aneurysm at the distal segment of the right anterior cerebral artery was identified by CT angiography; the subdural hemorrhage was evacuated and the aneurysm surgically clipped. In case 2, an aneurysm at the junction of the anterior communicating artery and the right anterior cerebral artery was revealed by CT angiography and digital subtraction angiography, and Guglielmi detachable coil embolization of the aneurysm was performed.

Cavernous Hemangioma of the Cavernous Sinus: A Case Report

Intracranial extra-axial cavernous hemangioma of the cavernous sinus is a very rare vascular malformation. It usually appears as a round non-encapsulated mass with well-defined borders, mimicking meningioma. We describe a case of cavernous hemangioma of the cavernous sinus, including the radiologic imaging findings, and also review the literature.

Intraventricular Hemorrhage Caused by Lateral Ventricular Meningioma: A Case Report

Meningiomas causing intracranial hemorrhage are rare, and hemorrhage from a lateral ventricular meningioma seems to be even rarer. We report a case of trigonal meningioma in a 43-year-old woman who presented with intraventricular hemorrhage, and describe the CT, MRI and angiographic findings.

Warthin's Tumor of Extraparotid Location in Neck: A Case Report

Warthin's tumor is a benign lesion of the salivary and principally-parotid gland. An extraparotid location is rare. We report a case of Warthin 's tumor which was located in the neck, far from the parotid gland.

Takayasus Arteritis with Pregnancy Induced Eclampsia / 대한뇌혈관학회지

We experienced a case of Takayasus arteritis with eclampsia in a 43-year-old woman. The patient had angiographically definite Takayasus arteritis with the involvement of right common and internal carotid arteries. On MR images performed at clinical manifestations of eclampsia, unilateral involvement of T2 high signal intensities were demonstrated in right cerebral hemisphere. We report this case with a literature review.

MR Distinction between Multiple Myeloma and Metastasis Involving the Spine

PURPOSE: To differentiate multiple myeloma from metastasis involving the spine at MR imaging. MATERIALS AND METHODS: Twenty-five patients with multiple myeloma and 37 with vertebral metastasis were included in this study. MR images were retrospectively analyzed with regard to infiltration and enhancement patterns, signal intensity, the involvement of three consecutive vertebrae, the number of lesions within one vertebra, and paraspinal and epidural masses. Using a 1.5-T imager, we obtained sagittal and axial, unen-hanced and enhanced T1-weighted images, and fast spin-echo images. For statistical analysis, Fisher's exact test was used. RESULTS: All cases of multiple myeloma and metastasis showed low signal intensity on T1-weighted images, and there were no significant differences in signal intensities or enhancement patterns. Infiltration and enhancement patterns were classified as focal (52% in multiple myeloma vs 68% in metastasis, p> 0.05), diffuse (32% vs 32%, p > 0.05) or salt and pepper (16% vs 0%, p 0.05), isoin-tensity (36% vs 3%, p 0.05). Paraspinal and epidural masses played little part. CONCLUSION: The salt and pepper infiltration pattern, the presence of more than five lesions within one vertebra, and the involvement of more than three consecutive vertebrae were useful MR findings for differentiation between multiple myeloma and metastasis involving the spine. In most cases, however, it is difficult to distinguish between the two conditions.

Disturbed Functional Asymmetry of Sensorimotor Cortex in Schizophrenia: A Study with Functional Magnetic Resonance Imaging

PURPOSE: The purpose of this study was to investigate the pattern of cerebral response to motor tasks in patients with schizophrenia compared with normal subjects using functional MRI. MATERIALS AND METHODS: Nine right handed-schizophrenic patients and six right-handed normal subjects were included. We used right hand movement as task. Series of 120 consecutive echo-planar images per section were acquired during three cycles of task and rest activations. Lateralization index of cortical response was measured and compared between patients and normal subjects. RESULTS: Right hand motor task was associated with greater activation in left sensorimotor cortex than the right in normal subjects. Schizophrenia patients showed relatively decreased activation in left cortex and increased activation in right cortex compared with normal subjects. In one patient, reversed lateralization was noted. CONCLUSION: Normal hemispheric asymmetry of cortical response to motor task was found in different pattern in schizophrenia. Our result is consistent with functional disturbance of motor circuitry in this disorder. Functional MRI will play an important role in diagnosis and research of this disorder.

Stable Xenon-CT Cerebral Blood Flow Imaging in Patients with Cerebral nfarction

BACKGROUND: Stable xenon-CT has been known to be a useful technique for measuring cerebral blood flow (CBF) and its direct correlation with CT anatomy. We evaluated the usefulness and limitations of stable xenon-CT cerebral hemodynamic status. METHODS: Xenon-CT was administered to 23 patients. Ten were normal controls and 13 were stroke patients (acute 4, subacute 5, chronic 2, hemorrhagic 2). Time dependent Xenon concentrations within various tissue segments of the brain was used to derive both the local partition-coefficient (lamda) and CBF in each tissue volume (voxel) of the CT image. RESULTS: In the controls, the regional CBF (rCBF) (ml/100 gm/min) was as follows: frontal 22.9+/-7.3(Mean+/-SD), inferior temporal 23.9+/-3.2, superior temporal 27.4+/-7.3, parietal 30.0+/-10.1, occipital 24.3+/-8.4, cerebellar hemisphere 24.3+/-8.3, thalamus 31.1+/-7.1, and corona radiata 18.1+/-4.7. The cortical differences was within 10%. In the stroke patients, the rCBF in the infarcted area ranged from 0 to 26.5 ml/100 gm/min and interhemispheric cortical difference was above 50%. The routine CT revealed no abnormalitiy, particularly in acute stroke (within 6 hours after onset). However, a xenon-CBF showed perfusion defect which correlated with clinical signs. CONCLUSIONS: With xenon CT, CBF can be obtained within a few hours of stroke onset, result of which can be correlated with CT. In an acute stroke state, a Xenon-CBF map can be a more sensitive method than routine CT imaging. Low value of blood-flow and patient's in cooperation may limit use of Xe-CT.

Diagnostic Value of MR Imaging in Differentiation of Meniscal Tear Patterns

PURPOSE: To evaluate the diagnostic accuracy of magnetic resonance (MR) imaging in the differentiation ofmeniscal tear patterns of the knee. MATERIALS AND METHODS: MR images of 93 patients with meniscal tear wereincluded in this study. On the basis of arthroscopic findings, the configuration of meniscal tears was classifiedas horizontal (n=44), longitudinal (n=34), transverse (n=11), or oblique (n=5). Oblique sagittal and coronal MRimages were obtained and com-pared with the arthroscopic findings. RESULTS: Among 94 cases ofarthroscopically-proven meniscal tears, 35 of 44 horizontal and 27 of 34 longitudi-nal configurations werecorrectly interpreted on MR images. Sensitivity and specificity for horizontal configu-ration were 80 % and 80 %,respectively, while the corresponding values for longitudinal configuration were 79 % and 95 %. On MR images, tworadial configurations were correctly interpreted from 11 confirmed tears and only one oblique configuration fromfive confirmed tears. CONCLUSION: MR imaging was useful for the differentiation of horizontal and longitudinaltears, but inaccurate in cases involving radial or oblique tears.

Usefulness of 2D PC MRA of the Circle of Willis in the Evaluation of Acute Cere b ral Infarction

PURPOSE: To evaluate the usefulness of axial 2-D PC MRA of the circle of Willis in the evaluation of acute cerebral infarction. MATERIALS AND METHODS: We evaluated 42 patients with acute cerebral infarction who had undergone T2 weighted and diffusion weighted MR imaging (T2WI, DWI) and 2-D PC MRA of the circle of Willis within 72 hours of the onset of symptoms. In conjunction with high-signal lesions on DWI, the findings of 2-D PC MRA were classified as normal, stenotic, or indicative of arterial occlusion; negative 2-D PC MRA was not considered useful. In addition, the signal intensity of T2WI and DWI was compared. RESULTS: (The findings of 2-D PC MRA showed that 15 cases (35.7%) were normal, 13(31%) were stenotic, and that in 14 (33.3 %), occlusion was present). Thus, 2-D PC MRA detected vascular abnormality in 27 cases (64.3 %). On T2WI, six cases (14.3 %) showed no signal change and 36 (85.7 %) showed high signal change. In six cases without signal change, MR images were obtained within 12 hours of ictus; in one of these patients MRA findings were normal, one had stenosis, and in four, occlusion was noted. CONCLUSION: 2-D PC MRA is a useful modality for the detection of vascular abnormality in patients with acute cerebral infarct.

Neuronal Laterality & Postoperative Changes of GABA+Glu. Activity by In Vivo 1H MRS

Object of this study was to to evaluate the laterality of local cerebral cellular metabolism in various locations of the brain related to the symptomatic side of patients with clinically diagnosed idiopathic Parkinson's disease (IPD) and to verify GABA-related pathophysiology in IPD by comparing postoperative changes in (GABA+Glutamate)/Cr ratio from patients with IPD after stereotactic pallidotomy and thalamotomy. Fourteen patients with IPD(10 males and 4 females: age range 39-67 years) participated in the study. The patients were classified into two disease subgroups, one for tremor dominant group(n=7, T group), and the other bradykinesia and rigidity dominant one(n=7, B&R group). For T group, stereotactic VL(Vop, Vim) thalamotomy and subthalamotomy was performed and for the B&R group, stereotactic posteroventrolateral pallidotomy was selected. In Vivo 1H MRS study was performed on a 1.5 T MRI/MRS system(GE Sigma Advantage, version 4.8) using STEAM sequence after water suppression with CHESS RF pulse and dephasing gradients. After peak areas of creatine/phosphocreatine(Cr), choline-containning compound(Cho), N-Acetyl Aspartate(NAA), r-aminobutyric acid, (GABA) and glutamate(Glu) were calculated and processed, the metabolic ratios of NAA/Cr, Cho/Cr, and (GABA+Glu)/Cr in three different locations were calculated and compared with clinical symptoms and its changes after surgery. For the neuronal laterality in patients with IPD, there was significant differences of NAA/Cr ratio between the right and left sides of substantia nigra, thalamus and pallidum(p=0.00170). The magnitude of difference in NAA/Cr ratios between right and left side were significantly larger in substantia nigra(p=0.0141). Compared to the normal control values(1.82+/-0.52 in ages 27-50, 1.71+/-0.54 in ages 51-70 years), the neuronal loss was generally observed in at least one of three locationsin all patients. Moreover, NAA/Cr ratio was substantially lower in ipsilateral than contralateral substantia nigra of the parkinsonian symptomatic side. For preoperative(GABA+Glu)/Cr ratios of thalamus contralateral to the symptomatic side compared to that of ipsilateral, it was significant larger in thalamus of B&R group and significant smaller in T group. In the pallidotomy group, there was significant increase in the operated pallidum, whereas significant decrease in (GABA+Glu)/Cr ratios were noted in the operated side thalamus. And in the thalamotomy group, there were significant increase in the operated thalamus, whereas in the operated side pallidum, significant decrease in (GABA+Glu)/Cr ratios were noted. Neuronal laterality, pallidal neuronal loss and postoperative changes in GABA activity in patients with IPD were demonstrated on the basis of NAA/Cr and (GABA+Glu)/Cr ratio by In Vivo 1H MRS. The neuronal laterality was detected in the substantia nigra of all the parkinsonian patient, and NAA/Cr ratios in unilateral and bilateral disease were consistently lower in ipsilateral than in contralateral substantia nigra of the Parkinsonian disease side. Our result suggests that there may be another ongoing pathological process of ipsilateral neuronal degeneration with contralateral dopaminergic neuronal loss. The result of neuronal loss in pallidum supports with the previous reports concerning striatal degeneration in IPD. Our results concerning postoperative changes of (GABA+Glu)/Cr ratio suggests that separate pathophysiologic mechanisms may be involved in the development of two dominant symptom groups of IPD. That is, for the B&R group, pallidal overinhibition to the thalamus by the GABA-ergic system as previously noted, but for T group, a process other than GABA inhibitory mechanism with or without it may be involved.

Metastatic Brain Tumor from Cardiac Chondrosarcoma: A Case Report

Primary chondrosarcoma of the heart and its metastasis to the brain is extremely rare. We describe the case ofa patient who underwent resection of cardiac chon-drosarcoma only to relapse with brain metastasis two yearslater. MR images showed that these metastatic tumors were slightly hypointense relative to the brain onT1-weighted images and hyperintense on T2-weighted images. The masses were highly enhanced. Peritumoraledema appeared less extens ive and the focal cystic portion was seen within the mass, corresponding to myxoid degeneration.

Benign Versus Malignant Vertebral Compression Fractures: Distinction with T1-weighted, Fast Spin-EchoT2-weighted, and Fat-suppressed Gadolinium-enhanced T1-weighted Images

PURPOSE: To differentiate malignant vertebral compression fractures from benign fractures, as seen onspin-echo T1-weighted, fast spin-echo T2-weighted, and fat-suppressed gadolinium-enhanced T1-weighted MR images. MATERIALS AND METHODS: Thirty two benign (18 acute and 14 chronic) and 28 malignant vertebral collapses werestudied in 54 patients aged between 15 and 78 (mean, 51) years. Malignant compression fractures involved onlymetastasis. We obtained sagittal and axial fast spin-echo T2-weighted images, and unenhanced and fat-suppressedgadolinium-enhanced T1-weighted images, and analyzed MR signal intensity, enhancement patterns, and morphologicchanges including convex posterior cortex vs retropulsion of a bone fragment, focal vs diffuse paraspinal mass,and epidural mass. RESULTS: All cases of acute benign and malignant compression fractures showed low signalintensity within the vertebral body on T1-weighted images, and substantial contrast enhancement on fat-suppressedgadolinium-enhanced T1-weighted images. Acute benign and malignant compression fractures were distinguished on thebasis of three signal intensity characteristics: hypointense band (acute benign cases 77% ; malignant cases 0%),diffuse low signal intensity(17% vs 86%) and involvement of pedicle (0% vs 75%). Fast spin-echo T2-weighted imagesplayed little role in distinguishing between the two. Three morphologic changes were suggestive of malignancy:convex posterior cortex (malignant cases 75% ; benign 0%), epidural mass (79% vs 5%), and focal paraspinal mass(57% vs 0%). Retropulsion of a bone fragment (benign cases 63% ; malignant cases 14%) was preferable forbenignancy. in addition, thin diffuse paraspinal mass (benign cases 15% ; malignant cases 14%) was seen.CONCLUSION: The morphologic and signal intensity characteristics seen on T1-weighted images were useful fordistingushing benign and malignant vertebral compression fractures. Fast spin-echo T2-weighted and fat-suppressedgadolinium-enhanced T1-weighted images played little role in distinguishing between the two.

Benign Versus Malignant Vertebral Compression Fractures: Distinction with T1-weighted, Fast Spin-EchoT2-weighted, and Fat-suppressed Gadolinium-enhanced T1-weighted Images

PURPOSE: To differentiate malignant vertebral compression fractures from benign fractures, as seen onspin-echo T1-weighted, fast spin-echo T2-weighted, and fat-suppressed gadolinium-enhanced T1-weighted MR images. MATERIALS AND METHODS: Thirty two benign (18 acute and 14 chronic) and 28 malignant vertebral collapses werestudied in 54 patients aged between 15 and 78 (mean, 51) years. Malignant compression fractures involved onlymetastasis. We obtained sagittal and axial fast spin-echo T2-weighted images, and unenhanced and fat-suppressedgadolinium-enhanced T1-weighted images, and analyzed MR signal intensity, enhancement patterns, and morphologicchanges including convex posterior cortex vs retropulsion of a bone fragment, focal vs diffuse paraspinal mass,and epidural mass. RESULTS: All cases of acute benign and malignant compression fractures showed low signalintensity within the vertebral body on T1-weighted images, and substantial contrast enhancement on fat-suppressedgadolinium-enhanced T1-weighted images. Acute benign and malignant compression fractures were distinguished on thebasis of three signal intensity characteristics: hypointense band (acute benign cases 77% ; malignant cases 0%),diffuse low signal intensity(17% vs 86%) and involvement of pedicle (0% vs 75%). Fast spin-echo T2-weighted imagesplayed little role in distinguishing between the two. Three morphologic changes were suggestive of malignancy:convex posterior cortex (malignant cases 75% ; benign 0%), epidural mass (79% vs 5%), and focal paraspinal mass(57% vs 0%). Retropulsion of a bone fragment (benign cases 63% ; malignant cases 14%) was preferable forbenignancy. in addition, thin diffuse paraspinal mass (benign cases 15% ; malignant cases 14%) was seen.CONCLUSION: The morphologic and signal intensity characteristics seen on T1-weighted images were useful fordistingushing benign and malignant vertebral compression fractures. Fast spin-echo T2-weighted and fat-suppressedgadolinium-enhanced T1-weighted images played little role in distinguishing between the two.

Diffusion-weighted Imaging of Cerebral Ischemic Infarcts: Comparison with T2-weighted Imaging in Signal Intensity

PURPOSE: To investigate whether ischemic infarct can be staged by evaluating signal intensities on diffusionweighted (DWI) and turbo spin echo T2-weighted images(T2WI). MATERIALS AND METHODS: DWI and T2WI of 27 patientswith ischemic infarct were retrospectively evaluated. Infarcts were divided into five stages depending on time ofonset : hyperacute within 12 hours, acute between 12 hours and 3 days, subacute between 3 and 10 days, earlychronic between 10 and 30 days, and late chronic after 30 days. Signal intensities of these lesions compared withnormal brain on DWI and T2WI were visually evaluated and divided into six patterns. Pattern 1 included high signalon DWI and iso-signal on T2WI, pattern 2 showed high signal on both DWI and T2WI with higher contrast on DWI,pattern 3 showed the same high signal on both images; pattern 4 revealed high signal on both images with highercontrast on T2WI, pattern 5 showed iso-signal on DWI and high signal on T2WI, and pattern 6 revealed low signal onDWI and high signal on T2WI. These five clinical stages and six MRI patterns were correlated in each patient. RESULTS: Six cases were hyperacute, six were acute, eight were subacute, three were early chronic, and four werelate chronic. At the hyperacute stage, five cases showed pattern 1 (83%) and one case, pattern 2. At the acutestage, all six cases showed pattern 2. At the subacute subcute stage, seven cases showed pattern 2(87.5%) and onecase pattern 4. At the early chronic stage, two cases showed pattern 2(66.7%) and one case, pattern 5. At the latechronic stage, all cases showed pattern 6. CONCLUSION: DWI is useful for the detection of early ischemic infarct,and stages of ischemic infarcts can be estimated by evaluating signal intensities on DWI and T2WI.