다분절을 침범한 안면신경초종의 영상학적 양상 분석 1예

A 47-year-old female patient presented with an acute onset of facial palsy and otitis media on the left side. Temporal bone CT scans revealed an irregularly shaped lesion in the middle ear cavity extending into the mastoid air cells. MRI images confirmed intra- and extra-temporal involvement of the facial nerve schwannoma. The correlation of distinct imaging findings of the facial nerve schwannoma along the course of the facial nerve and anatomical features of the temporal bone is discussed.ope

Increased contralateral cerebellar uptake of technetium-99m-HMPAO on ictal brain SPECT

Crossed cerebellar diaschisis (CCD) is a well-known brain SPECT finding in stroke patients. Two reports, however, have described supratentorial and contralateral cerebellar hyperperfusion (crossed cerebellar hyperperfusion) on ictal brain SPECT in epileptic patients. The purpose of this study was to assess the usefulness of crossed cerebellar hyperperfusion (CCH) for the detection of epileptic foci on ictal scan. METHODS: Twelve patients with complex partial seizures having characteristic clinical, electroencephalographic (EEG) and brain SPECT findings were included. Fifteen to 20 mCi 99mTc-HMPAO were injected intravenously during the seizure period or the aura for the ictal SPECT study. The SPECT findings were visually assessed to determine whether the finding of CCH was valuable in the localization of ictal foci. RESULTS: Epileptic foci were found in the right temporal (n = 6), left temporal (n = 4), right occipital (n = 1) and left frontal (n = 1) areas. CCH was observed in 8 (75%) of the 12 patients. In two patients, contralateral cerebellar uptake was more obvious than that in the epileptic foci. In the interictal scans, cerebellar activity, which was increased in ictal period, was equalized in seven of eight patients, while perfusion was diminished in the remaining patient. CONCLUSION: CCH is a frequent finding of ictal brain SPECT and may aid in the lateralization of epileptic foci.ope

A Study on Effects of the Transient Compression by Tightly Tied Necktie on Blood Flow in the Internal Jugular Veins Using 2D-PC MRA

The 25 healthy male volunteers aged from 20 to 50years old have been employed in this study. 2D-PC MRA was performed to measure the velocity of the blood flow in the internal carotid artery and internal jugular veins using 3.0T MRI Whole body (signa VH/i GE). ECTRICKS-CEMRA was performed to evaluate the pattern of blood circulation from internal carotid artery to internal jugular vein. Using 2D-PC MRA, the cross-section of the 4th and 5th cervical discs was scanned with 24cm FOV. Then the speed of blood flow was measured for internal carotid artery and internal jugular vein when the subject wears a necktie tightly and no tie. The average of maximum velocity of internal carotid arteries without a necktie was 72.13cm/sec in the right side and 74.96cm/sec in the left side(average 73.54cm/sec in both sides) while the average of maximum velocity of internal jugular veins without a necktie was -34.45cm/sec in the right side and -24.99cm/sec in the left side (-29.72cm/sec in both sides). However, when wearing a necktie tightly, the average of maximum velocity of internal carotid arteries was 61.35cm/sec in the right side and 65.19cm/sec in the left side(average 63.27cm/sec in both sides) while the average of maximum velocity of internal jugular veins was -22.14cm/sec in the right side and -17.93cm/sec in the left side(-20.03cm/sec in both sides). With the necktie tightly knotted, the average blood flow speed of both internal carotid arteries slightly decreased to 86% (63.27/73.54cm/sec) compared to no tie case in which both internal jugularveins significantly went down to 67% (-20.03/-29.72 cm/sec). Thus it is suggested that wearing a necktie affects the circulation of internal jugular veins(33% decrease in blood flow speed) more significantly than that of internal carotid artery(14% decrease in blood flow speed). Without a necktie, ECTRICKS-CEMRA showed natural blood circulation patterns of internal carotid arteries and internal jugular veins without any disturbances or compressions. However, when wearing a necktie tightly, ECTRICKS-CEMRA showed severe compression onto both internal jugular veins in all 25 volunteers. In conclusion, the result of the study showed that the tightly worn necktie instantly presses more internal jugular veins than internal carotid arteries, thereby significantly reducing the blood flow speed and leading to the temporary occlusion. Thus, the defecation or washing the face under the tightly tied necktie situations can cause the unexpected and temporary compression or occlusion of the internal jugular veins, subsequently leading to the occurrences of the stroke due to the secondary intracranial venous hypertension.ope

HMPAO SPECT to assess neurologic deficits during balloon test occlusion

The purpose of this study was to determine if one could objectively and preoperatively predict the safety of permanent occlusion of an internal carotid artery with 99mTc-HMPAO brain SPECT. METHODS: Twenty-four patients underwent balloon test occlusion of the internal carotid arteries because of neck and skull base tumors. We assessed the uptake of both middle cerebral artery territories before and during balloon test occlusion with 99mTc-HMPAO brain SPECT using the semiquantitative analysis. The results were compared with other factors, including neurologic examination, arterial stump pressure and electroencephalogram. RESULTS: Nineteen patients experienced no neurological deterioration or any problem during balloon test occlusion. The comparative uptake of their middle cerebral artery territories was 95%-101% of the pre-balloon test occlusion state. The remaining five patients showed severe neurologic symptoms, such as transient hemiplegia and unconsciousness. The comparative uptake of their middle cerebral artery territories was 77%-85% of the pre-balloon test occlusion state and was well matched with other factors. CONCLUSION: Technetium-99m-HMPAO brain SPECT before and during balloon test occlusion seems to be a simple and objective method for predicting permanent neurologic deficits when the comparative uptake of middle cerebral artery territories during balloon test occlusion is less than 85% of that before balloon test occlusion.ope

MR of Mandibular Invasion in Patients with Oral and Oropharyngeal Malignant Neoplasms

Purpose: To investigate whether MR imaging is an accurate means of assessing mandibular invasion in patients with carcinoma. Methods: We retrospectively studied the MR scans of 22 patients with pathologic or surgical confirmation of mandibular invasion from oral and oropharyngeal cancers. The MR images were blindly analyzed using primary criteria of: (a) cortical breakdown, (b) replacement of bone marrow fat, or (c) gadopentetate dimeglumine enhancement of a mass at the bone marrow defect. Secondary criteria of: (a) contiguous soft-tissue mass, and (b) mass on both sides of the mandibular cortex were also examined. Mandibular invasion was graded as periosteal/cortical, medullary, or no invasion. Results: Primary positive findings of cortical breakdown and abnormal bone marrow signal were highly sensitive (100%) for periosteal/cortical invasion and medullary involvement, respectively. However, a high rate of false-positive studies hampered the MR accuracy, which fell into the 73% to 77% range. A negative MR study was highly predictive, but a positive study was less valuable. Gadolinium enhancement added little to the MR study's accuracy. False-positive studies mainly occurred in the setting of prior irradiation, osteoradionecrosis, and odontogenic infections. Conclusions: MR imaging is a sensitive method for detecting mandibular invasion but has a low positive predictive value. A negative study virtually excludes cortical/periosteal or bone marrow invasion.ope

Transient MR signal Changes in Patients with Generalized Tonicoclonic Seizure or Status Epilepticus: Periictal Diffusion-weighted Imaging

BACKGROUND AND PURPOSE: Our purpose was to investigate transient MR signal changes on periictal MR images of patients with generalized tonicoclonic seizure or status epilepticus and to evaluate the clinical significance of these findings for differential diagnosis and understanding of the pathophysiology of seizure-induced brain changes. METHODS: Eight patients with MR images that were obtained within 3 days after the onset of generalized tonicoclonic seizure or status epilepticus and that showed seizure-related MR signal changes had their records retrospectively reviewed. T1- and T2-weighted images were obtained of all eight patients. Additional diffusion-weighted images were obtained of five patients during initial examination. After adequate control of the seizure was achieved, follow-up MR imaging was performed. We evaluated the signal changes, location of the lesions, and degree of contrast enhancement on T1- and T2-weighted images and the signal change and apparent diffusion coefficient (ADC) on diffusion-weighted images. We also compared the signal changes of the initial MR images to those of the follow-up MR images. RESULTS: The initial MR images revealed focally increased T2 signal intensity, swelling, and increased volume of the involved cortical gyrus in all eight patients. The lesions were located in the cortical gray matter or subcortical white matter in seven patients and at the right hippocampus in one. T1-weighted images showed decreased signal intensity at exactly the same location (n = 6) and gyral contrast enhancement (n = 4). Diffusion-weighted images revealed increased signal intensity at the same location and focally reduced ADC. The ADC values were reduced by 6% to 28% compared with either the normal structure opposite the lesion or normal control. Follow-up MR imaging revealed the complete resolution of the abnormal T2 signal change and swelling in five patients, whereas resolution of the swelling with residual increased T2 signal intensity at the ipsilateral hippocampus was observed in the other two patients. For one of the two patients, hippocampal sclerosis was diagnosed. For the remaining one patient, newly developed increased T2 signal intensity was shown. CONCLUSION: The MR signal changes that occur after generalized tonicoclonic seizure or status epilepticus are transient increase of signal intensity and swelling at the cortical gray matter, subcortical white matter, or hippocampus on periictal T2-weighted and diffusion-weighted images. These findings reflect transient cytotoxic and vasogenic edema induced by seizure. The reversibility and typical location of lesions can help exclude the epileptogenic structural lesions.ope

Kikuchi Disease: CT and MR Findings

Two cases of Kikuchi disease showed variable nodal enhancing features, including homogeneous enhancement and focal or extensive nodal necrosis on contrast-enhanced CT scans. At MR imaging, the area of central necrosis was isointense or hypointense on T1-weighted images and had a lower signal than nonnecrotic areas on T2-weighted images. The CT appearance of Kikuchi disease can be variable and can mimic not only lymphoma but various nodal diseases with nodal necrosis, including metastasis and tuberculosis.ope

A case of antiphospholipid antibody syndrome accompanied by valvular heart disease and Moya Moya syndrome.

A case of antiphospholipid antibody syndrome, accompanied by valvular heart disease and Moya moya syndrome, has never been reported. Here, we report on a case that had mitral regurgitation and Moya moya syndrome, associated with antiphospholipid antibody syndrome secondary to systemic lupus erythematosus. This patient underwent a mitral valve replacement for mitral valve regurgitation. The postoperative course was uneventful, and the pathological findings of the mitral valve showed a degenerative change, due to chronic inflammation, a proliferative fibrous change and calcification, but without thrombus formation. However, the patient returned to the hospital with a cerebral hemorrhage, which was caused by Moya moya syndrome. Surgical drainage was performed, and the patient was discharged without any complications. The patient is on anticoagulation and immunosuppression drugs, with no problems to date.ope

Resting-state fMRI reveals network disintegration during delirium

Delirium is characterized by inattention and other cognitive deficits, symptoms that have been associated with disturbed interactions between remote brain regions. Recent EEG studies confirm that disturbed global network topology may underlie the syndrome, but lack an anatomical basis. The aim of this study was to increase our understanding of the global organization of functional connectivity during delirium and to localize possible alterations. Resting-state fMRI data from 44 subjects were analyzed, and motion-free data were available in nine delirious patients, seven post delirium patients and thirteen non-delirious clinical controls. We focused on the functional network backbones using the minimum spanning tree, which allows unbiased network comparisons. During delirium a longer diameter (mean (M) = 0.30, standard deviation (SD) = 0.05, P = .024) and a lower leaf fraction (M = 0.32, SD = 0.03, P = .027) was found compared to the control group (M = 0.28, SD = 0.04 respectively M = 0.35, SD = 0.03), suggesting reduced functional network integration and efficiency. Delirium duration was strongly related to loss of network hierarchy (rho = -0.92, P = .001). Connectivity strength was decreased in the post delirium group (M = 0.16, SD = 0.01) compared to the delirium group (M = 0.17, SD = 0.03, P = .024) and the control group (M = 0.19, SD = 0.02, P = .001). Permutation tests revealed a decreased degree of the right posterior cingulate cortex during delirium and complex regional alterations after delirium. These findings indicate that delirium reflects disintegration of functional interactions between remote brain areas and suggest long-term impact after the syndrome resolves.ope

MRI Findings of a Cholesteatomatous Labyrinthine Fistula Showing Abnormal Inner Ear Enhancement

A 59-year-old male patient presented with sudden onset of vertigo and hearing loss. Labyrinthitis due to lateral semicircular canal fistula caused by cholesteamatous otitis media was suspected from temporal bone computed tomography (CT) and clinical symptoms. The patient was treated with canal wall down mastoidectomy with removal of the cholesteatoma and lateral semicircular canal occlusion. Preoperative gadolinium-enhanced magnetic resonance imaging (MRI) images of the inner ear revealed increased signal in the cochlea as well as vestibule. Correlation of the MRI findings and the inner ear involvement in labyrinthine fistula is discussedope