Coexistence of different types of Duane's retraction syndrome manifesting as a congenital gaze palsy.
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Adult↗
Biomedical subjects
Jae Hyoung Kim
Publications and source records attributed to Jae Hyoung Kim.
Fiber tracking by diffusion tensor imaging in corticospinal tract stroke: Topographical correlation with clinical symptoms.
Fiber tracking of the white matter using diffusion tensor imaging is a new imaging technique to visualize the integrity of the white matter. This study investigated the capability of this technique to localize the lacunar infarctions, particularly with respect to the body parts affected, by correlating the location of the lesion with the clinical symptoms topographically. Twenty-seven patients with capsular and pericapsular small acute infarctions underwent diffusion tensor imaging and subsequent fiber tracking of the corticospinal tract (CST). According to the lesion topography with regard to the CST, the infarctions were classified into four types: (1) the anterior type (n = 9) involving the anterior part of the CST, (2) the central type (n = 9) involving the middle or whole part of the CST, (3) the posterior type (n = 5) involving the posterior part of the CST and (4) the intact type (n = 4) not involving the CST. Motor weakness of the face, upper extremities and lower extremities was found at 100%, 67% and 44%, respectively in the anterior type, at 89%, 100% and 89%, respectively in the central type and at 20%, 80% and 100%, respectively in the posterior type. The intact type was not associated with motor weakness. In conclusion, the fiber tracking technique of the CST enables the specific localization of capsular and pericapsular infarctions with regard to the body parts affected. These results also confirm the topographical accuracy of the fiber tracking of the CST.
Aged↗
Magnetic resonance imaging in patients with abduction deficit found after head trauma.
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Abducens Nerve Diseases↗
Managing the CT data explosion: initial experiences of archiving volumetric datasets in a mini-PACS.
Two image datasets (one thick section dataset and another volumetric dataset) were typically reconstructed from each single CT projection data. The volumetric dataset was stored in a mini-PACS with 271-Gb online and 680-Gb nearline storage and routed to radiologists' workstations, whereas the thick section dataset was stored in the main PACS. Over a 5-month sample period, 278 Gb of CT data (8976 examinations) was stored in the main PACS, and 738 Gb of volumetric datasets (6193 examinations) was stored in the mini-PACS. The volumetric datasets formed 32.8% of total data for all modalities (2.20 Tb) in the main PACS and mini-PACS combined. At the end of this period, the volumetric datasets of 1892 and 5162 examinations were kept online and nearline, respectively. Mini-PACS offers an effective method of archiving every volumetric dataset and delivering it to radiologists.
Database Management Systems↗
Presence of the abducens nerve according to the type of Duane's retraction syndrome.
OBJECTIVE: To analyze whether the presence of the abducens nerve might depend upon the type of Duane's retraction syndrome (DRS). DESIGN: Observational case series. PARTICIPANTS: Sixteen patients with type 1 DRS, 2 patients with type 2 DRS, and 5 patients with type 3 DRS. METHODS: Ophthalmologic examination and thin-sectioned magnetic resonance imaging (MRI) at the brain stem level were performed in 23 DRS patients. To confirm the accuracy of the procedure, we compared the results obtained with those of a control group of 30 individuals using the same technique. MAIN OUTCOME MEASURES: Examination of ductions and versions and the presence of the abducens nerve on MRI. RESULTS: The abducens nerve on the affected side could not be observed using MRI in 18 (100%) of 18 eyes (16 patients) with type 1 DRS and in 3 of 5 eyes with type 3 DRS. Conversely, the abducens nerve was observed in 2 of 2 eyes with type 2 DRS and 2 of 5 eyes with type 3 DRS. The abducens nerve was observed in 60 (100%) of 60 eyes screened as controls. CONCLUSIONS: The abducens nerve on the affected side was absent in type 1 DRS patients and some type 3 DRS patients, but present in type 2 DRS patients as well as in some type 3 DRS patients. In terms of the presence or absence of the abducens nerve, type 1 and type 2 DRS were homogenous, and type 3 DRS was heterogenous.
Abducens Nerve↗
Hypoplastic oculomotor nerve and absent abducens nerve in congenital fibrosis syndrome and synergistic divergence with magnetic resonance imaging.
OBJECTIVE: There is only one neuropathologic report of congenital fibrosis of the extraocular muscles (CFEOM), and none of synergistic divergence. The aim of this report was to study the oculomotor nerve and the abducens nerve in 2 such patients with magnetic resonance imaging. DESIGN: Observational case reports. METHODS: Ophthalmologic examination and thin-sectioned magnetic resonance imaging across the brainstem level were performed in 2 patients with CFEOM and synergistic divergence. To confirm the accuracy of the procedure, we compared the results obtained with those of a control group of 40 individuals using the same technique. MAIN OUTCOME MEASURES: The oculomotor nerve and the abducens nerve on magnetic resonance imaging. RESULTS: Magnetic resonance imaging disclosed bilateral hypoplasia of the oculomotor nerve in both patients, and absence of the abducens nerve on the affected side of synergistic divergence. The oculomotor and abducens nerves were observed in 80 of 80 eyes (100%) screened as controls. CONCLUSIONS: In both patients with CFEOM and synergistic divergence, the oculomotor nerve was hypoplastic bilaterally, and the abducens nerve was absent on the side exhibiting synergistic divergence.
Abducens Nerve↗
Normal abduction in a patient with duplicated abducens nerve.
PURPOSE: To our knowledge, there has been no report of ophthalmologic findings related with a duplicated abducens nerve in the ophthalmic literature. This study reports such findings. METHODS: An ophthalmologic examination was performed in one patient with a duplicated abducens nerve, revealed with thin-sectioned magnetic resonance imaging (MRI) across the brainstem level. RESULTS: The MRI disclosed a duplicated left abducens nerve. The patient was orthotropic in five cardinal positions, and her ductions and versions were full. CONCLUSIONS: One patient with a duplicated abducens nerve showed orthotropia and normal ocular movement.
Abducens Nerve↗
Usefulness of MR imaging in children without characteristic clinical findings of Duane's retraction syndrome.
BACKGROUND AND PURPOSE: Duane's retraction syndrome (DRS) consists of a congenital abduction deficit of the eyeball accompanied by retraction of the globe on attempted adduction and by upshoots or downshoots of the affected eye on adduction. These characteristic diagnostic signs of DRS, however, might not be manifested in early childhood. We evaluated the usefulness of MR imaging as a diagnostic tool in such cases. METHODS: Thin-section gradient-echo imaging at the brain stem level was performed in two pediatric patients with only abduction deficit and 10 control children. Imaging findings were analyzed focused on the presence or absence of the abducens nerve. RESULTS: The abducens nerve on the affected side was absent in three of three affected eyes in two patients. The right and left abducens nerves were well identified in all 10 control subjects. CONCLUSION: MR imaging is useful for the differential diagnosis of abduction deficit of the eyeball in pediatric patients. The absence of the abducens nerve suggests DRS strongly in children with abduction deficit.
Abducens Nerve Diseases↗
Endovascular treatment of wide-necked aneurysms by using two microcatheters: techniques and outcomes in 25 patients.
BACKGROUND AND PURPOSE: The endovascular occlusion of aneurysms with unfavorable configurations such as a broad neck and an important branch from the fundus remains a technical challenge. The purpose of this study was to evaluate the radiologic and clinical results of complicated aneurysm treatment by using two microcatheters. METHODS: Twenty-five aneurysms in 25 patients were treated by using two microcatheters, from August 2001 to February 2004. Fourteen patients presented with a subarachnoid hemorrhage (SAH) and 11 had unruptured aneurysms. The aneurysms were of the basilar top (7), middle cerebral artery bifurcation (4), posterior communicating artery (4), anterior communicating artery (3), superior cerebellar artery (2), ophthalmic artery (2), and one aneurysm of each of cavernous internal carotid artery (ICA), dorsal ICA, and midbasilar artery. In 16 aneurysms (64%), the width of the aneurysm was the same or longer than the height. In 19 (76%), important branches arose from the aneurysm base, and some were even incorporated with the aneurysm fundus. The mean dome (height)-to-neck ratio was 1.23 +/- 0.37 (range, 0.65-2.33), and this was greater than or equal to 1.0 in 19 aneurysms (76%). RESULTS: All aneurysms were successfully embolized. Immediate postembolization angiography showed no residual contrast filling in eight aneurysms (32%), and some residual contrast filling in 16. The aneurysm remnants, however, were intentionally left to preserve important branches in 12 of the 16 aneurysms with incomplete occlusion. Two complications occurred, including one thromboembolic and one coil protrusion, but they were successfully resolved and produced no clinical symptoms. All patients except one showed excellent clinical outcomes. One patient revealed moderate cognitive dysfunction. During the follow-up period, no new bleeding occurred. CONCLUSION: Our experience with 25 cerebral aneurysm patients shows that the technique of using two microcatheters is feasible and safe for coil embolization of aneurysms with unfavorable configurations. Although the lack of angiographic follow-up prevents us from drawing conclusions about its effectiveness as compared with other techniques such as stent placement and balloon-neck protection, we believe that this technique offers a reliable alternative for endovascular therapy of complicated aneurysms.
Adult↗
Delayed encephalopathy of acute carbon monoxide intoxication: diffusivity of cerebral white matter lesions.
BACKGROUND AND PURPOSE: Carbon monoxide intoxication has delayed effects on the cerebral white matter characterized by bilateral, confluent lesions that reflect diffuse demyelination. To increase our understanding of this process, we assessed the diffusion characteristics of these lesions. METHODS: Five consecutive patients with delayed encephalopathy of CO intoxication were examined with diffusion MR imaging. Diffusion-weighted images (DWIs) were obtained 25-95 days after their exposure to CO and during a relapse of neuropsychiatric symptoms, which occurred after an initial recovery. Imaging was performed at 1.5 T by using a spin-echo echo-planar sequence with diffusion gradients of 0, 500, and 1000 s/mm(2). DWIs and apparent diffusion coefficient (ADC) maps were visually evaluated, and mean ADCs were calculated from the periventricular white matter and the centrum semiovale, where confluent hyperintensity was seen on T2-weighted images. Findings were compared with those of normal-looking white matter. RESULTS: In all five patients, both T2-weighted images and DWIs showed the white matter lesions as bilateral, diffuse, confluent areas of hyperintensity in the periventricular white matter and centrum semiovale. On ADC maps, these lesions were isointense, with focal areas of hypointensity (n = 4) or diffuse hypointensity (n = 1). Mean ADC values of the white matter lesions were significantly lower than those of normal-looking white matter, regardless of their isointensity or hypointensity on ADC maps (P <.05). CONCLUSION: Bilateral, confluent, white matter lesions in patients with delayed encephalopathy of CO intoxication show decreased diffusivity.
Aged↗
The Fourth Asian-Oceanian Congress of Neuroradiology and Head & Neck Radiology.
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Asia↗
Multiphasic perfusion computed tomography in hyperacute ischemic stroke: comparison with diffusion and perfusion magnetic resonance imaging.
PURPOSE: The purpose of this study was to compare multiphasic perfusion computed tomography (CT) with diffusion and perfusion magnetic resonance imaging (MRI) in predicting final infarct volume, infarct growth, and clinical severity in patients with hyperacute ischemia untreated by thrombolytic therapy. METHOD: Multiphasic perfusion CT was performed in 19 patients with ischemic stroke within 6 hours of symptom onset. Two CT maps of peak and total perfusion were generated from CT data. Diffusion-weighted imaging (DWI) and perfusion MRI were obtained within 150 minutes after CT. Lesion volumes on CT and MRI were compared with final infarct volume and clinical scores, and mismatch on CT or MRI was compared with infarct growth. RESULTS: The lesion volume on the CT total perfusion map strongly correlated with MRI relative cerebral blood volume (rCBV), and that on the CT peak perfusion map strongly correlated with MRI relative cerebral blood flow (rCBF) and rCBV (P < 0.001). The lesion volume on unenhanced CT or DWI moderately correlated with final infarct volume, but only lesion volume on unenhanced CT weakly correlated with baseline clinical scores (P = 0.024). The lesion volumes on the CT peak perfusion map and MRI rCBF similarly correlated with final infarct volume and clinical scores and more strongly than those on mean transit time (MTT) or time to peak (TTP). DWI-rCBF or CT mismatch was more predictive of infarct growth than DWI-MTT or DWI-TTP mismatch. CONCLUSION: Multiphasic perfusion CT is useful and of comparable utility to diffusion and perfusion MRI for predicting final infarct volume, infarct growth, and clinical severity in acute ischemic stroke.
Acute Disease↗