Wallerian degeneration is well known as the anterograde degeneration of axon and their accompanying myelin sheath from injury to the proximal portion of the axon or its cell body. The most common cause of wallerian degeneration is cerebral infarction. Authors experienced three patients with old hemispheric infarct with typical wallerian degeneration in the brain stem, which was demonstrated by magnetic resonance imaging (MRI) in two cases and CT in one case. This report demonstrates the wallerian degeneration in the corticospinal tract on the MRI and CT with the brief review of the literatures.
Axons ; Brain Stem ; Brain* ; Cell Body ; Cerebral Infarction ; Humans ; Magnetic Resonance Imaging* ; Myelin Sheath ; Pyramidal Tracts ; Wallerian Degeneration*

The CT findings of the acute cerebral infarction are well known. However the CT findings of early stroke within 24 hours of the onset have not been sufficiently reported. The purpose of this study is to evaluate early acute cerebral infarction on CT within 24 hours after ictus. The early and accurate CT diagnosis could lead to the appropriate therapy and improved outcome of the patients. Authors retrospectively analyzed 16 patients with early acute cerebral infarction. Acute cerebral infarction was confirmed by follow-up CT in 11 patients, SPECT in 4 patients, and MRI in 1 patient. The CT findings of early acute cerebral infarction include effacement of cortical sulci or cistern (n=16, 100%), hyperattenuation of MCA (n=3), obscuration of lentiform nucleus (n=6), loss of insular ribbon (n=6) and subtle low density in hemisphere (n=5). The most frequent findings was effacement of cortical sulci in our study, and it was though to be the most important sign of early acute cerebral infarction.
Cerebral Infarction* ; Corpus Striatum ; Diagnosis ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Retrospective Studies ; Stroke ; Tomography, Emission-Computed, Single-Photon

No abstract available.
Pregnancy*

No abstract available.
Humans ; Hydronephrosis* ; Radioisotope Renography*

PURPOSE: The purpose of this study was to evaluate the spectrum of MR characteristics of cystic acoustic neurinomas and to correlate with pathologic findings. MATERIALS AND METHODS: We retrospectively reviewed the MR findings of 12 patients with cystic acoustic neurinomas. The signal intensity and enhancement pattern of the cystic components as well as the location relative to the tumors were analyzed. RESULTS: A total of 30 cysts were found in 15 acoustic neurinomas;28 were intratumoral cysts and the remaining two were extratumoral cysts. The signal intensity of all 28 intratumoral cysts was higher than that of CSF on Tl-weighted images, and isointense to CSF on T2-weighted images, while the signal intensity of the two extratumoral cysts was same as CSF on both Tl-weighted and T2-weighted images. Rim enhancement was seen in 27 of 28 intratumoral cysts but in none of the two extratumoral cysts. CONCLUSION: We concluded that intratumoral cyst was due to tumoral necrosis, hemorrhage or degenerative change and extratumoral cyst due to secondary arachnoid cyst formation.
Acoustics* ; Arachnoid ; Hemorrhage ; Humans ; Necrosis ; Neuroma, Acoustic* ; Retrospective Studies

OBJECTIVE: To describe normal postoperative MR findings and MR findings of postoperative discitis in patients who underwent operation due to herniated intervertebral disc. MATERIALS AND METHODS: We retrospectively reviewed normal postoperative MR findings and MR findings of discitis in 30 patients(21-61yrs.) (13 cases dignosed as discitis and 17 cases as normal) who previonsly underwent laminectomy and discectomy, or bony fusion. We analyzed signal intensity of end plate and disc, end plate destruction, and enhancement of end plate and disc on T1- and T2-weighted images(WI) of 1.5T MRI. RESULTS: Among 14 out of 17 patients with no evidence of discitis, 7 patients showed high signal of the posterior portion of disc on T1- and T2-WI and 11 patients revealed enhancement at the same sites. In all 13 patients suspected of having discitis, end plate and disc showed low signal on T1-WI, high signal on T2-WI, heterogeneous enhancement, and irregular destruction of end plate. Meanwhile, 3 cases with no evidence of postoperative discitis clinically who underwent bony fusion showed similiar findings to those of the above 13 patients, except for homogeneous enhancement of end plate and vertebral body. CONCLUSION: The MR findings of postoperative discitis were low signal on T1-WI, high signal on T2-WI, and heterogeneous enhancement of and plate and disc, and destruction of end plate.
Discitis* ; Diskectomy ; Humans ; Intervertebral Disc* ; Laminectomy ; Magnetic Resonance Imaging ; Retrospective Studies

No abstract available.
Mediastinitis*

No abstract available.
Mediastinitis*

Spinal epidural abscesses were evaluated using Gadolinium-enhanced magnetic resonance imaging (MRI) in 19 surgically and clinically confirmed cases, including 13 with tuberculous spondylitis and 6 with pyogenic spondylitis. We observed rim enhancement patterns in 10 patients and diffuse enhancement patterns in 9 patients. The spread patterns were localized to ventral or dorsal epidural space and encircled entire epidural space. We conclude that rim enhancement indicates abscess and diffuse enhancement indicates granulation tissue and fibrosis. Tuberculous epidural abscess spreads to ventral epidural space and pyogenic epidural abscess encircles entire epidural space.
Abscess ; Epidural Abscess* ; Epidural Space ; Fibrosis ; Granulation Tissue ; Humans ; Magnetic Resonance Imaging* ; Spondylitis

The magnetic resonance images (MRI) of 30 patients with surgically or biochemically confirmed pituitary adenomas (20 macroadenomas, 10 microadenomas) were retrospectively evaluated. Ten patients had hyperprolactinemia, another eight had acromegaly, another eight had nonfunctioning adenoma and four had Cashing disease. The examination were performed at a 1.5-T superconducting MR system using a multisection spin-echo technique with 3mm-thick sections and a 256×224 matrix. TI weighted sagittal and coronal images were obtained before and within 30 minutes after the administration of Gd-DTPA (0.1mmol/kg). Analysis of the MRI was focused on the signal intensity and enhamcement patterns of the pituitary adenoma before and after Gd-DTPA administration. Compared with endocrinologic diagnosis, macroadenoma showed heterogeneous enhacement in 55%, rim enhancement in 35% and homogeneous enhancement in 10%, Conclusively, the enhancement patterns of the pituitary adenoma did not correlate with the subtypes made according to hormone production.
Acromegaly ; Adenoma ; Diagnosis ; Gadolinium DTPA ; Humans ; Hyperprolactinemia ; Magnetic Resonance Imaging* ; Pituitary Neoplasms* ; Retrospective Studies