Mercuric Chloride-Induced Acute Tubular Necrosis in the Rabbits: Gd-DTPA Enhanced Dynamic IVIR Imaging

PURPOSE: To evaluate potential usefulness of dynamic Gd-DTPA enhanced MRI in the diagnosis of HgCI2 induced acute tubular necrosis of rabbits. MATERIALS AND METHODS: Sixteen rabbits were used as control group, and 14 rabbits and 12 rabbits were used as acute tubular necrosis groups of 24 hours and 48 hours after HgCI2 injection, respectively. Sequential dynamic MR imagings were acquired using Gd-DTPA(0.25mmol/kg), and time-signal intensity curves were obtained from cortex, outer medulla and inner medulla. RESULTS: In control group, a dark band, which reflects concentrated Gd-DTPA, migrated from cortex to inner medulla of the kidney, and the ratio of the signal intensity of post Gd-DTPA injection to the signal intensity of pre Gd-DTPA injection(RSI) decreased below 1 at 13sec and 26sec (mean:17 +/- 6.2sec) in cortex, at 52sec (mean :52sec) in outer medulla, and after 117sec(mean :112 +/- 33.9sec) in inner medulla of the kidney. In acute tubular necrosis group of 24 hours after HgCI2 injection, the dark band did not appear and signal intensity in cortex and medulla increased diffusely, and RSI increased above 1 in all locations. In acute tubular necrosis group of 48 hours after HgCI2 injection, the dark band appeared only in the cortex and no sign of migration was observed, and RSI is little changed except in cortex at 13sec(0.76 +/- 0.05) and 26sec(0.86 +/- 0.06). There were statistically significant differences in the time-RSI curves among cortex, outer medulla, and inner medulla in study groups, respectively (p<0.0001). CONCLUSION: Dynamic Gd-DTPA enhanced MRI of the kidney could be utilized to evaluate both renal structure and functional changes.

Measurement of Normal Corpus Callosum with MRI in Korean Adults and Morphological Change of Corpus Callosum by Grade of Hydrocephalus

PURPOSE: To measure the size of normal corpus callosum in each portion using objective and reproducible method with MRI and evaluation of morphological change of corpus callosum by grade of hydrocephalus. MATERIALS AND METHODS: Midsagittal Tl-weighted MR imaging of the corpus callosum was investigated in 41 volunteers of normal Korean adults and 19 patients with hydrocephalus. Corpus callosum was measured for the anteroposterior length(A), height(B), and the thickness of genu(C), body (D), splenium(E), and the narrowest portion of body(F). And the analysis of morphology and signal intensity of the corpus callosum were also evaluated. Hydrocephalus was graded as mild, moderate, and severe, and comparision of thickness with normal corpus callosum in each portion was done. RESULTS: The mean length and height were 72.3mm, 28.6mm in male, and 70.7ram, 28.9mm in female. And the mean dimention for C, D, E, and F were 13.1 ram, 8ram, 13.2mm, 5.2ram in male, and 12.8mm, 7.5ram, 12.3 ram, 5mm in female. The morphology of normal corpus callosum was "hook" shaped on midline sagittal Tl-weighted image. Narrowing at posterior third portion of body were present on 30 cases(73.2%) and even in thickness of the body in 11 cases(26.8%). The signal intensity of the corpus callosum on midsagittal Tl-weighted spin echo image of normal cases was homogeneous hyperintense as compared with cerebral gray matter. In hydrocephalus, A and B were increased and other portions were decreased in thickhess. Genu and the narrowest portion of body showed significant difference of thickness according to the grade of hydrocephalus. CONCLUSION: The mean dimention of all portion of corpus callosum were larger in male than female except for callosal height but not significant statistically with the exception of splenium. Hydrocephalus lead to morphological change of the corpus callosum. Among the portion of corpus callosum, genu and the narrowest portion of the body were thought to be the most sensitive indicators of degree in hydrocephalus.

Destructive lesions of vertebral body:CT findings and differential diagnosis of inflammation and malignancy

The CT findings and their differential points were evaluated by reviewing the CT scans of 47 patients with destructive lesions of vertebral bodies which included tuberculous spondylitis(23), pyogenic infection(9), syphilitic spondylitis(1) and malignant lesions(14). Twenty-one(91.3%) of 23 patients with tuberculous spondylitis showed mixed osteolytic and osteosclerotic patterns of bony destruction. Six(66.7%) of 9 patients with pyogenic infection and 10(71.4%) of 14 malignant lesions showed osteolytic pattern of bony destruction. Thirty(90.9%) of 33 infections lesions including pyogenic infection and tuberculous spondylitis involved intervertebral disc, while the involvement of intervertebral disc was not found in malignant lesions. The Swisscheese appearance of bony destruction was commonly seen in tuberculous spondylitis, but pyogenic infections and malignant lesions more commonly revealed geographic or moth-eaten appearance. The sequestral pattern and sclerotic rims in and around bony destruction were mainly seen in tuberculous spondylitis, and they were thought to be specific findings in tuberculous spondylitis. CT of the spine appears to offer the detailed findings of vertebral body destruction and may be a useful adjunct in differentiation between tuberculous spondylitis, pyogenic infections and malignant lesions of the spine.

Brain MRI findings of complex partial seizure in children

Twenty-two children(4 months to 17 years old)with a clincial diagnosis of complex partial seizure(CPS) were examined with a 0.5T MRI scanner using spin-echo sequences. Eleven patients showed abnormal brain MRI findings; two had focal lesions with corresponding seizure foci on the EEG, one arising from temporal lobe(Hippocampal Formation atrophy) and the other from the frontal lobe. Nine patients showed diffuse lesions with inconsistent seizure foci on EEG. The remaining 11 patients were normal on bran MRI; two of them had normal EEG findings and the others either focal or diffuse abnormalities on EEG.

Comparison of brain MRI and CT of diffuse axonal injury(DIA)

A retrospective comparative study of MRI and CT in 24 patients with diffuse axonal injury (DIA) was undertaken. Three-quaters of the lesions were non-hemorrhagic, and the sites of involvement were lobar white matter (96%), corpus callosum (70%), and rostral brainstem (42%), in descending order. MRI was singnificantly more sensitive than CT in detecting DAI lesions. The average number of DAI lesions was higher with increasing clinical stage of the injury. MRI is more valuable than CT for staging the full magnitude of the injury and in predicting the neurologic prognosis of DAI lesions.

Radiological evaluation of the intracranial arteriovenous nalformat- ion

No abstract available.

A case of the vein of Galen malformation

The vein of Galen malformation is a rare midline intracranial arteriovenous malformation. The majority of themalformations were seen in neonate, infancy and childhood, and the clinical symptoms and prognosis depended on ageof presentation. The authors report a case of the vein of Galen malformation in 17 month-old female withhydrocephalus, which is confirmed by CT and digital subtraction angiography.

Plain film analysis of acetabular fracture

Acetabular fracture can result in severe limitation of the motion of the hip joint, which supports totalweight of human body. Beause of different methods of surgical approach a ccording to fracture type, preciseinterpretation of X-ray films of acetabular fracture is required. We reviewed 38 cases of simple X-ray filmsshowing acetabular fracture. The results were as follows: 1. Almomst 60% of the cases-were in their 2nd and 3rddecades. 2. Twenty cases were male, and 18 cases were female. 3. The most common cause of the injury was trafficaccident(33 cases, 86.8%), followed by fall down (4 ases, 10.5%) and slip down(1 case, 2.7%). 4. Elementaryfractures were 21 cases(55.3%) and associated fractures were 17 cases(44.7%). 5. Among elementary fractures,posterior wall fractures were 9 cases(23.7%), followed by anterior column fractures(8 ases, 21.1%), anterior wallfractures(4 cases, 10.5%). 6. Among associated fractures, T-shaped fractures were 8 cases(21.1%), followed by bothcolumn fractures(6 cases, 15.8%), anterior and hemitransverse fractures(3 cases, 7.8%). 7. Other pelvic bonefractures associated with the acetabular fracture were as follows: farcture of contralateral pubic rami(6 ases,15.8%) contralateral iliac bone (1 case, 2.6%) and ipsilateral iliac bone (1 case, 2.6%). 8. Injuries of otherorgans adjacent to the acetabulum were as follows: rupture of the bladder (3 cases, 7.9%), urethra(2 cases, 5.3%)and uterus (1 cases, 2.6%).

KAIS Resistive NMR-CT and Its Clinical Application

This paper contains the results of cl inical studies with 0.1 and 0.15 Tesla KAIS NMR Tomograph which was developed by Korea Advanced 1 nstitute of 5cience. A variety of imaging modes such as saturation recovery(SR), spin echo(SE), and inversion recovery(SR) as well as echo and repetition times were applied. Clinical imagings were performed on 22 patients with dlseases of brain (15 cases), cervical spine(2 cases}, chest (2 cases), pancreas (2 cases), and kidney (1 case). In SR imaglng, we have obtained images strongly dependent on the hydrogen nuclei density. SE with long echo time and IR are effective for T2 and T1 dependent images, respectively. Results of clinical NMR imaging are presented and compared with X-CT and the other radiological examinations. Obtained results appear promising and with further examinations along with parameter adjustment, it is expected that the NMR imaging will not only substitute many conventional diagnostic methods such as X.ray CT but also be useful for the early detection of tumor and other lesions not obtainable with other modalities.