PURPOSE: To assess regional cerebral blood volume and perfusion rate by MR imaging. MATERIALS AND METHODS:Eight normal volunteers and one patient underwent MR imaging after bolus injection of a double dose ofgadoinium(0.2mMol/kg). Gradient-echo EPI pulse sequencing was used, with TR/TE 1500/40msec, flip angle 90o, matrixsize 256X128. One hundred sequential images at the same level were obtained. The time-signal intensity curve wasplotted and converted to a time-concentration ( R2) curve. Relative cerebral blood volume was determined, withintegration of time-concentration curve pixel by pixel. Perfusion rate was determined by calculating maximal slopeof the R2 curve and the time taken to attain this. RESULTS: On volume maps, clear differentiation of gray matter,white matter and major vessels was established. The mean gray and white matter ratio of blood volume was2.78+/-0.43. Slope and volume maps were similar, but in one patient perfusion was apparently greater on the ratemap than on the volume map. CONCLUSION: Cerebral blood volvme and slope map images reflect changes in cerebralhemodynamics. It is thought that these findings can be clinically applied to the determination of vascularity inbrain tumors and acute cerebral ischemia
Blood Volume* ; Brain Ischemia ; Healthy Volunteers ; Humans ; Magnetic Resonance Imaging ; Perfusion*

PURPOSE: To demonstrate the incidence and variation of the meniscofemoral ligament in Koreans. MATERIALS AND METHODS: A total of 100 MR studies of 95 patients were reviewed with special attention to the appearance and incidence of the meniscofemoral ligaments. The ligament of Wrisberg was classified according to proximal insertion: type I, insertion at the posterofemoral condyle ; type II, insertion at the distal portion of the posteriorcruciate ligament ; type III, insertion at the distal portion of the posterior cruciate ligament. On T2-weighted images, the high signal at the meniscal insertion of the meniscofemoral ligament was classified according to itsshape. RESULTS: The ligament o Humprey was observed in 17 cases and the ligament of Wrisberg was in 90:type I in41 cases;type II, 19 cases;type III, in 28 cases; unclassified, in 2 cases. In 77 cases, the cleft with high signal intensity was seen between the meniscofemoral ligament and the posterior cruciate ligament. CONCLUSION: From our results, the incidence of the ligament of Wrisberg on MRI was moe prevelant than the ligament of Humprey. An exact knowledge of the meniscofemoral ligament could be helpful in distinguishing it from pathologic lesions.
Classification* ; Humans ; Incidence* ; Knee ; Ligaments* ; Magnetic Resonance Imaging* ; Posterior Cruciate Ligament

A Reversible Posterior Leukoencephalopathy Syndrome(RPLS) consists of neurologic symptoms and signs - headache, consciousness change, seizure, visual impairment - and brain imaging finding showing brain(espicially white matter) edema usually involving the posteior parietal-temporal-occipital areas. The causes are thought to be hypertensive encephalopathy, pre-eclampsia or eclampsia, renal failure with fluid overload and immunosuppressive agents such as cyclosporin A or FK506. RPLS may usually reversible if treated early by decreasing blood pressure and discontinuing offending drugs. A 23-year-old man had been hemodialyzed with chronic renal failure for two years. His blood pressure elevated to 240/150mmHg 3 days before admission and he complained of severe headache, vomiting, and total visual loss at the day of admission. Brain T2-weighted MRI imaging showed increased signal intensity involving the both parietal, posterior temporal, and occipital lobes. After antihypertensive and dexamethason treatment, a follow-up brain MRI performed on 7 days after admission showed nearly normalized findings and all symptoms including visual loss were recovered completely in one week.
Blindness ; Blood Pressure ; Brain ; Consciousness ; Cyclosporine ; Eclampsia ; Edema ; Female ; Follow-Up Studies ; Headache ; Humans ; Hypertensive Encephalopathy ; Immunosuppressive Agents ; Kidney Failure, Chronic* ; Leukoencephalopathies ; Magnetic Resonance Imaging ; Neuroimaging ; Neurologic Manifestations ; Occipital Lobe ; Posterior Leukoencephalopathy Syndrome* ; Pre-Eclampsia ; Pregnancy ; Rabeprazole ; Renal Insufficiency ; Seizures ; Tacrolimus ; Vomiting ; Young Adult