Persistent Carotid-Vertebrobasilar Anastomosis: Radiologic Findings

PURPOSE: To evaluate the radiologic findings of carotid-vertebrobasilar anastomosis and associated anomalies. MATERIALS AND METHODS: Thirteen patients with fourteen cases of carotid-vertebrobasilar anastomosis collectedfrom January 1992 to December 1997 were reviewed. Clinical diagnosis refered for cerebral angiography werecerebral infarction(n=3), intracranial hemorrhage(n=2), subarachnoid hemorrhage(n=1), brain tumor(n=3),arteriovenous malformation(n=3) and trigeminal neuralgia(n=1). Cerebral angiograms and clinical symptoms wereretrospectively analyzed. RESULTS: The fourteen carotid-vertebrobasilar anastomsis consisted of eleven cases ofpersistent trigeminal artery and three cases of type I proatantal intersegmental artery. Persistent trigeminalarteries were associated with anterior communicating artery aneurysm(n=1), posterior fossa arteriovenousmalformation(n=2) and persistent trigeminal artery variant(n=5). Type I proatantal intersegmental arteries wereassociated with hypoplastic vertebral arteries(n=2) : only proximal segment in one, and proximal and distalsegments in one case. Only one patient had clinical symptom related to the carotid-vertebrobasilar anastomosiswhich was trigeminal neuralgia. CONCLUSION: Knowledge of the anatomical and radiologic findings ofcarotid-vertebrobasilar anastomosis and associated anomalies will aid in the accurate diagnosis of neurovasculardisease and prevent possible complications during surgical and interventional procedures.

MR Findings of Cerebral Palsy: Comparison Between Preterm Patients and Fullterm Patients

PURPOSE: To observe the MR findings of cerebral palsy by evaluating cerebral damage resulting from hypoxic ischemic injury and other variable causes and to compare the findings between preterm and full-term patients. MATERIALS AND METHODS: We reviewed the MR findings of 102 cerebral palsy patients (71 full-term and 31 preterm). These were analysed with regard to deep and peripheral white matter, gray matter, basal ganglia, the thalamus, brainstem, cerebellum, corpus callosum and ventricles, according to the pattern of injury such as hypoxic ischemic injury, migration anomaly and early intrauterine injury, the findings of full-term and preterm patients were then compared. RESULTS: MR findings of preterm patients (n=31) were as follows ; hypoxic ischemic injury (n=26), normal (n=2), and migration anomaly (n=3), while those of full-term patients (n=71) were hypoxic ischemic injury (n=41), normal (n=24), migration anomaly (n=4), early uterine injury (n=2), and perirolandic ischemic injury (n=6); in 5 patients, this latter condition was combined with status marmoratus. Periventricular leukomalacia was the most common finding in both preterm patients and full-term patients; selective neuronal necrosis, parasagittal injury and perirolandic injury were observed only in full-term patients. CONCLUSION: On MRI, variable findings of cerebral palsy were clearly observed; periventricular leukomalacia was the most common finding in both preterm and full-term patients.

Gd-DTPA Enhancement of Lumbar Discs on MRI: Frequency and Pattern

PURPOSE: To assess the frequency and pattern of disc enhancement of lumbar spine on enhanced MR images and to determine whether enhanced MR images are useful for locating internal disc lesions. MATERIALS AND METHODS: MR images of a total of 225 discs from 45 patients were reviewed. Fifteen discs from 15 patients who had previously undergone an operation were excluded and 210 discs were therefore studied. T1-, T2-, and gadolinium-enhanced T1-weighted images were obtained after intravenous injection of Gd-DTPA(0.2 ml/kg). Findings were analyzed retrospectively. RESULTS: Sixty-nine(32.6%) of 210 discs showed enhancement. The pattern of enhancement was intradiscal(linear or nodular) or extradiscal. Of 165 morphologically normal discs, 34(20.6%) discs were enhanced; 32 showed linear and two showed nodular enhancement. All of six ruptured discs were enhanced. Six patients were operated on after MRI study ; one case of intradiscal linear enhancement revealed a bulging disc, three of five patients were confirmed on surgery as having ruptured discs in view of the extradiscal enhancement and the other two patients were confirmed having protruded discs. CONCLUSION: The pattern of disc enhancement is classifiedinto intradiscal and extradiscal. The former is further classified into linear and nodular. Gd-DTPA enhanced MRimages may be helpful in diagnosing ruptured discs and in detecting pathologic conditions in those patients whose discs appear to be morphologically normal before enhancement.