Neuroradiological correlative study of pateints with transient ischemic attacks [TIAs] with special emphasis on the role of MRA

ABSTRACT

Accurate evaluation of the intracerebral vasculature is essential for proper diagnosis and treatment of many neurological disorders including TIAs. Vascular anatomy of brain can be assessed by many modalities including Direct angiography, MRA, CT angiography and transcranial sonography. This study aimed to compare the validity and clinical matching of the different radiological and para-radiological modalities of examination in the evaluation of the cause of TlAs, with special interest to evaluate MRA and relation of TIAs to congenital vascular anomalies. 28 patients presented recently with TIAs were the subject of this study. Conventional CT of the brain, MRI brain, MRA brain and neck were performed to all patients while Duplex Doppler study of neck vessels was performed in 20/28 patients. MRA Brain showed positive findings in 20/28 patients while MRA neck showed positive results in 8 patients and both were negative in 2 patients [either one or both were positive in 26 patients] and they match clinical presentation in 20/28 of the patients and mismatch the clinical diagnosis in 8/28 of patients. combined MRA and MRI studies for the patients increase the diagnostic accuracy to 79% . .MRA neck showed 100% matching with D. Doppler examination of the neck vessels. MRI diagnosed 12/28 patients while CT diagnosed only 6/28 patients. Congenital anomalies of brain vessels occurred in 13/28 patients. The most common anomaly was absent Al segment in 28% of patients followed by absent P1 segment in 11% of patients. MRA missed the diagnosis in 2/28 patients while MRI proved it. Vertigo was a deceiving symptom, with the least accuracy and matching with all modalities of examination. MRA is the technique of choice to evaluate brain vascularity [accurate, safe, no contrast medium and no Ionizing radiation] with high accuracy and matching with clinical presentation. There is direct relation between the incidence of TIAs and congenital anomalies of the brain. MRI examination is very helpful in few patients while conventional CT can be replaced by MRI as it adds nothing and miss the diagnosis in many patients. Duplex Doppler study of neck vessels can replace MRA neck. We recommend the following scheme for evaluation of patients with TIAs1. MRI brain, 2. MRA brain, 3. D.Doppler neck vessels