Showing papers in "Journal of the Korean Society of Radiology in 1998"

Persistent Carotid-Vertebrobasilar Anastomosis: Radiologic Findings

Abstract: 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 collected from January 1992 to December 1997 were reviewed. Clinical diagnosis refered for cerebral angiography were cerebral 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 were retrospectively analyzed. Results : The fourteen carotid-vertebrobasilar anastomosis consisted of eleven cases of persistent trigeminal artery and three cases of type I proatantal intersegmental artery. Persistent trigeminal arteries were associated with anterior communicating artery aneurysm(n=1), posterior fossa arteriovenous malformation(n=2) and persistent trigeminal artery variant(n=5). Type I proatantal intersegmental arteries were associated with hypoplastic vertebral arteries(n=2): only proximal segment in one, and proximal and distal segments in one case. Only one patient had clinical symptom related to the carotid-vertebrobasilar anastomosis which was trigeminal neuralgia. Conclusion : Knowledge of the anatomical and radiologic findings of carotid-vertebrobasilar anastomosis and associated anomalies will aid in the accurate diagnosis of neurovascular disease and prevent possible complications during surgical and interventional procedures.

Squalene Aspiration Pneumonia: Thin-Section CT and Histopathologic Findings

Abstract: Purpose : The purpose of this study was to describe the thin-section computed tomography (CT) findings and histopathologic findings of squalene aspiration pneumoma. Materials and Methods: Thin-section CT scans were obtained from nine patients with proven exogenous lipoid pneumonia resu1ting from aspiration of squalene(derived from shark liver oil). The condition was diagnosed by biopsy (n=3), bronchoalveolar lavage(n=4), or sputum cytology and clinical history (n = 2) ; a clinical history of squalene use was confirmed in all patients. Specimens oftransbronchiallung biopsy were also reviewed and compared with thin-section CT findings. Results : Thin-section CT findings included ground-glass attenuation(n=8), consolidations obliterating vascular marking(n=4), scattered centrilobular ground-glass attenuation(n=2), and interlobular interstitial thickening(n=6). Geographic lobular distribution with peripheral spared lobules was observed in all patients. These diseases involved multiple lobes (n=S) and abnormalities were usually located in the dependent portion of the lung. ln three cases, histopathol ogical correlation showed that ground-glass attenuation reflected intra-alveolar infiltration of lipid-laden macrophages with exudative fluid. lnterlobular septal thickening represented hyperplasia oftype II pneumonocy tes with mild fibrosis . Conclusion : On the basis of these results, we concluded that squalene aspiration pneumonia can be reliably diagnosed by thin-section CT findings particularly when the appropriate history is known.

Intrathoracic Major Vessels, Trachea and Main Bronchi: The Effect of Respiration on Size

Abstract: Purpose : To evaluate the effect of respiration on the sizes of intrathoracic vasculature, and the trachea, and the main bronchus. Materials and Methods : Seventeen volunteers (10 males aged 20 39 years and 7 females aged 20 39 years) underwent spiral CT, between the apex and lowest base ofthe lung, collimation was 10 mm, pitch was 1, and images were obtained at breath hold forced end-inspiration and breath hold forced end-expiration. Cross secional areas or diameters were measured in each respiration state at the aorta (ascending, descending , lower thoracic) and great branches, the IVC (thoracic, abdominal), the SVC, pulmonary artery (right main, left descending) and the tracheobronchus (trachea, left upper bronchus). Changes in the size ofvessels and airways between the respiration states were evaluated and compared between inspiration and expiration. Results : During breath-hold forced end-inspiration CT, the ascending, descending, and lower thoracic aorta and its branches (brachiocephalic, left common carotid , left subclavian) as well as the thoracic IVC and SVC and the right main and left descending pulmonary arteries decreased in size : during breath-hold forced end-expiration CT, the size of all these vessels increased. For the trachea, left up per lobe bronchus and abdominal IVC , the situation was reversed. Statistically sig nificant changes(p < 0.05) were noted in the ascending aorta and descending aorta, the lower thoracic aorta, the thoracic and abdominal IVC , the SVC, the right main and left pulmonary arteries, and the trachea. Conclusion : During respiration, changes in the size of the thoracic vasculature and airways is probably due to changes in intrathoracic pressure. In the measurement and diagnosis of stenosis or dilatation in the intrathoracic vesculature and airways, respiration states should therefore be considered.

Three-Dimensional Short-Range MR Angiography and Multiplanar Reconstruction Images in the Evaluation of Neurovascular Compression in Hemifacial Spasm

Abstract: Purpose: To evaluate the diagnostic efficacy of three-dimensional (3D) short-range MR angiography (MRA) and multiplanar reconstruction (MPR) imaging in hemifacial spasm(HS). Materials and Methods : Two hundreds patients with HS were studied using a 1. 5T MRI system with a 3D time-of-flight (TOF) MRA sequence. To reconstruct short-range MRA , 6 10 source images near the 7 8th cranial nerve complex were processed using a maximum-intensity projection technique . In addition, an MPR technique was used to investigate neurovascular compression. We observed the relationship between the root-exit zone (REZ) ofthe 7th cranial nerve and compressive vesse l, and identified the compressive vessels on symptomatic sides. To investigate neurovascular contact, asymptomatic contralateral sides were also evaluated. Results : MRI showed that in 197 of 200 patients there was vascular compression or contact with the facial nerve REZ on symptomatic sides. One of the three remaining patients was suffering from acoustic neurinoma on the symptomatic side, while in two patients there were no definite abnormal findings . Compressive vessels were demonstrated in all 197 patients; 80 cases involved the anterior inferior cerebellar artery(AICA), 74 the posterior cerebellar artery(PICA), 13 the vertebral artery(V A) , 16 the VA and AICA, eight the V A and PICA, and six t~ξ AICA and PICA. In all 197 patients, compressive vessels were reconstructeß/on \\--one 3D short-range MRA image without discontinuation from vertebral or)Sasilar arteries. 3D MPR studies provided additional information such as the divéction of compression and course ofthe compressive vessel. In 31 patients there was neurovascular contact on the contralateral side at the 7-8th cranial nerve complex. Conclusion : In patients with HS, 3D short-range MRA and MPR images are excellent and very helpful for the investigation of neurovascular compression and the identification of compressive vessels.