Imaging of Distal Dural Ring Plane and Paraclinoid Internal Carotid Artery Aneurysms with 3D Rotational Angiography / 신경중재치료의학

PURPOSE: The distal dural ring (DDR) plane separates the intradural from extradural paraclinoid internal carotid artery (ICA) aneurysm. The purpose of this study was to evaluate the feasibility of the localization of the DDR plane drawn by the bony landmarks in patients with paraclinoid ICA aneurysms at 3D rotational angiography (3DRA). MATERIALS AND METHODS: 13 consecutive patients who underwent a 3DRA for the evaluation of 16 paraclinoid ICA aneurysms were reviewed retrospectively. On a dedicated workstation, multiplanar reconstruction (MPR) image along the virtual plane of DDR was reconstructed from the mask run image of 3DRA. Three bony landmarks were used to locate virtual plane of DDR: tuberculum sellae, inferior root of anterior clinoid process (ACP) and supero-medial aspect of optic strut. The MPR image was fused with 3D volume-rendered reconstruction image. Medial and posterior inclination angle of virtual plane of DDR was measured. The location of the paraclinoid ICA aneurysm was categorized into indradural, transdural, and extradural. RESULTS: In all cases, the DDR plane was identified and the relationship between the DDR plane and the paraclinoid ICA aneurysm was successfully determined on fusion image of 3DRA mask and contrast runs by dual volume visualization. The aneurysm locations determined with 3DRA were 8 intradural, 6 transdural and 2 extradural. The medial and posterior inclination angles of DDR plane ranged at 8 to 43degrees(mean 17.4degrees), and -2 to 20degrees(mean 6.4degrees), respectively. CONCLUSION: Localization of the paraclinoid ICA aneurysm in relation to the virtual plane of DDR is feasible with 3DRA and dual volume visualization.

Clinical and Imaging Findings in Spinal Cord Arteriovenous Malformations

PURPOSE: To evaluate the findings of magnetic resonance (MR) imaging and selective spinal angiography of spinal cord arteriovenous malformations (SCAVMs) and to investigate the correlation of these findings with the development of clinical symptoms. MATERIALS AND METHODS: In 16 patients diagnosed as suffering from SCAVMs, MR imaging and selective spinal angiograms were retrospectively analyzed and correlated with clinical symptoms. Clinical data were reviewed, especially concerning the mode of onset of clinical symptoms, and MR images of SCAVMs were evaluated with regard to the following parameters: spinal cord swelling with T2 hyperintensity, cord atrophy, intramedullary hemorrhage, and contrast enhancement of the spinal cord. Selective spinal angiographic findings of SCAVMs were also evaluated in terms of the following parameters: type of SCAVM, presence of aneurysms, and patterns of venous drainage. Imaging findings were also correlated with the development of clinical symptoms. RESULTS: Neurologic deficits, either acute (n=4) or insidious (n=11), were noted in 15 patients. One case without any neurologic deficit was found incidentally. MR showed spinal cord swelling (10/6), atrophy (2/16), intramedullary hemorrhage (0/16), and contrast enhancement of the cord (8/12); spinal angiograms showed the presence of associated aneurysms (6/16) and radicular venous drainage (8/16). SCAVMs. were metameric (n=4), intramedullary (n=9), or fistular (n=3). Nine of 11 patients with insidious onset showed spinal cord swelling and no radicular venous drainage with prominent perimedullary venous dilatation. Aneurysms were present in all four patients with abrupt symptoms. CONCLUSION: Systematic evaluation of the findings of MR imaging and angiography provides detailed information on the type of AVM and status of the spinal cord parenchyma, and this can be correlated with clinical manifestations of SCAVM. In patients suffering from this condition, spinal cord dysfunction due to venous congestion appears to be the main cause of clinical symptoms.

Focal Hepatic Lesions: Dynamic Multi-slice MR Imaging

PURPOSE: To evaluate the dynamic enhancement patterns of focal hepatic lesions using breath-hold dynamic MR imaging for differential diagnosis. MATERIALS AND METHOD: Thirty three patients (24 men and 12 women, mean age of 55 years) with 56 known liver masses on CT scan and US underwent MR imaging with 1.5T. After Tl-weighted fast multiplanar spoiled gradient recalled (FMPSPGR) imaging, breath-hold FMPSPGR images were obtained at 0, 1, 3, 5, and 10 minutes after bolus injection of Gd-DTPA. The cases consisted of 16 hepatocellular carcinomas, 24 hemangiomas, 6 metastases, 3 cholangiocellular carcinomas, and 7 hepatic cysts. The dynamic enhancement patterns were evaluated on the basis of initial enhancement study and, the degree of enhancement was also levaluaied. RESULTS: Of 24 hemangiomas, most cases showed centripetal filling-in pattern of enhancement except 3 cases which showed homogeneous enhancement pattern on the early dynamic phase. All hemangiomas showed very high signal intensity which persisted to the delayed phase. The eccentric enhancement pattern was the most common type in hemangiomas (63%). Hepatocellular carcinomas had heterogeneous enhancement pattern on early and delayed phase (81, 88%) and showed diminished signal intensity on the delayed images. 14 of 16 hepatocellular carcinomas (88%) had peritumoral halo. Variable enhancement pattern was observed in metastases including progressive centripetal filling-in pattern (67%). All metastases showed prominent peritumoral halos and low signal intensity. Cholangiocellular carcinomas showed early centripetal filling-in and heterogeneous enhancement pattern on delayed phase. None of hepatic cysts showed enhancement. CONCLUSIONS: Dynamic breath-hold MR imaging with Gd enhancement allows accurate assessment of hemodynamic status of hepatic lesions and is useful in differential diagnosis of focal hepatic lerions.

Focal Hepatic Lesions: Dynamic Multi-slice MR Imaging

PURPOSE: To evaluate the dynamic enhancement patterns of focal hepatic lesions using breath-hold dynamic MR imaging for differential diagnosis. MATERIALS AND METHOD: Thirty three patients (24 men and 12 women, mean age of 55 years) with 56 known liver masses on CT scan and US underwent MR imaging with 1.5T. After Tl-weighted fast multiplanar spoiled gradient recalled (FMPSPGR) imaging, breath-hold FMPSPGR images were obtained at 0, 1, 3, 5, and 10 minutes after bolus injection of Gd-DTPA. The cases consisted of 16 hepatocellular carcinomas, 24 hemangiomas, 6 metastases, 3 cholangiocellular carcinomas, and 7 hepatic cysts. The dynamic enhancement patterns were evaluated on the basis of initial enhancement study and, the degree of enhancement was also levaluaied. RESULTS: Of 24 hemangiomas, most cases showed centripetal filling-in pattern of enhancement except 3 cases which showed homogeneous enhancement pattern on the early dynamic phase. All hemangiomas showed very high signal intensity which persisted to the delayed phase. The eccentric enhancement pattern was the most common type in hemangiomas (63%). Hepatocellular carcinomas had heterogeneous enhancement pattern on early and delayed phase (81, 88%) and showed diminished signal intensity on the delayed images. 14 of 16 hepatocellular carcinomas (88%) had peritumoral halo. Variable enhancement pattern was observed in metastases including progressive centripetal filling-in pattern (67%). All metastases showed prominent peritumoral halos and low signal intensity. Cholangiocellular carcinomas showed early centripetal filling-in and heterogeneous enhancement pattern on delayed phase. None of hepatic cysts showed enhancement. CONCLUSIONS: Dynamic breath-hold MR imaging with Gd enhancement allows accurate assessment of hemodynamic status of hepatic lesions and is useful in differential diagnosis of focal hepatic lerions.