The diagnostic value of 3D-TOF-MRA in combination with 3D-FIESTA-C in preoperative evaluation of vascular compressive trigeminal neuralgia / 实用放射学杂志

Objective To investigate the diagnostic value of three-dimensional time-of-flight magnetic resonance angiography(3D-TOF-MRA)in combination with three-dimensional fast imaging employing steady-state acquisition with phase cycling (3D-FIESTA-C),using multiplanar reconstruction and image fusion technology in preoperative evaluation of vascular compressive trigeminal neuralgia (TN) and to improve the diagnostic accuracy.Methods 3D-TOF-MRA and 3D-FIESTA-C images using MPR and image fusion technology of 70 patients with TN confirmed by surgery were reviewed retrospectively,and compared with intraoperative findings separately and together.Results Microvascular decompression (MVD)surgery was performed in all 70 patients.Compared with surgical results, 3D-TOF-MRA showed presence of the offending vessel around the cisternal segment of trigeminal nerve in 55 cases with a positive rate of 79%.3D-FIESTA-C showed the presence of the offending vessel in 60 cases with a positive rate of 85%.65 cases were found when combining both 3D-TOF-MRA and 3D-FIESTA-C images,with a positive rate of 93%.No positive imaging findings were seen in 5 cases.Operation showed that offending vessels were small arteries in 3 cases and were petrosal veins in 2 cases.The main offending vessels were superior cerebellar artery and basilar artery.Conclusion Combining images of 3D-TOF-MRA and 3D-FIESTA-C using MPR and image fusion technology can show the relationship between offending vessels and the trigeminal nerve clearly in patients,and provide guidance for MVD surgery.There are still some deficiencies in the display of venules,and other sequences of MRI (such as CE-3D-FIESTA sequences)may be helpful.

Mismatch between TOF MR Angiography and CT Angiography of the Middle Cerebral Artery may be a Critical Sign in Cerebrovascular Dynamics

PURPOSE: Although time-of-flight (TOF)-magnetic resonance angiography (MRA) can clearly depict intracranial arteries, the arterial flow of middle cerebral artery (MCA) is occasionally not detected. We evaluated this phenomenon with reference to cerebrovascular dynamics. MATERIALS AND METHODS: Seventeen patients with suspected occlusion of MCA or internal carotid artery on TOF-MRA were enrolled. All patients underwent CT angiography (CTA) and quantitative cerebral blood flow (CBF) examination for measurement of resting CBF and cerebrovascular reactivity (CVR). Depending on appearance, patients were categorized into three groups. Group A (n=6) had MCA delineation on both MRA and CTA, while groups B (n=6) and C (n=5) had no signal on MRA, but Group B had a MCA delineation on CTA.

The comparative study of showing the responsible blood vessels for neurovascular compression in trigeminal neuralgia by 3D-FIESTA-C and 3D-TOF-MRA / 实用放射学杂志

Objective To compare the diagnostic efficiency in showing the responsible blood vessels for neurovascular compression in patients with trigeminal neuralgia by 3D‐FIESTA‐C and 3D‐TOF‐MRA sequences .Methods The imaging data of 60 patients with primary trigeminal neuralgia were analyzed retrospectively .After MRI examination ,all of the patients underwent micro‐vascular de‐compression (MVD) .3D‐TOF‐MRA and 3D‐FIESTA‐C sequences were performed to evaluate the three‐dimensional relationship be‐tween trigeminal nerve and blood vessels through the original and reconstructed image .The intraoperative endoscopic findings were set as the gold standard comparing to the manifestations of 3D‐TOF‐MRA and 3D‐FIESTA‐C .Results The sensitivities of 3D‐TOF‐MRA and 3D‐FIESTA‐C for the diagnosis of the existence of responsible vessels were 85 .7% ,89 .3% ,the specificities were 75 .0% , 100% ,and the accuracies were 85 .0% ,90 .0% ,respectively (P=1 .000) .Furthermore ,the sensitivities of 3D‐TOF‐MRA and 3D‐FIESTA‐C for the diagnosis of the existence of responsible arteries were 94 .1% ,88 .2% (P=0 .244) ,while the sensitivities of the responsible veins were 0 .00% and 88 .2% (P=0 .009) .Conclusion Both the 3D‐FIESTA‐C and 3D‐TOF‐MRA sequences can accurately deter‐mine the existence of responsible vessels in trigeminal neuralgia before surgery .3D‐FIESTA‐C sequence is superior to 3D‐TOF‐MRA for presenting the responsible veins ,which can be used as a supplemental diagnostic tool before operation .

Rat Model of Hindlimb Ischemia Induced via Embolization with Polyvinyl Alcohol and N-Butyl Cyanoacrylate

OBJECTIVE: To investigate the feasibility of a rat model on hindlimb ischemia induced by embolization from the administration of polyvinyl alcohol (PVA) particles or N-butyl cyanoacrylate (NBCA). MATERIALS AND METHODS: Unilateral hindlimb ischemia was induced by embolization with NBCA (n = 4), PVA (n = 4) or surgical excision (n = 4) in a total of 12 Sprague-Dawley rats. On days 0, 7 and 14, the time-of-flight magnetic resonance angiography (TOF-MRA) and enhanced MRI were obtained as scheduled by using a 3T-MR scanner. The clinical ischemic index, volume change and degree of muscle necrosis observed on the enhanced MRI in the ischemic hindlimb were being compared among three groups using the analysis of variance. Vascular patency on TOF-MRA was evaluated and correlated with angiographic findings when using an inter-rater agreement test. RESULTS: There was a technical success rate of 100% for both the embolization and surgery groups. The clinical ischemic index did not significantly differ. On day 7, the ratios of the muscular infarctions were 0.436, 0.173 and 0 at thigh levels and 0.503, 0.337 and 0 at calf levels for the NBCA, PVA and surgery groups, respectively. In addition, the embolization group presented increased volume and then decreased volume on days 7 and 14, respectively. The surgery group presented a gradual volume decrease. Good correlation was shown between the TOF-MRA and angiographic findings (kappa value of 0.795). CONCLUSION: The examined hindlimb ischemia model using embolization with NBCA and PVA particles in rats is a feasible model for further research, and muscle necrosis was evident as compared with the surgical model.