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Esame neurologico obiettivo: test delle sensibilità
| A Comparison of 4D Time-Resolved MRA with Keyhole and 3D Time-of-Flight MRA at 3.0 T for the Evaluation of cerebral Aneurysms |
| Scritto da BMC Neurology |
 ObjectiveTo evaluate the feasibility of 4D time-resolved MRA with keyhole (4D-TRAK) for the diagnostic accuracy and reliability of the detection and characterization of cerebral aneurysms (CAs), with a comparison of 3D time-of-flight MRA (3D-TOF-MRA) by using DSA as a reference.Materials and methods3D-TOF-MRA, 4D-TRAK and 3D-DSA were performed sequentially in 52 patients with suspected CAs. 4D-TRAK was acquired using a combination of sensitivity encoding (SENSE) and CE timing robust angiography (CENTRA) k-space sampling techniques at a contrast dose of 10 ml at 3 T. Accuracy, sensitivity, specificity of 4D-TRAK and 3D-TOF-MRA were calculated and compared for the detection of CAs on patient-based and aneurysm-based evaluation using 3D-DSA as a reference.Results:The overall image quality of 4D-TRAK with a contrast dose of 10 ml was in the diagnostic range but still cannot be compared with that of 3D-TOF-MRA. In 52 patients with suspected CAs, fifty-eight CAs were confirmed on 3D-DSA finally. Fifty-one (with 2 false-positives and 9 false-negatives) and 58 (with 1 false-positive and 1 false-negative) CAs were visualized on 4D-TRAK and 3D-TOF-MRA, respectively. Accuracy, sensitivity and specificity on patient-based evaluation of 4D-TRAK and 3D-TOF-MRA were 92.31 %, 93.33 %, 85.71 % and 98.08 %, 100 %, 85.71 %, respectively, and 74.07 %, 75.00 %, 66.67 % and 96.30 %, 95.83 %, 100 % on aneurysm-based evaluation in patients with multiple CAs, respectively. Subgroup analysis revealed that for 19 very small CAs (maximal diameter <3 mm, measured on 3D-DSA), 9 were missed on 4D-TRAK and 1 on 3D-TOF-MRA (P¿=¿0.008). However, for 39 CAs with maximal diameter ¿ 3 mm, the diagnostic accuracy is equally (39 on 4D-TRAK vs. 39 on 3D-TOF-MRA) (P¿=¿1). In four larger CAs with maximal diameter ¿ 10 mm, 4D-TRAK provided a better characterization of morphology than 3D-TOF-MRA.Conclusion:4D-TRAK at a lower contrast dose of 10 ml with a combination of SENSE and CENTRA at 3 T could provide similar diagnostic accuracy rate for CAs with maximal diameter¿¿¿3 mm, and a better characterization of morphology for larger CAs with maximal diameter¿¿¿10 mm compared to 3D-TOF-MRA. However, further study is still needed to improve the ¿vascular edge¿ artifact and the compromise in spatial resolution in depiction of CAs with maximal diameter¿3 mm.Fonte: BMC Neurology |