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Time-resolved MR angiography of the legs at 3 T using a low dose of gadolinium: initial experience and contrast dynamics.

ABSTRACT: This article describes our initial clinical experience with time-resolved MR angiography (MRA) of the legs using the time-resolved imaging with stochastic trajectories (TWIST) technique with a half dose of gadolinium.Thirty-four patients underwent a TWIST examination of the legs at 3 T. Thirty-three patients also underwent a bolus-chase MRA examination in the same setting. Times elapsed between the start of contrast injection and the appearance of contrast material (t(A)) and peak enhancement of the arteries in the legs (t(B)) were analyzed. The number of patients with examinations affected by venous contamination was determined. The differences in t(A) and t(B) between cases in which venous contamination was present or absent were evaluated using a two-tailed Student t test.The TWIST technique using a half dose of gadolinium provided diagnostic-quality images of all patients. The mean t(A) was 35.5 ± 8.8 (SD) seconds (range, 17.8-60.4 seconds), and the mean t(B) was 59.1 ± 15.1 seconds (range, 31-98.8 seconds). Venous contamination was observed in bolus-chase MRA images of 52.9% of patients. The relationship between venous contamination and t(A) was not statistically significant (p = 0.13). The incidence of venous contamination was higher in patients with lower values of t(B) (p = 0.01).The described low-dose clinical experience with TWIST and the contrast dynamics information gained from this study could aid radiologists in planning protocols for leg MRA examinations.

SUBMITTER: Sandhu GS

PROVIDER: S-EPMC3963831 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature

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Time-resolved MR angiography of the legs at 3 T using a low dose of gadolinium: initial experience and contrast dynamics.

Sandhu Gurpreet Singh GS Rezaee Rod P RP Jesberger John J Wright Katherine K Griswold Mark A MA Gulani Vikas V

AJR. American journal of roentgenology 20120301 3

<h4>Objective</h4>This article describes our initial clinical experience with time-resolved MR angiography (MRA) of the legs using the time-resolved imaging with stochastic trajectories (TWIST) technique with a half dose of gadolinium.<h4>Materials and methods</h4>Thirty-four patients underwent a TWIST examination of the legs at 3 T. Thirty-three patients also underwent a bolus-chase MRA examination in the same setting. Times elapsed between the start of contrast injection and the appearance of ...[more]

PMID: 22358010

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Project description:Background and purposeThe diagnosis of spinal vascular malformations may be challenging on conventional MR imaging because neither the location of the signal abnormality in the spinal cord nor the level of the abnormal flow voids correlates with the level of the fistula. We conducted a retrospective evaluation of the utility of using a time-resolved imaging of contrast kinetics sequence in the diagnosis, characterization, and localization of spinal vascular malformations, comparing it with the criterion standard of spinal DSA.Materials and methodsFifty-five consecutive patients with a suspected diagnosis of spinal vascular malformation underwent time-resolved imaging of contrast kinetics followed by spinal DSA. All scans were performed on a 1.5T scanner by using a standard 8-channel spine coil and were reported by a neuroradiologist before the DSA was performed.ResultsForty-seven lesions were confirmed on time-resolved imaging of contrast kinetics and classified as spinal dural arteriovenous fistulas (n = 33, with 1 patient having a type Ib fistula), perimedullary spinal cord arteriovenous fistulas (n = 10), and intramedullary arteriovenous malformations (n = 3). One patient had an extradural spinal vascular malformation. Time-resolved imaging of contrast kinetics identified the location of the arterial feeder to within 1 vertebral level in 27/33 patients (81.8%) with spinal dural arteriovenous fistulas and correctly predicted the side in 22/33 (66.6%) patients. Perimedullary spinal cord arteriovenous fistulas were erroneously considered to represent spinal dural arteriovenous fistulas before spinal DSA. The anatomy of the arterial supply to intramedullary arteriovenous malformations was also poorly characterized on time-resolved contrast-enhanced MR angiography.ConclusionsIt has been our experience that time-resolved imaging of contrast kinetics is a useful confirmatory tool when a spinal vascular malformation is suspected on the basis of clinical and conventional MR imaging findings. As experience with the technique grows and sequences are refined, it may be possible to rely on time-resolved imaging of contrast kinetics as a screening tool for the diagnosis of spinal vascular malformations.

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Dataset Information

Time-resolved MR angiography of the legs at 3 T using a low dose of gadolinium: initial experience and contrast dynamics.

Publications

Time-resolved MR angiography of the legs at 3 T using a low dose of gadolinium: initial experience and contrast dynamics.

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