Nonenhanced MR angiography of the pulmonary arteries using single-shot radial quiescent-interval slice-selective QISS: a technical feasibility studyReportar como inadecuado




Nonenhanced MR angiography of the pulmonary arteries using single-shot radial quiescent-interval slice-selective QISS: a technical feasibility study - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Journal of Cardiovascular Magnetic Resonance

, 19:48

First Online: 30 June 2017Received: 06 March 2017Accepted: 16 June 2017

Abstract

BackgroundFor evaluation of the pulmonary arteries in patients suspected of pulmonary embolism, CT angiography CTA is the first-line imaging test with contrast-enhanced MR angiography CEMRA a potential alternative. Disadvantages of CTA include exposure to ionizing radiation and an iodinated contrast agent, while CEMRA is sensitive to respiratory motion and requires a gadolinium-based contrast agent. The primary goal of our technical feasibility study was to evaluate pulmonary arterial conspicuity using breath-hold and free-breathing implementations of a recently-developed nonenhanced approach, single-shot radial quiescent-interval slice-selective QISS MRA.

MethodsBreath-hold and free-breathing, navigator-gated versions of radial QISS MRA were evaluated at 1.5 Tesla in three healthy subjects and 11 patients without pulmonary embolism or arterial occlusion by CTA. Images were scored by three readers for conspicuity of the pulmonary arteries through the level of the segmental branches. In addition, one patient with pulmonary embolism was imaged.

ResultsScan time for a 54-slice acquisition spanning the pulmonary arteries was less than 2 minutes for breath-hold QISS, and less than 3.4 min using free-breathing QISS. Pulmonary artery branches through the segmental level were conspicuous with either approach. Free-breathing scans showed only mild blurring compared with breath-hold scans. For both readers, less than 1% of pulmonary arterial segments were rated as -not seen- for breath-hold and navigator-gated QISS, respectively. In subjects with atrial fibrillation, single-shot radial QISS consistently depicted the pulmonary artery branches, whereas navigator-gated 3D balanced steady-state free precession showed motion artifacts. In one patient with pulmonary embolism, radial QISS demonstrated central pulmonary emboli comparably to CEMRA and CTA. The thrombi were highly conspicuous on radial QISS images, but appeared subtle and were not prospectively identified on scout images acquired using a single-shot bSSFP acquisition.

ConclusionsIn this technical feasibility study, both breath-hold and free-breathing single-shot radial QISS MRA enabled rapid, consistent demonstration of the pulmonary arteries through the level of the segmental branches, with only minimal artifacts from respiratory motion and cardiac arrhythmias. Based on these promising initial results, further evaluation in patients with suspected pulmonary embolism appears warranted.

KeywordsRadial Quiescent-interval slice-selective Breath-holding Navigator-gated Cardiac AbbreviationsbSSFPBalanced steady-state free precession

CEContrast enhanced

CTAComputed tomography angiography

ECGElectrocardiogram

MRAMagnetic resonance angiography

PEPulmonary embolism

QISSQuiescent-interval slice-selective

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Autor: Robert R. Edelman - Robert I. Silvers - Kiran H. Thakrar - Mark D. Metzl - Jose Nazari - Shivraman Giri - Ioannis Koktz

Fuente: https://link.springer.com/article/10.1186/s12968-017-0365-3







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