Multislice CT angiography

doi:10.1016/S0720-048X(00)00271-0

European Journal of Radiology

Volume 36, Issue 2, November 2000, Pages 86-96

https://doi.org/10.1016/S0720-048X(00)00271-0 Get rights and content

Abstract

Multislice CT has overcome past limitations of CT angiography (CTA): Scan length and spatial resolution can be simultaneously optimized with multislice CTA, contrast medium can be saved, and the evaluation of large anatomic areas and vessels smaller than 1 mm become possible. This article describes how to optimize scanning protocols and contrast injection, and discusses the main clinical applications of this new technique. Only three main scanning protocolssuffice for all indications. A high speed / high-volume protocol (using 4*2mm or 4*2.5mm collimation) can be employed to scan the chest or abdomen in 8-10s, or to cover the whole abdominal aorta and the peripheral runoff including the feet within 40-65s. A high resolution protocol (using 4*1mm or 4*1.25mm) can be employed for the aorta and most regional vascular beds. It allows for near isotrophic imaging and depicts fine vascular structures with excellent detail. Ultra-high resolution protocols (using 2*0.5mm or 4*0.5mm collimation) yield totally isotropic data sets, and are mainly reserved for cerebrovascular imaging. Image processing techniques, and, in particular, volume rendering have made image presentation faster and easier. Multislice CTA exceeds MRA in spatial resolution and is now able to display even small vascular side branches. Its main indications will be aortic diseases, suspected pulmonary embolism but also renal artery stenoses, preoperative workup of abdominal or cerebral vessels, and acute vascular diseases. Multisplice CTA will become a strong competitor of other minimally invasive vascular imaging techniques.

Introduction

CT angiography (CTA) is an established minimally invasive tool for imaging of most major vessels in the body. It can almost completely substitute for arterial angiography in the diagnostic evaluation of the most common vascular diseases but has not experienced wide spread use when vessels other than the aorta and pulmonary arteries were involved. The reason for this were the limitations of spatial resolution when longer scan ranges had to be covered and the cumbersome data editing and processing tools available in the past.

With the advent of multislice CT in 1998 and with increasingly simple and fast postprocessing workstations, CTA has experienced a considerable boost and is now available for routine use in most diagnostic settings. At present, most major vendors offer multislice CT with subsecond rotation (0.5–0.8 s) and four active detector rows. These new scanners are now up to 8 times faster than 1 s spiral CT scanners and allow for almost isotropic imaging (1 mm sections) and extremely long scan ranges of up to 150 cm [1], [2], [3]. With multislice CTA spatial resolution no longer poses a problem, and even studies of the coronary arteries become possible. At present, multislice CTA can be considered the imaging technique of choice for a vast number of vascular indications.

Section snippets

Scanning technique

In spiral CT, and thus, CTA, there is always a trade-off between scan length and spatial resolution along the z-axis (patient long axis). With a 1 s scanner, only 30 rotations can be covered with a single detector row within a 30 s breath hold phase. This strongly limits the available scan range if thin sections are employed or requires use of thicker sections in order to be able to cover larger scan volumes.

With multislice CT scanners, at present four simultaneous sections are acquired and the

Current indications of multislice CTA

CTA can presently substitute for most diagnostic DSA studies, and multislice CTA can be expected to further expand its spectrum of indications: now a total carotid workup form the arch to the intracerebral circulation is possible as well as peripheral run-off studies including the abdominal aorta and the leg vessels down to the foot. CTA has found a fixed role in planning an intervention, especially when stent grafts are involved. So far, there are only very few publications available the

Summary

Arterial DSA is being substituted for by less invasive technique such as CTA, MRA and color coded duplex ultrasound. At present multislice CTA provides the best spatial resolution for almost all vascular territories and may be used even in patients with stents or heavy calcifications that can be hard to evaluate with MRA or ultrasound. Multislice CTA has expanded and dramatically improved most applications of CTA and in many cases will become the new gold standard for vascular imaging.

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View full text

Multislice CT angiography

Abstract

Introduction

Section snippets

Scanning technique

Current indications of multislice CTA

Summary

Aorta and iliac arteries: single versus multiple detector-row helical CT angiography

Radiology

Multi-slice helical CT: scan and reconstruction

Med. Phys.

Subsecond multi-slice computed tomography: basics and applications

Eur. J. Radiol.

The effect of pitch in multislice spiral/helical CT

Med. Phys.

Aortic and hepatic contrast medium enhancement at CT: Part II. Effect of reduced cardiac output in a porcine model

Radiology

Aortic and hepatic contrast medium enhancement at CT. Part I: Prediction with a computer model

Radiology

Current status of three-dimensional spiral CT scanning for imaging the vasculature

Radiol. Clin. North Am.

Mathematical analysis of arterial enhancement and optimization of bolus geometry for CT angiography using the discrete fourier transform

JCAT

Improved uniformity of aortic enhancement with customized contrast medium injection protocols at CT angiography

Radiology

Tailored timing as a critical factor in CT angiography

AJR

Determination of scan delay time in spiral CT-angiography: utility of a test bolus injection

J. Comput. Assist. Tomogr.

Neues Verfahren zur Bestimmung der individuellen Verzögerungszeit fur die Bolusapplikation im Spiral-CT

Röfo

Spiral CT angiography of the abdomen

Abdominal Imaging