State-of-the-art in CT hardware and scan modes for cardiovascular CT

Abstract

Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography Basic and Emerging Sciences and Technology Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging.

Conflict of interest statement

Conflict of interest: Dr. Dey has research grants from the American Heart Association and Siemens Medical Solutions (CT Division). Dr. Einstein was supported in part by National Institute of Health grant 1R01 HL109711, by a Victoria and Esther A boodi Assistant Professorship, and by the Louis V. Gerstner Jr Scholars Program and has received a research grant from GE Healthcare. Dr. R. George has received research grants from General Electric Healthcare and Toshiba Medical Systems and is also a consultant for ICON Medical Imaging. Dr. Halliburton has received research grants from Siemens Healthcare (Angio Division) and Philips Medical Systems (CT Division). Dr. Arbab-Zadeh is a member of the CORE320 steering committee which is sponsored by Toshiba Medical Systems. The other authors report no conflicts of interest. Dr. Halliburton is chair of the Basic and Emerging Sciences and Technology (BEST) Working Group.

Copyright © 2012 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

Schematic of the detector row configurations for current state-of-the-art multidetector row CT scanners from the major CT manufacturers.

Figure 2

Diagram showing retrospective ECG-gated helical CT data acquisition, with continuous gantry rotation and simultaneous patient table translation. Radiation dose from the scan is (A) highest with ECG-based tube current modulation turned off, (B) lower with the full tube current applied for only a portion (e.g., from 40%–80%) of the cardiac cycle, and (C) lowest with full tube current applied during only a single phase of the cardiac cycle.

Figure 3

An example of an arrhythmia rejection algorithm. A schematic of ECG tracings from several cardiac cycles is shown. Based on the breath-hold exercise, the length of the first R-R interval was expected; however, the next R-R interval is much shorter as the result of a premature atrial complex. The system skipped the shorter cardiac cycle and initiated scanning in the next cycle with expected R-R interval.

Figure 4

Diagram showing prospective ECG-triggered axial CT data acquisition. Scan is initiated by the patient’s ECG signal at a phase when cardiac motion is minimal while the patient table is stationary. Data are collected (A) over multiple heartbeats with most scanners, with the patient table advancing every other heartbeat and (B) during a single heartbeat with very wide detector array scanners [for HR ≤ 65 bpm (Table 2)].

Figure 5

Diagram showing prospective ECG-triggered helical data acquisition. Helical data acquisition is initiated by the patient’s ECG signal. Data are collected (A) over multiple heartbeats or (B) during a single heartbeat with dual-source scanners, which can achieve very high pitch (~3) values.