Fully Automated Scan Technique Optimisation of Scan Timing in Chest CT

Summary

Computed Tomography Angiography (CTA) is a non-invasive imaging tool widely used for various indications. Contrast media (CM) is used to enhance the intravascular lumen and organ parenchyma, depending on the indication. Recent technical advances in CT scan techniques allow for a very fast scan acquisition with substantially increased image quality in terms of temporal and spatial resolution. However, with faster scan acquisition, challenges arise with regard to CM bolus timing. The risk of outrunning the CM bolus in these fast acquisitions is higher, resulting in a decreased intravascular attenuation and subsequent hypothetical increase in non-diagnostic image quality.

Previous studies have investigated the reduction of CM volume. When reducing the CM volume, the total injection time decreases and the window of peak enhancement shortens and becomes more narrow. The latter increases when injecting small CM volumes with higher flow rates. Although the peak enhancement increases, the window of peak enhancement decreases more rapidly. Thus, when administered with the same flow rate, the peak of the enhancement curve will be lower, narrower and faster compared to larger CM volumes. This, in combination with the faster scan acquisition makes the timing of the start of the scan highly important, since scanning at the peak enhancement is necessary to achieve a diagnostic image quality.

New bolus tracking auto-delay software (Fully Automated Scan Technique, FAST, Siemens Healthineers) automatically estimates the delay needed to scan at the peak of the enhancement curve. With help of this software, the optimal individual scan delay and enhancement can be achieved, and the risk of non-diagnostic scans should decrease. Therefore, this study aims to evaluate the performance of the Bolus Tracking Auto-Delay (FAST) software in patients receiving a standard chest CT with regard to the number of non-diagnostic scans (\< 300 HU) and compare this with standard care (manual set pre-scan delay).

Conditions

• Pulmonary Disease

Interventions

OTHER

FAST start software delay

Scan delay will be determined by the FAST software bolus tracking technique. Before the start of bolus tracking (the time between start injection and start bolus tracking), a delay of 8 s is chosen. Bolus tracking threshold is set at 100 HU with a cycle time of 1.13 s and scan time of 0.25 s. After reaching the 100 HU threshold the FAST START software calculates the delay.

OTHER

Manual bolus tracking delay

Scan delay will be determined by the standard bolus tracking technique. Before the start of bolus tracking (the time between start injection and start bolus tracking), a delay of 8 s is chosen. Bolus tracking threshold is set at 100 HU with a cycle time of 1.13 s and scan time of 0.25 s. After reaching the 100 HU threshold a delay of 6 s is chosen (table movement and breath hold command) and the scan starts.

Sponsors & Collaborators

• Maastricht University Medical Center

  lead OTHER

Principal Investigators

• Joachim E Wildberger, Prof. · Maastricht University Medical Center

Study Design

Allocation

RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2018-04-05

Primary Completion

2018-12-31

Completion

2018-12-31

Countries

• Netherlands

Study Locations