Body Imaging – Bowel
CEUS is a safe, versatile and reliable tool for imaging the bowel in the following clinical contexts:
- To detect, evaluate and objectively quantify the presence of bowel inflammation and its complications in patients with IBD
- To differentiate the nature of inflammatory masses found in patients with IBD
- To differentiate strictures in IBD
- To monitor response to IBD therapy
CEUS uses ultrasound contrast agents (UCAs) to improve the clarity and reliability of conventional ultrasound scans. UCAs are comprised of liquid suspensions of biodegradable gas-filled microspheres (sometimes called “microbubbles”). When they are injected into a patient’s arm vein during an ultrasound exam, they flow through the body’s microcirculation without impediment, and are metabolized and expelled from the body within minutes.
Imaging is performed with patient is a supine position. The transducer is placed at the region of interest (ROI) selected on the initial grayscale assessment. The abnormal bowel segment is evaluated in a sagittal orientation to minimize out-of-plane effects of respiratory motion and to facilitate generation of quality TIC allowing for quantification analysis. After contrast is injected through the patient’s IV, a continuous acquisition is initiated, even before the arrival of the first bubble in the field of view, and lasting for 2 min with no motion of the transducer. Most ultrasound equipment will allow for initial evaluation of the quantification curves at the bedside to assess technical quality of the time–intensity curve and to obtain preliminary results. If CEUS fails, or is technically inadequate, a second contrast injection may be performed, after a several minute delay.
CONTRAST AGENT DOSING
Dependence on transducer and instrumentation, body habitus. In general, twice the dose used for liver imaging is perfect for evaluation of the bowel. For the majority of adult patients, a dose of 3.0-4.8 ml Lumason; Definity 0.4-0.8ml; Optison inadequate literature.
- Barr, Richard G., et al., Society of Radiologists in Ultrasound (SRU): Contrast-enhanced Ultrasound—State of the Art in North America Ultrasound Quarterly: September 2020 – Volume 36 – Issue 4S – p S1-S39 doi: 10.1097/RUQ.0000000000000515
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- Sidhu PS., et.al. The EFSUMB Guidelines and Recommendations for the Clinical Practice of Contrast-Enhanced Ultrasound (CEUS) in Non-Hepatic Applications: Update 2017. Ultraschall in Med 2018; 39: e2–e44.
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