CT Scan IV Enhancement

Study Notes

IV enhancement is only required in thoracic CT for specific indications, including lung cancer staging, CT pulmonary angiography (CTPA), CT coronary angiography (CTCA), and aortic evaluation.

Patient factors: body size (measured by body mass index and body surface area), and cardiac output
Contrast medium factors: iodine delivery rate (dependent on iodine concentration, injected volume, and rate of injection)
Timing of acquisition: influenced by automated bolus triggering, test bolus, or set delay to initiate CT data acquisition
Changes in respiration: suboptimal pulmonary artery opacification in CTPA on deep inspiration due to various suggested mechanisms

Recommended protocol: 100 mL of 150 mg mL−1 of iodine injected at a rate of 2.5 mL s−1 after a 25-second delay for general thoracic work
Recommended protocol for CTPA: 120 to 140 mL of 240 to 300 mg mL−1 of iodine injected at a rate of 3 to 4 mL s−1, with either a fixed delay or automated triggering mechanisms

Caused by:
- Reduced acquisition time due to MDCT
- Newer technology, such as DECT
- Need to reduce contrast agent dose to minimize potential nephrotoxicity
- Increasing feasibility of ‘triple-rule-out’ CT for simultaneous evaluation of coronary arteries, pulmonary arteries, aorta, and other intrathoracic abnormalities in patients with acute chest pain

IV enhancement is only required in thoracic CT for specific indications, including lung cancer staging, CT pulmonary angiography (CTPA), CT coronary angiography (CTCA), and aortic evaluation.

Patient factors: body size (measured by body mass index and body surface area), and cardiac output
Contrast medium factors: iodine delivery rate (dependent on iodine concentration, injected volume, and rate of injection)
Timing of acquisition: influenced by automated bolus triggering, test bolus, or set delay to initiate CT data acquisition
Changes in respiration: suboptimal pulmonary artery opacification in CTPA on deep inspiration due to various suggested mechanisms

Recommended protocol: 100 mL of 150 mg mL−1 of iodine injected at a rate of 2.5 mL s−1 after a 25-second delay for general thoracic work
Recommended protocol for CTPA: 120 to 140 mL of 240 to 300 mg mL−1 of iodine injected at a rate of 3 to 4 mL s−1, with either a fixed delay or automated triggering mechanisms

Caused by:
- Reduced acquisition time due to MDCT
- Newer technology, such as DECT
- Need to reduce contrast agent dose to minimize potential nephrotoxicity
- Increasing feasibility of ‘triple-rule-out’ CT for simultaneous evaluation of coronary arteries, pulmonary arteries, aorta, and other intrathoracic abnormalities in patients with acute chest pain