Related Experiment Video
Updated: May 16, 2026
Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
Pulmonary 64-MDCT angiography with 30 mL of IV contrast material: vascular enhancement and image quality
Carol C Wu1, Edward W Lee, Robert D Suh
1Department of Radiology, Division of Thoracic Imaging and Interventions, Massachusetts General Hospital, Boston, MA, USA.
Objective:
The objective of our study was to determine whether vascular enhancement and image quality can be preserved in pulmonary CT angiography (CTA) performed on a 64-MDCT scanner with 30 mL of IV contrast material.
Materials And Methods:
This retrospective matched-cohort study compared image quality of pulmonary CTA performed using 30 mL of IV contrast material versus 100 mL of IV contrast material. CT images of 50 patients (46 men, four women; mean age, 66 years) who underwent pulmonary CTA on a 64-MDCT scanner using a low dose (30 mL) of iodixanol 320 and another 50 patients (49 men, one woman; mean age, 65 years) who underwent pulmonary CTA using a regular dose (100 mL) of contrast material during the same time period were selected for review. The 30- and 100-mL pulmonary CTA studies were retrospectively evaluated by two thoracic radiologists in random order. Attenuation values were recorded over the main, right main, selected lobar, segmental, and subsegmental pulmonary arteries. Image quality was also subjectively assessed using visual scores on a scale from 1 (nondiagnostic) to 5 (excellent).
Results:
The average attenuation measurements of the main, right main, selected lobar, segmental, and subsegmental pulmonary arteries were 260, 262, 280, 316, and 338 HU, respectively, on the 30-mL studies and 313, 301, 316, 344, and 349 HU, respectively, on the 100-mL studies. The average visual score was 4.0 for both the 30- and 100-mL groups. A visual score of 4 or 5 was given to 82% of studies in the 30-mL group and 78% of studies in the 100-mL group.
Conclusion:
Contrast agent dose for pulmonary CTA using a 64-MDCT scanner can be significantly reduced without compromising diagnostic image quality.
Insights
Reducing intravenous contrast material for pulmonary CT angiography (CTA) on a 64-MDCT scanner to 30 mL is safe and effective. This lower dose preserves diagnostic image quality and vascular enhancement, offering a potential benefit for patients undergoing CTA scans.
Area of Science:
- Radiology
- Medical Imaging
- Cardiovascular Imaging
Background:
- Pulmonary CT angiography (CTA) is crucial for diagnosing pulmonary embolism.
- Optimizing contrast material dose is important for patient safety and cost-effectiveness.
Purpose of the Study:
- To evaluate if reduced intravenous contrast material (30 mL) maintains vascular enhancement and image quality in pulmonary CTA.
- To compare diagnostic image quality between low-dose (30 mL) and standard-dose (100 mL) contrast material in pulmonary CTA.
Main Methods:
- Retrospective matched-cohort study comparing 50 patients receiving 30 mL of contrast with 50 patients receiving 100 mL.
- Image quality assessed by two thoracic radiologists using attenuation measurements and a 5-point visual scale.
- Evaluated main, lobar, segmental, and subsegmental pulmonary arteries.
Main Results:
- Average attenuation values were comparable between the 30 mL and 100 mL groups across different pulmonary artery segments.
- Mean visual image quality scores were 4.0 for both low-dose and standard-dose groups.
- 82% of low-dose studies and 78% of standard-dose studies received a diagnostic score (4 or 5).
Conclusions:
- A significant reduction in contrast agent dose for pulmonary CTA is feasible with a 64-MDCT scanner.
- Diagnostic image quality is preserved even with a 30 mL dose of contrast material.
- Reduced contrast volumes can be used without compromising diagnostic accuracy in pulmonary CTA.
Related Concept Videos
01:13Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...
01:28Imaging Studies for Cardiovascular System V: CT
01:29Pulmonary Embolism II: Diagnostic Studies and Interprofessional Care
01:27Imaging Studies III: Computed Tomography
01:30Radiological Investigation II: MRI and Ventilation Perfusion Scan
Magnetic Resonance Imaging (MRI) and Ventilation Perfusion Scans are two radiological investigations that offer detailed diagnostic images of the body, particularly lung structures.
MRI
MRI uses magnetic fields and radiofrequency signals to distinguish between normal and abnormal tissues. This technology provides a more detailed diagnostic image than CT scans, enabling it to characterize pulmonary nodules, stage bronchogenic carcinoma, and evaluate inflammatory activity in...
01:19Imaging Studies VII: Vascular Imaging