Multidetector CT imaging of pleura: comparison of two contrast infusion protocols

Abstract

Objectives: Imaging of the pleura by multidetector CT (MDCT) can be challenging. There is no clear evidence or guidelines on contrast infusion parameters for imaging pleura. We compared two contrast protocols for assessing pleural pathology on MDCT.Methods: This was a prospective study in which consecutive patients with MDCT for suspected pleural disease on chest radiograph were randomised into two groups. The first group received 150 ml of intravenous contrast at a rate of 2.5 ml s -1 and the second group received 100 ml at 2 ml s -1. Images were acquired after a 60 s delay. Hounsfield units of the pleura, thoracic aorta, main pulmonary artery, portal vein and superior mesenteric artery were measured and analysed by two independent readers. Results: 40 patients (20 in each group) who had pleural enhancement on MDCT were included for final analysis. The mean pleural enhancement value was 83 HU (Group A) vs 59 HU (Group B) (p50.0004). The mean aortic enhancement was 241 HU (A) vs 141 HU (B) (p,0.0001); main pulmonary artery enhancement was 208 HU (A) vs 139 HU (B) (p,0.0002); portal venous enhancement was 169 HU (A) vs 115 HU (B) (p,0.0001); and the superior mesenteric artery enhancement was 215 HU (A) vs 128 HU (B) (p,0.0001). Conclusion: Enhancement of the pleura and major vessels was significantly higher in the group receiving more contrast at a greater infusion rate. This technique of a single scan through the entire pleural surface with a delayed acquisition is promising. When pleural disease is suspected, contrast infusion protocols should be modified to achieve the best results and clinicians should be encouraged to specifically request a ''pleural CT''.

The use of multi-detector computed tomography and ultrasonography for evaluation of pleural lesions

“…In our study, we found that MDCT was sensitive in diagnosing all cases of pleural lesions, and this result was in accordance with Raj et al [14] who stated that MDCT allows detailed evaluation of the pleura and differentiation of benign from malignant pleural disease. Adequate enhancement of the pleura enables differentiation of the thickened pleura from adjacent effusion or aerated or collapsed lung.…”

The diagnostic performance of routinely acquired and reported computed tomography imaging in patients presenting with suspected pleural malignancy

“…However the primary objective of this study was to assess the incidence of pulmonary emboli [7] and the diagnostic performance of CTPA for PM was not reported. In a small randomised study, Raj et al previously demonstrated better enhancement of the pleura utilising delayed phase (at 60–90 s post-contrast) CT acquisition [8], Therefore venous-phase CT should be requested in all patients with suspected PM, and this may have been used more frequently in the Hallifax study. Our study clearly demonstrates that this approach is frequently not taken in a more generalizable population and may be even less frequently used than reported here, since our centres did have a stated interest in pleural disease and were recruiting to DIAPHRAGM.…”

The Role of CT Pulmonary Angiography in the Investigation of Unilateral Pleural Effusions

“…However, this could be further improved by altering some of the imaging parameters, such as kV, without significantly reducing scan quality. Some units have developed scan protocols with prolonged contrast bolus injections that allow intermediate vessel enhancement and good quality pleural imaging [17] in a single scan acquisition, thereby minimizing radiation. However, pulmonary artery opacification is not as high as with formal CTPA, and thus, PE could be potentially overlooked.…”