Value of contrast-enhanced MR angiography and helical CT angiography in chronic thromboembolic pulmonary hypertension

The aim of this study was to evaluate the diagnostic value of contrast-enhanced MR angiography (ce MRA) and helical CT angiography (CTA) of the pulmonary arteries in the preoperative workup of patients with chronic thromboembolic pulmonary hypertension (CTEPH). The ce MRA and CTA studies of 32 patients were included in this retrospective evaluation. Image quality was scored by two independent blinded observers. Data sets were assessed for number of patent segmental, subsegmental arteries, and number of vascular segments with thrombotic wall thickening, intraluminal webs, and abnormal proximal to distal tapering. Image quality for MRA/CTA was scored excellent in 16 of 16, good in 11 of 14, moderate in 2 of 5, and poor in no examinations. The MRA/CTA showed 357 of 366 patent segmental and 627 of 834 patent subsegmental arteries. CTA was superior to MRA in visualization of thrombotic wall thickening (339 vs 164) and of intraluminal webs (257 vs 162). Abnormal proximal to distal tapering was better assessed by MRA than CTA (189 vs 16). In joint assessment of direct and indirect signs, MRA and CTA were equally effective (353 vs 355). MRA and CTA are equally effective in the detection of segmental occlusions of the pulmonary arteries in CTEPH. CTA is superior for the depiction of patent subsegmental arteries, of intraluminal webs, and for the direct demonstration of thrombotic wall thickening.