Role of Maximum Intensity Projection Technique in Delineating Segmental and Subsegmental Branches of Pulmonary Artery Compared to Multiplanar Recont Technique in Evaluating Pulmonary Embolism

Background Computed tomography pulmonary angiography (CTPA) is the gold standard investigation for diagnosing pulmonary embolism (PE). Maximum Intensity Projection (MIP) is an advanced post-processing technique that may enhance the delineation of segmental and subsegmental pulmonary arteries without additional radiation exposure or patient morbidity. Objective To assess the diagnostic efficacy of MIP technique in delineating segmental and subsegmental pulmonary arteries in patients with suspected PE, and to compare outcomes with standard Multiplanar Reconstruction (MPR). Methods Thirty patients referred for CTPA with suspected PE were prospectively included. Images were reconstructed using both MIP and MPR techniques. Quantitative analysis assessed the proportion of analyzable segmental and subsegmental arteries in each lung. Subjective image quality was evaluated using a 4-point Likert scale. Statistical comparisons were performed using the chi-square test and Mann-Whitney U test. Results The mean age of patients is 54.1 ± 19.9 years. In the right lung, 66.7% of branches were analyzable with MIP which is only 53.3% with MPR. In the left lung, 60.0% were analyzable with MIP which is 33.3% with MPR (p = 0.038). Overall combined analyzability was significantly higher with MIP (63.3% vs 43.3%; p = 0.028; RR = 1.46). Subjective image quality assessed by Likert scoring was significantly better with MIP (median 3 [IQR 3–3]) compared to MPR (median 2 [IQR 1–2]; p < 0.001). Conclusion MIP technique is considered to have better diagnostic efficacy in delineating segmental and subsegmental pulmonary arteries compared to standard MPR, with particular advantage in the left lung. Its integration into routine CTPA reporting is recommended.