The Influence of Long-Term Medications and Patient Conditions on CT Image Quality

Background/Objectives: This study investigated the influence of long-term medications and patient conditions on pulmonary arterial enhancement and image quality in computed tomography pulmonary angiography (CTPA). A cohort matched for age was divided into two main groups: a medication group (Captopril, Albuterol, and control) and a condition group (obesity, COPD, and control). Methods: Temporal enhancement (Hounsfield Units, HU), area under the curve (AUC), and washout rates were analyzed alongside image quality metrics (signal-to-noise ratio, SNR; contrast-to-noise ratio, CNR). Results: The results demonstrated significant intergroup differences. In the medication group, Albuterol was associated with significantly higher peak enhancement (368.9 ± 16.3 HU) compared to control (327.1 ± 13.8 HU; p = 0.001), while Captopril showed significantly lower baseline HU (153.5 ± 7.3 vs. 185.3 ± 9.3; p < 0.001) and reduced total AUC. In the condition group, both obesity and COPD exhibited significantly lower peak HU values, slower washout rates, and reduced total AUC compared to controls (p < 0.0001). Consequently, SNR and CNR were significantly lower in the obesity and COPD groups (p = 0.001). Linear mixed-effects models confirmed significant group × time interactions for both medication and condition groups after adjustment for confounders. Furthermore, pulmonary arterial enhancement (HU) showed a very strong positive correlation with both SNR (R² = 0.9956) and CNR (R² = 0.9848, p < 0.001). Conclusions: The findings indicate that patient-specific factors significantly impact CTPA image quality. Albuterol was associated with peak vascular opacification, whereas conditions like obesity and COPD were consistently associated with reduced enhancement and inferior image quality. The strong correlation between HU and objective image quality metrics underscores vascular enhancement as a key determinant of diagnostic CTPA quality.