Department of Diagnostic and Interventional Radiology, Heart Center Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany.
Department of General and Geriatric Medicine, St. Elisabeth-Hospital Leipzig, Biedermannstr. 84, 04277, Leipzig, Germany.
Eur Radiol. 2024 Mar;34(3):1921-1931. doi: 10.1007/s00330-023-10101-8. Epub 2023 Sep 1.
To investigate the feasibility and image quality of high-pitch CT pulmonary angiography (CTPA) with reduced iodine volume in normal weight patients.
In total, 81 normal weight patients undergoing CTPA for suspected pulmonary arterial embolism were retrospectively included: 41 in high-pitch mode with 20 mL of contrast medium (CM); and 40 with normal pitch and 50 mL of CM. Subjective image quality was assessed and rated on a 3-point scale. For objective image quality, attenuation and noise values were measured in all pulmonary arteries from the trunk to segmental level. Contrast-to-noise ratio (CNR) was calculated. Radiation dose estimations were recorded.
There were no statistically significant differences in patient and scan demographics between high-pitch and standard CTPA. Subjective image quality was rated good to excellent in over 90% of all exams with no significant group differences (p = 0.32). Median contrast opacification was lower in high-pitch CTPA (283.18 [216.06-368.67] HU, 386.81 [320.57-526.12] HU; p = 0.0001). CNR reached a minimum of eight in all segmented arteries, but was lower in high-pitch CTPA (8.79 [5.82-12.42], 11.01 [9.19-17.90]; p = 0.005). Median effective dose of high-pitch CTPA was lower (1.04 [0.72-1.27] mSv/mGy·cm; 1.49 [1.07-2.05] mSv/mGy·cm; p < 0.0001).
High-pitch CTPA using ultra-low contrast volume (20 mL) rendered diagnostic images for the detection of pulmonary arterial embolism in most instances. Compared to standard CTPA, the high-pitch CTPA exams with drastically reduced contrast medium volume had also concomitantly reduced radiation exposure. However, objective image quality of high-pitch CTPA was worse, though likely still within acceptable limits for confident diagnosis.
This study provides valuable insights on the performance of a high-pitch dual-source CTPA protocol, offering potential benefits in reducing contrast medium and radiation dose while maintaining sufficient image quality for accurate diagnosis in patients suspected of pulmonary embolism.
• High-pitch CT pulmonary angiography (CTPA) with ultra-low volume of contrast medium and reduced radiation dose renders diagnostic examinations with comparable subjective image quality to standard CTPA in most patients. • Objective image quality of high-pitch CTPA is reduced compared to standard CTPA, but contrast opacification and contrast-to-noise ratio remain above diagnostic thresholds. • Challenges of high-pitch CTPA may potentially be encountered in patients with severe heart failure or when performing a Valsalva maneuver during the examination.
探讨在正常体重患者中使用低碘量进行高螺距 CT 肺动脉造影（CTPA）的可行性和图像质量。
回顾性纳入 81 例因疑似肺动脉栓塞而行 CTPA 的正常体重患者：41 例行高螺距模式，使用 20 ml 造影剂（CM）；40 例行标准螺距，使用 50 ml CM。采用 3 分制评估主观图像质量并进行评分。对于客观图像质量，在从主干到节段水平的所有肺动脉中测量衰减和噪声值。计算对比噪声比（CNR）。记录辐射剂量估计值。
高螺距和标准 CTPA 组的患者和扫描特征无统计学差异。所有检查中，主观图像质量评分均在 90%以上，且无显著组间差异（p=0.32）。高螺距 CTPA 的造影剂充盈中位数较低（283.18[216.06-368.67]HU，386.81[320.57-526.12]HU；p=0.0001）。所有分段动脉的 CNR 均达到 8 以上，但高螺距 CTPA 较低（8.79[5.82-12.42]，11.01[9.19-17.90]；p=0.005）。高螺距 CTPA 的有效剂量中位数较低（1.04[0.72-1.27]mSv/mGy·cm；1.49[1.07-2.05]mSv/mGy·cm；p<0.0001）。
高螺距 CTPA 使用超低对比量（20 ml）在大多数情况下可用于诊断肺动脉栓塞。与标准 CTPA 相比，大幅减少对比剂用量的高螺距 CTPA 检查同时降低了辐射暴露。然而，高螺距 CTPA 的客观图像质量较差，但仍可能在有信心进行诊断的可接受范围内。
本研究提供了高螺距双源 CTPA 方案性能的有价值见解，为疑似肺栓塞患者提供了减少造影剂和辐射剂量的潜在益处，同时保持足够的图像质量以进行准确诊断。
高螺距 CT 肺动脉造影（CTPA）采用超低对比剂剂量和降低的辐射剂量，在大多数患者中可获得具有可比主观图像质量的诊断检查。
与标准 CTPA 相比，高螺距 CTPA 的客观图像质量降低，但对比增强和对比噪声比仍保持在诊断阈值以上。
高螺距 CTPA 可能在严重心力衰竭患者或检查中进行瓦尔萨尔瓦动作时存在挑战。
