Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients

• Published in: Clinical radiology Vol. 70; no. 1; pp. 54 - 61
• Main Authors: Megyeri, B, Christe, A, Schindera, S.T, Horkay, E, Sikula, J, Cullmann, J.L, Kollar, J, Heverhagen, J.T, Szucs-Farkas, Z
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2015
• Subjects: Adult; Aged; Angiography - methods; Angiography - standards; Body Mass Index; Female; Humans; Male; Middle Aged; Obesity - diagnostic imaging; Overweight - diagnostic imaging; Pulmonary Artery - diagnostic imaging; Pulmonary Embolism - diagnostic imaging; Radiology; Retrospective Studies; Tomography, X-Ray Computed - methods; Tomography, X-Ray Computed - standards
• ISSN: 0009-9260; 1365-229X
• DOI: 10.1016/j.crad.2014.09.014

Aim To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100 kg. Materials and methods The present retrospective study comprised 216 patients (BWs of 75–99 kg, 114 patients; 100–125 kg, 88 patients; >125 kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25 kg/m2 , BMI = 25–29.9 kg/m2 , and BMI ≥30 kg/m2 , i.e., normal weight, overweight, and obese patients) were compared using the Kruskal–Wallis test. Results Vessel attenuation was higher and SDDE was lower in the 75–99 kg group than at higher BWs ( p- values between <0.001 and 0.03), with no difference between the 100–125 and >125 kg groups ( p  = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups ( p  = 0.225 and 1). CNR was lower ( p  < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups ( p =  0.105). Conclusion CTPA at 100 kVp tube voltage can be used in patients weighing up to 125 kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125–150 kg BW range needs further testing in larger collectives.