Korean J Radiol.  2018 Apr;19(2):265-271. 10.3348/kjr.2018.19.2.265.

Effect of Patient Characteristics on Vessel Enhancement at Lower Extremity CT Angiography

• Masuda T
• Nakaura T
• Funama Y
• Sato T
• Higaki T
• Kiguchi M
• Yamashita
• Imada N
• Awai K

• KMID: 2404923
• DOI: http://doi.org/10.3348/kjr.2018.19.2.265

Abstract

OBJECTIVE
To evaluate the effect of patient characteristics on popliteal aortic contrast enhancement at lower extremity CT angiography (LE-CTA) scanning.
MATERIALS AND METHODS
Prior informed consent to participate was obtained from all 158 patients. All were examined using a routine protocol; the scanning parameters were tube voltage 100 kVp, tube current 100 mA to 770 mA (noise index 12), 0.5-second rotation, 1.25-mm detector row width, 0.516 beam pitch, and 41.2-mm table movement, and the contrast material was 85.0 mL. Cardiac output (CO) was measured with a portable electrical velocimeter within 5 minutes of starting the CT scan. To evaluate the effects of age, sex, body size, CO, and scan delay on the CT number of popliteal artery, the researchers used multivariate regression analysis.
RESULTS
A significant positive correlation was seen between the CT number of the popliteal artery and the patient age (r = 0.39, p < 0.01). A significant inverse correlation was observed between the CT number of the popliteal artery and the height (r = −0.48), total body weight (r = −0.52), body mass index (r = −0.33), body surface area (BSA) (r = −0.56), lean body weight (r = −0.56), and CO (r = −0.35) (p < 0.001 for all). There was no significant correlation between the enhancement and the scan delay (r = 0.06, p = 0.47). The BSA, CO, and age had significant effects on the CT number (standardized regression: BSA −0.42, CO −0.22, age 0.15; p < 0.05, respectively).
CONCLUSION
The BSA, CO, and age are significantly correlated with the CT number of the popliteal artery on LE-CTA.

Keyword

MDCT; CECT; Contrast medium; Cardiac output; Lower extremity CT angiography

MeSH Terms

Angiography*
Body Mass Index
Body Size
Body Surface Area
Body Weight
Cardiac Output
Humans
Informed Consent
Lower Extremity*
Popliteal Artery
Tomography, X-Ray Computed

Figure

• 

  Fig. 1 CT attenuation measurement in popliteal artery.A. Volume-rendering image of at LE-CTA in 77-year-old man. B. Maximum-intensity projection at LE-CTA. C. Measurement sites of volume rendering image for popliteal arteries at level of patella. D. Measurement sites of axial image for popliteal arteries at level of patella. CT = computed tomography, LE-CTA = lower extremity CT angiography

• 

  Fig. 2 Relationship between popliteal arterial enhancement and patient characteristics.Scattergrams of relationship between arterial enhancement obtained with protocol, using fixed dose of iodinated contrast material and patient age (A), HT (B), TBW (C), BMI (D), BSA (E), LBW (F), CO (G), and scan delay (H). There was significant positive correlation between CT number of popliteal artery and age (r = 0.39, p < 0.01). Correlation was inverse with HT (r = −0.48), TBW (r = −0.52), BMI (r = −0.33), BSA (r = −0.56), LBW (r = −0.53), and CO (r = −0.35) by linear regression analysis (p < 0.01 for all). There was no significant correlation between vessel enhancement and scan delay (r = 0.06, p = 0.47). BMI = body mass index, BSA = body surface area, CO = cardiac output, HT = height, HU = Hounsfield units, LBW = lean body weight, TBW = total body weight

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