Determination of glomerular filtration rate using dynamic CT-angiography: simultaneous acquisition of morphological and functional information.
OBJECTIVE
To determine the feasibility of a dynamic CT angiography-protocol in regard to simultaneous assessment of morphology and function.


METHODS
Fourteen patients with renal graft dysfunction received a dynamic computed tomography angiography (CTA) using a 128-slice CT-scanner with continuous bi-directional table movement, allowing to cover a scan range of 18 cm within 1.75 seconds. Twelve scans of the entire kidney were acquired every 3.5 seconds with the aim to simultaneously obtain CTA and renal function data. The glomerular filtration rate (GFR) was calculated by a modified Patlak method and compared with creatinine-based formulas (MDRD 4 and endogenous creatinine clearance), that served as reference standard.


RESULTS
GFR obtained from dynamic CTA correlates well with the GFR derived by creatinine-based formulas with a correlation coefficient of r = 0.8986; P < 0.0001. The average absolute deviation was 8.1 mL/min. The mean amount of contrast medium required was 35 mL. The average effective dose was 13.8 mSv.


CONCLUSIONS
Dynamic CTA offers the possibility to determine the GFR and thus facilitates simultaneous assessment of morphology and function. Additionally, our dynamic CTA-protocol helps to significantly reduce the amount of contrast medium, which is beneficial for patients with impaired renal function.
Helck
Andreas
A
Department of Clinical Radiology, University Hospitals Grosshadern, Ludwig-Maximilians-University of Munich, Munich, Germany. andreas.helck@med.unimuenchen.de
Sommer
Wieland H
WH
Klotz
Ernst
E
Wessely
Matthias
M
Sourbron
Steven Pieter
SP
Nikolaou
Konstantin
K
Clevert
Dirk A
DA
Notohamiprodjo
Mike
M
Illner
Wolf D
WD
Reiser
Maximilian
M
Becker
Hans-Christoph
HC
D000328:Adult; D000368:Aged; D000465:Algorithms; D000792:Angiography / Q000379:methods*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult