Radiation risk and image quality assessment of digital variance angiography
Elek Richárd
Theoretical and Translational Medicine Division
Dr. Kellermayer Miklós
Szülészeti és Nőgyógyászati Klinika, Üllői úti részleg, előadóterem
2026-05-28 09:00:00
Cellular and Molecular Physiology
Dr. Hunyady László
Dr. Osváth Szabolcs
Dr. Liliom Károly
Dr. Czifrus Szabolcs
Dr. Karlinger Kinga
Dr. Voszka István
Dr. Madas Balázs
The thesis investigates the efficacy of Digital Variance Angiography (DVA) and
compares it to the prevalent technology, Digital Subtraction Angiography (DSA). The scope
includes the radiological risk assessment of Peripheral Artery Disease (PAD) and Prostatic
Artery Embolisation (PAE) procedures, complemented with the subjective image quality
assessment of the latter. For the objective image quality evaluation of DVA, this work also
presents the development of a new test object (IQTO).
For the risk assessment of PAD procedures (54 DVA and 53 DSA patients), the
PENELOPE MC particle transport code was adapted. Simulations rely on the image metadata
to estimate organ absorbed dose, effective dose and lifetime attributable cancer risk. A
prospective randomised controlled trial enrolled 70 patients for PAE with normal dose (ND,
35) and ultra-low dose (ULD, 35). Three experienced radiologists evaluated the visualisation
of large vessels, small vessels, tissue blush and background noise of DVA and DSA images on
a 5-point ordinal scale. Statistical analysis of ratings included Mann-Whitney U-tests for
intragroup comparisons, Spearman correlation for consistency, Kendall Tau-b and
Bangdiwala’s B for interrater agreement. The radiological risks from PAE were also estimated.
For the objective image quality assessment, the development of an IQTO with a rotating insert
was required, having the same features as the currently standardised IQTO.
Radiation dose indices and risks were reduced by about 60% for PAD, while it is about
80% for PAE procedures in stationary acquisitions. Subjective visual evaluation from three
raters conclusively found that DVA images are favoured for the visualisation of large vessels,
small vessels and tissue blush with any dose settings. Consensus was lacking for background
noise. The CNR on DVA images made with the new IQTO may be up to 3 times higher than
for the summed DSA images.
DVA significantly improves image quality compared to DSA of the procedures included
in the presented studies, which allows up to 80% reduction of radiation burden to patients and
staff alike, while it also maintains diagnostic image quality.
Future research may focus on the investigation of staff dose reduction, patients at-risk
along the potential reduction of contrast media.
