Publish in OALib Journal
APC: Only $99
Objectives: There is an increasing use of three-dimensional rotational angiography (3D-RA) during catheterization of congenital heart disease. Dose-area-product (DAP) measured by the angiography system and computed-tomography dose index (CTDI) do not appear practical for dose assessment. Hence, we performed real dose measurements in anthropomorphic phantoms. Methods: Three different anthropomorphic phantoms (10 kg, 19 kg and 73 kg bodyweight) equipped with thermoluminescent dosimeters (TLD) were used. We used a typical standard diagnostic program and a low-dose program. The effective dose (ED) was calculated according to the International Commission on Radiological Protection (ICRP) 103. The 3D distribution of radiation in the body was assessed. Results: ED for the male 10 kg phantom was 0.192 mSv in the diagnostic program and 0.050 mSv (male) in the low-dose program. The 19 kg phantom received an ED of 0.205 mSv (male) in the diagnostic program. In the low-dose program the ED reached 0.058 mSv (male). The male adult 73 kg phantom was exposed with an ED of 0.730 mSv in the diagnostic program and 0.282 mSv in the low-dose program. ED for the female phantoms was slightly higher for both acquisition-programs. Dose distribution was inhomogeneous with a dose maximum in the esophageal region behind the heart, whereas in the brain, intestine and gonads we found nearly no radiation. Conclusions: 3D-RA imaging in the interventional catheter laboratory is possible with an effective dose lower than 1 mSv. With its potential to reduce fluoroscopic time and the number of control angiographies in catheterization and intervention in complex anatomy, it can decrease the radiation dose.
Evaluation of radiation efficiency of dual source high-pitch (DSHP) chest CT in
comparison to single source technique with special regards to individual
patient anatomy. Methods: 150 consecutive patients who underwent chest CT with
automated tube current modulation were evaluated retrospectively and divided
into three study groups, each with an equal quantity of 50 patients (DSHP vs.
single source 128 slices vs. single source 16 slices). By using a dedicated
workstation, volumetric analyses of each of the scanned anatomic area were
performed and correlated to the individual dose length product (DLP). The
calculated result was defined as dose efficiency. Results: DLP was 203 mGycm
(DSHP), vs. 269 mGycm (single source) vs. 273 mGycm (16 slice CT). The total
patient volume was lowest in the dual source group with 18956.3 cm3 (vs. 22481.2 cm3 vs. 22133.8 cm3). With regards to the
DLP, the calculated dose efficiency of dual source CT was better than the 128
slice CT (p = 0.045) and the 16 slice CT (p < 0.01). Conclusions: DSHP CT
has considerably better dose efficiency compared to 16 slice CT. Compared to
128 slice single source technique, the high-pitch mode does not cause any dose
penalty when performing chest CT.