Radiation Dose Savings for Adult Pulmonary Embolus 64-MDCT Using Bismuth Breast Shields, Lower Peak Kilovoltage, and Automatic Tube Current Modulation

Abstract

The use of bismuth breast shields together with a lower kVp and automatic tube current modulation will reduce the absorbed radiation dose to the breast and lungs without degradation of image quality to the organs of the thorax for CTA detection of PE.

Iterative reconstruction of pulmonary MDCT angiography: Effects on image quality, effective dose and estimated organ dose to the breast

“…These values achieved are at the very low end of the dose ranges published 5,18,20,21 despite being obtained in routine clinical settings and in an unselected population with a wide range of BMI, spanning from 15.8 to 48.8. Additionaly, the lower radiation dose achieved with iterative image reconstruction was associated with a significantly better objective and subjective image quality than standard filtered back projection, suggesting possible further dose reduction.…”

“…Organ doses to the breast ranged from 3.9 to 20 mGy 15,20,21 . However, in the study of Hurwitz et al 18 , on 120 kV and 140 kV protocols, large anthropomorphic phantom measurements showed average breast doses of 44 mGy at 120 kV and even 62 mGy when scanning at 140 kV (without breast shielding). For comparison, two-view digital mammography and screen-film mammography involve average mean glandular radiation doses of 3.7 and 4.7 mGy, respectively 22 .…”

“…Although some authors advocate their use owing to their significant breast dose reducing effect 9,17,18 , other studies referred to increased noise level, decreased image quality, and the presence of streak and beam hardening artifacts induced by the shields 10,11 . Consequently, the American Association of Physicists in Medicine recently issued a statement on the use of bismuth shielding in CT scanning which makes note of several disadvantages to their use.…”

Familiarity with radiation exposure dose from diagnostic imaging for acute pulmonary embolism and current patterns of practice

“…Low or nonionizing alternatives to V/Q scanning include singlephoton emission computed tomography (SPECT), which is a three-dimensional nuclear medicine scan that shows comparable sensitivity and specificity to those of CTPA; pulmonary magnetic resonance angiography and venography; and the reduction of CTPA radiation dosages through technical (e.g., adjust voltage or current, limit z-axis coverage) or traditional (e.g., shielding) strategies, but further investigation is required. 13,[38][39][40][41] …”

The value of tomographic ventilation/perfusion scintigraphy (V/PSPECT) for follow-up and prediction of recurrence in pulmonary embolism

“…Scintigraphy with tomographic (V/P SPECT) technique has higher sensitivity and specificity than with planar (V/P PLANAR) technique [1][2][3].The strength of V/P SPECT is based on its sensitivity, specificity, and applicability to all patients, regardless of age, kidney function or any other diseases [4]. Moreover, V/P SPECT confers a lower and predictable radiation burden [5] particularly regarding absorbed breast doses [6,7]. Both V/P SPECT and MDCT not only allow diagnosis of PE, but also enable visualisation of other cardiopulmonary diseases [4].…”