Low-dose abdominal radiography based on high peak kilovoltage: image quality at standard dose abdominal radiography and potentially 64% dose reduction in a randomized trial.

BACKGROUND

Acute abdomen is a common clinical emergency requiring rapid and accurate diagnosis. Abdominal radiography (AR) remains a first-line imaging tool due to its accessibility and specificity for certain conditions, but minimizing radiation exposure is a persistent concern. This study aimed to evaluate the effectiveness of a low-dose abdominal radiography (LDAR) protocol for patients with acute abdomen.

METHODS

A total of 354 patients (189 men, 165 women; mean age, 50 years) who underwent acute abdominal surgery after being admitted with an acute abdomen were randomly assigned to a LDAR group [121 kVp, with automatic exposure control (AEC)] and a standard-dose abdominal radiography group (SDAR; 81 kVp, with AEC) group. Plain LDAR and SDAR were independently reviewed by two radiologists for the overimpression, diaphragm, and intestinal gas, and program analysis was performed in a delayed manner, with diaphragm sharpness computed by Matlab. The mean values of parameters assessed by the two radiologists were compared.

RESULTS

All images, from both the LDAR group and the SDAR group, were appropriate for direct diagnosis. No patients were exposed to additional doses in this study. The imaging quality of plain LDAR was superior to that of the plain SDAR, with higher mean scores for overimpression (4.97±0.18 vs. 4.68±0.55; P<0.001), diaphragm (4.97±0.18 vs. 4.69±0.55; P<0.001), and lower diaphragm sharpness (1.27±0.35 vs. 1.90±0.48; P<0.001). There was no statistically significant difference between the LDAR and SDAR groups based on the mean scores of intestinal gas (P=0.057). The radiation dose was significantly lowered by approximately 64% for entrance skin dose (ESD; 1.13±0.22 vs. 3.13±1.30, P<0.001) and effective dose (ED; 0.19±0.04 vs. 0.53±0.22, P<0.001) demonstrated in the LDAR group.

CONCLUSIONS

The LDAR with 121 kVp could significantly reduce radiation dose while maintaining comparable image quality to that of SDAR, holding value in specific clinical scenarios.

TRIAL REGISTRATION: Chinese Clinical Trial Registry identifier: ChiCTR-DCD-15006231.