Clinical application of Hawkeye VG SPECT/CT imaging in the bleeding position of lower gastrointestinal

Objective: To evaluate the clinical application of Hawkeye VG SPECT/CT imaging on diagnosing and locating lower gastrointestinal bleeding using in vivo labeling ⁹⁹Tc^m-RBC. Methods: Fifty-six patients (42 males, 14 females, age ranging from 10 to 76 years) who had definite lower gastrointestinal bleeding were studied retrospectively. All patients had intravenous injection with 370 MBq ⁹⁹Tc^m-RBC and then underwent planar, SPECT, and CT imaging respectively in the abdomen before exploratory laparotomy. Images from SPECT and CT were fused thereafter to locate the active bleeder, if any. χ² test was performed to show the differences of diagnostic sensitivity and accuracy between planar and SPECT/CT imaging. Results: In 56 patients with lower gastrointestinal bleeding, 50 patients showed abnormally concentrated radionuclide activity with planar images and 52 patients showed the similar imaging pattern with SPECT/CT. Among these patients, concordant bleeding with operation findings was found in 31 patients with planar images and 48 patients with SPECT/CT images. The sensitivity and accuracy were 89.3% (50/56) and 73.8% (31/42) in planar images, and 92.9% (52/56) and 92.3% (48/52) in SPECT/CT images (χ²=0.11, P>0.05; χ²=4.63, P<0.05). Conclusion: Hawkeye VG SPECT/CT imaging shows an effective, simple and accurate method and could be used for diagnosing and locating lower gastrointestinal bleeding. (authors)