BACKGROUND: We examined the utility of transient hepatic attenuation differences (THADs) detected in the arterial phase of computed tomography for the diagnosis of acute gangrenous cholecystitis (AGC). METHODS: We examined 83 consecutive patients who underwent cholecystectomy within 72 h of undergoing three-phase dynamic computed tomography scans for acute cholecystitis between 2009 and 2018 (histopathological examination later confirmed 42 with AGC, 41 without). The THAD volume (cm3 ) was calculated by multiplying the total area of the enhancing lesions (traced on axial images) by the thickness of the scan (0.5-cm slices). We evaluated the sensitivity and specificity of the THAD volume and other computed tomography findings of AGC. RESULTS: The THAD volume was significantly larger in the AGC group than in the non-gangrenous acute cholecystitis group (P < 0.0001). The cutoff value of 78 cm3 , determined using a receiver operating characteristics curve, yielded a sensitivity of 88.1% and specificity of 75.6% for detecting AGC. Multivariate analysis revealed a THAD volume of >78 cm3 to be an independent predictor of AGC. CONCLUSIONS: Acute gangrenous cholecystitis can be diagnosed using THAD volume, resulting in improved treatment and fewer serious complications.
BACKGROUND: We examined the utility of transient hepatic attenuation differences (THADs) detected in the arterial phase of computed tomography for the diagnosis of acute gangrenous cholecystitis (AGC). METHODS: We examined 83 consecutive patients who underwent cholecystectomy within 72 h of undergoing three-phase dynamic computed tomography scans for acute cholecystitis between 2009 and 2018 (histopathological examination later confirmed 42 with AGC, 41 without). The THAD volume (cm3 ) was calculated by multiplying the total area of the enhancing lesions (traced on axial images) by the thickness of the scan (0.5-cm slices). We evaluated the sensitivity and specificity of the THAD volume and other computed tomography findings of AGC. RESULTS: The THAD volume was significantly larger in the AGC group than in the non-gangrenous acute cholecystitis group (P < 0.0001). The cutoff value of 78 cm3 , determined using a receiver operating characteristics curve, yielded a sensitivity of 88.1% and specificity of 75.6% for detecting AGC. Multivariate analysis revealed a THAD volume of >78 cm3 to be an independent predictor of AGC. CONCLUSIONS:Acute gangrenous cholecystitis can be diagnosed using THAD volume, resulting in improved treatment and fewer serious complications.