Computed tomographic evaluation of pancreatic perfusion in healthy dogs

Computed tomographic measurements of pancreatic thickness in clinically normal dogs

Pancreatic thickness is an indicator for evaluating pancreatic diseases. The transverse and cross-sectional pancreatic thickness observed on computed tomography (CT) may differ. This study aimed to provide a normal reference range for pancreatic thickness on the transverse plane based on body weight (BW) and assess pancreatic thickness to aorta (P/Ao) ratio. In addition, we aimed to establish the normal short and long dimensions of the pancreas based on cross-sectional image through the long axis of the pancreas using multiplanar reconstruction (MPR). The short dimension to aorta (S/Ao) and long dimension to aorta (L/Ao) ratios were also established in clinically normal dogs. The pancreatic thickness was measured using CT results of 205 clinically normal dogs. The pancreatic thickness on the transverse plane and the short and long dimensions in the cross-sectional image of the pancreas were measured using MPR. The diameter of the Ao was measured on the transverse plane and the P/Ao, S/Ao, and L/Ao ratios were calculated. Our study showed that the mean normal pancreatic thicknesses (mean ± standard deviation [SD]) of the pancreatic body, left and right lobe in the transverse plane were 10.92 ± 2.54 mm, 8.92 ± 2.26 mm and 9.96 ± 2.24 mm, respectively. The P/Ao ratios of the pancreatic body, left and right lobes were 1.85 ± 0.33, 1.50 ± 0.27 and 1.68 ± 0.29, respectively. The mean short dimension (mean ± SD) in the cross-sectional image of the pancreatic body, left and right lobe were 8.98 ± 1.97 mm, 7.99 ± 1.89 mm and 8.76 ± 2.03 mm, respectively. In conclusion, pancreatic thickness increased with BW, while the P/Ao, S/Ao, and L/Ao ratios could be used regardless of BW.

Computed tomographic evaluation of pancreatic perfusion in 10 dogs with acute pancreatitis

Severe canine acute pancreatitis can be fatal; imaging features that can predict the clinical course of disease are useful for clinicians. On computed tomography (CT), both pancreatic heterogeneous contrast enhancement and portal vein thrombosis have been correlated with poorer outcome. Perfusion CT is used in human medicine to evaluate pancreatic microcirculation to predict the future development of severe sequela to pancreatitis; this technology has yet to be explored in dogs with acute pancreatitis. The objective of this prospective, case-control study is to evaluate pancreatic perfusion using contrast-enhanced CT in dogs with acute pancreatitis and compare it with previously established values obtained in healthy dogs. Ten client-owned dogs preliminarily diagnosed with acute pancreatitis received a full abdominal ultrasound, specific canine pancreatic lipase (Spec cPL), and perfusion CT. Computer software calculated pancreatic perfusion, peak enhancement index, time to peak enhancement, and blood volume for 3-mm and reformatted 6-mm slices. The data was analyzed using Shapiro-Wilk test, linear mixed model, and Spearman's rho. Values for 3-mm slices were similar to 6-mm slices (all P < 0.05). Dogs with acute pancreatitis had a faster time to peak enhancement than healthy dogs (P = 0.04-0.06). Dogs with acute pancreatitis and homogeneous pancreatic enhancement had higher perfusion, faster time to peak enhancement, and greater blood volume compared to healthy dogs and dogs with acute pancreatitis and heterogeneous pancreatic enhancement (all P = / < 0.05). Pancreatic perfusion decreased with increased pancreatitis severity. No correlation was identified between Spec cPL and pancreatic perfusion (all P > 0.05). These findings preliminarily support perfusion CT in dogs with acute pancreatitis.

Application of 3D reconstruction through CT to measure the abdominal cavity volume in the treatment of external abdominal hernia

OBJECTIVE

To evaluate 3D reconstruction through CT in the measurement of abdominal cavity volume.

METHODS

From January 1, 2019 to December 31, 2019, 61 patients diagnosed as external abdominal hernia were included in this prospective study. Multislice computed tomography (MSCT) was applied to patients scanning, and the images were transferred to post-processing workstation for further analysis. We measured the abdominal cavity volumes using volume rendering (VR) method and diameter rendering (DR) method, and the results were used to test whether there is a correlation between them. In addition, the time required for the measurement was recorded and analyzed.

RESULTS

In this study, we found that there was no significant difference in the abdominal cavity volumes between these two groups (VR vs. DR = 7857.316 ± 2035.786 cm³ vs. 7967.268 ± 2925.792 cm³, P > 0.05). Besides, the correlation analysis between the measured values of VR method and DR method showed there was a significant positive correlation (r = 0.922, P < 0.01). The linear regression equation based on the scatter plot was established as follows: y = 0.6417x + 2745, R² = 0.8504. Furthermore, this regression equation was simplified as follows: y = 0.64x + 2800, R² = 0.8499. Meanwhile, the time required for measurement of VR was significantly longer than that of DR (VR vs. DR = 64.3 ± 7.1 min vs. 2.6 ± 0.6 min, P < 0.01).

CONCLUSION

In conclusion, the DR method can quickly measure and calculate the abdominal cavity volume, and its accuracy can more suitable for clinical requirement.