Effect of slice thickness on computed tomographic perfusion analysis of the pancreas in healthy dogs

Abstract

OBJECTIVE To evaluate the effect of slice thickness on CT perfusion analysis of the pancreas in healthy dogs. ANIMALS 12 healthy Beagles. PROCEDURES After precontrast CT scans, CT perfusion scans of the pancreatic body were performed every second for 30 seconds by sequential CT scanning after injection of contrast medium (iohexol; 300 mg of 1/kg) at a rate of 3 mL/s. Each dog underwent CT perfusion scans twice in a crossover-design study with 2 different slice thicknesses (2.4 and 4.8 mm). Computed tomographic pancreatic perfusion variables, including blood flow, blood volume determined with the maximum slope model, times to the start of enhancement and peak enhancement, permeability, and blood volume determined by Patlak plot analysis, were measured independently by 2 reviewers. The CT perfusion variables were compared between slice thicknesses. Interoperator reproducibility was determined by ICC calculation. RESULTS Interoperator reproducibility of CT perfusion variable measurements was excellent on 2.4-mm (mean ± SD ICC, 0.81 ± 0.17) and 4.8-mm (0.90 ± 0.07) slice thicknesses, except for time to peak pancreatic enhancement on 2.4-mm-thick slices, which had moderate reproducibility (intraclass correlation coefficient, 0.473). There was no significant difference in measurements of blood flow, blood volume by either method, times to the start and peak of pancreatic enhancement, or permeability between slice thicknesses. CONCLUSIONS AND CLINICAL RELEVANCE Results supported that a thin slice thickness of 2.4 mm can be used for assessment of pancreatic perfusion variables in healthy dogs.

Dynamic contrast‐enhanced computed tomography in dogs with nasal tumors

“…Dynamic contrast‐enhanced computed tomography has been used in dogs, and several proof‐of‐principle studies have assessed normal tissues and tumors, and compared DCECT to 18F‐fluorodeoxyglucose positron emission tomography‐computed tomography. 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 Two studies specifically reported DCECT in nasal tumors but did not find correlation with histogenesis or survival. 33 , 39 Our objectives were (a) to assess baseline perfusion parameters in dogs with nasal tumors based on histopathological type, (b) to characterize changes in perfusion parameters with changes in tumor volume after the start of RT, and (c) to evaluate if a correlation existed of either objective 1 or objective 2 with survival.…”

“…Dynamic contrast‐enhanced computed tomography has been used in dogs, and several proof‐of‐principle studies have assessed normal tissues and tumors, and compared DCECT to 18F‐fluorodeoxyglucose positron emission tomography‐computed tomography 26‐42 . Two studies specifically reported DCECT in nasal tumors but did not find correlation with histogenesis or survival 33,39 .…”