Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: Jin-Woo Jung x
  • Refine by Access: All Content x
Clear All Modify Search

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.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To investigate the efficacy of a phospholipid-stabilized sulfur hexafluoride microsphere (SHM) contrast agent and water for hydrosonography of the upper portion of the gastrointestinal tract of dogs.

ANIMALS

12 healthy adult Beagles.

PROCEDURES

In a crossover study, each dog was anesthetized and underwent noncontrast ultrasonography then hydrosonography following administration of tap water (30 mL/kg) without (water method) or with SHM (0.1 mL; SHM method) via an orogastric tube. There were at least 3 days between hydro-sonographic procedures. Wall thickness, wall layer definition, conspicuity of the mucosal-luminal interface, and image quality were evaluated separately in the near and far fields for the gastric cardia, body, and pylorus and descending duodenum and compared among the 3 scanning methods.

RESULTS

Mean wall thickness measurements did not differ significantly between the water and SHM methods at any location except the far-field gastric cardia where the mean wall thickness for the SHM method was less than that for the water method. In general, the SHM method improved wall layer definition and conspicuity of the mucosal-luminal interface of structures in the near field, compared with noncontrast method. The water and SHM methods both resulted in superior image quality relative to the noncontrast method for the near-field gastric cardia, far-field gastric cardia, and far-field duodenum.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that, for dogs, gastrointestinal hydrosonography by use of the SHM method improved wall layer definition and mucosal conspicuity, particularly in near-field images of the upper portion of the gastrointestinal tract. (Am J Vet Res 2021;82:712–721)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To investigate the diagnostic usefulness of split-bolus CT enterography in dogs.

ANIMALS

6 healthy Beagles.

PROCEDURES

CT enterography was performed in all dogs in a nonrandomized crossover study design involving 3 techniques: a dual-phase technique and 2 techniques involving splitting of the administered contrast agent dose (ie, split technique and split-bolus tracking technique). For the 2 techniques involving dose splitting (ie, split CT enterography), contrast agent was injected twice, with the first injection consisting of 60% of the total dose, followed by injection of the remaining 40%. Then, a single set of CT images was obtained when the arterial and venous phases matched (dual-phase and split techniques) or when enhancement of the abdominal aorta reached 100 HU (split-bolus tracking technique). Enhancement of the intestinal wall and mesenteric vessels was assessed qualitatively and quantitatively.

RESULTS

The total number of images required for interpretation was significantly lower for the split technique than for the dual-phase technique. The amount of time needed to complete CT enterography was significantly less for the split-bolus tracking technique than for the other 2 techniques. For all 3 techniques, adequate contrast enhancement of the mesenteric vessels and intestinal wall was achieved. The split technique provided contrast enhancement of the intestinal wall and mesenteric vessels similar to that provided with the dual-phase technique, whereas contrast enhancement of these structures was lowest for the split-bolus tracking technique.

CONCLUSIONS AND CLINICAL RELEVANCE

Split-bolus CT enterography at a contrast agent allocation ratio of 60:40 enabled simultaneous evaluation of the enhanced intestine wall and mesenteric vessels and yielded image quality similar to that of dual-phase CT enterography in healthy dogs.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To investigate radiographic variables for correlation with splenic size as estimated with CT in cats.

ANIMALS

38 healthy adult cats.

PROCEDURES

The width and height of the splenic head and total length, segmental length, and width of the spleen were measured on radiographic and CT images obtained from 10 cats in prospective, exploratory experiments. Distance between the splenic head and left kidney, anatomic locations of the head and tail of the spleen, and CT-derived splenic volume were also assessed. Correlation and agreement between radiographic and CT measurements and interobserver agreement for measurements with each method were determined. A retrospective evaluation of radiographs obtained without sedation or anesthesia for 28 cats was performed to establish preliminary guidelines for the measurement deemed the most reliable estimator of splenic size.

RESULTS

Radiographic measurements of total and segmental splenic length were significantly correlated with the respective CT measurements and with splenic volume. Agreement between radiographic and CT measurements of segmental length was good; interobserver agreement was excellent for all variables. In retrospective evaluations, median segmental length of the spleen was 57.87 mm (range, 34.72 to 105.44 mm) on radiographs; the caudal border of the splenic head on lateral views was located from the cranial part of L1 to the caudal part of L2, and the caudal border of the splenic tail on ventrodorsal views was located from the caudal part of L2 to the caudal part of L5.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that segmental length of the spleen on radiographs is a reliable estimator of splenic size in healthy cats.

Full access
in American Journal of Veterinary Research