Background: Quantitative evaluation of renal cortical echogenicity (RCE) has been tried anddeveloped in human and veterinary medicine. Objectives: The objective of this study was to propose a method for evaluating RCEquantitatively and intuitively, and to determine associations between ultrasonographic renalstructural distinction and estimated glomerular filtration rate (eGFR) in canine chronickidney disease (CKD). Methods: Data were collected on 63 dogs, including 27 with normal kidney function and 36CKD patients. Symmetric dimethylarginine and creatinine concentrations were measuredfor calculating eGFR. RCE was evaluated as 3 grades on ultrasonography images accordingto the distinction between the renal cortex and outer medulla. The RCE grade of each kidneywas measured. Results: There was a significant difference in eGFR between the group normal and CKD (p< 0.001). As mean of RCE grades (the mean values of each right and left kidney's RCE grade)increases, the proportion of group CKD among the patients in each grade increases (p <0.001). Also, severity of RCE (classified as "high" if any right or left kidney evaluated as RCEgrade 3, "low" otherwise) and eGFR is good indicator for predicting group CKD (p < 0.001). Conclusions The degree of distinction between the renal cortex and the outer medulla isclosely related to renal function including eGFR and the RCE grade defined in this study canbe used as a method of objectively evaluating RCE.

OBJECTIVE: To document the signal characteristics of intracerebral hemorrhage (ICH) at evolving stages on diffusion-weighted images (DWI) by comparison with conventional MR images. MATERIALS AND METHODS: In our retrospective study, 38 patients with ICH underwent a set of imaging sequences that included DWI, T1-and T2-weighted imaging, and fluid-attenuated inversion recovery (FLAIR). In 33 and 10 patients, respectively, conventional and echo-planar T2* gradient-echo images were also obtained. According to the time interval between symptom onset and initial MRI, five stages were categorized: hyperacute (n=6); acute (n=7); early subacute (n=7); late subacute (n=10); and chronic (n=8). We investigated the signal intensity and apparent diffusion coefficient (ADC) of ICH and compared the signal intensities of hematomas at DWI and on conventional MR images. RESULTS: DWI showed that hematomas were hyperintense at the hyperacute and late subacute stages, and hypointense at the acute, early subacute and chronic stages. Invariably, focal hypointensity was observed within a hyperacute hematoma. At the hyperacute, acute and early subacute stages, hyperintense rims that corresponded with edema surrounding the hematoma were present. The mean ADC ratio was 0.73 at the hyperacute stage, 0.72 at the acute stage, 0.70 at the early subacute stage, 0.72 at the late subacute stage, and 2.56 at the chronic stage. CONCLUSION: DWI showed that the signal intensity of an ICH may be related to both its ADC value and the magnetic susceptibility effect. In patients with acute stroke, an understanding of the characteristic features of ICH seen at DWI can be helpful in both the characterization of intracranial hemorrhagic lesions and the differentiation of hemorrhage from ischemia.
Acute Disease ; Adult ; Aged ; Cerebral Hemorrhage/*diagnosis ; Chronic Disease ; Comparative Study ; Diffusion ; Disease Progression ; Female ; Human ; Magnetic Resonance Imaging/*methods ; Male ; Middle Age ; Retrospective Studies ; Signal Processing, Computer-Assisted

Use of a saline chaser has been reported to allow reduction of contrast dose and artifacts during computed tomography (CT) examination in humans. This study assesses the extent of contrast dose by using a saline chaser in abdominal CT scans of normal dogs. Five beagles underwent abdominal CT scans. Three protocols were applied: 600 mg I/kg iohexol without saline chaser (protocol 1), 30% lower dose of iohexol (420 mg I/kg) followed by a 10 mL saline chaser (protocol 2), and 40% lower dose of iohexol (360 mg I/kg) followed by a 10 mL saline chaser (protocol 3). Attenuation values were obtained from aorta, portal vein, and liver parenchyma. The maximum enhancement values (MEVs) in protocol 2 were significantly higher than those in protocols 1 and 3 in the aorta; no difference was seen in the portal vein in all protocols. The liver parenchymal MEVs in protocols 1 and 2 were significantly higher than those obtained in protocol 3. In this study, the use of a saline chaser and a reduced dose of contrast material did not affect vessel enhancement. In conclusion, use of a saline chaser for abdominal CT of dogs is recommended because it allows a 30% reduction of contrast dose without decreasing vascular and hepatic parenchymal enhancement.
Abdomen ; Animals ; Aorta ; Artifacts ; Dogs ; Humans ; Iohexol ; Liver ; Portal Vein ; Tomography, X-Ray Computed