Answers to Case1-3-9
1. Figure 2.1.1a-c are longitudinal ultrasound images through a normal right (a)
and left (b) kidney, and transverse image through the right kidney (c). The left
side of the image corresponds to the cranial or right side of the patient, depending
on whether the probe is orientated longitudinally or transversely. Lying
immediately above/adjacent to the kidney on the right is the liver, and on the left
the spleen.
2. The kidneys have a hypoechoic (i.e. darker) outer cortex which should be iso- or
hypoechoic compared to the adjacent liver or spleen. If the cortex is hyperechoic,
this is a non-specifi c sign of renal parenchymal disease. In thinner patients the medullary
pyramids may be distinguished from the renal cortex, lying more centrally
adjacent to the renal sinus. These are normally hypoechoic compared to the cortex.
The renal sinus, seen centrally/medially, is hyperechoic due to its high fat content.
The renal vessels and pelvicalyceal system may be seen within this region.
Non-dilated ureters are not usually well seen on ultrasound except at the vesicoureteric
junction.
3. Cut surface of a normal kidney showing (1) renal cortex (2) medullary ray
(3) column of Bertin (4) renal papilla (5) renal pelvis (6) calyx (7) ureter.
Hangiandreou NJ. AAPM/RSNA physics tutorial for residents: topics in US.
B-mode US: basic concepts and new technology.
Radiographics . 2003;23:
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