System for interpretation of the AXR

28 System for interpretation of the AXR



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Fig. 28.1 A normal AXR.


This chapter aims to provide the reader with a checklist of structures to look at when interpreting an AXR.



Technical factors


The abdomen is almost exclusively soft tissue with air in the GI tract. Radiographic exposure factors are less critical than for the CXR.


It is important to ensure that the whole abdomen is imaged, including the hernial orifices (the radiograph should include the whole bony pelvis).


Also bear in mind that detail on the AXR in obese patients may be suboptimal.


Structures can be subtle in the abdomen as all organs are of soft tissue density and can only be seen because of subtle differences in thickness and density. Some organs are surrounded by fat, which can help.


Start by assessing any lines or tubes – these may include a PEG tube, or abdominal drains, catheters etc.



Organs that can be seen



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Fig. 28.2 The liver edge is subtle but can be seen (arrows). Look for liver enlargement.


Look in the region of the liver for abnormal gas in the biliary tree (see Chapter 31) or portal venous gas (see Chapter 37), which can be a poor prognostic sign in various conditions.


Look for gallstones in the region of the gallbladder.



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Fig. 28.3 The renal outline can also be seen, usually just lateral to the upper psoas shadow. It can be seen because it is surrounded by fat in the perinephric space (arrows). The renal outline is important for a number of reasons. Kidney stones may be seen projected over the kidney. The kidney may also be enlarged, as in polycystic kidney disease. Look for gas in emphysematous pyelonephritis (Chapter 40).


Knowledge of the course of the ureter is also important as a stone can be found at any point along its length. The ureter emerges from the medial aspect of the kidney and descends into the pelvis at the level of the tips of the transverse processes of the lumbar vertebrae. The ureter then crosses the pelvic brim and turns inward to enter the bladder at the level of the ischial spine. Use these landmarks to help you. The approximate course of the ureter is drawn in.


Ultrasound is the best initial modality for investigating renal disease.

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Aug 20, 2016 | Posted by in ULTRASONOGRAPHY | Comments Off on System for interpretation of the AXR

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