In hospitals where 24-hour access to CTU is not possible, patients with suspected ureteric colic may be admitted for pain relief, and undergo a CTU the following morning. It is our policy, when CT urography is not immediately available (between the hours of midnight and 8 a.m.), to perform an abdominal ultrasound in all patients over the age of 50 years who present with flank pain suggestive of a possible stone. This is done to exclude serious pathology such as a leaking abdominal aortic aneurysm and to demonstrate any other gross abnormalities due to non-stone-associated flank pain.
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FIGURE 3.4. a: On a 1-hour postcontrast film the right ureter is still not opacified. Only the outline of the kidney and renal collecting system is visible because of the distal obstruction. b: In this case it takes 2 hours for the IVU to demonstrate the stone and its position in the right lower ureter.
3. NONTRAUMATIC RENAL EMERGENCIES 25
FIGURE 3.4. Continued
Plain abdominal x-ray and renal ultrasound are not sufficiently sensitive or specific for their routine use for diagnosing stones.
Magnetic Resonance Urography (Fig. 3.5)
This is a very accurate way of determining whether or not a stone is present in the ureter (Louca et al. 1999; O'Malley 1997).
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FIGURE 3.5. Magnetic resonance urogram. Stones appear as "black holes.'
However, at the present time, cost and resticted availability limit its usefulness as a routine diagnostic method of imaging in cases of acute flank pain. This may change as MR scanners become more widely available.
Acute Management of Ureteric Stones
The management of any acutely presenting ureteric stone starts with pain relief. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac (Voltarol) given by intramuscular or intravenous injection, by mouth, or per rectum can, in many cases, provide rapid and effective pain control (Laerum et al. 1996). In other cases opiate analgesics such as pethidine or morphine are required, in addition to NSAIDs.