Ureteric colic and ureteric stones

What it is

A stone in the ureter gives ureteric colic. The obstructed stone presents with unilateral flank tenderness, colicky pain radiating to the groin and hematuria. During the acute episode the goals are only two: alleviate the pain and facilitate stone passage.

How it presents

Renal colic stands in the same list as appendicitis, ectopic pregnancy, testicular torsion, ovarian torsion, IBD and pyelonephritis when a patient comes with lower abdominal pain, and the urine dipstick separates them: white cells for UTI, hematuria for a stone. Genitalia must be examined in every male who comes with lower abdominal pain, and a pregnancy test is done in every patient of child-bearing age, even at 15 years.

How it is diagnosed

Non-contrast CT KUB is the gold standard for the diagnosis of a ureteric stone: it gives size, location and back pressure effect, and it detects all stones, including uric acid and xanthine. The pages differ on what to order first: one asks for the most appropriate investigation for a patient with a kidney stone, among ultrasound, KUB and helical CT of the abdomen and pelvis, and marks KUB as its answer. On another page ultrasound is the primary diagnostic imaging tool for a renal stone, and non-contrast CT is used to confirm the stone after that initial ultrasound in a patient with acute flank pain, which is a strong recommendation. Immediate imaging is indicated with fever or a solitary kidney, and when the diagnosis is doubtful. Low-dose CT protocols reduce radiation with preserved accuracy, and a KUB X-ray is useful for radiopaque stones and for follow-up after treatment. In pregnancy the order is ultrasound first, then MRI without gadolinium, then low-dose CT as a last resort, with minimum risk before the 8th week and after the 23rd week. In children ultrasound is first-line, with X-ray KUB or low-dose CT if it is inconclusive.

So for the man who comes with loin pain and ureteric colic, the investigation is the non-contrast CT: NCCT is the gold standard investigation for ureteric colic. The USG abdomen and the X ray KUB appear on the same page, but they appear there as the follow up after medical expulsive therapy, not as the way the colic is diagnosed in the first place.