Mandatory medical device diagnostics.
- Abdominal ultrasonography (ultrasonography of abdominal organs) – for basic diagnosis in adults, pregnant women, and children; also to exclude common differential diagnoses [sensitivity of ultrasonography (percentage of diseased patients in whom the disease is detected by use of the procedure, i.e., a positive finding occurs), especially in combination with calyx dilatation (calyx dilation) is up to 96% for kidney stones or ureteral stones (ureteral stones) >5 mm; with regard to urinary stones. Urinary stones: sensitivity (percentage of diseased patients in whom the disease is detected by the application of the procedure, i.e. a positive finding occurs) 60-90%, specificity (probability that actually healthy people who do not suffer from the disease in question are also detected as healthy by the procedure) 84-100%; in the case of ureteral stones, sonographically usually only the urinary congestion is detectable]Note: The diameter of stones was estimated by abdominal ultrasonography on average 3.3 mm too large!
- Computed tomography (CT) of the abdomen (abdominal CT) as a native computed tomography (“non-contrast CT”, NCCT) – for suspected ureteral stones or for the exact localization of the stone in case of unclear findings [constant sensitivity independent of stone size: calculi < 3 mm: approx. 96 %; calculi > 3 mm: 96-100 %; regarding. Urinary stones: sensitivity 99%, specificity 99%; gold standard for imaging in known urinary stones or suspected urolithiasis]Low-dose CT can be performed in unclear cases au h in children.NCCT is increasingly replacing i.v. pyelogram because it provides more information for differential diagnosis with comparable radiation exposure.Contrast imaging is required before interventional stone therapy.
- Radiography of the abdomen/pelvis – for basic diagnosis for stone diagnosis, to determine the radiopacity and for follow-up in radiopaque calculi [sensitivity 44-77%, specificity 80-87%]In the first trimester (third trimester of pregnancy), radiography should be avoided.
Optional medical device diagnostics – depending on the results of the history, physical examination, laboratory diagnostics and obligatory medical device diagnostics – for differential diagnostic clarification.
- Dual-energy technique (DECT); technique performed by simultaneous acquisition of two sets of CT data; examination with different X-ray energies allows more accurate tissue differentiation than before – for differentiation of uric acid and nonuric acid stones in vivo [sensitivity: 95.5%; specificity: 98.5%].
- Color Doppler sonography (color-coded Doppler sonography; medical imaging technique that can dynamically visualize fluid flow (especially blood flow)) – Twinkling artifacts (confetti-like bands of color in the area of the acoustic shadow in highly reflective structures) facilitate the detection of even small stones:
- 24%: <5 mm diameter:
- 71 %: 5-10 mm
- 5 %: > 10 mm.
The average stone diameter was 7.3 ± 2.38 mm. The sensitivity was 97.2% and the specificity of 99.0%. The median values for native CT were 98% and 97%, respectively.The positive predictive value was 97.6% and the negative predictive value was 85.7%. The positive predictive value was 99.6% for native CT.CONCLUSION: Color Doppler sonography is nearly equivalent to native CT for the detection of ureteral stones.
- Magnetic resonance imaging (MRI)-urography – plays no role in the routine diagnosis of urinary stones; used mainly in children; also in cases of contrast agent intolerance.
- I.v. pyelogram (synonyms: IVP; i.v. urogram; urogram; i.v. urography; excretory urography; excretory pyelogram; intravenous excretory urogram; radiographic representation of the urinary organs esp. of the hollow system morphology or the urinary draining system) – performance only in the colic-free interval, since the renal pelvic caliceal system could rupture due to contrast medium-induced diuresis (increased urine excretion) in acute colic! Note: A blank image already shows calcium-containing stones, as these are shadowing. The sensitivity of excretory urography is between 51-87 %, the specificity between 92-100 %.Pyelogram can be performed in children for treatment planning.In the first trimester (third trimester) should not be X-ray examination.
- Antegrade or retrograde ureteropyelography (X-ray examination using a contrast medium to visualize the renal pelvis and ureters) – if an indication for urinary diversion has been made.