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| H. Urological, adrenal, and genitourinary systems | |||||||
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CLINICAL/DIAGNOSTIC PROBLEM |
INVESTIGATION |
RECOMMENDATION (GRADE) |
COMMENT |
DOSE |
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|
Haematuria, macro- or microscopic
|
IVU |
Indicated (B) |
There is wide variation in local policy. Imaging strategies should be agreed with local nephrologists and urologists. Neither IVU nor US and AXR is ideal for detecting upper urinary tract causes of bleeding: in most patients both IVU and US should be used, either together or in sequence. |
II |
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|
US and AXR/CT |
Indicated (B) |
In young patients with microscopic haematuria only US and AXR may be used to evaluate the upper tracts: this strategy misses some upper tract pathology, including some calculi. Bladder US detects many bladder tumours but is not sufficiently sensitive to obviate cystoscopy. There has been recent interest in using CT to evaluate the upper tracts in haematuria but there are insufficient data to make a recommendation. |
0 + I/II |
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| Hypertension without evidence of renal disease | IVU | Not Indicated (B) | IVU is not indicated for the evaluation of hypertension with no evidence of renal disease. | II | |||
| Hypertension: in the young adult or in patients unresponsive to medication | Angiography (DSA/CTA/MRA) | Specialised investigation (C) | To show stenosis if surgery or angioplasty is considered as a possible treatment. | III/III/0 | |||
| MRA | Specialised investigation (B) | Imaging is only appropriate if renovascular hypertension is clinically suspected, since the prevalence of renal artery stenosis in essential hypertensives is very low. MRA is the best non-invasive method to visualise the renal arteries directly. | 0
|
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| CTA | Specialised investigation (B) | CTA is as sensitive as MRA but more invasive (iodinated contrast medium, irradiation) and should only be used if MRA is not available. | III | ||||
| NM | Specialised investigation (B) | Captopril renography is best to check for functionally significant renal artery stenosis | II | ||||
| US | Specialised investigation (B) | Doppler US can be sensitive and specific but needs special expertise. | 0 | ||||
| Renal failure | Renal US and AXR | Indicated (B) | US is indicated as the first investigation in renal failure to measure kidney size and parenchymal thickness and to check for pelvicalyceal dilatation indicating possible obstruction. AXR is necessary to show calculi not detectable by US. | 0 + I | |||
| CT | Not indicated initially (B) | CT
(unenhanced or enhanced, depending on renal function) helps if US is
non-diagnostic or does not show the cause of obstruction. |
III | ||||
| IVU | Not indicated (B) | II | |||||
| MRI | Specialised investigation (C) | MRI is a possible alternative to CT and avoids potentially nephrotoxic contrast medium. On rare occasions, obstruction occurs without dilatation seen with any imaging method. | 0 | ||||
| Measurement of renal function | |||||||
|
NM | Specialised investigation (B) | GFR is preferred by many authorities to assess global renal function: Hippurate OIH labelled with either 1-123,1-125 or 1-131 is used, but Tc-99m MAG3 may be used as a substitute. | II | |||
|
NM | Specialised investigation (A) | Single-sample
Cr-51 EDTA at 3 hours if well calibrated and GFR >30 ml/min. Accurate preparation of standards and
injection without loss are crucial: 5ICr EDTA clearance, four-sample
method. |
II | |||
|
NM | Specialised investigation (A) | Tc-99m
MAG3 is recommended for the measurement of relative renal function. |
II | |||
|
NM | Specialised investigation (B) | Renal
Tc-99m MAG3 should be used with an established method of deconvolution
analysis for parenchymal transit time index for obstructive nephropathy
and mean parenchymal transit time for renovascular disorder. |
II | |||
| Suspected ureteric colic | CT | Indicated (B) | Unenhanced CT is the method of choice in suspected ureteric colic. | III | |||
| IVU | Indicated (B) | IVU
is a satisfactory alternative to CT. |
II | ||||
| US/AXR | Indicated only in specific circumstances (B) | US
and AXR may be used where radiation/contrast medium are contraindicated,
e.g. in cases of pregnancy and contrast allergy. To maximise US
sensitivity, patients should be well hydrated. US is less accurate
than CT or IVU. |
0 + I | ||||
| Renal calculi in absence of acute colic | AXR/CT | Indicated (B) | AXR
or CT provide the best baseline assessment in patients with renal stone
disease. In routine practice AXR is adequate to detect the
majority of renal calculi, which contain calcium. For detailed
detection of renal calculi, CT is more sensitive. |
I/III | |||
| US | Indicated only in specific circumstances (B) | US
is less sensitive than either AXR or CT for detecting renal calculi but
can detect orate calculi. |
0 | ||||
| Renal mass | US | Indicated (B) | US is sensitive at detecting renal masses > 2 cm and accurately characterises masses as cystic or solid. US helps to characterise some masses indeterminate at CT | 0 | |||
| IVU | Not indicated (B) | IVU is less sensitive than US for the detection of renal masses. IVU does not characterise renal masses accurately. | II | ||||
| CT | Indicated (B) | CT is sensitive at detecting renal masses or 1.0-1.5 cm or greater and accurately characterises masses. | III | ||||
| MRI | Specialised investigation (B) | MRI (including contrast-enhanced imaging) is as sensitive as contrast-enhanced CT for detecting and characterising renal masses. MRI should be used if masses are not accurately characterised by CT and US or if iodinated contrast medium is contra-indicated because of diminished renal function or allergy. | 0 | ||||
| Urinary tract obstruction | IVU | Indicated only in specific circumstances (B) | May
be used to define anatomy prior to surgery or other interventions |
II | |||
| US | Indicated (B) | Useful
to assess the upper tracts. |
0 | ||||
| NM | Indicated (A) | Tc-99m-MAG3 with frusemide diuresis is used. Output (outflow) efficiency study provides reliable quantification of frusemide response independent of renal function. Parenchymal transit time index measurements aid assessment of obstructive nephropathy. | II | ||||
| Urinary
tract infection in adults
(For children see section M) |
US and AXR | Indicated only in specific circumstances (B) | The majority of adults with urinary infection do not require imaging. Imaging is indicated (1) if infection does not settle rapidly with antibiotics and (2) after infection has settled in men with one proven UTI or women with a proven recurrence of UTI. | 0 + I | |||
| CT | Specialised investigation (B) | US and AXR offer a good first investigation. Contrast-enhanced CT may be necessary in severe infection not responsive to treatment, since CT detects renal sepsis and changes of pyelonephritis more sensitively than US. | III | ||||
| IVU | Indicated only in specific circumstances (B) | IVU may be helpful in the non-acute phase in patients who are suspected of having underlying renal disease (e.g. calculus, papillary necrosis, reflux nephropathy). | II | ||||
| Renal transplant evaluation | NM | Indicated (B) | Tc-99m-MAG3 studies are more sensitive than US for acute rejection after transplantation. Such changes in renal function usually predate clinical and chemical indices. This study is helpful for detection of renal artery stenosis and obstructive uropathy. | II | |||
| Urinary retention | IVU | Not indicated (B) | Has low yield | II | |||
| US | Indicated only in specific circumstances (B) | Renal US is indicated to check for upper tract dilatation (after catheterisation to relieve bladder distension), especially if renal function is impaired. | 0 | ||||
| Prostatism | IVU | Not indicated (B) | US is indicated to check for dilatation of the upper urinary tract. | II | |||
| US | Indicated (B) | Bladder US (with measurement of post-void residual volume and urine flow rate) is indicated in prostatism. Renal US is only necessary if there is a post-void residue, haematuria, raised serum creatinine, or infection. | 0 | ||||
| Scrotal mass or pain | US | Indicated (B | US is indicated for scrotal swelling and when presumed inflammatory scrotal pain does not respond to treatment. Allows differentiation of testicular from extra- testicular lesions. | 0 | |||
| Testicular torsion | US | Indicated (B | Frequently a clinical diagnosis. Urgent management is essential and imaging should not delay intervention when appropriate. Colour Doppler US has a high sensitivity in suspected testicular torsion. Intermittent torsion remains a significant diagnostic problem. | 0 | |||
| Adrenal medullary tumour | US/CT/MRI | Specialised investigation (B) | While US may identify lesions of this type, CT and MRI provide the best anatomical delineation. Imaging is rarely indicated in the absence of biochemical evidence of such tumours. | 0/III/0 | |||
| NM | Specialised investigation (B) | MIBG locates functioning tumours and is particularly useful for ectopic sites and metastases. | II | ||||
| Adrenal cortical lesion; Cushing's syndrome | CT/MRI, NM, and/or adrenal venous sampling | Specialised investigation (B) | Local advice on the most appropriate examination should be sought. CT/MRI may be able to identify an adrenal cause for Cushing's syndrome. However, nodular adrenal hyperplasia can occur in a significant proportion of patients with ACTH-dependent and ACTH-independent Cushing's syndrome. In such a situation CT may be unable to distinguish adrenal adenoma and nodular hyperplasia, and further investigation with scintigraphy and/or adrenal venous sampling may be required. | III/0, II/III | |||
| Adrenal cortical lesion; primary hyperaldosteronism (Conn's syndrome) | CT/MRI, NM, and/or adrenal venous sampling | Specialised investigation (B) | Local advice on the most appropriate examination should be sought. Both CT and MRI can distinguish between a unilateral adrenal adenoma and bilateral adrenal hyperplasia. NM may be useful in distinguishing between adrenal hyperplasia and an adenoma. However, adrenal venous sampling may be required where other imaging techniques are inconclusive. | III/0, II/III | |||
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