CT-urography: a nationwide survey by the Italian Board of Urogenital Radiology

Abstract

Computed tomography–urography is currently the imaging modality of choice for the assessment of the whole urinary tract, giving the possibility to detect and characterize benign and malignant conditions. In particular, computed tomography–urography takes advantage from an improved visualization of the urinary collecting system due to acquisition of delayed scan obtained after excretion of intravenous contrast medium from the kidneys. Nevertheless, the remaining scans are of great help for identification, characterization, and staging of urological tumors. Considering the high number of diseases, urinary segment potentially involved and patients’ features, scanning protocols of computed tomography–urography largely vary from one clinical case to another as well as selection and previous preparation of the patient. According to the supramentioned considerations, radiation exposure is also of particular concern. Italian radiologists were asked to express their opinions about computed tomography–urography performance and about its role in their daily practice through an online survey. This paper collects and summarizes the results.

Appendix

• 1. First name, family name, affiliation (optional)

• 2. Workplace:

  • URs: 61.6% General Hospital; 19.2% University Hospital; 19.2% Private Center

  • GRs: 57.4% General Hospital; 20.4% University Hospital; 22.1% Private Center

• 3. CT-scanner employed:

  • URs: 5.5% 16-slice MDCT; 45.2% 64-slice MDCT; 28.8% 128-slice MDCT; 1.4% 256-slice MDCT; 12.3% Dual-Energy CT-scan; 6.8% other (32-slice, 4-slice, 512-slice)

  • GRs: 11.8% 16-slice MDCT; 45.1% 64-slice MDCT; 22.7% 128-slice MDCT; 6.2% 256-slice MDCT; 7.3% Dual-Energy CT-scan; 6.9% other (32-slice; 80-slice; 640-slice; 320-slice; 19 × 2slice)

• 4. Which of these options do you consider appropriate for CTU performance? (multiple choice possible)

  • URs: hematuria 91.8%; lithiasis 46.6%; inflammatory diseases 31.5%; renal lesions characterization 53.4%; urothelial malignancy staging 78.1%; urinary tract trauma 86.3%; anatomic alterations (congenital or iatrogenic) 76.7%; organ donors 20.5%; other 1.1% (clinical-radiological mismatch in renal colic; according to ESUR guidelines; post-operative complications)

  • GRs: 88.5% hematuria; 51.8% lithiasis; 40.9% inflammatory diseases; 57.1% renal lesions characterization; 71.4% urothelial malignancy staging; 81.2% urinary tract trauma; 69.3% anatomic alterations (congenital or iatrogenic); 24.3% organ donors; other (renal tuberculosis; chronic inflammation of the urinary excretory system)

• 5. Does exam preparation include oral hydration?

  • URs: yes 39.7%; no 60.3%

  • GRs: yes 35.9%; no 64.1%

• 6. In case of slightly altered serum creatinine, do you provide the patient intravenous hydration before the beginning of the exam?

  • URs: yes 69.9%; no 30.1%

  • GRs: yes 81.5%; no 18.5%

• 7. If you have positively answered to the previous question, in which way do you provide hydration to the patient? *

  • URs (52/73): 80.8% saline (500 ml/250 ml); 13.5% Fluimucil; 5.7% other (oral hydrations; according to the GFR values of the patient; administration of sodium bicarbonate)

  • GRs (292/357): 80.8% saline (500 ml/250 ml); 11.3% Fluimucil; 7.9% other (saline and Fluimucil in conjunction; oral hydration the day before the exam; administration of sodium bicarbonate; on the basis of the nephrologist’s advice; according to ESUR guidelines; according to the anamnesis and serum creatine values of the patient; according to the GFR values of the patient; use of Ringer’s acetate).

• 8. In case of no contraindications, do you administer intravenous diuretic (furosemide) to the patient for CTU performance?

  • URs: yes 26%; no 74%

  • GRs: yes 17.6%; no 82.4%

• 9. If you have positively answered to the previous question, in which dose do you administer the intravenous diuretic? *

  • URs (19/73): 78.9% 10 mg; 21.1% 20 mg

  • GRs (62/357): 82.3% 10 mg; 17.7% 20 mg

• 10. If you have positively answered to the previous questions, in which phase do you administer the intravenous diuretic? *

  • URs (19/73): 36.8% before the beginning of the exam; 63.2% after the unenhanced phase

  • GRs (62/357): 32.3% before the beginning of the exam; 67.7% after the unenhanced phase

• 11. The unenhanced phase is generally performed using:

  • URs: 60.3% a standard protocol; 39.7% a low-dose protocol

  • GRs: 63.9% a standard protocol; 36.1% a low-dose protocol

• 12. In the non-enhanced scan, do you include the whole urinary tract?

  • URs: 91.8% yes; 0% no; 8.2% it depends on the clinical suspicion

  • GRs: yes 83.8%; no 0.2%; according to the clinical suspicion 16%

• 13. For CTU:

  • URs: 19.2% a standard protocol is generally used; 80.8% number and type of phases are acquired on the basis of clinical suspicion and patient’s age

  • GRs: 17.9% a standard protocol is generally used; 82.1% number and type of phases are acquired on the basis of clinical suspicion and patient’s age

• 14. Which one of these protocols do you use?

  • URs: 41.2% single-bolus; 21.9% "split-bolus"; 26% single-bolus with urographic phase; 11% Dual-Energy protocol (single- or split-bolus)

  • GRs: 47.9% single-bolus; 18.2% "split-bolus"; 29.4% single-bolus with urographic phase; 4.5% Dual-Energy protocol (single- or split-bolus)

• 15. While performing a single-bolus CTU, which phases do you acquire under suspicion of urothelial malignancy or for hematuria assessment? *

  • URs (62/73): 72.6% unenhanced, corticomedullary, nephrographic and excretory; 27.4% unenhanced, nephrographic and excretory

  • GRs (307/357): 79.8% unenhanced, corticomedullary, nephrographic and excretory; 20.2% unenhanced, nephrographic and excretory

• 16. While performing a split-bolus CTU, which phases do you acquire under suspicion of urothelial malignancy or for hematuria assessment? *

  • URs (34/73): 41.2% unenhanced and mixed nephrographic/excretory; 38.2% unenhanced, corticomedullary and mixed nephrographic/excretory; 20.6% unenhanced and mixed corticomedullary/excretory

  • GRs (127/357): 26% unenhanced and mixed nephrographic/excretory; 49.6% unenhanced, corticomedullary and mixed nephrographic/excretory; 24.4% unenhanced and mixed corticomedullary/excretory

• 17. While performing a single-bolus CTU, which is the amount of intravenous contrast medium? *

  • URs (71/73): 2.8% a fixed amount of contrast medium, independently from patient’s features and clinical suspicion; 97.2% adjusted on the basis of patient’s weight, clinical indication or contrast medium type

  • GRs (306/357): 4.9% a fixed amount of contrast medium, independently from patient’s features and clinical suspicion; 95.1% adjusted on the basis of patient’s weight, clinical indication or contrast medium type

• 18. While performing a split-bolus CTU, in which way do you divide the whole amount of intravenous contrast medium? *

  • URs (35/73): 34.3% split in half between the two injections; 60% 2/3 during first injection, 1/3 during second injection; 5.7% other (1/3 during first injection, 2/3 during the second injection)

  • GRs (130/357): 33.1% split in half between the two injections; 52.3% 2/3 during first injection, 1/3 during second injection; 14.6% other (1/3 first injection, 2/3 s injection; 30 ml first injection, 0.5 g iodine/kg second injection; 20%fisr injection 50% second injection, 30% third injection; 40% first injection, 60% second injection; 60% first injection, 40% second injection; 20–30 ml first injection, 20–30 ml second injection; 1/5 first injection, 4/5 s injection; 50% first injection, 30% second injection, 20% third injection; on the basis of the iodine concentration of the contrast medium used).

• 19. Which timing do you use for excretory phase acquisition?

  • URs: 5 min (6.8%); 7 min (37%); 10 min (38.4%); > 10 min (17.8%)

  • GRs: 5 min (6.7%); 7 min (26.1%); 10 min (42.9%); > 10 min (24.4%)

• 20. Do you put the patient on prone position before the excretory phase acquisition?

  • URs: yes, always 23.3%; no, never 76.7%

  • GRs: yes, always 19.3%; no, never 80.7%

• 21. If you have positively answered to the previous questions, do you acquire the excretory phase in prone (a) or supine (b) decubitus?

  • URs: (a) 28.8%; (b) 71.2%

  • GRs: (a) 42.3%; (b) 57.7%

• 22. How often it is required from the patient to cough or to perform Valsalva maneuver before excretory phase acquisition? *

  • URs (73/73): 23.3% always; 20.5% often; 34.2% rarely; 21.9% never

  • GRs (356/357): 20.5% always; 27.5% often; 27.6% rarely; 24.5% never

• 23. Do you always obtain MPR reconstructions on the coronal plane for excretory phase?

  • URs: yes 83.6%; no 16.4%

  • GRs: yes 90.5%; no 9.5%

• 24. How often do you use reconstruction algorithms with specific software (MIP, VR, etc.)?

  • URs: 49.3% always; 37% often; 12.3% rarely; 1.4% never

  • GRs: 51.8% always; 33.6% often; 11.2% rarely; 3.4% never

• 25. How often do you need to repeat the excretory phase scan?

  • URs: 4.1% always; 13.7% often; 79.5% rarely; 2.7% never

  • GRs: 1.4% always; 21.3% often; 72.5% rarely; 4.8% never

• 26. How often do you obtain an excretory phase with a delay higher than 30 min?

  • URs: 0% always; 1.4% often; 64.4% rarely; 34.2% never

  • GRs: 0.6% always; 2.5% often; 65.5% rarely; 31.4% never

• 27. How often in the daily clinical practice is it achieved the whole opacification of both the ureters (when patent) along their paths at the end of the exam? *

  • URs (72/73): 25% always; 72.2% often; 2.8% rarely; 0% never

  • GRs (357/357): 16.9% always; 77.2% often; 5.6% rarely; 0.3% never

• 28. How often do you obtain thin-slice section (< 2 mm) acquisitions during the excretory phase?

  • URs: 35.6% always; 26% often; 20.5% rarely; 17.8% never

  • GRs: 34.5% always; 22.7% often; 27.5% rarely; 15.4% never

• 29. Which GFR value do you consider inappropriate for CTU performance?

  • URs: 1.4% < 60 ml/min; 19.2% < 45 ml/min; 79.5% < 30 ml/min

  • GRs: 7% < 60 ml/min; 19.9% < 45 ml/min; 73.1% < 30 ml/min

• 30. How often a CTU is deferred due to inappropriate GFR values?

  • URs: 2.7% always; 13.7% often; 80.8% rarely; 2.7% never

  • GRs: 7.3% always; 11.2% often; 80.1% rarely; 1.4% never

• 31. While performing a single-bolus CTU, which is the mean value of radiation dose delivered? *

  • URs (51/73): 7.8% < 10 mSv; 39.2% 10–20 mSv; 33.3% 20–30 mSv; 19.6% 30–40 mSv; 0% > 40 mSv

  • GRs (204/357): 12.7% < 10 mSv; 34.8% 10––20 mSv; 35.8% 20–30 mSv; 13.2% 30–40 mSv; 3.4% > 40 mSv

• 32. While performing a split-bolus CTU, which is the mean value of radiation dose delivered? *

  • URs (30/73): 50% < 10 mSv; 26.7% 10–20 mSv; 13.3% 20–30 mSv; 10% 30–40 mSv; 0% > 40 mSv

  • GRs (111/357): 27.9% < 10 mSv; 41.4% 10–20 mSv; 18.9% 20–30 mSv; 6.3% 30–40 mSv; 5.4% > 40 mSv

Not compulsory questions are marked with an asterisk (*); the number of responders is reported between brackets.