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Multidetector CT Urography A new Scanning
Protocol for Improved Visualization of the
Urinary Tract  Yvonne Buijs1, Marjon Hepkema1 and
Harold Suliman2 Dept. of Radiology, St. Lucas
Andreas Hospital Amsterdam,The Netherlands 1
radiographer 2 radiologist
PURPOSE To evaluate and describe the degree of
opacification of the renal collecting system and
ureters on excretory-phase contrast-enhanced CT
using 750-1,000 mL oral ingestion of water. We
evaluated a new CT scanning protocol on the
depiction of the urinary tract by multidetector
CT. MATERIALS AND METHODS 2977 collecting
systems and ureters of 1490 consecutive patients
( age range, 25-92 yearsmean age, 54years) who
had dedicated urinary tract CT examinations were
evaluated in the period May 2007 to May 2008. The
indications for the examination included
hematurie(n1322), history of bladder cancer
(n36.) and suspected urinary obstruction
(n132). Each patient drank 750-1,000 mL of water
over a 15-20 min period before scanning began.
The protocol for evaluation of the patients
included the following 2-phase scanning
procedure unenhanced scan through the kidneys to
just below the symphysis pubis and
excretory-phase scan from the kidneys to just
below the symphisis pubis at 300 sec after IV
contrast injection. For unenhanced scans,
parameters were 3-mm slice thickness and 3-mm
increments. For the excretory phases, parameters
were 0.75-mm slice thickness and 0.5-mm
reconstruction increments. Parameters for
contrast-enhanced scans were 16x0.75mm detector
collimation, 12mm per rotational table speed,
0.5-sec gantry rotation speed, 120 kVp, and
120-150 mAs. All image data were reconstructed
with the body soft-tissue algorithm.
Excretory-phase data were used to evaluate the
degree of opacification of the collecting system
and ureters. The degree of opacification was
determined using axial scrolling and
reformatted and 3D imaging comprehensively.
RESULTS Among 2977 renal collecting systems
and ureters, the opacification scores of the
calyx and infundibulum by each of the three
reviewers were 3 (complete opacification) in 82
Fig. 12 (near complete opacification) in 15 and
1 (poor opacification) in 3. CONCLUS
ION We used oral hydration not only to increase
opacification of the renal collecting system and
ureter, but also to reduce the possibility of
renal toxicity. In our series, oral hydration was
devised as a simple substitutional for the
previously reported techniques of abdominal
compression, saline infusion, and furosemide
administration and allowed for a minimal amount
of wait time for the patient and reduced the
effect on workflow and room utilization.
Fig. 1- 42-year old woman with acute
hematuria. Complete opacification of bilateral
renal collecting systems and ureters shown on
anterior volume rendered 3D image. Opacification
score 3complete opacification