Initial study upon the rationale of MDCT abdomen in the clinical setting of acute renal pain.

1. NON-CONTRAST EENNHHAANNCCEEDD MMUULLTTIIDDEETTEECCTTOORR
CCOOMMPPUUTTEEDD TTOOMMOOGGRRAAPPHHYY VVEERRSSUUSS PPLLAAIINN XX--RRAAYY
UURRIINNAARRYY TTRRAACCTT FFIILLMM IINN AACCUUTTEE RREENNAALL PPAAIINN
HHaazzeemm AA.. YYoouusssseeff**,, MMoohhaammmmaadd KK.. OOmmaarr**,, HHoossssaamm AA..
****YYoouusssseeff**,, aanndd HHaassssaann AA.. AAbboolleellllaa
..RRaaddiioollooggyy DDeeppaarrttmmeenntt,, FFaaccuullttyy ooff MMeeddiicciinnee,, AAssssiiuutt UUnniivveerrssiittyy**
.. UUrroollooggyy DDeeppaarrttmmeenntt,, FFaaccuullttyy ooff MMeeddiicciinnee,, AAssssiiuutt UUnniivveerrssiittyy****

2. IINNTTRROODDUUCCTTIIOONN
Patients with suspected urinary tract disease are
often referred for multiple studies such as excretory
urography (EU), ultrasound (US), CT or MRI. Multi-examination
work-ups require much patient effort
and are expensive. A single imaging test that
comprehensively evaluates the urinary tract has
advantages both in terms of convenience and cost
(NOROOZIAN et al. 2004).

3. Patients often present to the urology or emergency
department with flank pain or colic due to ureteral
calculus. Because it provides fast results, unenhanced
multislice computed tomography (MSCT) has largely
supplanted intravenous urography, and, in the United
States, MSCT generally prevails as the standard
examination for detecting ureteral calculi (Wehrschuetz
et al. 2009).

4. OOBBJJEECCTTIIVVEE
The objective of the current study is to evaluate the
sensitivity, specificity, and overall accuracy of
unenhanced MSCT in the diagnosis of calcuar and
non calcular causes of acute flank pain compared
with those of plain X-ray (KUB).

5. PPAATTIIEENNTTSS AANNDD MMEETTHHOODDSS
Study Population
A total of 160 consecutive patients (97 males and 63
females, median age 41.2 years, range 2-80) with
suspected urinary calculi were included in this
retrospective pilot study from January through
September 2009.

6. Imaging protocol
Unenhanced MDCT images were acquired with a 64
detector row CT scanner VCT GE, Milwaukee, WI.
Five-millimeter contiguous unenhanced axial CT
images were obtained in a cephalocaudal direction
from the diaphragm to below symphysis pubis. No oral
or IV contrast was administered.
IV diuretic (20mg furesemide) was routinely
administered 15 minutes prior to scanning to
maximally distend the collecting system, ureters and
UB.

7. Scanning protocol
Scans were obtained with tube rotation time 0.8sec,
pitch 0.984:1, table feed/gantry rotation 39.75mm, a
tube voltage of 140 kVp and effective tube current-time
product of 548mAs.

8. Image processing
All datasets were sent to a commercially available
workstation (ADW4.4). In all patients 5mm MPR
images were obtained in addition to the following:
1) Thick slab MIP.
2)Volume rendering (VR).
3)Curved reformats for the ureters (CPR).

9. Image evaluation
Two independent radiologists and a urologist
analyzed the images. The observers were asked to
separately determine whether pyelocalyceal and
ureteral calculi were present. They were instructed
to document the location and size of each calculus
using standard measurement devices. Non calcular
causes of colic or associated abnormalities were
individually assessed and documented.
When KUB films were not available digital scout or
scan projection radiographs in lieu of conventional
radiographs were obtained.

10. RREESSUULLTTSS
Urinary calculi were detected in 10 patients referred
after inconclusive IVU and in 8 patients with ureteric
stents. In 2 patients with inconclusive IVU ureteric
stricture was the alternative diagnosis.

11. MMDDCCTT ddiiaaggnnoossiiss NNoo.. ooff ppaattiieennttss
OObbssttrruuccttiinngg uurreetteerriicc ccaallccuullii 9988
UUrreetteerriicc ssttrriiccttuurree 3322
UUrreetteerriicc mmaassss 33
UUBB mmaassss 33
RReettrrooppeerriittoonneeaall ffiibbrroossiiss 22
HHyyddrroouurreetteerroonneepphhrroossiiss wwiitthh nnoo lleessiioonn
iiddeennttiiffiieedd
33
PPUUJJ oobbssttrruuccttiioonn 55
NNoonn oobbssttrruuccttiivvee ccaallccuullii 111100
AAccuuttee aappppeennddiicciittiieess 55
PPeellvviicc aabbsscceessss 11
NNoorrmmaall 88

12. 8
1
5
110
5
3
2
3
3
32
98
0
20
40
60
80
100
120
Normal
Pelvic abscess
Acute appendicities
Non obstructive calculi
PUJ obstruction
Hydroureteronephrosis
with no lesion identified
Retroperitoneal fibrosis
UB mass
Ureteric mass
Ureteric stricture
Obstructing ureteric
calculi

13. NNoo.. ooff ssttoonneess// ppaattiieenntt NNoo.. ooff ppaattiieennttss
00 55
11 22
22 33
33 33
44 11
55 33
66 11
77 22
77--1155 22
1155<< 11
TToottaall 111100

14. RREEPPRREESSEENNTTAATTIIVVEE CCAASSEESS

16. CPR VR
CPR and VR images showing 3 ureteric calculi and non obstructive
lower calyceal calculus. Thickening of the ureteric walls and periureteric haziness
are also evident.

18. CPR VR
CPR and VR images showing non obstructive
left lower calyceal calculus.

20. CPR VR
CPR and VR images showing obstructive lamellated pelvic calculus
and non obstructive calyceal calculi.

21. MIP CPR VR
MIP, CPR and VR images showing obstructive middle ureteric calculus
with faintly opacified obstructed PCS and ureter.

23. CPR VR
CPR and VR images showing calcific lower ureteric stricture
with marked hydrouretronephrosis.

24. CPR VR
CPR and VR images showing incomplete douplex system of the
left kidney with distal ureteric fusion and obstructing lower ureteric calculus
with marked hydrouretronephrosis.

25. Coronal reformatted images showing the 2 ureters with distal fusion.

27. CPR and coronal reformatted images showing obstructing middle ureteric calculus
with marked hydrouretronephrosis, gas density within the PCS and stranded perirenal fat
indicating emphysematous pyelonephritis.

28. CPR images showing retroperitoneal mass entangling and medially displacing middle ureters
with bilateral hydrouretronephrosis diagnostic of retroperitoneal fibrosis.

29. Axial images showing the retroperitoneal mass entangling and medially displacing
middle ureters with bilateral hydrouretronephrosis.

30. CPR images showing left
hydrouretronephrosis with
stripping of the renal capsule
secondary to intramural
calculus. Note bilateral non
obstructive calyceal calculi.

31. CPR images showing right
hydrouretronephrosis caused
by a lower ureteric mass
extending into the UB.

32. CONCLUSION AANNDD RREECCOOMMMMEENNDDAATTIIOONNSS
The CTU has become the radiologists most robust
imaging tool for the evaluation of the kidneys, upper
urinary tracts, and UB.
Complete imaging of the kidneys and urinary tracts can
be performed with MDCT. Studies are tailored to the
clinical question and may be performed as noncontrast,
combined non-contrast and post-contrast or post-contrast
imaging studies only.

33. Finally radiologists need to educate emergency room
and referring physicians about the limitations of
unenhanced CT scans, as it does not detect infarcts,
pyelonephritis, small renal cell carcinomas, or small
ureteral tumors.

34. TTHHAANNKK YYOOUU