Aims and objectives
Nephrolithiasis is a common disorderwith a reported incidence of 12% in industrialized countries [1] and is globally increasing [2].
Colicky flank pain is the most common presenting symptom of obstructive urolithiasis [2].
Previous studies have shown that even renal stones that do not cause obstruction still may cause flank pain and that in the absence of a separate cause,
either clinical or evident on CT,
these stones are likely to be the cause of the symptoms [3,4,5].
Non-contrast (NC) multidetector computed tomography (MDCT) of the...
Methods and materials
For this retrospective study institutional review board approval was obtained.
Study population:
Fifty consecutive patientsundergoing MDCT of the kidneys according to our department’s fourth-phase standard protocol and having in the non-contrast phase (NCP) at least one kidney stone were included in the study.
We excluded cases: (1) where the calculus was located in the wall of a vessel or a cyst,
(2) where,
due to technical reasons,
the contrast enhancement of the renal cortex was poor,
(3) where the dose of intravenous injected contrast media...
Results
The ICC was calculated at 0.86.
The detection rate for renal stones in CMP and NGP,
by reviewer and totally,
are represented in Table 1.
Table 2 shows the detection rate for each phase stratified by size.
There was no statistically significant difference between the CMP and NGP for detecting renal stones (p=0.94).
The detection rate for stones measuring 3-5mm was 82-88% and 98% for stones ≥6mm.
Figures 1 to 5 show different examples of how the readers interpreted the examinations in various cases.
Conclusion
Our study showed that the intravenous administration of iodinated contrast media in abdominal CT does not preclude the detection of renal stones,
especially those that are more clinically important.
Contrast-enhanced abdominal CT,
irrespective of the phase that it is performed (CMP or NGP),
can reliably detect (98%) renal stones measuring 6mm or more,
meaning that stones with a higher risk of not passing spontaneously can be safely diagnosed [6,7].
Furthermore,
a high proportion (82-88%) of smaller stones (3-5mm) is confidently seen after the intravenous administration...
References
1) Detection of renal calculi on late arterial phase computed tomography images: Are Noncontrast Scans Always Needed to Detect Renal Calculi? Kawamoto S,
Horton KM,
Fishman EK.
Journal of computer assisted tomography; Nov-Dec,
2008,
vol 32 number 6,
p859-p864,
6p.
Baltimore.
2) What the radiologist needs to know about urolithiasis: Part 1 – Pathogenesis,
types,
assessment,
and variant anatomy.
Cheng PM,
Moin P, Dunn MD,
Boswell WDand Duddalwar VA.
AJR; Jun,
2012,
198 6,
pW540-pW547,
8p.
3) Nonobstructing renal stones on unenhanced CT: A real...