Indian Journal of Urology
ORIGINAL ARTICLE
Year
: 2007  |  Volume : 23  |  Issue : 2  |  Page : 119--121

Role of non-contrast spiral computerized tomography in acute ureteric colic


S Feroze1, Baldev Singh2, T Gojwari1, S Manjeet1, Bashir Athar2, Hussain Hamid1,  
1 Department of Radiodiagnosis, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, India
2 Department of Urology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, India

Correspondence Address:
S Feroze
Department of Radiodiagnosis, Sher-i-Kashmir Institute of Medical Sciences, Soura, Srinagar -190 011, GPO Post Bag No. 27, Kashmir
India

Abstract

Aim: To evaluate the sensitivity and specificity of noncontrast helical computerized tomography (CT) in ureteric colic with comparative evaluation of KUB and ultrasonography (USG). Setting: Tertiary care university hospital. Materials and Methods: One hundred patients aged between 20 and 75 years referred from the emergency department as acute ureteric colic were evaluated with KUB and USG followed by noncontrast helical CT. Results: Noncontrast helical CT was 91% sensitive and 98% specific in detecting urolithiasis compared to a sensitivity of 20% and 30% for KUB and USG and specificity of 94% and 98% respectively. Conclusion: Noncontrast helical CT is a very sensitive and specific investigation for evaluation of acute flank pain due to urolithiasis, besides helping in the detection of nonrenal causes of pain.



How to cite this article:
Feroze S, Singh B, Gojwari T, Manjeet S, Athar B, Hamid H. Role of non-contrast spiral computerized tomography in acute ureteric colic.Indian J Urol 2007;23:119-121


How to cite this URL:
Feroze S, Singh B, Gojwari T, Manjeet S, Athar B, Hamid H. Role of non-contrast spiral computerized tomography in acute ureteric colic. Indian J Urol [serial online] 2007 [cited 2020 Aug 15 ];23:119-121
Available from: http://www.indianjurol.com/text.asp?2007/23/2/119/32059


Full Text

Acute ureteric colic is one of the most common emergency admissions and needs an investigation which is sensitive, specific and quick to perform, not only to confirm urolithiasis but also to exclude serious nonrenal conditions in need of immediate intervention. Noncontrast helical computerized tomography (NCCT) fulfils most of these requirements.

 Materials and Methods



One hundred patients aged 20-75 years were referred from the Emergency Department over the last two years for evaluation of acute urteric colic. Out of 100 patients 68 were male and 32 were female with median age of 38 years in males and 33 years in females.

These patients were referred from casuality and had ureteric colic ranging in duration from a few hours to a maximum of 36h presenting first time or as second or third episode of ureteric colic. All the patients had plain KUB and ultrasonography (USG) followed by NCCT. The machine used for KUB was 500 mAs GE Wipro (nondigital), NCCT of whole abdomen was done on Siemens Emotion spiral CT with 8 mm slice thickness and 4 mm recon increment. Findings were evaluated by radiologist. Patients with positive and/or equivocal findings on KUB and USG (e.g., dilated pelvicalceal system) or negative results from the above modalties were subjected to NCCT. The radiologist knew the findings of these tests beforehand and he confirmed or negated the findings on NCCT. Besides direct signs of urolithiasis, indirect signs like hydronephroris, hydroureter and peri-ureteric or peri-nephric stranding were also recorded.[14] The findings were confirmed on operative retrieval or spontaneous passage. Patients after emergency NCCT were followed up in OPD for spontaneous passage, persistence or aggravation of symptoms. All these cases were followed for a few months to 18 months depending upon whether the stone was passed spontaneously or the patient was subjected to surgical intervention.

 Results



Urolithiasis was found in 20 patients on plain KUB, of which 14 constituted ureteric calculi. The USG showed direct evidence of urolithiasis in 27, renal calculi in 14, ureteric calculi in nine and both in four, the size of stone varied from 3 mm to 24 mm with median size 11 mm. Most calculi detected on USG were either at the pelviureteric or at the vesico-ureteric junction. Indirect signs of urolithiasis were seen in 36%. NCCT detected calculi in 40 patients, both ureteric [Figure 1],[Figure 2] and renal [Figure 3] in 17 and only ureteric calculi in the rest of the 23 patients.

In our study the true incidence of ureteric calculi was 43 on the basis of spontaneous passage or ureteroscopic removal. Twenty patients out of a total of 40 who had calculi on CT were missed on X-ray KUB and had median size of 9 mm, both ureteric as well as renal. The NCCT showed false positive result for stone in one patient, the ultrasound showed for one patient and KUB for three patients who had no stones.

Out of 40 patients who were labeled as having renal/ureteric calculus on NCCT one patient had renal parenchymal calcification and USG defined it better and easily whereas it was indistinguishable on NCCT and was taken as false positive. Variation in result due to different age group did not affect our study by NCCT, however, USG findings were difficult to obtain in obese patients.

Comparative sensitivity of KUB, USG and NCCT was 20%, 30% and 91% and specificity 94%, 98% and 98% in that order.

 Discussion



The conventional modalities of ureteric colic/ flank pain investigation are plain KUB, ultrasound and IVU. In one study plain KUB had sensitivity and specificity of 45% and 77% respectively.[1] USG alone has a sensitivity of 56%.[2] USG alone missed stones et al 2003[12] in their comments describe the high accuracy rate of helical CT scan in detecting urolithiasis even at low doses.[13] In conclusion helical noncontrast CT is a sensitive, specific and quick investigation for evaluation of urolithiasis, with additional benefit of detecting nonurinary causes of flank pain. Latest protocols of low-dose CT would further enhance its utility.

 Conclusion



Plain KUB and USG are less sensitive than NCCT although specificity is almost the same. USG diagnosed 27 cases and missed 13 cases whereas NCCT diagnosed all 40 cases. We recommend NCCT in all cases of clinical findings of urerteric colic where plain KUB and USG are negative or equivocal.

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