Radiofrequency ablation for benign thyroid nodules.

Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

Clinical application of low-dose phase contrast breast CT: methods for the optimization of the reconstruction workflow.

Results are presented of a feasibility study of three-dimensional X-ray tomographic mammography utilising in-line phase contrast. Experiments were performed at SYRMEP beamline of Elettra synchrotron. A specially designed plastic phantom and a mastectomy sample containing a malignant lesion were used to study the reconstructed image quality as a function of different image processing operations. Detailed evaluation and optimization of image reconstruction workflows have been carried out using combinations of several advanced computed tomography algorithms with different pre-processing and post-processing steps. Special attention was paid to the effect of phase retrieval on the diagnostic value of the reconstructed images. A number of objective image quality indices have been applied for quantitative evaluation of the results, and these were compared with subjective assessments of the same images by three experienced radiologists and one pathologist. The outcomes of this study provide practical guidelines for the optimization of image processing workflows in synchrotron-based phase-contrast mammo-tomography.

The role of CEUS in the characterization of hepatocellular nodules detected during the US surveillance program--current practices in Europe.

The basic pathological feature for the differential diagnosis between hepatocellular carcinoma (HCC) and non-malignant hepatocellular nodules in cirrhotic patients detected during ultrasound (US) is the vascular supply to the nodule. Computed tomography (CT) and magnetic resonance imaging (MRI) are considered reference imaging techniques for depicting hepatocellular nodule vascularity in the noninvasive diagnosis of HCC. Contrast-enhanced US (CEUS) improves the diagnostic performance of unenhanced US in the diagnosis of HCC, giving an overall diagnostic accuracy that is similar to that of CT, even for nodules smaller than 2 cm. An additional diagnostic feature of CEUS relative to CT is the possibility to visualize contrast wash-in to hepatic nodules during the arterial phase and contrast washout during the portal venous and late phases. Sensitivity for the diagnosis of HCC with combined assessment of CEUS and CT is higher than for separate assessments of CEUS and CT due to the reduction of false-negative findings. CEUS represents a competitive imaging method from an economic point of view, and is an effective imaging tool for assessing the therapeutic outcome after surgery, ablation therapy, and transarterial chemoembolization (TACE).

64-Slice CT urography: optimisation of radiation dose.

PURPOSE: This study assessed means by which to optimise 64-slice computed tomography urography (CTU) in evaluating the urinary tract, with a view to obtaining the best trade-off between image quality and radiation dose. MATERIALS AND METHODS: Image quality was analysed in terms of spatial and contrast resolution on several scans of a phantom performed with automatic dose modulation and different reconstruction kernels and accepted noise level. Data were compared with the radiation dose values recorded for 52 patients who underwent CTU examination. RESULTS: Radiation dose and image quality differed considerably depending on the reconstruction parameters, even though a higher dose did not always imply better image definition. Data obtained in the phantom were consistent with those obtained in patients. Depending on the clinical problem, the radiation dose varied from 6.2 to 17.6 mSv. CONCLUSIONS: CTU cannot be considered a standard examination: the scan parameters need to be adapted to the image quality required for the specific clinical problem.

64-Slice CT urography: 30 months of clinical experience.

PURPOSE: This study sought to assess the diagnostic accuracy of 64-slice computed tomography urography (CTU) in evaluation of the urinary tract. MATERIALS AND METHODS: A total of 322 CTU procedures were carried out in 317 consecutive patients (mean age 64.4 years). The findings were compared with previous and subsequent patient workup considering both laboratory and imaging studies, such as urine cytology, abdominal ultrasound and CT, cystoscopy, retrograde pyelography, surgery and pathology. RESULTS: Out of 322 CTU examinations, 169 showed significant urinary tract changes, whereas 153 revealed no urinary disease, in good agreement with the follow-up. In particular, in bladder evaluation, for which we have a direct comparison with cystoscopy in 125 patients, we calculated a CTU sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of 85%, 94%, 92%, 89% and 90%, respectively. CONCLUSIONS: CTU was accurate for urinary tract evaluation, but it cannot replace cystoscopy in patients in whom a malignant bladder disease is suspected.

64-Slice CT coronary angiography versus conventional coronary angiography: activity-based cost analysis.

PURPOSE: This study was done to analyse the costs of 64-slice computed tomography (CT) coronary angiography and conventional coronary angiography and determine the cost-effectiveness of the two modalities. MATERIALS AND METHODS: Detailed activity-based cost analyses of the two modalities were carried out at the departments of radiology and cardiology of a teaching hospital. The differential costs (equipment, variable, personnel), common costs and external costs were estimated. Finally, the full costs of the two procedures were obtained; the full cost of conventional coronary angiography also considered the cost of 1 day in hospital. The cost-effectiveness of the two procedures at different levels of pretest likelihood of coronary artery disease (CAD) was estimated. RESULTS: The costs of multidetector CT (MDCT) coronary angiography were as follows: differential cost 222.23 euro, common cost 5.50 euro, external cost 2.30 euro and full cost 230.03 euro. The costs of conventional coronary angiography were: differential cost 366.18 euro, common cost 0.50 euro, external cost 9.20 euro, hospitalisation cost 1,652 euro and full cost 2,027.88 euro. Cost-effectiveness analysis showed that the cost per correctly identified CAD patient decreased exponentially with increasing pretest likelihoods of CAD. MDCT coronary angiography was more cost effective than conventional coronary angiography up to a pretest likelihood of 86%. CONCLUSIONS: MDCT coronary angiography has far lower costs than conventional coronary angiography, and its cost-effectiveness is better in the large majority of patients.

CT urography: the end of IVU?

A review of the literature on the diagnostic accuracy of multidetector computed tomography urography (MDCTU) and intravenous urography (IVU) reveals a lack of comparative studies. However, the available data indicate that MDCTU has a high diagnostic accuracy. MDCTU is also preferred by patients, as it does not require bowel preparation. Full acceptance of this technique by the urologist will depend on optimisation of the communication process with a careful selection of the images to be transmitted. MDCTU has a higher cost than IVU but allows some diagnostic algorithms to be simplified. The real concern potentially limiting the widespread use of MDCTU is its higher radiation dose when compared with IVU. Although low-dose protocols will soon be available, a substantial dose reduction can already be achieved by tailoring MDCTU to the clinical problem rather than using a standardised approach. Our analysis indicates that IVU will definitely lose any residual role it may still have. In our department, the last urographic procedure was performed in May 2006.

Renal artery stenosis: comparative evaluation of gadolinium-enhanced MRA and DSA.

PURPOSE: This study was undertaken to evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in detecting renal artery stenosis using intra-arterial digital subtraction angiography (DSA) as the gold standard. MATERIALS AND METHODS: Thirty-five consecutive patients with possible renovascular hypertension were prospectively studied; 26 of them underwent both MRA and DSA. In these 26 cases, two readers assessed the number of renal arteries, the presence of stenoses and their degree. Results were compared with DSA, and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of MRA were determined. Interobserver variability was also calculated. RESULTS: DSA showed 51 main renal arteries (one patient had a single kidney) and six accessory arteries (total number of arteries 57) in the 26 patients considered. Both MRA readers detected all of the 51 main renal arteries and only one accessory vessel. When the presence of stenosis was considered, the readers' results, respectively, were as follows: sensitivity 77% and 72%, specificity 69% and 69%, PPV 86% and 85%, NPV 55% and 50% and diagnostic accuracy 75% and 71%. When the detection of significant stenosis was considered, the results, respectively, were: sensitivity 83% and 83%, specificity 73% and 78%, PPV 60% and 65%, NPV 90% and 91%, and diagnostic accuracy 76% and 80%. Interobserver variation was good when considering stenosis detection (kappa=0.69) and excellent when considering detection of significant stenosis (kappa=0.85). CONCLUSIONS: MRA results do not appear as positive as in the majority of papers in the literature. Multiple reasons can probably be invoked to explain this difference. The mean age of our patients, higher than in many other studies, should be noted and may have accounted for their possible poor cooperation. Moreover, all of the missed significant stenoses were distally located, and therefore, the failure to detect them might be related to the suboptimal spatial resolution of MRA. Nevertheless, MRA showed a high NPV for detecting significant stenoses, a finding of considerable clinical relevance in that it allows patients with normal MRA findings to be spared additional more invasive procedures.

US, colour-Doppler US and fine-needle aspiration biopsy in the diagnosis of thyroid nodules.

PURPOSE: The purpose of this study was to correlate the diagnosis of benign or malignant thyroid nodules obtained with grey-scale ultrasound (US) and colour-Doppler US with the cytological findings after US-guided fine-needle aspiration (FNA). MATERIALS AND METHODS: Between January 2004 and June 2005, 516 thyroid nodules in 420 patients (181 solitary thyroid nodules and 239 multiple nodules) were prospectively evaluated with US, colour-Doppler US and US-guided FNA. The nodules were classified as sonographically benign, suspicious or malignant in accordance with established US criteria. Cytological findings were classified as inadequate, benign, indeterminate, suspicious or malignant. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of US and colour-Doppler US were evaluated using FNA as the reference procedure. RESULTS: The sensitivity, specificity, PPV, NPV and overall accuracy values of grey-scale US were 46%, 73%, 34%, 82% and 67%, respectively, for solitary thyroid nodules and 35%, 72%, 14%, 90% and 68%, respectively, for multiple nodules. The evaluation of nodule vascularity with colour-Doppler US produced a slight increase in sensitivity but a slight reduction in specificity. CONCLUSIONS: Thyroid nodules cannot be accurately characterised using grey-scale US or colour-Doppler US.

The radiologist and the cytologist in diagnosing thyroid nodules: results of cooperation.

PURPOSE: This study was done to evaluate the effectiveness of cooperation between the radiologist and the cytopathologist in ultrasound-guided fine-needle aspiration biopsy (FNAB) of thyroid nodules. MATERIALS AND METHODS: Since 1995, FNAB of thyroid nodules at our department has been performed under ultrasound guidance by the radiologist with a cytopathologist present on-site. The results of ultrasound-guided FNAB procedures performed at our department in 1995, 1999, and 2005 were retrospectively evaluated and compared with those of other departments in the Trieste Province where thyroid nodules are sampled by palpation-guided FNAB performed by a clinician. RESULTS: From 1995 to 2005, the number of ultrasound-guided FNAB procedures performed at our department rose steadily, whereas the number of inadequate samples fell progressively. In patients who underwent surgery, the number of discrepancies between the cytological findings and the final histological diagnoses decreased progressively. CONCLUSIONS: Ultrasound-guided FNAB performed by the radiologist with a cytopathologist present on-site is superior to palpation-guided FNAB. The results are optimised by cooperation between the radiologist and cytologist.

MR angiography versus intra-arterial digital subtraction angiography of the lower extremities: activity-based cost analysis.

PURPOSE: The aim of this study was to analyse the costs pertaining to the radiology department of magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA) in the evaluation of arterial disease of the lower limbs. MATERIALS AND METHODS: The differential cost of the two procedures, i.e. the sum of equipment costs (amortisation and service contract), variable costs (supplies and related services) and personnel costs (radiologist, radiographer and nurse) was determined. The common cost (auxiliary personnel and indirect internal costs) was also calculated. Finally, the full cost of the two procedures was obtained (sum of differential and common costs). RESULTS: The differential cost of MRA was 186.14 euro (equipment costs: 50.80 euro, variable costs: 75.04 euro, personnel costs: 60.30 euro) while the differential cost of intra-arterial DSA was 238.18 euro (equipment costs: 57.60 euro, variable costs: 90.13 euro, staff costs: 90.45 euro). The estimated common cost was 5.62 euro. Therefore, the full cost of MRA was 191.76 euro and the full cost of intra-arterial DSA was 243.80 euro (27.1% higher). DISCUSSION AND CONCLUSIONS: Intra-arterial DSA costs more than MRA, mainly because of the higher costs of supplies used during the procedure and higher personnel costs (as a result of the longer duration of intra-arterial DSA). It should be noted that our evaluation considers costs pertaining to the radiology department only. It is evident that an economic analysis considering hospital costs as well would result in much higher costs for DSA if post-procedure hospitalisation is required. Our results cannot be simply exported to other radiology departments since they refer to the technology and organisation adopted in our department. However, our cost analysis model can be easily applied to other environments. MRA provides good diagnostic accuracy in the evaluation of arteries of the lower extremities, and its biological cost is far lower than that of intra-arterial DSA (MRA is noninvasive, it does not use ionising radiation, and the contrast medium is safe). Its lower cost is another argument in favour of the use of MRA instead of intra-arterial DSA in the evaluation of lower-extremity arterial disease.

Diffusion-weighted MRI in the evaluation of renal lesions: preliminary results.

The purpose of this study was to evaluate the capability and the reliability of diffusion-weighted MRI in the evaluation of normal kidney and different renal lesions. 39 patients (10 normal volunteers and 29 patients with known renal lesions) underwent MRI of the kidneys by using a 1.5 T superconducting magnet. Axial fat suppressed turbo spin echo (TSE) T(2) and coronal fast field echo (FFE) T(1) or TSE T(1) weighted images were acquired for each patient. Diffusion-weighted (DW) images were obtained in the axial plane during breath-hold (17 s) with a spin-echo echo planar imaging (SE EPI) single shot sequence (repetition time (TR)=2883 ms, echo time (TE)=61 ms, flip angle=90 degrees ), with b value of 500 s mm(-2). 16 slices were produced with slice thickness of 7 mm and interslice gap of 1 mm. An apparent diffusion coefficient (ADC) map was obtained at each slice position. The ADC was measured in an approximately 1 cm region of interest (ROI) within the normal renal parenchyma, the detected renal lesions and the collecting system if dilated. ADC values in normal renal parenchyma ranged from 1.72 x 10(-3) mm(2) s(-1) to 2.65 x 10(-3) mm(2) s(-1), while ADC values in simple cysts (n=13) were higher (2.87 x 10(-3) mm(2) s(-1) to 4.00 x 10(-3) mm(2) s(-1)). In hydronephrotic kidneys (n=6) the ADC values of renal pelvis ranged from 3.39 x 10(-3) mm(2) s(-1) to 4.00 x 10(-3) mm(2) s(-1). In cases of pyonephrosis (n=3) ADC values of the renal pelvis were found to be lower than those of renal pelvis of hydronephrotic kidneys (0.77 x 10(-3) mm(2) s(-1) to 1.07 x 10(-3) mm(2) s(-1)). Solid benign and malignant renal tumours (n=7) showed ADC values ranging between 1.28 x 10(-3) mm(2) s(-1) and 1.83 x 10(-3) mm(2) s(-1). In conclusion diffusion-weighted MR imaging of the kidney seems to be a reliable way to differentiate normal renal parenchyma and different renal diseases. Clinical experience with this method is still preliminary and further studies are required.

An unusual use of AMS 800 artificial urinary sphincter cuff in the treatment of sphincteric neurogenic incontinence: case report.

STUDY DESIGN: Case report of an unusual use of AMS 800 (American Medical Systems, Inc., Minnetonka, Minnesota) artificial urinary sphincter cuff in a female patient affected by neurogenic urinary incontinence. OBJECTIVE: To describe this rare surgical solution. SETTING: Department of Urology in Italy. METHODS: A 43-year-old woman affected by flaccid paraplegia, acontractile bladder and incompetent bladder neck, underwent an implantation of an artificial urinary sphincter AMS 800. After 7 years, a mechanical failure of the device occurred and pubovaginal sling (PVS) utilizing the cuff of the sphincter was employed due to the poor quality of rectus fascia and the development of previous allergy for some heterologous materials. RESULTS: At 17 months follow-up, the patient is content and able to empty the bladder by clean intermittent self-catheterization (CIC). CONCLUSION: The risk of developing an allergy reaction due to the employment of heterologous materials and the impossibility to use the rectus fascia obliged us to adopt the pre-existent cuff of the artificial urinary sphincter AMS 800.

Comparison between the efficacy of dimeric and monomeric non-ionic contrast media (iodixanol vs iopromide) in urography in patients with macroscopic haematuria.

Non-ionic dimers induce less diuresis than non-ionic monomers, resulting in increased opacification of the urinary tract in intravenous urography. This trial compared the diagnostic efficacy of iodixanol and iopromide in patients with macroscopic haematuria. One hundred consecutive patients with normal renal function and macroscopic haematuria entered a double blind, comparative, randomised, parallel trial. Contrast media were given with bolus injection in doses of 300 mgI/kg b.w. Radiographs were blindly evaluated by three radiologists who analysed different parameters (calyceal density and filling, papillary blush detection, delineation of collecting ducts, renal pelvis opacification, visualisation of ureters, bladder density, bladder distention) and estimated the diagnostic confidence (whether abnormal findings were definitely absent, probably absent, doubtful, probably present or certainly present). Radiological diagnoses were compared with final diagnoses. Results were summarised as the ratio of the odds of having a worse performance of iopromide vs iodixanol. Iodixanol showed a significantly better calyceal density and filling [odds ratio (OR): 1.96; 95% confidence interval (CI): 1.60-2.41], a significantly better pelvis opacification (OR 2.91; CI 2.02-4.18) and a significantly more frequent papillary blush detection (OR 1.95; CI 1.29-2.95). Iopromide showed a significantly better ureteral visualisation (OR 0.67; CI 0.48-0.92) and a significantly higher bladder distention (OR 0.59; CI 0.36-0.99). Iodixanol allowed a significantly higher diagnostic confidence as to calyceal evaluation (OR 1.35; CI 1.01-1.79). No significant differences were found with regard to other parameters. The results confirmed theoretical expectations. The higher opacification provided by iodixanol allowed better results and a higher diagnostic confidence in the upper excretory pathway.

Contrast medium extravasation injury: guidelines for prevention and management.

Extravasation of contrast material is a well-recognized complication of contrast-enhanced imaging studies. The management of this complication is contentious; therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and issue guidelines. A comprehensive literature search was carried out. The resulting report was discussed at the 8th European Symposium on Urogenital Radiology in Genoa, Italy. Automated power injection may result in extravasation of large volumes and may or can lead to severe tissue damage. Infants, young children and unconscious and debilitated patients are particularly at risk of extravasation during contrast media injection. Fortunately, most extravasations result in minimal swelling or erythema, with no long-term sequelae; however, severe skin necrosis and ulceration may occur. Large volumes of high osmolar contrast media are known to induce significant tissue damage. Compartment syndrome may be seen associated with extravasation of large volumes. Conservative management is often adequate, but in serious cases the advice of a plastic surgeon is recommended. Based on the review simple guidelines for prophylaxis and management of contrast medium extravasation injuries are proposed.

Percutaneous ethanol injection of the prostate as minimally invasive treatment for benign prostatic hyperplasia: preliminary report.

OBJECTIVE: To evaluate the feasibility, safety and efficacy of a minimally invasive treatment for benign prostatic hyperplasia (BPH) consisting of percutaneous ethanol injection inside the prostate under ultrasound surveillance. MATERIAL AND METHODS: Transperineal ethanol injection into the prostate was performed in 8 patients who were affected by obstructive BPH according to AUA symptom score, impaired urinary flow, and volume of postvoiding residual urine. Injections were performed under transrectal ultrasound surveillance at four sites of the prostate for an overall amount of 6 ml of ethanol per patient. The procedure was performed under local anesthesia. RESULTS: The patients' median age was 69.7 years (range 57-83). No major intraoperative or postoperative complications were encountered. The median symptom score decreased from 21+/-5.2 (range 14-28) to 10+/-4.4 (range 1-14) at 3 months postoperatively (p<0.0001). The median peak flow rate increased significantly from 11 ml/s (range 7-17) before the procedure to 16 ml/s (range 12-20) after it (p<0.001). The median volume of post-voiding residual urine dropped from 130 ml (range 36-200) before treatment to 27 ml (range 11-42) after it (p<0.01). The same parameters were assessed at 6 months without significant differences. A mild side effect was observed in 1 patient who reported severe urge incontinence and moderate perineal pain the first month after the procedure. CONCLUSION: Percutaneous ethanol injection therapy of the prostate is a safe, easy and minimally invasive procedure for treating BPH, especially when there is an high operative risk.

[Ultrasonography plus direct radiography of the abdomen in the diagnosis of renal colic: still a valid approach?]. / Ecografia e radiogramma diretto dell'addome nella diagnostica della colica renale: un approccio ancora valido?

PURPOSE: The authors analyze whether the imaging approach consisting of ultrasonography and plain film in patients with renal colic is still of value when urography is replaced by unenhanced helical CT (UHCT) in unsolved cases. MATERIAL AND METHODS: Eight hundred and three consecutive patients were investigated with US following hydration and KUB, 164 of whom (20.4%) subsequently underwent UHCT (42 with the aim of mapping the excretory pathway and 122 (15.2%) because US and KUB were not considered as fully diagnostic). RESULTS: The 42 patients with detectable ureteral stone (plus possible hydronephrosis) on KUB + US and subsequently examined by UHCT to plan interventional treatment all had a positive UHCT examination. In 62 patients the diagnosis following KUB + US was uncertain (possible stone or possible hydronephrosis) and UHCT depicted the stone and/or the hydronephrosis in 34. In 60 patients the combination of KUB + US was negative but colic recurred and UHCT was positive in 17 patients. DISCUSSION: The comparison of the present results with a previous study in which KUB and US were followed by IVU in unsolved cases underscores the value of the first approach with KUB and US. The need for further diagnostic investigations when KUB + US are either not conclusive or negative and colic recurs is also confirmed. On the basis of our present data and in agreement with the literature IVU can be safely replaced by UHCT. CONCLUSIONS: It is authors' opinion that in settings where KUB, US and UHCT are available throughout the 24 hr the approach consisting of KUB plus US and UHCT in unsolved cases can be preferred in view of its on lower cost and above all lower X-ray dose to patients as compared to UHCT as the sole investigation.

Current iodinated contrast media.

The number of scientific papers on iodinated contrast media is declining. Indeed, comparative trials between high-osmolality and low-osmolality agents largely showed the higher safety and tolerability of the latter, and this is no longer a matter of discussion. Only financial constraints could prevent a total conversion to low-osmolality agents. Research comparing low-osmolality (nonionic monomers, ionic dimer) and iso-osmolality contrast media (nonionic dimers) are still ongoing. Both classes of nonionic compounds proved safer than the ionic dimer. The relative merits of nonionic monomers and nonionic dimers are a matter for debate, and criteria for a selective use of different agents for different procedures could be discussed.

Present-day imaging of patients with renal colic.

In the past decade alternatives to urography have been proposed for the study of patients with renal colic. In 1992 it was suggested to replace urography with KUB and ultrasonography. In 1993 the combination of KUB and ultrasonography followed by urography in unresolved cases was proposed and, in 1995, it was suggested to replace urography with unenhanced helical CT (UHCT). This article illustrates the contribution of UHCT to the study of patients with renal colic and analyses advantages and shortcomings of the technique compared with other diagnostic approaches. Diagnostics of the patient with renal colic is based on the detection of direct and indirect signs which allow identification of not only the calculus, with a sensitivity of 94-100% and accuracy of 93-98% according different authors, but also other signs that can serve to guide patient management and evaluate long-term prognosis. Unenhanced helical CT has the capability to detect extraurinary abnormalities which present with flank pain and mimic renal colic. The examination technique affects the quality of the images and therefore diagnostic accuracy as well as the dose to the patient. With regard to setting parameters, the choice of thickness and table feed should be guided by numerous factors. Multiplanar reconstruction is indicated in the study of the entire ureter course to identify the exact site of the calcification for the urologist to perform an evaluation similar to that obtained by urography. Many authors consider UHCT to be a valuable tool for suggesting the best therapeutic approach. Among these there are also urologists. The evaluation is based on the stone detection, its size and level in the urinary tract. Cost analysis shows that the cost of UHCT is equal to or inferior to the cost of urography. With regard to the dose, different data are reported in the literature. A high pitch (more than 1.5) and a thin collimation (3-mm thickness) are good compromise between quality and dose which can be compared to the dose of normal urography. What is to be done if helical CT is not available? If helical CT is not available, plain film plus ultrasonography should be considered. This approach does not solve all the cases; in unresolved cases urography is indicated. It should also be noted that US has a good sensitivity in detecting other conditions such as biliary lithiasis, acute pancreatitis, acute appendicitis and abdomino-pelvic masses which are responsible for pain that mimics renal colic. In conclusion, IVU should not have any more the priority in investigating the patients with renal colic. Helical CT should be the first choice in imaging a patient with renal colic. If this technique is not available, plain film and ultrasonography should be considered adding urography in unresolved cases.