Evaluation Of Acute Flank Pain Research Articles

When flank pain leads to fainting: a case of a ruptured angiomyolipoma diagnosed by point-of-care ultrasound

BackgroundAcute flank pain is a common presentation in the Emergency Department (ED). Point-of-care ultrasound (PoCUS) has emerged as an invaluable tool in the evaluation of acute flank pain and provides real-time images resulting in the early identification of the underlying pathology.Case ReportHere we report a case of a young lady presented to the ED with a complaint of right flank pain followed by a syncopal episode. The diagnosis of ruptured angiomyolipoma was made using a PoCUS and an immediate consult to interventional radiology and urology was provided.ConclusionThis case highlights the importance of PoCUS in assessing patients presented to the ED with acute flank pain. Its incorporation into clinical practice promises to revolutionize the approach to renal emergencies, emphasizing its important role in delivering timely and effective care.

Profile of patients subjected for intravenous urography

In the evaluation of acute flank pain, ultrasonography (US) is limited primarily to pregnant patients. While US demonstrates renal calculi, it is poor at detecting ureteral stones. Doppler sonography has been suggested as a method of indirectly determining obstruction by measuring the resistive index in renal arteries and evaluating the direction and magnitude of ureteral jets. 100 patients of symptoms of unilateral acute renal colic are subjected to Doppler evaluation of control and case kidney and the RI of both kidneys were obtained and delta RI was calculated by difference in RI of case and control kidney. Of 100 patients, 77 were men and 23 were women. The mean age (in years) in men is 31.36 ± 11.23 (17-61) was lower as compared to women 32.69 ± 12.55 (17-65). This difference was not statistically significant (p value 0.6502).

Re: Imaging the urologic patient: the utility of intravenous pyelogram in the CT scan era

We read with great interest the recent article by Hale et al. [1] on the comparative study of intravenous urography (IVU) and computerized tomography (CT). They concluded that IVU has a limited clinical role on the evaluation of the urologic patient, and thus, its use should be strictly limited to highly select cases. We congratulate the authors for their work and thank them for bringing this important topic to our attention; however, we feel that some issues described in their paper need further discussion. We know that noncontrast CT is the most accurate imaging method for identifying urinary stones, and it has become the standard test for diagnosis of acute flank pain [2]. It offers the advantages over IVU of avoiding contrast allergy or nephrotoxicity and has ability to determine the other causes for abdominal pain. However, most of the patients with a history of flank pain return with similar symptoms and need to undergo repetitive CT examinations. Furthermore, current EAU guidelines recommend a contrast study (enhanced CT or IVU) if stone removal is planned, because the anatomy of the renal collecting system needs to be assessed prior to stone surgery or shock wave lithotripsy [2]. But use of repeated CT or IVU would increase the risk of cancer development. Epidemiological trials have reported an association between doses of radiation administered in CT and an increased risk of malignancy [3]. Recently, published studies also reported a theoretic increased risk of fatal cancer in pediatric and adult population as a result of single CT scan, based on data from similar levels of exposure to radiation during the atomic bombings of Nagasaki and Hiroshima [4, 5]. It was underlined that a single abdomen CT in infants would cause in one CT-related death per 550 scans [6]. Therefore, we believe that combination of ultrasonography and abdominal radiography may be considered in the evaluation of acute flank pain especially in children and patients with known urinary stone disease. Noncontrast CT may be reserved for those patients with suspected urolithiasis but negative findings on plain radiography and ultrasonography.

Alternate and incidental diagnoses on noncontrast-enhanced spiral computed tomography for acute flank pain.

Our aim was to determine the incidence and spectrum of significant alternate or incidental diagnoses established or suggested on spiral computed tomography (CT) in a large series of patients with suspected renal colic. Records of all patients that had undergone spiral CT (5-mm to 7-mm slice thickness) for acute flank pain during a 5-year period were reviewed. The radiological diagnoses of urinary calculi and obstruction as well as clinical entities not suspected otherwise were analyzed. A total of 4000 CTs had been performed in the evaluation of acute flank pain. Urinary calculi had been identified in 3120 patients (78.0%). There were 398 patients (9.9%) who had an alternate cause of flank pain or an incidentally detected condition on CT. Of these patients, 102 (25.6%) had more than one additional finding. A total of 153 clinical conditions had been identified mimicking flank pain secondary to calculus and obstruction. In 47 patients (1.2%), incidental solid masses had been detected. Spiral CT is a valuable technique in the evaluation of acute flank pain with uncertain clinical diagnosis. A wide spectrum of alternate and additional diagnoses including abdominal solid organ tumors and other significant abdominal conditions such as pancreatitis can be established or suggested on spiral CT performed for suspected acute urinary colic.

Reply

As clearly and compendiously stated by the reviewer, magnetic resonance urography (MRU) has the potential to be the much anticipated alternative to investigations that require the use of ionizing radiation and contrast. The oncogenic risks 1 Pearce M.S. Salotti J.A. Little M.P. et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. Lancet. 2012; 380: 499-505 Abstract Full Text Full Text PDF PubMed Scopus (2493) Google Scholar attributed to computed tomography (CT) are augmented in urologic studies, which typically require dual or triple phase scanning. 2 Silverman S.G. Leyendecker J.R. Amis Jr., E.S. What is the current role of CT urography and MR urography in the evaluation of the urinary tract?. Radiology. 2009; 250: 309-323 Crossref PubMed Scopus (191) Google Scholar Although CT with or without contrast has by and large replaced intravenous urography (IVU), 2 Silverman S.G. Leyendecker J.R. Amis Jr., E.S. What is the current role of CT urography and MR urography in the evaluation of the urinary tract?. Radiology. 2009; 250: 309-323 Crossref PubMed Scopus (191) Google Scholar , 3 Fielding J.R. Steele G. Fox L.A. et al. Spiral computerized tomography in the evaluation of acute flank pain: a replacement for excretory urography. J Urol. 1997; 157: 2071-2073 Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar we are not alone in the belief that the latter cannot yet be written off, 4 Whitfield A.H. Whitfield H.N. Is there a role for the intravenous urogram in the 21st century?. Ann R Coll Surg Engl. 2006; 88: 62-65 Crossref PubMed Scopus (7) Google Scholar more so in resource-poor settings. It is again the cost, along with ease of interpretation, excellent spatial resolution and, quite often, clinician familiarity, which give CT urography the edge over MRU in most cases. Editorial CommentUrologyVol. 81Issue 3PreviewThe authors offer use of static magnetic resonance urography (MRU) in diagnosing hydronephrotic or obstructed renal pathology as opposed to conventional intravenous urography (IVU). They found that the sensitivity and the specificity of MRU was 95% and 100%, respectively, for finding hydronephrosis, although determining the exact grade of obstruction was not as precise (from 33.3% to 92.6% with increasing grades of hydronephrosis). Calculus disease was only determined in 46.6% of imaging studies, but this review was based on elective imaging only. Full-Text PDF

Correlation of volume, position of stone, and hydronephrosis with microhematuria in patients with solitary urolithiasis

BackgroundThe aim of this study was to determine the relationship between hematuria and volume, position of stone, and hydronephrosis in patients with a solitary stone, using unenhanced multidetector computed tomography (MDCT).Material/MethodsThis retrospective study evaluated the clinical and radiological records of 83 patients undergoing MDCT for the evaluation of acute flank pain and suspected renal colic, who also underwent a microscopic urinalysis at the emergency department of our hospital during a 1-year period. Inclusion criteria of the MDCT study were solitary urolithiasis and cumulative stone diameter under 1 cm.ResultsA total of 83 patients were included in the study, with a mean age of 42.1±14.4 years; 48 (57.8%) were females and 35 (42.2%) were males. Detection of 5 or more red cells on urinalysis was regarded as microscopic hematuria, and was positive in 46 patients (55.4%). There was a positive correlation between the position of the stone (especially upper two-thirds ureteral stones) and microhematuria rate (r: 0.28, p=0.009). There was a statistically significant difference in presence of hydronephrosis between the microhematuria (36 patients, 78%) and non-microhematuria (12 patients, 32%) groups (p<0.001). The median stone volume between the microhematuria and non-microhematuria groups were not statistically different, 37.5 mm3 (range 5–425) and 28 mm3 (range 4–412), respectively (p=0.39).ConclusionsAlthough stone volume is one of the best indicators of stone burden, it was not correlated with microhematuria. However, in patients with renal colic, microhematuria requires ultrasound examination whether hydronephrosis and ureteral stones are present or not. Further studies with larger sample sizes are warranted.

Predictive Value of Current Imaging Modalities for the Detection of Urolithiasis During Pregnancy: a Multicenter, Longitudinal Study

We determined the optimal imaging study by which to diagnose and treat pregnant patients with suspected urolithiasis. A retrospective, multicenter study was performed to determine the comparative accuracy of imaging modalities used before the surgical management of suspected urolithiasis in pregnant patients. Patients with a clinical suspicion of urolithiasis were evaluated with directed imaging including renal ultrasound alone, renal ultrasound and low dose computerized tomography, or renal ultrasound and magnetic resonance urography. When indicated, patients underwent therapeutic ureteroscopy. The rate of negative ureteroscopy was determined and the positive predictive values of the imaging modalities were calculated. A total of 51 pregnant patients underwent ureteroscopy. The mean age of the cohort was 27 years. Mean gestational age was 24.4 weeks. Of the women 24 (47%) underwent renal ultrasound and low dose computerized tomography, 22 (43%) underwent ultrasound alone, and 5 (10%) underwent renal ultrasound and magnetic resonance urography. Negative ureteroscopy occurred in 7 of the 51 patients (14%). The rate of negative ureteroscopy among patients who underwent renal ultrasound alone, renal ultrasound and low dose computerized tomography, and renal ultrasound and magnetic resonance urography was 23%, 4.2% and 20%, respectively. The positive predictive value of computerized tomography, magnetic resonance and ultrasound was 95.8%, 80% and 77%, respectively. The rate of negative ureteroscopy was 14% among pregnant women undergoing intervention in our series. Of the group treated surgically after imaging with ultrasound alone, 23% had no ureteral stone, resulting in the lowest positive predictive value of the modalities used. Alternative imaging techniques, particularly low dose computerized tomography, offer improved diagnostic information that can optimize management and obviate unnecessary intervention.

HASTE MRU in the evaluation of acute flank pain

A 20 year old, otherwise healthy, G2PO, 21 week pregnant female presented to the emergency de-partment with a one day history of left flank pain, nau-sea, and vomiting. She denied a history of fevers, chills, or dysuria. Physical examination revealed left costo-vertebral angle tenderness. Laboratory evaluation was significant for leukocytosis (14,000), normal creatinine (0.6), and unremarkable urinalysis. Renal ultrasound demonstrated mild left hydroureteronephrosis without evidence of stone. Subsequent HASTE magnetic reso-nance urography (MRU) revealed a 3mm left ureteral stone, mild hydronephrosis, and a forniceal rupture (Figure-1). The patient was managed conservatively with hydration and oral narcotics. Urolithiasis is not an uncommon finding in pregnancy with an estimated incidence of 1/1,500 pregnancies (1). Although pregnancy does not confer an increased risk of urolithiasis, a shift in stone profile in pregnant patients has been observed. Specifically, there is an increased incidence of calcium phosphate stones as opposed to calcium oxalate stones most commonly observed in non-pregnant females. Rea-sons for this shift in stone composition include an ab-sorptive hyercalciuria and relatively alkaline urine pH that occur in this population (2). Despite the common occurrence of stone disease in pregnancy, safe and ac-curate diagnosis remains a dilemma. When subjecting pregnant patients to diag-nostic imaging studies the potential impact to the fe-tus must be considered. Computed tomography (CT), the gold standard for stone diagnosis, exposes the pa-

Re: Efficacy of Selective α1D-Blocker Naftopidil as Medical Expulsive Therapy for Distal Ureteral Stones

No AccessJournal of UrologyLetter to the Editor/Errata1 Mar 2010Re: Efficacy of Selective α1D-Blocker Naftopidil as Medical Expulsive Therapy for Distal Ureteral StonesX. Sun, L. He, W. Ge and J. Lv J Urol 2009; 181: 1716–1720 T.J. Nirmal T.J. NirmalT.J. Nirmal More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2009.11.066AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "Re: Efficacy of Selective α1D-Blocker Naftopidil as Medical Expulsive Therapy for Distal Ureteral Stones." The Journal of Urology, 183(3), pp. 1260–1261 References 1 : Is there a role for tamsulosin in the treatment of distal ureteral stones of 7 mm or less? Results of a randomised, double-blind, placebo-controlled trial. Eur Urol2009; 56: 407. Google Scholar 2 : Time to stone passage for observed ureteral calculi: a guide for patient education. J Urol1999; 162: 688. Link, Google Scholar 3 : Medical therapy to facilitate urinary stone passage: a meta-analysis. Lancet2006; 368: 1171. Google Scholar 4 : Low dose unenhanced helical computerized tomography for the evaluation of acute flank pain. J Urol2002; 167: 1687. Link, Google Scholar 5 : A systematic review of medical therapy to facilitate passage of ureteral calculi. Ann Emerg Med2007; 50: 552. Google Scholar Department of Urology, Christian Medical College, Vellore, India© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 3March 2010Page: 1260-1261 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information T.J. Nirmal More articles by this author Expand All Advertisement PDF downloadLoading ...

A Novel Method of Imaging Calcium Urolithiasis Using Fluorescence

In the surgical management of urolithiasis the goal of treatment is not only to remove calculi, but also prevent future stone formation by rendering the patient stone-free/fragment-free. Achieving this goal is often difficult with endoscopic procedures due to the inability to visualize small calculi well even with x-ray or ultrasound. We evaluated fluorescence probes as a novel method of identifying calculi in the urinary tract. In vitro calcium stones were incubated with each of the Osteosense 680 and Osteosense 750 calcium binding fluorescence probes, and imaged with a near infrared fluorescence imaging system. Using a mouse model calculi were placed in the renal pelvis and the probes were injected intravenously. Imaging was performed at various times after injection. In vitro the Osteosense 680 probe demonstrated high binding affinity for calcium oxalate-struvite, calcium phosphate-struvite and ammonium urate-calcium oxalate-calcium phosphate stones, and lower binding affinity for the calcium phosphate stone. In contrast, the Osteosense 750 probe demonstrated high binding affinity for calcium oxalate-struvite and calcium phosphate-struvite stones, and lower binding affinity for calcium phosphate and ammonium urate-calcium oxalate-calcium phosphate stones. In vivo intravenous administration of the probes was successful in labeling all calcium stone types tested. Fluorescence imaging provides a new method for identifying calculi in the urinary tract. The improved visualization of these stones/fragments would make endoscopic procedures less difficult, decrease the risk of complications and increase the chance of rendering the patient stone-free/fragment-free.

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

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.

Role of Helical Nonenhanced Computed Tomography in the Evaluation of Acute Flank Pain

To evaluate the role of helical nonenhanced computed tomography (NECT) in the diagnosis of acute flank pain. Seventy-five consecutive patients were analysed retrospectively for profile, loin pain, urine analysis and NECT findings. Diagnostic accuracy of NECT for urolithiaisis was calculated. The value of combined microhaematuria and NECT in the diagnosis of flank pain was also highlighted. The potential for identifying phleboliths and alternative diagnoses on NECT was also explored. There were 46 males and 29 females with an average age of 42.2 years. Forty-four patients presented with acute left flank pain. NECT carries a sensitivity and specificity of 96% for the diagnosis of stone disease. Combined with microhaematuria, NECT has 100% accuracy in picking up urinary tract stones. NECT is the first imaging investigation of choice for the evaluation of patients presenting to the emergency department with flank pain and suspected renal colic.

In reply

Academic Emergency MedicineVolume 13, Issue 6 p. 704-705 Free Access In reply Romolo Gaspari MD, MSc, RMDS, Corresponding Author Romolo Gaspari MD, MSc, RMDS (gasparir@ummhc.org)Search for more papers by this authorKurt Horst MD, Kurt Horst MD University of Massachusetts School of Medicine, Worcester, MASearch for more papers by this author Romolo Gaspari MD, MSc, RMDS, Corresponding Author Romolo Gaspari MD, MSc, RMDS (gasparir@ummhc.org)Search for more papers by this authorKurt Horst MD, Kurt Horst MD University of Massachusetts School of Medicine, Worcester, MASearch for more papers by this author First published: 28 June 2008 https://doi.org/10.1197/j.aem.2006.01.013AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References Sheafor DH, Hertzberg BS Freed KS, et al. Nonenhanced helical CT and US in the emergency evaluation of patients with renal colic: prospective comparison. Radiology. 2000; 217: 792– 7. Ege G, Akman H, Kuzucu K, Yildiz S. Acute ureterolithiasis: incidence of secondary signs on unenhanced helical CT and influence on patient management. Clin Radiol. 2003; 58: 990– 4. Miller OF, Rineer SK Reichard SR, et al. Prospective comparison of unenhanced spiral computed tomography and intravenous urogram in the evaluation of acute flank pain. Urology. 1998; 52: 982– 7. Vieweg J, Teh C Freed K, et al. Unenhanced helical computerized tomography for the evaluation of patients with acute flank pain. J Urol. 1998; 160: 679– 84. Volume13, Issue6June 2006Pages 704-705 ReferencesRelatedInformation

Renal colic: Radiological approach

Acute flank pain is commonly caused by urolithiasis. This paper discusses advantages and disadvantages of procedures used for evaluation of acute flank pain. In our institution, the diagnostic algorithm includes ultrasonography and plain film radiography, and unenhanced spiral CT in equivocal cases.

Editorial comment

Noncontrast enhanced helical CT scanning will detect urinary tract stones in roughly 95% to 98% of patients who have them. 1 Fielding J.R. Steele G. Fox L.A. et al. Spiral computerized tomography in the evaluation of acute flank pain a replacement for excretory urography. J Urol. 1997; 157: 2071-2073 Abstract Full Text Full Text PDF PubMed Scopus (215) Google Scholar , 2 Dalrymple N.C. Verga M. Anderson K.R. et al. The value of unenhanced helical computerized tomography in the management of acute flank pain. J Urol. 1998; 159: 735-740 Abstract Full Text Full Text PDF PubMed Scopus (297) Google Scholar Making an accurate diagnosis in the remaining 2% to 5% of patients with undetected urinary tract stones represents a diagnostic challenge. In these uncommon cases, urologists and radiologists must rely on “secondary” signs of ureteral obstruction. Historically, these signs have included hydronephrosis, hydroureter, unilateral renal enlargement, perinephric stranding, periureteral stranding, and the ureteral tissue rim sign. Of these signs, however, only hydronephrosis and hydroureter occur with relative frequency (70% to 90% of cases) and, hence, have a reasonably high sensitivity. 3 Ege G. Akman H. Kuzucu K. et al. Acute ureterolithiasis incidence of secondary signs on unenhanced helical CT and influence on patient management. Clin Radiol. 2003; 58: 990-994 Crossref PubMed Scopus (55) Google Scholar The other signs occur with less frequency and are, therefore, only helpful if they are present (high specificity but low sensitivity).

Advanced imaging in stone management

Stone disease continues to plague humankind. Recent innovations in minimally invasive surgery, however, have decreased morbidity for the treatment of lithiasis, once only amenable to open surgical techniques. These advances in stone management have also been paralleled in the radiographic armamentarium. Herein, we describe the evolution of initial radiographic workup for urolithiasis, from abdominal radiograph to three-dimensional computed tomography and some of the novel applications thereof. Previously, abdominal radiography was the only modality available for the visualization of calculi. Subsequently, the development of intravenous contrast aided in evaluating renal function, detecting the presence and location of obstruction, and in identifying filling defects. Most recently, prospective randomized trials have demonstrated improved sensitivity and specificity using noncontrast helical computed tomography rather than intravenous pyelogram with regard to the initial evaluation of acute flank pain. Further attempts to lower the overall radiation dose without compromising efficacy have also been introduced. Currently, the volume of calculus disease can be better quantified and somewhat qualified from three-dimensional computer software, thereby optimizing stone management. Considerable progress has been made using minimally invasive techniques in the treatment of nephrolithiasis. Furthermore, advances in radiographic computer hard- and software applications allow for a rapid acquisition time and improved image quality without sacrificing diagnostic accuracy. In time, it is likely that the combination of these enhanced imaging modalities will lead to an improvement in stone localization, fragmentation and stone-free rates.

Unenhanced helical computed tomography in the evaluation of acute flank pain.

The purpose of this study was to determine the value of unenhanced helical computed tomography (UHCT) in the diagnosis of acute flank pain at our institution. Two hundred and thirty-three consecutive UHCT examinations, performed for suspected renal/ureteral colic between July 2000 and August 2001 were reviewed, along with pertinent medical records. Ureteral calculi were identified in 148 (64%) examinations, evidence of recent passage of calculi was found in 10 (4%) and no calculi were found in 75 (32%). Thirty-two of the conservatively managed patients were excluded for inadequate follow-up. In the remaining 201 patients, sensitivity of UHCT in diagnosing calculi was 99% and specificity was 98%, while the positive predictive value was 99% and negative positive predictive value was 98%. Overall, an alternative or additional diagnosis was established in 28 (12%) patients. Upon diagnosis of ureterolithiasis on UHCT, none of the patients required additional imaging studies for confirmation. UHCT is a highly sensitive imaging modality for the detection of urinary tract calculi and obstruction.

Modern approach of diagnosis and management of acute flank pain: review of all imaging modalities.

Acute flank pain is a common and complex clinical problem which might be caused by a variety of urinary and extraurinary abnormalities among which ureterolithiasis being the most frequent cause. Plain abdominal radiographs combined with intravenous urography (IVU) have been the standard imaging procedures of choice for the evaluation of acute flank pain over the last decades. Direct detection of even small ureteral calculi is achieved in 40-60%, whereas using indirect signs such as ureteral and renal pelvic dilatation stone detection is possible in up to 80-90% of all cases. However, IVU might be hampered by poor quality due to lack of bowel preparation, by nephrotoxicity of contrast agents, by serious allergic and anaphylactic reactions in 10% and 1% of the patients, respectively, and by significant radiation exposure. The use of ultrasonography (US) in the management of acute flank pain has been growing and when combining the findings of pyeloureteral dilatation, direct visualization of stones, and the absence of ureteral ejaculation, the sensitivity to detect ureteral dilatation can be as high as 96%. Recently, unenhanced helical CT (UHCT) has been introduced as imaging modality with a high sensitivity and specificity for the evaluation of acute flank pain. UHCT has been demonstrated to be superior since (1) it detects ureteral stones with a sensitivity and specificity from 98% to 100% regardless of size, location and chemical composition, (2) it identifies extraurinary causes of flank pain in about one third of all patients presenting with acute flank pain, (3) it does not need contrast agent, and (4) it is a time saving imaging technique being performed within 5min. Based on the data published, one can predict that UHCT will become the imaging procedure of choice for evaluation of acute flank pain within the next years. The purpose of this review is to critically evaluate the role all imaging modalities available for a modern approach of diagnosis and management of acute flank pain with regard to their sensitivity, specificity, positive and negative predictive values and their complications, toxicicty and morbidity.

Low Dose Unenhanced Helical Computerized Tomography For The Evaluation Of Acute Flank Pain

Unenhanced helical computerized tomography (CT) has proved to be an excellent diagnostic tool for evaluating acute flank pain with reported 95% to 100% sensitivity, 92% to 100% specificity, 96% to 100% positive and 91% to 100% negative predictive values. The diagnostic value of a new low dose protocol was prospectively studied and compared with the results of conventional unenhanced helical CT in a previous series with an effective dose equivalent (HE) of 3.1 to 4.3 mSv. and in current literature with an estimated HE of 4.3 to 4.7 mSv. In 109 patients 18 to 86 years old with acute flank pain we performed low dose unenhanced helical CT in addition to abdominal ultrasound and urinalysis with new CT parameters (120 kV. 70 mA., 5 mm. collimation, pitch 2 and incremental reconstruction each 5 mm.) that led to a more than 50% decrease in radiation exposure to 1.50 mSv. in females and 0.98 mSv. in males. Ureteral calculi were confirmed or excluded by retrograde ureteropyelography in 51 cases. In the other cases the diagnosis was verified by the clinical and ultrasound course, and/or stone asservation. In 80 of the 109 patients the flank pain was caused by a ureteral calculus. Low dose unenhanced helical CT precisely identified 77 ureteral calculi with 1 false-positive finding. Thus, the sensitivity and specificity of low dose unenhanced helical CT were 96% and 97% with a 99% positive and 90% negative predictive value. In 15 of 29 patients with CT findings negative for stone disease different causes of pain were established by low dose unenhanced helical CT. Even with the significantly decreased radiation exposure of the low dose protocol unenhanced helical CT is still an excellent and rapid diagnostic tool for evaluating acute flank pain with lower radiation exposure than excretory urography (HE 1.3 to 2.3 mSv.) at our departments. Only in obese patients with a body mass index of greater than 31 kg./m.2 is conventional unenhanced helical CT with higher radiation exposure recommended to achieve adequate image quality.

Low Dose Unenhanced Helical Computerized Tomography For The Evaluation Of Acute Flank Pain

Low Dose Unenhanced Helical Computerized Tomography For The Evaluation Of Acute Flank Pain