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Prod'homme S, Bouzerar R, Forzini T, Delabie A, Renard C. Detection of urinary tract stones on submillisievert abdominopelvic CT imaging with deep-learning image reconstruction algorithm (DLIR). Abdom Radiol (NY) 2024; 49:1987-1995. [PMID: 38470506 DOI: 10.1007/s00261-024-04223-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 03/14/2024]
Abstract
PURPOSE Urolithiasis is a chronic condition that leads to repeated CT scans throughout the patient's life. The goal was to assess the diagnostic performance and image quality of submillisievert abdominopelvic computed tomography (CT) using deep learning-based image reconstruction (DLIR) in urolithiasis. METHODS 57 patients with suspected urolithiasis underwent both non-contrast low-dose (LD) and ULD abdominopelvic CT. Raw image data of ULD CT were reconstructed using hybrid iterative reconstruction (ASIR-V 70%) and high-strength-level DLIR (DLIR-H). The performance of ULD CT for the detection of urinary stones was assessed by two readers and compared with LD CT with ASIR-V 70% as a reference standard. Image quality was assessed subjectively and objectively. RESULTS 266 stones were detected in 38 patients. Mean effective dose was 0.59 mSv for ULD CT and 1.96 mSv for LD CT. For diagnostic performance, sensitivity and specificity were 89% and 94%, respectively, for ULDCT with DLIR-H. There was an almost perfect intra-observer concordance on ULD CT with DLIR-H versus LDCT with ASIR-V 70% (ICC = 0.90 and 0.90 for the two readers). Image noise was significantly lower and signal-to-noise ratio significantly higher with DLIR-H compared to ASIR-V 70%. Subjective image quality was also significantly better with ULDCT with DLIR-H. CONCLUSION ULD CT with Deep Learning Image Reconstruction maintains a good diagnostic performance in urolithiasis, with better image quality than hybrid iterative reconstruction and a significant radiation dose reduction.
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Affiliation(s)
- Sarah Prod'homme
- Department of Radiology, Amiens University Hospital, 1 Rond-Point du Professeur Christian Cabrol, 80054, Amiens Cedex 01, France
| | - Roger Bouzerar
- Biophysics and Image Processing Unit, Amiens University Hospital, Amiens, France
| | - Thomas Forzini
- Department of Urology and Transplantation, Amiens University Hospital, Amiens, France
| | - Aurélien Delabie
- Department of Radiology, Amiens University Hospital, 1 Rond-Point du Professeur Christian Cabrol, 80054, Amiens Cedex 01, France
| | - Cédric Renard
- Department of Radiology, Amiens University Hospital, 1 Rond-Point du Professeur Christian Cabrol, 80054, Amiens Cedex 01, France.
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Tamborino F, Cicchetti R, Mascitti M, Litterio G, Orsini A, Ferretti S, Basconi M, De Palma A, Ferro M, Marchioni M, Schips L. Pathophysiology and Main Molecular Mechanisms of Urinary Stone Formation and Recurrence. Int J Mol Sci 2024; 25:3075. [PMID: 38474319 DOI: 10.3390/ijms25053075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/16/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
Kidney stone disease (KSD) is one of the most common urological diseases. The incidence of kidney stones has increased dramatically in the last few decades. Kidney stones are mineral deposits in the calyces or the pelvis, free or attached to the renal papillae. They contain crystals and organic components, and they are made when urine is supersaturated with minerals. Calcium-containing stones are the most common, with calcium oxalate as the main component of most stones. However, many of these form on a calcium phosphate matrix called Randall's plaque, which is found on the surface of the kidney papilla. The etiology is multifactorial, and the recurrence rate is as high as 50% within 5 years after the first stone onset. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more effective drugs. This review aims to understand the pathophysiology and the main molecular mechanisms known to date to prevent recurrences, which requires behavioral and nutritional interventions, as well as pharmacological treatments that are specific to the type of stone.
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Affiliation(s)
- Flavia Tamborino
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Rossella Cicchetti
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Marco Mascitti
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Giulio Litterio
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Angelo Orsini
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Simone Ferretti
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Martina Basconi
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Antonio De Palma
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Matteo Ferro
- Division of Urology, European Institute of Oncology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), 20141 Milan, Italy
| | - Michele Marchioni
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
| | - Luigi Schips
- Department of Medical Oral and Biotechnological Science, Università degli Studi "G. d'Annunzio" of Chieti, 66100 Chieti, Italy
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Lee S, Park YS, Park B, Lee J, Choi JW, Kim KA, Lee CH. Usefulness of Corticomedullary-Phase CT Urography in Patients with Suspected Acute Renal Colic Visiting the Emergency Department. JOURNAL OF THE KOREAN SOCIETY OF RADIOLOGY 2023; 84:923-933. [PMID: 37559807 PMCID: PMC10407065 DOI: 10.3348/jksr.2022.0098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/28/2022] [Accepted: 10/02/2022] [Indexed: 08/11/2023]
Abstract
PURPOSE To evaluate the sensitivity of corticomedullary-phase imaging for detecting urinary stones in patients with renal colic who visited the emergency department. MATERIALS AND METHODS This retrospective study included 253 patients with suspected renal colic from two tertiary hospitals in South Korea, who visited the emergency department and underwent CT urography. Two radiologists blinded to the clinical history independently reviewed the corticomedullary-phase images. The sensitivity for identifying urinary stones were evaluated for each reviewer. After the initial evaluation, the images were re-evaluated based on patient history. The sensitivity of re-evaluation were recorded. RESULTS Of 253 patients, 150 (59%) had urinary stones. Among them, significant stones were observed in 138 patients (92%), and obstructive changes on CT in 124 patients (82.7%). For identifying significant urinary stones, the sensitivity was 98.6% (136/138) for both the reviewers. For identifying significant urinary stones with urinary obstruction, the sensitivity was 99.2% (123/124) for reviewer 1, and 100% (124/124) for reviewer 2. The sensitivity for identifying significant stones increased from 98.6% to 100% for reviewer 1, and from 98.6% to 99.3% for reviewer 2 in the re-evaluation session. CONCLUSION The corticomedullary-phase CT urography was sensitive for diagnosing urolithiasis in patients with acute renal colic who visited the emergency department.
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Hyperspectral Image Classification Based on Parameter-Optimized 3D-CNNs Combined with Transfer Learning and Virtual Samples. REMOTE SENSING 2018. [DOI: 10.3390/rs10091425] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Recent research has shown that spatial-spectral information can help to improve the classification of hyperspectral images (HSIs). Therefore, three-dimensional convolutional neural networks (3D-CNNs) have been applied to HSI classification. However, a lack of HSI training samples restricts the performance of 3D-CNNs. To solve this problem and improve the classification, an improved method based on 3D-CNNs combined with parameter optimization, transfer learning, and virtual samples is proposed in this paper. Firstly, to optimize the network performance, the parameters of the 3D-CNN of the HSI to be classified (target data) are adjusted according to the single variable principle. Secondly, in order to relieve the problem caused by insufficient samples, the weights in the bottom layers of the parameter-optimized 3D-CNN of the target data can be transferred from another well trained 3D-CNN by a HSI (source data) with enough samples and the same feature space as the target data. Then, some virtual samples can be generated from the original samples of the target data to further alleviate the lack of HSI training samples. Finally, the parameter-optimized 3D-CNN with transfer learning can be trained by the training samples consisting of the virtual and the original samples. Experimental results on real-world hyperspectral satellite images have shown that the proposed method has great potential prospects in HSI classification.
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Can ureteral stones cause pain without causing hydronephrosis? World J Urol 2015; 34:1285-8. [PMID: 26685981 DOI: 10.1007/s00345-015-1748-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022] Open
Abstract
INTRODUCTION While computerized tomography (CT) is the gold standard for diagnosis of ureterolithiasis, ultrasound is a less costly and radiation-free alternative which is commonly used to evaluate patients with ureteral colic. The purpose of this study was to evaluate the frequency with which patients with ureteral stones and renal colic demonstrate hydronephrosis in order to better understand the evaluation of these patients. METHODS Two hundred and forty-eight consecutive patients presenting with ureteral colic and diagnosed with a single unilateral ureteral stone on CT scan in an urban tertiary care emergency department were retrospectively reviewed. Radiology reports were reviewed for stone size, diagnosis, and degree of hydronephrosis. RESULTS Of the 248 patients evaluated for suspected ureteral stone, 221 (89.1 %) demonstrated any hydronephrosis, while 27 (10.9 %) did not. Hydronephrosis grade, available in 194 patients, was as follows: mild-70.6 %, moderate-27.8 %, and severe-1.5 %. Mean patient age was 47.0 years (SD 15.5), gender distribution was 35.9 % female and 64.1 % male, and mean stone axial diameter was 4.1 mm (SD 2.4). Stone location was as follows: ureteropelvic junction-4.1 %, proximal ureter-21 %, distal ureter-24.9 %, and ureterovesical junction-47.1 %. Axial stone diameter and coronal length (craniocaudal) were both significant predictors of degree of hydronephrosis (ANOVA, p < 0.001 for both). Age (ANOVA, p = NS), stone location (Chi square, p = NS), and gender (Chi square, p = NS) were not associated with degree of hydronephrosis. CONCLUSIONS In patients with ureteral stones and colic, nearly 11 % do not demonstrate any hydronephrosis and a majority (nearly 71 %) will demonstrate only mild hydronephrosis. Stone diameter appears to be related to degree of hydronephrosis, whereas age, gender, and stone location are not. The lower incidence of hydronephrosis for small stones causing renal colic may explain the lower diagnostic accuracy of ultrasound when compared to CT for detecting ureteral stones.
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Reddy K, Mohammed A, Reeve R, England R. Computed tomography urography 2: clinical applications. Br J Hosp Med (Lond) 2013; 74:619-24. [PMID: 24220523 DOI: 10.12968/hmed.2013.74.11.619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kiran Reddy
- FY1 in Urology in the Department of Urology, Kettering General Hospital, Kettering, Northants
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Kim S, Choi SK, Lee SM, Choi T, Lee DG, Min GE, Jeon SH, Lee HL, Chung JY, Joh JH, Yoo KH. Predictive Value of Preoperative Unenhanced Computed Tomography During Ureteroscopic Lithotripsy: A Single Institute's Experience. Korean J Urol 2013; 54:772-7. [PMID: 24255760 PMCID: PMC3830971 DOI: 10.4111/kju.2013.54.11.772] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 08/09/2013] [Indexed: 11/23/2022] Open
Abstract
Purpose Ureteroscopic stone removal is frequently used to remove ureteral stones. Mucosal edema and bleeding are the two most important obstacles to a successful operation. This study analyzed relationships between unenhanced computed tomography (UECT) findings and ureteroscopic findings to determine whether ureteroscopic results could be predicted preoperatively by using UECT imaging. Materials and Methods From January 2009 to July 2011, 675 patients were diagnosed with ureteral stones through UECT. Among them, we retrospectively reviewed 92 cases of patients who underwent ureteroscopy (URS). We identified findings such as hydronephrosis, rim sign, periureteral fat stranding, and perinephric fat stranding on the UECT and then categorized these findings into four categories (none, mild, moderate, and severe) according to their severity. We also divided the URS findings of mucosal edema and bleeding into four categories (none, mild, moderate, and severe) and compared these findings with the UECT images. Results A total of 92 study patients were included in this study: 59 were male and 33 were female patients. According to the location of the stone, 31 cases were classified as upper ureteral stones, 15 were midureteral stones, and 46 were lower ureteral stones. Hydronephrosis identified with UECT was correlated with the mucosal edema severity observed during URS (p=0.004). The rim signs identified with UECT were proportional to the grade of mucosal edema (p=0.010). Conclusions Hydronephrosis and rim signs observed during UECT can be used as a predictive factor for intraoperative mucosal edema in patients undergoing URS.
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Affiliation(s)
- Sunchan Kim
- Department of Urology, Kyung Hee University School of Medicine, Seoul, Korea
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WELLS ITP, FREEMAN SJ. Investigation of loin pain. IMAGING 2013. [DOI: 10.1259/imaging.20110059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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What the Radiologist Needs to Know About Urolithiasis: Part 2???CT Findings, Reporting, and Treatment. AJR Am J Roentgenol 2012; 198:W548-54. [DOI: 10.2214/ajr.11.8462] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Tang VCY, Attwell-Heap A. Computed tomography versus ureteroscopy in identification of renal tract stone with ureteral stent in situ. Ann R Coll Surg Engl 2011; 93:639-41. [PMID: 22041243 DOI: 10.1308/003588411x13165261993996] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION The aim of this study was to validate the use of non-contrast computed tomography (CT) with a ureteral stent in situ instead of ureteroscopy for identification of renal tract stones. METHODS All patients who had stents inserted for renal tract stones and underwent non-contrast CT with the stent in situ followed by ureteroscopy between May 2008 and October 2009 at The Canberra hospital, Australia, were analysed retrospectively. Statistical analysis was performed to compare any differences between CT and ureteroscopy in the identification of stones. RESULTS Overall, 57 patients were included in the study. The difference between CT and ureteroscopy findings was statistically significant. CT identification of stones with a stent in situ had a sensitivity of 86%, a specificity of 46%, a positive predictive value of 63%, a negative predictive value of 76% and an accuracy of 67%. CONCLUSIONS Our study suggests that non-contrast CT is inferior to the 'gold standard' of ureteroscopy. It lacks sensitivity, specificity, positive predictive value, negative predictive value and accuracy. Therefore, we cannot recommend using non-contrast CT to replace ureteroscopy.
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Kambadakone AR, Eisner BH, Catalano OA, Sahani DV. New and Evolving Concepts in the Imaging and Management of Urolithiasis: Urologists’ Perspective. Radiographics 2010; 30:603-623. [DOI: 10.1148/rg.303095146] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Low-dose unenhanced CT protocols according to individual body size for evaluating suspected renal colic: cumulative radiation exposures. Radiol Med 2009; 115:105-14. [DOI: 10.1007/s11547-009-0476-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2008] [Accepted: 08/27/2008] [Indexed: 10/20/2022]
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Wehrschuetz M, Gallé G, Wehrschuetz E, Sorantin E, Schaffler G. Thick curved planar reformation of unenhanced multislice computed tomography demonstrating urolithiasis. Urology 2009; 74:528-30. [PMID: 19589570 DOI: 10.1016/j.urology.2008.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2007] [Revised: 12/08/2008] [Accepted: 12/22/2008] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To determine what slice thickness provides optimal curved planar reformation (CPR) images of the urinary tract. METHODS A total of 75 consecutive patients with acute flank pain were included in a retrospective pilot study and underwent unenhanced multislice computed tomography (MSCT) (collimation 3.75 mm, pitch 6, reconstruction increment 3 mm, working voltage 120 kV, and tube current 100 mA) with CPR reconstruction of the urinary tract. CPRs with differing slice thicknesses of 3-20 mm at 1-mm increments to reformat each ureter were assessed in each patient separately. Two radiologists and a urologist evaluated the quality of the reformatted images by judging each ureter in terms of the delineation of all its parts using a 5-point scale (insufficient, poor, moderate, good, and excellent). RESULTS Of the 75 patients in our cohort, 52 (69%) had urolithiasis. CPR images could be made of all ureters in all patients. Good to excellent image quality was found in the CPRs performed with a slice thickness of 8-12 mm: 27.7% at 8 mm, 14.3% at 9 mm, 26.9% at 10 mm, 12.6% at 11 mm, and 18.5% at 12 mm. Thus, a slice thickness of 8-12 mm determined a cumulative likelihood of 96.7% to demonstrate the ureter totally. CONCLUSIONS The results of our study have shown that CPR is a feasible and quick useful tool. CPRs of the urinary tract with a slice thickness of 8-12 mm are best for good delineation of the whole ureter.
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Affiliation(s)
- M Wehrschuetz
- Department of Radiology, Medical University Graz, Graz, Austria.
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Park SJ, Yi BH, Lee HK, Kim YH, Kim GJ, Kim HC. Evaluation of patients with suspected ureteral calculi using sonography as an initial diagnostic tool: how can we improve diagnostic accuracy? JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2008; 27:1441-1450. [PMID: 18809954 DOI: 10.7863/jum.2008.27.10.1441] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE The purpose of this study was to evaluate the usefulness of sonography as an initial diagnostic tool in patients with suspected ureterolithiasis. METHODS We performed a prospective study of 318 patients with suspected ureteral stones over a 14-month period. All patients underwent sonography after fasting for 8 hours and bladder filling. If no cause of the flank pain was found by sonography, computed tomography or intravenous urography was performed immediately to confirm the absence of ureteral stones. RESULTS We found urolithiasis with sonography in 291 of 296 patients with confirmed urolithiasis. The 5 remaining cases were identified after non-contrast-enhanced computed tomography (n = 3), intravenous urography (n = 1), or the passage of a stone (n = 1, pregnant patient). We detected 313 calculi in the 291 patients with sonography as follows: 307 ureteral calculi in 285 patients, 5 urinary bladder calculi that were probably passed from the ureter in 5 patients, and 1 urethral calculus. The locations of the 313 calculi in the 291 patients with a sonographic diagnosis were as follows: 21 were in the ureteropelvic junction, 96 in the proximal half of the ureter, 69 in the distal half of the ureter, 121 in the ureterovesical junction, 5 in the urinary bladder, and 1 in the urethra. Hydronephrosis was seen in 200 of the 291 patients with calculi identified by sonography (68.7%). Twinkling artifacts helped confirm the presence of tiny calculi in 184 of the 214 calculi (86%). CONCLUSIONS Sonography can be used as an initial diagnostic tool in patients with suspected ureterolithiasis.
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Affiliation(s)
- Seong Jin Park
- Department of Radiology, Soonchunhyang University Bucheon Hospital, Gyeonggi-do 420-021, Korea.
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Affiliation(s)
- Mark Thomas
- Department of Nephrology, Royal Perth Hospital, Box X2213, Perth WA 6001, Australia.
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Jindal G, Ramchandani P. Acute Flank Pain Secondary to Urolithiasis: Radiologic Evaluation and Alternate Diagnoses. Radiol Clin North Am 2007; 45:395-410, vii. [PMID: 17601499 DOI: 10.1016/j.rcl.2007.04.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This article discusses the radiologic management of the patient who has acute flank pain. It describes the evolution of radiologic imaging in patients who present with acute symptoms caused by suspected urolithiasis, the advantages of unenhanced helical CT and the limitations of abdominal radiography, intravenous urography, and ultrasonography in this setting, and the alternative diagnoses encountered within the urinary tract, abdomen, and pelvis.
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Affiliation(s)
- Gaurav Jindal
- Department of Radiology, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA
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Jacobson FL, Berlanstein BP, Andriole KP. Paradigms of Perception in Clinical Practice. J Am Coll Radiol 2006; 3:441-5. [PMID: 17412099 DOI: 10.1016/j.jacr.2006.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Indexed: 11/16/2022]
Abstract
Display strategies for medical images in radiology have evolved in tandem with the technology by which images are made. The close of the 20th century, nearly coincident with the 100th anniversary of the discovery of x-rays, brought radiologists to a new crossroad in the evolution of image display. The increasing availability, speed, and flexibility of computer technology can now revolutionize how images are viewed and interpreted. Radiologists are not yet in agreement regarding the next paradigm for image display. The possibilities are being explored systematically through the Society for Computer Applications in Radiology's Transforming the Radiological Interpretation Process initiative. The varied input of radiologists who work in a large variety of settings will enable new display strategies to best serve radiologists in the detection and quantification of disease. Considerations and possibilities for the future are presented in this paper.
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Affiliation(s)
- Francine L Jacobson
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Freire Filho EDO, Jesus PEMD, D'Ippolito G, Szejnfeld J. Tomografia computadorizada sem contraste intravenoso no abdome agudo: quando e por que usar. Radiol Bras 2006. [DOI: 10.1590/s0100-39842006000100011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A tomografia computadorizada sem contraste intravenoso tem sido freqüentemente proposta na avaliação inicial de pacientes com suspeita de abdome agudo, ocupando o espaço de outros métodos diagnósticos. Os autores apresentam uma revisão bibliográfica dos principais aspectos e eficácia da tomografia computadorizada sem contraste intravenoso no diagnóstico de apendicite aguda, cólica nefrética, diverticulite, pancreatite aguda, apendicite epiplóica, pneumoperitônio e obstrução intestinal. Discutem quais as vantagens e limitações desta técnica de exame, bem como seus aspectos práticos.
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Kim BS, Hwang IK, Choi YW, Namkung S, Kim HC, Hwang WC, Choi KM, Park JK, Han TI, Kang W. Low-dose and standard-dose unenhanced helical computed tomography for the assessment of acute renal colic: prospective comparative study. Acta Radiol 2005; 46:756-63. [PMID: 16372698 DOI: 10.1080/02841850500216004] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To compare the efficacy of low-dose and standard-dose computed tomography (CT) for the diagnosis of ureteral stones. MATERIAL AND METHODS Unenhanced helical CT was performed with both a standard dose (260 mAs, pitch 1.5) and a low dose (50 mAs, pitch 1.5) in 121 patients suspected of having acute renal colic. The two studies were prospectively and independently interpreted for the presence and location of ureteral stones, abnormalities unrelated to stone disease, identification of secondary signs, i.e. hydronephrosis and perinephric stranding, and tissue rim sign. The standard-dose CT images were interpreted by one reviewer and the low-dose CT images independently by two reviewers unaware of the standard-dose CT findings. The findings of the standard and low-dose CT scans were compared with the exact McNemar test. Interobserver agreements were assessed with kappa analysis. The effective radiation doses resulting from two different protocols were calculated by means of commercially available software to which the Monte-Carlo phantom model was given. RESULTS The sensitivity, specificity, and accuracy of standard-dose CT for detecting ureteral stones were 99%, 93%, and 98%, respectively, whereas for the two reviewers the sensitivity of low-dose CT was 93% and 95%, specificity 86%, and accuracy 92% and 94%. We found no significant differences between standard-dose and low-dose CT in the sensitivity and specificity for diagnosing ureter stones (P >0.05 for both). However, the sensitivity of low-dose CT for detection of 19 stones less than or equal to 2 mm in diameter was 79% and 68%, respectively, for the two reviewers. Low-dose CT was comparable to standard-dose CT in visualizing hydronephrosis and the tissue rim sign. Perinephric stranding was far less clear on low-dose CT. Low-dose CT had the same diagnostic performance as standard-dose CT in diagnosing alternative diseases. Interobserver agreement between the two low-dose CT reviewers in the diagnosis of ureter stones and alternative diseases, the identification of secondary signs, and tissue rim sign were high, with kappa values ranging from 0.769 to 0.968. On standard-dose CT scans, the calculated mean effective radiation dose was 7.30 mSv for males and 10.00 mSv for females. On low-dose CT scans, the calculated mean effective radiation dose was 1.40 mSv for males and 1.97 mSv for females. CONCLUSION Compared with standard scans using 260 mAs, low-dose unenhanced helical CT using a reduced tube current of 50 mAs results in a concomitant decrease in the radiation dose of 81%. Although low-dose CT was limited in its ability to depict small-sized calculi less than or equal to 2 mm, it is still comparable to standard-dose CT for the diagnosis of ureter stones and alternative disease.
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Affiliation(s)
- Bong Soo Kim
- Department of Diagnostic Radiology, Cheju National University College of Medicine, Jeju, Korea.
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21
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Goldman SM, Faintuch S, Ajzen SA, Christofalo DMJ, Araújo MP, Ortiz V, Srougi M, Kenney PJ, Szejnfeld J. Diagnostic value of attenuation measurements of the kidney on unenhanced helical CT of obstructive ureterolithiasis. AJR Am J Roentgenol 2004; 182:1251-4. [PMID: 15100127 DOI: 10.2214/ajr.182.5.1821251] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of this study was to assess the diagnostic value of attenuation measurements of the kidney on unenhanced helical CT in patients with obstructive ureterolithiasis. MATERIALS AND METHODS Consecutive unenhanced helical CT scans of patients referred for acute unilateral renal colic were retrospectively reviewed. Patients with CT evidence of other urinary system diseases were excluded. Included scans (n = 145) were assessed for ureteral stone and secondary signs of obstruction such as unilateral collecting system or ureteral dilatation, perinephric stranding, and periureteral edema. Renal attenuation in Hounsfield units was measured in the upper, middle, and lower portions of the parenchyma, and a mean value was determined for each kidney. RESULTS Ureteral stones were present in 76 patients. Renal attenuation on the side with lithiasis was lower than on the opposite kidney: 27.2 +/- 3.9 H vs 32.6 +/- 3.4 H (p < 0.001). Attenuation differences between kidneys were higher for patients with ureterolithiasis: 5.4 +/- 3.2 H (range, -3.3 to 13.0 H) versus 1.2 +/- 1.0 H (range, 0-4.7 H) (p < 0.001). An attenuation difference between kidneys greater than or equal to 5.0 H had 61% sensitivity, 100% specificity, 100% positive predictive value, 69% negative predictive value, and 79% accuracy for diagnosis of ureteral lithiasis. CONCLUSION Attenuation difference between kidneys greater than or equal to 5.0 H was a valuable sign and had diagnostic performance similar to other secondary signs of obstructive ureterolithiasis. Furthermore, attenuation difference had the advantage of being an objective, measurement-based indicator.
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Affiliation(s)
- Suzan M Goldman
- Department of Radiology, Federal University of São Paulo School of Medicine, Rua Napoleão de Barros 800, São Paulo CEP 04024-002, Brazil
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23
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Maher MM, Kalra MK, Rizzo S, Mueller PR, Saini S. Multidetector CT urography in imaging of the urinary tract in patients with hematuria. Korean J Radiol 2004; 5:1-10. [PMID: 15064553 PMCID: PMC2698107 DOI: 10.3348/kjr.2004.5.1.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This review article comprehensively discusses multidetector CT urography protocols and their role in imaging of the urinary tract in patients with hematuria.
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Affiliation(s)
- Michael M. Maher
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, USA
| | - Mannudeep K. Kalra
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, USA
| | - Stefania Rizzo
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, USA
| | - Peter R. Mueller
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, USA
| | - Sanjay Saini
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, USA
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24
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Akbar SA, Mortele KJ, Baeyens K, Kekelidze M, Silverman SG. Multidetector CT urography: techniques, clinical applications, and pitfalls. Semin Ultrasound CT MR 2004; 25:41-54. [PMID: 15035531 DOI: 10.1053/j.sult.2003.11.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For two decades, computed tomography (CT) has challenged intravenous urography (IVU) in the evaluation of urinary tract abnormalities. Compared with IVU, CT is more sensitive and specific in the detection and characterization of a variety of urinary tract disorders, including renal masses and urolithiasis. The last purported advantage of IVU has been its ability to depict subtle and mucosal abnormalities of the urothelium. Now, using multidetector CT (MDCT), this challenge has been overcome. In this article, we review the current role of MDCT urography in the evaluation of the urinary tract.
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Affiliation(s)
- Syed A Akbar
- Division of Abdominal Imaging and Intervention, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
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25
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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. [PMID: 14654033 DOI: 10.1016/s0009-9260(03)00294-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM The purpose of this study was to determine the incidence of secondary signs associated with ureteral stones on unenhanced helical computed tomography (CT) of patients with acute renal colic, and to correlate these with patient management and outcome. MATERIALS AND METHODS One hundred and ten patients with ureterolithiasis were evaluated prospectively for the secondary signs of obstruction on unenhanced helical CT. Our attention was focused primarily on the presence or absence of seven secondary signs on unenhanced helical CT, including hydronephrosis, unilateral renal enlargement, perinephric oedema, unilateral absence of the white pyramid, hydroureter, periureteral oedema and lateroconal fascial thickening. RESULTS Of the 110 patients, 91 (82.7%) had hydroureter, 88 (80%) had hydronephrosis, 65 (59%) had periureteric oedema and 63 (57.2%) had unilateral renal enlargement. Ninety stones passed spontaneously and 21 required intervention. CONCLUSION Secondary signs of urinary tract obstruction are useful and supportive findings in interpretation of the CT examination. In our experience, the most reliable signs indicating ureteral obstruction are hydroureter, hydronephrosis, periureteral oedema and unilateral renal enlargement, respectively. In addition, stones larger than 6 mm, located within the proximal two thirds of the ureter, and seen associated with five or more the secondary signs of obstruction, are more likely to require endoscopic removal and/or lithotripsy.
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Affiliation(s)
- G Ege
- Department of Radiology, Istanbul International Hospital, Istanbul, Turkey.
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26
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Abstract
Unenhanced CT has been demonstrated to be the most accurate and efficient diagnostic imaging means to evaluate urinary lithiasis, with capability of directing management, and has become well accepted by radiologists, urologists, and emergency department physicians such that it is now the standard of practice. It is the duty of the radiologist to be aware of proper technique and the details of interpretation. The radiologist also has a duty to be aware of the limitations of unenhanced CT for detection and evaluation of various nonstone disorders, particularly with poor patient selection, and to extend the examination if appropriate. Controversies and future developments include cost containment with care for the selection of patients. Further attempts to reduce radiation exposure should be made. Optimal CT technique is not needed in general merely to detect urinary lithiasis. A consensus should be developed regarding use of CT in pregnant patients. Further improvements in the digital scout view would be useful for following patients.
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Affiliation(s)
- Philip J Kenney
- GU Radiology Section, Department of Radiology, JT N370, University of Alabama at Birmingham, 619 South 19th Street, Birmingham, AL 35233, USA.
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Wang JH, Lin WC, Wei CJ, Chang CY. Diagnostic Value of Unenhanced Computerized Tomography Urography in the Evaluation of Acute Renal Colic. Kaohsiung J Med Sci 2003; 19:503-9. [PMID: 14620676 DOI: 10.1016/s1607-551x(09)70498-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This study prospectively evaluated the diagnostic value of unenhanced computerized tomography (CT) urography in patients with acute renal colic. Fifty-nine patients with clinical manifestations of acute renal colic underwent unenhanced helical CT to evaluate urinary tract abnormalities. Reformatted three-dimensional CT urography was performed in all patients. The findings were correlated with ureteroscopy, surgical findings, histopathologic findings, and clinical course. CT urography detected urinary abnormalities in 57 of 59 patients with the clinical manifestation of acute renal colic, including 45 cases of urolithiasis, three urinary malignancies, one congenital abnormality, and eight ureteral strictures (due to chronic inflammation or fibrosis). CT urography showed negative findings in the urinary system in two patients, and after clinical follow-up, urinary abnormality was excluded in these patients. Incidental findings of extrarenal disease were noted in six patients (pulmonary abnormalities, n = 2; gallstones, n = 4). Only one patient with urolithiasis was misdiagnosed as having a renal tumor by CT urography. The sensitivity and specificity of CT urography in diagnosing urolithiasis was 97.8% (44/45) and 100% (14/14), respectively. Three-dimensional CT urography is a newly developed modality to evaluate anomalies of the urinary tract. The highly accurate diagnostic value of CT urography makes it a suitable alternative or substitutive modality in patients with acute flank pain.
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Affiliation(s)
- Jia-Hwia Wang
- Department of Radiology, Taipei Veterans General Hospital, Taiwan
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28
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Tamm EP, Silverman PM, Shuman WP. Evaluation of the patient with flank pain and possible ureteral calculus. Radiology 2003; 228:319-29. [PMID: 12819343 DOI: 10.1148/radiol.2282011726] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Flank pain due to urolithiasis is a common problem in patients presenting to emergency departments. Radiology plays a vital role in the work-up of these patients. Many modalities can be used, including ultrasonography, nuclear medicine, and the traditionally used techniques of intravenous urography and conventional radiography. The development of nonenhanced computed tomography (CT) (single- or multi-detector row helical) has provided a means to enable detection and characterization of urolithiasis with unprecedented sensitivity, specificity, and accuracy while yielding important information for treatment planning, including the size and location of calculi. This technique can also help detect causes for flank pain outside the genitourinary tract. However, close attention must be paid to all aspects of the CT study to prevent misdiagnoses.
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Affiliation(s)
- Eric P Tamm
- Department of Diagnostic Imaging, MD Anderson Cancer Center, 1515 Holcombe Blvd, Box 57, Houston, TX 77030, USA.
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Holdgate A, Chan T. How accurate are emergency clinicians at interpreting noncontrast computed tomography for suspected renal colic? Acad Emerg Med 2003; 10:315-9. [PMID: 12670843 DOI: 10.1111/j.1553-2712.2003.tb01342.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess the accuracy of emergency physicians and trainees in the interpretation of noncontrast helical computed tomography (NCHCT) for suspected renal colic by examining the interrater reliability between emergency department (ED) clinicians and radiologists. METHODS Information was collected prospectively on all ED patients undergoing NCHCT for suspected renal colic over a 12-month period. Emergency physicians and trainees were asked to report the absence or presence of specific renal parameters (renal tract abnormality, calculus, hydroureter, hydronephrosis, perinephric stranding, and renal parenchymal edema) and nonrenal parameters (nonrenal abnormality, free gas, free fluid, and aortic diameter >3 cm). These reports were compared with the formal radiology report, which was used as the reference standard. The sensitivity, specificity, accuracy, and kappa coefficient were calculated for each of the parameters. RESULTS Over the 12-month period, 212 patients underwent NCHCT for suspected renal colic, of whom 127 had both ED and formal radiological reporting. There was an excellent degree of interrater reliability between the ED clinicians and the radiologists (kappa > 0.75) for the presence of renal tract abnormality and renal tract calculus. There was intermediate interrater reliability (kappa 0.4-0.75) for nonrenal tract abnormalities, hydroureter, hydronephrosis, and perinephric stranding. Four patients had potentially significant nonrenal abnormalities missed by ED clinicians. CONCLUSIONS Emergency clinicians are able to identify renal calculi with a high degree of accuracy but may miss important nonrenal abnormalities. Therefore, all patients without evidence of renal tract calculus on NCHCT must have early and appropriate follow-up.
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Affiliation(s)
- Anna Holdgate
- Department of Emergency Medicine, St. George Hospital, Gray Street, Kogarah NSW 2217, Sydney, Australia.
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30
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Kalra MK, Maher MM, Sahani DV, Blake M, Saini S. Current status of multidetector computed tomography urography in imaging of the urinary tract. Curr Probl Diagn Radiol 2002. [DOI: 10.1067/mdr.2002.127633] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Colistro R, Torreggiani WC, Lyburn ID, Harris AC, Al-Nakshabandi NA, Nicolaou S, Munk PL. Unenhanced helical CT in the investigation of acute flank pain. Clin Radiol 2002; 57:435-41. [PMID: 12069457 DOI: 10.1053/crad.2001.0871] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Unenhanced helical CT has emerged as the imaging technique of choice for the investigation of patients presenting with acute flank pain and suspected nephroureteric stone disease. There are several signs identifiable on unenhanced CT that support a diagnosis of stone disease. However, there are many pitfalls, that may confound a correct diagnosis. Some of the common pitfalls, together with methods to avoid such occurrences, will be discussed. A review of some of the common alternative diagnoses that may mimic the symptoms of nephroureteric stone disease is illustrated.
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Affiliation(s)
- Robert Colistro
- Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, Canada
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32
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Catalano O, Nunziata A, Altei F, Siani A. Suspected ureteral colic: primary helical CT versus selective helical CT after unenhanced radiography and sonography. AJR Am J Roentgenol 2002; 178:379-87. [PMID: 11804898 DOI: 10.2214/ajr.178.2.1780379] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to compare the accuracy of unenhanced helical CT with combined sonography and unenhanced radiography in patients with acute flank pain suggestive of ureteral colic. SUBJECTS AND METHODS From January 1997 to December 1999, 181 consecutive patients with acute flank pain underwent unenhanced radiography, sonography, and unenhanced helical CT (protocol A). From January 2000 to December 2000, 96 consecutive patients arriving at the emergency department with acute flank pain were alternately submitted either to primary unenhanced helical CT (protocol B, 48 patients) or to unenhanced radiography and sonography with the addition of helical CT in unclear cases (protocol C, 48 patients). RESULTS When compared with the diagnostic accuracy for ureterolithiasis of the combined sonography and radiography in the same group of subjects (protocol A), CT had a greater sensitivity (92% vs 77%), negative predictive value (87% vs 68%), and overall accuracy (94% vs 83%). Among patients who underwent primary CT (protocol B), we found three false-negatives (all with spontaneous stone passage) and no false-positives. Among patients initially examined with unenhanced radiography and sonography (protocol C), we found one false-positive (leading to patient admission and needless repeated radiographic and sonographic studies) and six false-negatives (all followed by an uncomplicated course and spontaneous passage); CT depicted four of these stones but did not result in change in treatment. Fourteen percent of the patients in protocol C required invasive treatment, but combined sonography and radiography showed stones and hydronephrosis in all these patients. CONCLUSION Unenhanced CT was the most accurate modality for determining the presence of ureterolithiasis. The combination of abdominal radiography and sonography, however, yielded comparable results with no clinically important misdiagnoses and thus can be used as an alternative when CT resources are limited.
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Affiliation(s)
- Orlando Catalano
- Department of Radiology, S. Maria delle Grazie Hospital, Via Domitiana Località La Schiana, Pozzuoli (Na), Italy
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33
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Eshed I, Kornecki A, Rabin A, Elias S, Katz R. Unenhanced spiral CT for the assessment of renal colic. How does limiting the referral base affect the discovery of additional findings not related to urinary tract calculi? Eur J Radiol 2002; 41:60-4. [PMID: 11750154 DOI: 10.1016/s0720-048x(01)00404-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The value of unenhanced spiral CT (UESCT) for investigating acute flank pain suggestive of urinary tract calculi is increasingly appreciated in the last few years. Recent studies have identified the advantages of UESCT in recognizing alternative findings within or outside the urinary tract. We sought to determine how narrowing the referral base for the UESCT would affect the discovery of potentially significant alternative findings in patients with acute flank pain suggestive of renal colic. Between January 1999 and December 1999, 425 patients, 271 (63.8%) men and 154 (36.2%) women who were 1-90 years old (mean 45.7 years old) with acute flank pain were studied with UESCT. CT studies were solely ordered by urologists, and only patients with intractable renal colic or patients that returned more than once to the emergency room with the complaint of acute flank pain were studied. A calculus within the ureter was diagnostic of an obstructive stone. Any other abnormality within the abdomen and pelvis was reported. A ureteral calculus was detected on 251 (59%) CT scans. Nineteen (4.5%) CT scans were consistent with recent excretion of a stone. In 112 (26.3%) CT scans, the cause for the patient's acute flank pain could not be explained. Forty-three (10.1%) alternative significant diagnoses that explain the patient's complaints were found. Nineteen (44%) were findings related to the urinary tract, and 24 (56%) were not related to the urinary tract. Ninety-seven (22.3%) additional findings not significant to the patient's current complaint were also reported. Even when narrowing the indications for the UESCT, about 10% of significant alternative findings to urinary stones were encountered. The variety of diagnoses found unexpectedly on the UESCT that alter a patient's management demonstrates the pivotal role of UESCT in triaging these patients rapidly towards optimal therapy. The UESCT can be used as a useful screening tool, sometimes revealing the exact pathology and sometimes directing the radiologist to the modality by which to continue.
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Affiliation(s)
- I Eshed
- Department of Diagnostic Radiology, Wolfon Medical Center, Holon, Israel.
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Caoili EM, Cohan RH, Korobkin M, Platt JF, Francis IR, Gebremariam A, Ellis JH. Effectiveness of abdominal compression during helical renal CT. Acad Radiol 2001; 8:1100-6. [PMID: 11721809 DOI: 10.1016/s1076-6332(03)80721-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
RATIONALE AND OBJECTIVES The authors performed this study to assess the effect of abdominal compression on opacification and distention of the proximal renal collecting system during helical computed tomography (CT). MATERIALS AND METHODS Abdominal compression was applied during helical CT in 31 patients who were scanned 150 and 300 seconds after initiating a dynamic bolus injection of contrast material. Two reviewers assessed renal collecting system opacification and measured the maximal short-axis diameter of the collecting system at three locations: the upper pole, the lower pole, and the proximal ureter. A similar evaluation was performed in a control group of 29 patients who underwent CT without compression at 300 seconds after initiating the injection of contrast material. RESULTS Both reviewers noted collecting system opacification at all locations in 52 of 56 noncompressed collecting systems scanned at 300 seconds, 57 of 59 compressed collecting systems scanned at 300 seconds, but only 26 of 59 compressed collecting systems scanned at 150 seconds. Measured collecting system distention was statistically significantly greater at 300 seconds in patents who received compression than in patients who did not (P = .0013). For patients who received compression, measured collecting system distention was statistically significantly greater on scans obtained at 300 seconds than on scans obtained at 150 seconds (P = .0001). CONCLUSION Abdominal compression during renal helical CT produces a detectable increase in renal collecting system distention. In patients who receive compression, scanning at 300 seconds rather than at 150 seconds results in greater collecting system distention and more consistent opacification.
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Affiliation(s)
- E M Caoili
- Department of Radiology, University of Michigan Medical Center, Ann Arbor 48109-9723, USA
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35
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Affiliation(s)
- J E Langer
- Department of Radiology, University of Pennsylvania Medical Center, 3400 Spruce St, Philadelphia, PA 19104, USA
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Diel J, Perlmutter S, Venkataramanan N, Mueller R, Lane MJ, Katz DS. Unenhanced helical CT using increased pitch for suspected renal colic: an effective technique for radiation dose reduction? J Comput Assist Tomogr 2000; 24:795-801. [PMID: 11045705 DOI: 10.1097/00004728-200009000-00023] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To determine the accuracy and utility of unenhanced helical CT for suspected renal colic, using a pitch of either 2.5 or 3.0. METHODS 59 consecutive patients underwent unenhanced helical CT. 5 mm contiguous images were obtained at a kVP of 120 and an mA of 260. Thirty-four patients were imaged at a pitch of 2.5, and 25 patients were imaged at a pitch of 3.0. Two radiologists, an attending (reader 1), and a second-year resident (reader 2), independently and retrospectively reviewed the CT images, blinded to the clinical outcome. The presence or absence of a ureteral stone was recorded and image quality was graded. A third radiologist determined accuracy for each reader. Average entrance exposure was estimated using a CT phantom at a variety of pitches. RESULTS Overall sensitivity, specificity, and accuracy for reader 1 were 91, 96, and 93%. For reader 2, they were 86, 93, and 90%. There was no significant difference in accuracy using a pitch of 3.0 compared with 2.5 for either reader. Readers 1 and 2 rated image quality at 2.5 pitch as excellent for 88 and 76% of scans, respectively; at 3.0 pitch the scans were rated by both readers as excellent for 40% and acceptable for 60%. Average entrance exposures were estimated at 461, 553. and 913 mR at pitches of 3.0, 2.5, and 1.5. CONCLUSION Increasing the pitch on unenhanced helical CT for suspected renal colic to 2.5 or 3.0 appears to be an effective method of reducing radiation dose. Although accuracy of the technique did not significantly change using a pitch of 3.0 in one group of patients, compared with a pitch of 2.5 in another group of patients, image quality did decrease.
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Affiliation(s)
- J Diel
- Department of Radiology, Winthrop University Hospital, Mineola, Long Island, NY 11501, USA
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Assi Z, Platt JF, Francis IR, Cohan RH, Korobkin M. Sensitivity of CT scout radiography and abdominal radiography for revealing ureteral calculi on helical CT: implications for radiologic follow-up. AJR Am J Roentgenol 2000; 175:333-7. [PMID: 10915669 DOI: 10.2214/ajr.175.2.1750333] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We compared the sensitivity of CT scout radiography with that of abdominal radiography in revealing ureteral calculi on unenhanced helical CT. MATERIALS AND METHODS Over a 6-month period, patients presenting to the emergency department with acute flank pain were examined with standard abdominal radiography and unenhanced helical CT, which included CT scout radiography. In 60 patients in whom a diagnosis of ureteral calculus was made, CT scout radiographs and abdominal radiographs were examined by two interpreters who assessed whether stones could be visualized. All CT scout radiographs were viewed on a workstation using optimized window settings. RESULTS CT scout radiography and abdominal radiography revealed 28 (47%) and 36 (60%) of 60 ureteral calculi, respectively. All ureteral calculi that appeared on CT scout radiography also appeared on abdominal radiography. However, eight calculi that were visible on abdominal radiography were not visible on CT scout radiography. CT scout radiography and abdominal radiography revealed 28% and 46% of 39 calculi less than or equal to 3 mm in diameter, respectively. For 21 calculi larger than 3 mm, the sensitivity of CT scout radiography and abdominal radiography was 81% and 86%, respectively. CONCLUSION Abdominal radiography is more sensitive than CT scout radiography in revealing ureteral calculi; however, some calculi revealed on unenhanced helical CT cannot be seen on either abdominal radiography or CT scout radiography. Ureteral calculi not visible on either study can only be followed, when necessary, with unenhanced helical CT.
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Affiliation(s)
- Z Assi
- Department of Radiology, University of Michigan Hospital, Ann Arbor 8109-0030, USA
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Smith RC, Levine J, Rosenfeld AT. Helical CT of urinary tract stones. Epidemiology, origin, pathophysiology, diagnosis, and management. Radiol Clin North Am 1999; 37:911-52, v. [PMID: 10494278 DOI: 10.1016/s0033-8389(05)70138-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Urolithiasis is a common medical problem. The diagnosis of this entity in the setting of acute flank pain presents an interesting challenge to the radiologist. Unenhanced helical CT has recently entered the fray and has quickly become the imaging study of choice when evaluating patients with acute flank pain and suspected ureterolithiasis. The nature and origin of ureteral stones and the pathophysiology of ureteral obstruction provide a basis for understanding the imaging findings in these patients.
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Affiliation(s)
- R C Smith
- Department of Diagnostic Imaging, Yale University School of Medicine, New Haven, Connecticut, USA.
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40
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Denton ER, Mackenzie A, Greenwell T, Popert R, Rankin SC. Unenhanced helical CT for renal colic--is the radiation dose justifiable? Clin Radiol 1999; 54:444-7. [PMID: 10437695 DOI: 10.1016/s0009-9260(99)90829-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
AIM The purpose of this study was to define and compare the radiation doses to patients undergoing computed tomography (CT) or intravenous urography (IVU) for the investigation of renal colic. METHODS The IVU dose was calculated from dose area product measurements for 27 abdominal films (AXR) and a review of 30 IVUs performed to investigate renal colic. The effective dose to a patient undergoing CT was calculated using anthropomorphic model data. Fifty patients underwent CT for the investigation of renal colic over a 6-week period. RESULTS CT following our protocol confers an average effective dose of 4.7 mSv. An IVU to investigate renal colic used 2.5 AXRs. A 3 film IVU gives an average dose of 1.5 mSv. Forty-two CT examinations were abnormal and the findings are described in the text. CONCLUSION Although unenhanced CT confers diagnostic advantages and avoids the risks of intravenous contrast medium, this should be considered against the increased radiation dose to the patient which in our institution is over three times that of an IVU.
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Affiliation(s)
- E R Denton
- Department of Radiology, Guys Hospital, Guys and St Thomas' Hospitals Trust, London, UK
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41
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Smith RC, Levine J, Dalrymple NC, Barish M, Rosenfield AT. Acute flank pain: a modern approach to diagnosis and management. Semin Ultrasound CT MR 1999; 20:108-35. [PMID: 10222519 DOI: 10.1016/s0887-2171(99)90042-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Acute flank pain is a common and complex clinical problem. In addition to flank pain caused by ureterolithiasis, other urinary and extraurinary abnormalities can result in a similar clinical picture. Unenhanced CT can rapidly, accurately, and safely determine the presence or absence of ureteral obstruction. When obstruction is caused by ureterolithiasis, CT allows precise determination of stone size and location. These are the two most important factors used for patient management. In addition to direct stone visualization, there are many secondary CT signs of ureteral obstruction that are direct manifestations of the underlying pathophysiology. On the other hand, when obstruction is absent, CT can diagnose or exclude most other abnormalities that result in flank pain. As a result of its many advantages, unenhanced helical CT should become the dominant imaging modality for evaluation of all patients with acute flank pain in whom a clinical diagnosis is uncertain.
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Affiliation(s)
- R C Smith
- Yale University School of Medicine, New Haven, CT 06520, USA
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Van Gansbeke D, Poncelet P, Sourtzis S, Nicaise N. Apport du CT-scanner hélicoïdal dans les coliques néphrétiques. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1164-6756(00)88307-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Fielding JR, Silverman SG, Samuel S, Zou KH, Loughlin KR. Unenhanced helical CT of ureteral stones: a replacement for excretory urography in planning treatment. AJR Am J Roentgenol 1998; 171:1051-3. [PMID: 9762995 DOI: 10.2214/ajr.171.4.9762995] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to determine whether unenhanced helical CT alone can be used for diagnosis and treatment planning of patients with obstructing ureteral stones. MATERIALS AND METHODS Medical records of 100 patients with ureteral stones and a clearly discernible clinical outcome who had undergone unenhanced helical CT were reviewed to determine the number of urography procedures and results of excretory urograms performed within 72 hr of helical CT. CT scans were then reviewed by two radiologists for six findings: in-plane stone diameter, z-axis stone diameter, location of stone, periureteral stranding, hydronephrosis, and perinephric fluid. Seventy-one patients passed stones spontaneously, and 29 patients required intervention including basket retrieval, extracorporeal shock-wave lithotripsy, laser lithotripsy, or a combination of the three treatments. Data were analyzed to determine those findings that correlated with the need for intervention. RESULTS Five excretory urograms were obtained, all of which agreed with findings revealed by CT. Excretory urography added no information. CT findings of in-plane diameter (p < .001), z -axis diameter (p < .001), and location of stone (p = .003) all significantly correlated with the need for intervention. CONCLUSION Helical CT can be used in place of excretory urography to plan treatment of patients with flank pain caused by obstructing ureteral stones. Stones that are larger than 5 mm, located within the proximal two thirds of the ureter, and seen on two or more consecutive CT images are more likely to require endoscopic removal, lithotripsy, or both.
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Affiliation(s)
- J R Fielding
- Department of Radiology, Brigham and Women's Hospital, Boston, MA 02115, USA
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