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Pinto DS, George A, Hoisala RV. MR urogram findings and diffusion restriction in the renal papilla and calyx in papillary necrosis-a new finding: preliminary report. BJR Case Rep 2017; 3:20150476. [PMID: 30363219 PMCID: PMC6159245 DOI: 10.1259/bjrcr.20150476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/09/2016] [Accepted: 11/26/2015] [Indexed: 01/27/2023] Open
Abstract
Renal papillary necrosis is a clinicopathological entity where any or all of the papillae undergo selective necrosis, which can be demonstrated either radiologically or histologically. The most important causes are diabetes, pyelonephritis, obstructive uropathy, tuberculosis, analgesic abuse or overuse, sickle cell disease and renal vein thrombosis. Although this condition was first described in the 19th century the clinical diagnosis of this condition remains a problem to this day. Uncomplicated papillary necrosis may initially remain occult to imaging by ultrasound and non-contrast CT, but may later be complicated by obstructive uropathy. A few studies have described renal papillary necrosis on CT urogram. In this case series, the authors describe the finding of calyceal filling defect with diffusion restriction in the calyx and the tip of the renal pyramid on MR urogram, along with other findings that are classically seen on intravenous urogram or CT urogram. To the best of our knowledge, the finding of diffusion restriction at the tip of the renal pyramid has not been described before. Further, literature review showed only a single study describing the classical findings of papillary necrosis on an MR urogram. The early diagnosis of papillary necrosis on MR imaging equips the radiologist to suggest short-term clinical and radiological follow-up to check for the development of hydronephrosis. Additionally, such risk stratification may enable early ureteric stenting to prevent the development of obstructive uropathy.
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Affiliation(s)
- Denver Steven Pinto
- Department of Radiodiagnosis, St Johns Medical College, Koramangala, Bangalore, India
| | - Arun George
- Department of Radiodiagnosis, St Johns Medical College, Koramangala, Bangalore, India
| | - Ravi V Hoisala
- Department of Radiodiagnosis, St Johns Medical College, Koramangala, Bangalore, India
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Schroeder J, Thacker PG, Purves TJ. Magnetic resonance urography of renal papillary necrosis. Pediatr Radiol 2014; 44:491-3. [PMID: 24526279 DOI: 10.1007/s00247-014-2883-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 12/16/2013] [Accepted: 01/16/2014] [Indexed: 11/25/2022]
Affiliation(s)
- Jennifer Schroeder
- Medical University of South Carolina, College of Medicine, Charleston, SC, USA
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Muthusami P, Bhuvaneswari V, Elangovan S, Dorairajan LN, Ramesh A. The role of static magnetic resonance urography in the evaluation of obstructive uropathy. Urology 2013; 81:623-7. [PMID: 23290346 DOI: 10.1016/j.urology.2012.10.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 10/19/2012] [Accepted: 10/23/2012] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To assess the diagnostic accuracy of static magnetic resonance urography (MRU) in hydronephrosis and to compare parameters of hydronephrosis in MRU with intravenous urography (IVU). MATERIALS AND METHODS Sixty-nine patients were included in this study of which 55 patients with a total of 63 hydronephrotic units underwent both IVU and MRU. MRU was performed on a 1.5 T scanner using heavily T2-weighted sequences. The level, grade, and cause of obstruction on each modality were interpreted by 2 radiologists. These were compared with the final diagnosis based on other appropriate modalities including imaging, intraoperative and histopathologic diagnosis. RESULTS The sensitivity and specificity MRU in detecting hydronephrosis were 95% and 100%, respectively. In determining the level of obstruction, the strength of agreement between IVU and MRU using kappa statistics was κ = 0.66, which corresponds to a good level of agreement. The Spearman correlation coefficient for the grade of hydronephrosis on MRU and IVU was 0.92 (95% confidence interval 0.86-0.95), with a P value of < .0001. The correct diagnosis was made in 89.2% of the cases by IVU and in 93.8% of the cases by MRU. CONCLUSION Along with a high sensitivity and specificity in detecting the presence, level, and grade of hydronephrosis, MRU without contrast also shows a good agreement with IVU. Static MRU can reliably replace IVU when the latter is contraindicated or technically difficult.
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Affiliation(s)
- Prakash Muthusami
- Department of Radiodiagnosis, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India.
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Abstract
Excellent contrast resolution and lack of ionizing radiation make magnetic resonance urography (MRU) a promising technique for noninvasively evaluating the entire urinary tract. While MRU currently lags behind CT urography (CTU) in spatial resolution and efficiency, new hardware and sequence developments have contributed to a resurgence of interest in MRU techniques. By combining unenhanced sequences with multiphase contrast-enhanced and excretory phase imaging, a comprehensive assessment of the kidneys, ureters, bladder, and surrounding structures is possible with image quality rivaling that obtained with other techniques. At the same time, formidable challenges remain to be overcome and further clinical validation is necessary before MRU can replace other forms of urography. In this article, we demonstrate the current potential of MRU to demonstrate a spectrum of urologic pathology involving the kidneys, ureters, and bladder while discussing the limitations and current status of this evolving technique.
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Affiliation(s)
- John R Leyendecker
- Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Ramos de Campos M, Juan Escudero JU, Navalón Verdejo P, Ordoño Domínguez F, Fabuel Deltoro M, Zaragoza Orts J. Uso de la urografía por resonancia magnética en el estudio del aparato urinario frente a la urografía convencional. Actas Urol Esp 2007; 31:253-61. [PMID: 17658154 DOI: 10.1016/s0210-4806(07)73631-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UNLABELLED Conventional urography (IVU) is an essential examination for the assessment of urinary tract but it is not free of complications, such as adverse reactions to contrast agents used (vasovagal and anaphylactic reactions), neurotoxicity, nephrotoxicity, as well as the damage due to the ionizing irradiation applied to the patient. For this reason, alternative imaging techniques such as magnetic resonance (MR) urography or uro-resonance have been developed. OBJECTIVE We present a case study assessing the diagnostic accuracy, specificity and sensitivity of uro-resonance and IVU as a morphological and functional examination of the urinary tract: and a quality study of the urographic images obtained with MR versus IVU. MATERIALS AND METHODS 150 patients have submited to a MR study, 63 of them with an IVU study already performed, acquiring high-intensity signals at T2 corresponding to abdominal and retroperitoneal fluid, initially using furosemide at low doses and, in a final study, administering gadolinium at a rate of 0.1 mg/Kg. The test was indicated in patients with antecedents of adverse reactions to iodine contrast, acute or chronic kidney failure, functional cancellation of the kidneys, pregnant patients and those in paediatric age. The capacity of diagnosis of urinary obstruction and the aetiology of this obstruction of both tests was studied, as well as the quality of the images obtained by the urographic study using MR. RESULTS High resolution images were obtained of all the upper urinary tracts using MR, especially in the renal pelvis, without artefacts caused by peristalsis or intestinal fluid interposition. In 83.3% of cases, examinations revealed urological pathology. The diagnostic accuracy of the involvement cause of the urinary tract was 83.3%, with a sensitivity of 89.6%, a specificity of 69.2%. a positive predictive value of 86.6% and a negative predictive value of 75%. CONCLUSION MR urography is a high sensitive technique for the study of urinary tract, used as an alternative to conventional urography particularly in cases of the contraindication of ionizing radiation or allergy to the contrast agent, as well as in patients with renal failure, and offers a wider morphological and functional study, with a high image quality, able to displace conventional examinations in the short or medium term.
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Affiliation(s)
- M Ramos de Campos
- Servicio de Urología, Consorcio Hospital General Universitario de Valencia.
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6
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Rohrschneider WK, Schenk JP. [Functional and morphological MR imaging of the upper urinary tract in the pediatric age group]. Radiologe 2006; 45:1092-100. [PMID: 16184374 DOI: 10.1007/s00117-005-1247-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
MR imaging is being increasingly used for the diagnosis of congenital urinary tract obstruction. The following conditions have to be fulfilled to provide an MR urography technique which is useful for the pediatric age group: (1) the combination of morphology and function, (2) a high-resolution morphological image, (3) a morphological image independent of kidney function, (4) reliable determination of split renal function and (5) of urinary excretion. This is best accomplished with a combination of a T1-weighted fast GE sequence post-contrast and a heavily T2-weighted 3D IR-TSE sequence. Selected sequence parameters are important for optimization as well as for a correct functional assessment. Then MR urography is superior to the conventional methods of excretory urography, ultrasound, and scintigraphy in the morphological depiction of the urinary tract even of complex malformations as well as in a detailed functional assessment. In particular, this method is useful in the situation of complicated duplex kidneys, dystopic kidneys, unclear morphology, or discrepant former results and perioperative assessment. The main advantages are avoiding radiation and obtaining a simultaneous functional-morphological diagnosis.
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Affiliation(s)
- W K Rohrschneider
- Sektion Pädiatrische Radiologie, St.-Annastiftskrankenhaus Ludwigshafen. wiltrud.rohrschneider@st.-annastiftskrankenhaus.de
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Boss A, Schaefer JF, Martirosian P, Hacker HW, Darge K, Claussen CD, Küper K, Schick F, Schlemmer HP. Contrast-enhanced dynamic MR nephrography using the TurboFLASH navigator-gating technique in children. Eur Radiol 2006; 16:1509-18. [PMID: 16770653 DOI: 10.1007/s00330-006-0182-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Revised: 01/17/2006] [Accepted: 01/24/2006] [Indexed: 01/17/2023]
Abstract
The purpose of this work was to test the feasibility of an MR examination protocol for the comprehensive assessment of renal morphology, excretion and split renal function using a navigator-gated TurboFLASH sequence. A navigator-gated T1-weighted single-slice TurboFLASH sequence suitable for dynamic MR urography and nephrography was implemented. A protocol was developed allowing for assessment of urinary excretion and split renal function by recording the renal clearance of a gadolinium (Gd) diethylene-triamine-pentacetic-acid (DTPA) bolus. Ten patients aged between 14 months and 14 years (mean age 4.8+/-4.6 years) were evaluated with the following indications: pelvicalyceal dilatation (n=4), follow-up after pyeloplasty (n=1), duplex systems (n=3), large renal cyst (n=1), and renal insufficiency (n=1). Dynamic MR urography and MR split renal function were compared to MAG3 scintigraphy. Evaluation of morphology, excretion and function required 50-60 minutes examination time, plus 10 minutes for post-processing. The TurboFLASH sequence yielded image acquisition at nearly identical diaphragm positions allowing for accurate region-of-interest evaluation within the renal parenchyma and the urinary passage. Static and dynamic MR urography showed the morphology of the urinary tract and excretion with sufficient diagnostic imaging quality, and the results were in diagnostic compliance with scintigraphy. MRI and scintigraphy yielded similar results for split renal function with a correlation coefficient of R=0.968 determined by linear regression. Our conclusions were that the method is robust, easy to perform on a clinical 1.5 T MRI system, rapid to evaluate and post-process and, therefore, easy to incorporate into clinical routine. Compared to scintigraphy, the higher spatial resolution of the MR examination provides additional important information improving the management of the pediatric patients without the application of radioactive tracers.
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Affiliation(s)
- Andreas Boss
- Department of Diagnostic Radiology, Section of Experimental Radiology, Eberhard-Karls University, Hoppe Seyler Strasse 3, 72076, Tübingen, Germany.
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Memarsadeghi M, Riccabona M, Heinz-Peer G. [MR urography: principles, examination techniques, indications]. Radiologe 2006; 45:915-23. [PMID: 15971042 DOI: 10.1007/s00117-005-1225-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
MR urography is an evolving and promising technique in the evaluation of the urinary tract. MR urography is currently considered the method of choice for imaging of the renal parenchyma and the collecting systems in patients who cannot undergo routine radiographic studies such as pregnant women, pediatric patients, patients allergic to iodinated contrast agents, or patients with impaired renal function. The future development of MR urography in terms of functional, cellular, and molecular imaging is presently the subject of research. The ability of MR imaging to provide quantitative functional information (e.g., on blood flow, perfusion, glomerular filtration rate, and excretion as well as urine drainage) in addition to morphologic assessment of the parenchyma and the collecting system could lead to a single, "all-in-one approach" examination technique.
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Affiliation(s)
- M Memarsadeghi
- Klinik für Radiodiagnostik, Medizinische Universität Wien, Osterreich.
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Abstract
PURPOSE OF REVIEW Urolithiasis during pregnancy is not common, however, it is a difficult condition to both diagnose and treat. There are many safety concerns that must be considered for both the mother and fetus. In this review we detail the different options available to the urologist and we highlight a treatment algorithm that we use when faced with a pregnant patient suspect of having a urinary calculus. RECENT FINDINGS Changes in ultrasound, limited intravenous urograms and magnetic resonance imaging have improved our ability to diagnose urolithiasis in pregnancy. Additionally ureteroscopy has emerged not only as a diagnostic tool but also as a modality for definitive treatment that can safely be used during the intrapartum period. SUMMARY When diagnosing urolithiasis in the gravid patient, the first line study should be ultrasound, using change in resistive index and transvaginal ultrasound. If these are not diagnostic, then a limited intravenous urograms should be performed. Once a diagnosis has been established, initial treatment should be conservative since 70-80% of patients will pass their stones. When intervention is necessary, the placements of an internal stent or percutaneous nephrostomy tube or ureteroscopy with definitive stone treatment are all reasonable options.
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Affiliation(s)
- Sarah J McAleer
- Division of Urology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA
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10
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Abstract
CT urography and MR urography are an evolving concept and developing technique. As the technology matures, CT urography will combine the ultimate diagnostic capabilities of intravenous urography and CT. In the near future, many intravenous urograms will be replaced by CT urography to evaluate patients with hematuria and other genitourinary conditions. MR urography currently serves as an alternative imaging technique to intravenous urography and CT urography for children and pregnant women and for patients with contraindications to iodinated contrast media.
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Affiliation(s)
- Akira Kawashima
- Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA.
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Oh-oka H, Fujisawa M, Kin K, Oshima T, Okada H, Arakawa S, Kamidono S. Usefulness of MR-seminography using Gd-DTPA in intermediate magnetic field MRI equipment. Magn Reson Imaging 2003; 21:497-502. [PMID: 12878259 DOI: 10.1016/s0730-725x(03)00077-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
T(2)-weighted fast advanced spin-echo imaging with gadolinium (hereinafter referred to as "MR-seminography") of the genital tract was evaluated for its usefulness in non-invasive investigation into the morphology of these organs. Twenty healthy male volunteers who are confirmed as free of genital tract obstruction were entered into the study. The genital tract was imaged using the 0.5 T MRI system by fast advanced spin echo (FASE) method. Based on quantitative evaluation, visibility evaluation, and the visualization of the genital tract in each subject, the contrast-enhanced images were assessed in comparison with those at pre-injection of the contrast agent by four specialists. Also examined were the morphology of the seminal vesicle according to age group using "Ishigami-Mori's classification," and the age angle of the main ducts. MR-seminography produced high contrast images and revealed a significantly decreased signal in the pelvic organs under investigation. In the analysis of individual subjects, the area from the proximal portion of the vas deferens to the ampulla and the seminal vesicles was on the whole well visualized except for the distal portion of the vas deferens and the ejaculatory duct. With regard to seminal vesicle morphology, type II was predominant. The age angle showed a trend toward widening with age. MR-seminography is non-invasive, useful, and therefore a highly recommended procedure for observation of the morphology in the area from the proximal portion of the vas deferens to the seminal vesicle.
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Affiliation(s)
- Hitoshi Oh-oka
- Department of Urology, Kawachi General Hospital, 28, Yokomakurahigashi, Higashiosaka-shi, Osaka 578-0955, Japan.
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Hughes J, Jan W, Goodie J, Lund R, Rankin S. MR urography: evaluation of different techniques in non-dilated tracts. Clin Radiol 2002; 57:989-94. [PMID: 12409109 DOI: 10.1053/crad.2002.1070] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To assess the effectiveness of different MRI sequences for the visualisation of the different components of the non-dilated urinary tract. METHOD 20 asymptomatic individuals were prospectively evaluated using 2 different heavily T2 weighted sequences, and after the injection of 2 different doses of gadolinium (Gd-DTPA). Images were independently scored. RESULTS The low dose Gd-DTPA enhanced MR urography (MRU) sequence was the best overall sequence for the visualisation of both the pelvicalyceal systems and ureters. The combination of information from the other sequences was additive. CONCLUSIONS Combined use of heavily T2 weighted and Gd-DTPA enhanced MRU produces diagnostic images and does not require pre-imaging preparation other than oral hydration.
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Affiliation(s)
- J Hughes
- Department of Clinical Radiology, Guy's and St. Thomas' Hospital, London, UK.
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Rohrschneider WK, Haufe S, Wiesel M, Tönshoff B, Wunsch R, Darge K, Clorius JH, Tröger J. Functional and morphologic evaluation of congenital urinary tract dilatation by using combined static-dynamic MR urography: findings in kidneys with a single collecting system. Radiology 2002; 224:683-94. [PMID: 12202700 DOI: 10.1148/radiol.2243011207] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess combined static-dynamic magnetic resonance (MR) urography in the evaluation of congenital urinary tract dilatation in infants and children. MATERIALS AND METHODS Sixty-two patients with urinary tract dilatation underwent prospective examination with combined static-dynamic MR urography. A combination examination involved use of a static T2-weighted three-dimensional inversion-recovery fast spin-echo sequence and a dynamic T1-weighted two-dimensional fast field-echo sequence with gadopentetate dimeglumine-DTPA and furosemide application. Twelve additional patients underwent examination with only static MR urography. Thus, both image quality and morphologic features were assessed in 74 patients with the use of MR urography. The results were compared with those of ultrasonography and, when available, conventional urography or surgery. In 62 patients, the dynamic sequence was used to calculate split renal function from renograms generated from parenchymal regions of interest and to assess urinary excretion from whole-kidney renograms. Results were compared with those of diuretic renal scintigraphy (DRS) for split function (Spearman rank correlation coefficient) and urinary excretion (kappa coefficient). RESULTS Stenoses at the ureteropelvic (n = 33) and ureterovesical (n = 31) junctions and within the ureter (n = 3) and nonstenotic dilatation (n = 23) were clearly depicted, while the normal urinary tract (n = 51) was depicted in its entirety in 47 of 51 examinations. Image quality was considered good or excellent in 95% of the kidney-ureter units. For split renal function, dynamic MR urography and DRS showed significant correlation (r = 0.92, P <.001). For urinary excretion, MR urography and DRS showed strong agreement (kappa = 0.67), with concordant classification of urinary excretion in 59 (81%) of 73 abnormal kidney-ureter units and in all 47 (100%) normal kidney-ureter units. CONCLUSION Combined static-dynamic MR urography provides high-quality depiction of the urinary tract in infants and children, while allowing accurate determination of single-kidney function and reliable evaluation of urinary excretion.
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Affiliation(s)
- Wiltrud K Rohrschneider
- Dept of Pediatric Radiology, Radiological Clinic, Univ of Heidelberg, Im Neuenheimer Feld 153, Germany.
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Katzberg RW, Buonocore MH, Ivanovic M, Pellot-Barakat C, Ryan JM, Whang K, Brock JM, Jones CD. Functional, dynamic, and anatomic MR urography: feasibility and preliminary findings. Acad Radiol 2001; 8:1083-99. [PMID: 11721808 DOI: 10.1016/s1076-6332(03)80720-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
RATIONALE AND OBJECTIVES The authors assessed the feasibility of using magnetic resonance (MR) urography to acquire functional, dynamic, and anatomic information in human subjects with normal and hydronephrotic kidneys. MATERIALS AND METHODS In subjects known to have or suspected of having hydronephrosis, split renal filtration fractions were measured with a customized magnetization-prepared, inversion-prepared gradient-recalled echo sequence to determine the T1 of flowing blood in the inferior vena cava and aorta before and after contrast medium administration and in the renal veins and arteries after contrast medium administration. Multiple timed sets of coronal fast spoiled gradient-echo 70 degrees flip-angle images were acquired before and after contrast medium administration to derive MR renograms from changes in the signal intensity of the cortex and medulla. Precontrast T2-weighted images were obtained with a three-dimensional fast spoiled gradient-echo maximum intensity projection pulse sequence, and postcontrast T1 maximum intensity projection images were also obtained to depict the renal anatomy. RESULTS Split filtration fraction differentiated normal from hydronephrotic kidneys. MR renograms depicted vascular, tubular, and ductal phases and differentiated between normal and hydronephrotic kidneys (P < .05, n = 20). Contrast medium dose correlated with the peak of the cortical signal intensity curves on the renogram (r = 0.7, P < .0005; n = 20). The sensitivities for the visual determination of hydronephrosis and unilateral delayed excretion of contrast material were both 100%, and the specificities were 64% and 85%, respectively. CONCLUSION The preliminary findings show promise for the use of MR urography in the comprehensive assessment of renal function, dynamics, and anatomy.
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Affiliation(s)
- R W Katzberg
- Department of Radiology, University of California-Davis, Medical Center, Research Imaging Center, Sacramento 95817, USA
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Sudah M, Vanninen R, Partanen K, Heino A, Vainio P, Ala-Opas M. MR urography in evaluation of acute flank pain: T2-weighted sequences and gadolinium-enhanced three-dimensional FLASH compared with urography. Fast low-angle shot. AJR Am J Roentgenol 2001; 176:105-12. [PMID: 11133546 DOI: 10.2214/ajr.176.1.1760105] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The aim of this study was to compare the usefulness of breath-hold heavily T2-weighted sequences with gadolinium-enhanced three-dimensional fast low-angle shot (3D FLASH) MR urography in the evaluation of patients with acute flank pain. SUBJECTS AND METHODS Forty consecutive patients with symptoms of acute flank pain underwent MR urography followed immediately by excretory urography. Heavily T2-weighted (combined thin-slice half-Fourier acquisition single-shot turbo spin-echo [HASTE] and thick-slab single-shot turbo spin-echo) and 3D FLASH sequences were evaluated separately and independently by two experienced radiologists for the presence, cause, level, and degree of obstruction. Interobserver agreement was calculated using the kappa statistic. Excretory urography and the final clinical diagnosis were used as reference. RESULTS Twenty-six patients were found to have unilateral obstruction caused by ureteral stones. Both MR urography methods were excellent for detecting obstruction. In the detection of stones 3D FLASH was superior, with a sensitivity of 96.2% and 100% and specificity of 100% and 100% for observers A and B, respectively, compared with a sensitivity of 57.7% and 53.8% and a specificity of 100% and 100%, respectively, for T2-weighted sequences. The best degree of obstruction was seen with 3D FLASH, and the interobserver agreement was excellent for stone detection (kappa = 0.97). CONCLUSION T2-weighted sequences alone are not sufficient for examining patients with acute flank pain. However, the combined use of both T2-weighted and 3D FLASH sequences will ensure better confidence in the evaluation of acute suspected renal colic. MR urography can replace conventional excretory urography when the latter is contraindicated or undesirable.
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Affiliation(s)
- M Sudah
- Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, FIN-70211 Kuopio, Finland
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Staatz G, Nolte-Ernsting CC, Adam GB, Hübner D, Rohrmann D, Stollbrink C, Günther RW. Feasibility and utility of respiratory-gated, gadolinium-enhanced T1-weighted magnetic resonance urography in children. Invest Radiol 2000; 35:504-12. [PMID: 10946978 DOI: 10.1097/00004424-200008000-00007] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate the feasibility and utility of respiratory-gated, gadolinium-enhanced T1-weighted magnetic resonance (MR) urography in children. METHODS In a prospective study, 30 consecutive children, aged 3 weeks to 13.8 years, underwent MR urography. After intravenous injection of low-dose furosemide and gadopentetate dimeglumine, respiratory-gated, coronal, T1-weighted 3D-gradient-echo sequences were obtained at 1.5 T 5 to 30 minutes after contrast administration. Postprocessing of the data was performed using a maximum-intensity projection algorithm. In addition, precontrast half-Fourier rapid acquisition with relaxation enhancement MR urograms were obtained in 29 children. RESULTS Respiratory-gated, T1-weighted MR urography was successfully performed in all children without the need for sedation. Compared with the final diagnosis, prospective analysis of MR urography images revealed the correct diagnosis in 56 of 58 pelvicaliceal systems (96%). The ureteral morphology was correctly evaluated in 59 of 64 ureters (92%). The method showed limited efficiency for evaluating nonfunctioning renal units. CONCLUSIONS Respiratory-gated, gadolinium-enhanced T1-weighted MR urography is a feasible and effective diagnostic tool in the assessment of upper urinary tract morphology in children. It is especially useful in depicting nondilated collecting systems and ureters.
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Affiliation(s)
- G Staatz
- Department of Diagnostic Radiology, University Hospital of the RWTH, Aachen, Germany.
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Hwang SI, Kim SH, Kim YJ, Kim AY, Cho JY, Lee JW, Kim HS, Yeon KM. Effectiveness of MR urography in the evaluation of kidney which failed to opacify during excretory urography: comparison with ultrasonography. Korean J Radiol 2000; 1:152-8. [PMID: 11752946 PMCID: PMC2718184 DOI: 10.3348/kjr.2000.1.3.152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The purpose of this study was to compare the effectiveness of MR urography (MRU) with that of ultrasonography (US) in the evaluation of urinary tract when this failed to opacify during excretory urography (EXU). MATERIALS AND METHODS Twelve urinary tracts in 11 patients were studied. In each case, during EXU, the urinary system failed to opacify within one hour of the injection of contrast media, and US revealed dilatation of the pelvocalyceal system. Patients underwent MRU, using a HASTE sequence with the breath-hold technique; multi-slice acquisition was then performed, and the images were reconstructed using maximal intensity projection. Each set of images was evaluated by three radiologists to determine the presence, level, and cause of urinary tract obstruction. RESULTS Obstruction was present in all twelve cases, and in all of these, MRU accurately demonstrated its level. In this respect, however, US was successful in only ten. The cause of obstruction was determined by MRU in eight cases, but by US in only six. In all of these six, MRU also successfully demonstrated the cause. CONCLUSION MRU is an effective modality for evaluation of the urinary tract when this fails to opacify during EXU, and appears to be superior to US in demonstrating the level and cause of obstruction.
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Affiliation(s)
- Sung-Il Hwang
- Department of Radiology, Seoul National University Hospital, Korea
| | - Seung Hyup Kim
- Department of Radiology, Seoul National University Hospital, Korea
| | - Young Jun Kim
- Department of Radiology, Seoul National University Hospital, Korea
| | - Ah Young Kim
- Department of Radiology, Seoul National University Hospital, Korea
| | - Jung Yun Cho
- Department of Radiology, Seoul National University Hospital, Korea
| | - Joon Woo Lee
- Department of Radiology, Seoul National University Hospital, Korea
| | | | - Kyung Mo Yeon
- Department of Radiology, Seoul National University Hospital, Korea
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Nolte-Ernsting C, Adam G, Bücker A, Berges S, Bjørnerud A, Günther RW. Contrast-enhanced magnetic resonance urography. First experimental results with a polymeric gadolinium bloodpool agent. Invest Radiol 1997; 32:418-23. [PMID: 9228608 DOI: 10.1097/00004424-199707000-00008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
RATIONALE AND OBJECTIVES The authors investigated the feasibility of contrast-enhanced excretory magnetic resonance urography to visualize the nonobstructed urinary tract with a macromolecular gadolinium-based bloodpool agent. METHODS Excretory magnetic resonance imaging was performed in seven pigs using a T1-weighted three dimensional fast-field-echo sequence before and up to 120 minutes after administration of a gadolinium bloodpool prototype agent. RESULTS During the first 15 minutes after injection, the urographic effect was predominantly poor. Visualization of the entire urinary tract was excellent in four pigs and incomplete but satisfactory in three 105 minutes after injection. Furosemide application was tested in one case, which improved image quality effectively. Corresponding to the physiological excretion rate, signal measurements in the renal parenchyma revealed a gradual decrease of the initially distinct contrast enhancement. CONCLUSIONS T1-weighted contrast-enhanced magnetic resonance urography using a polymeric gadolinium bloodpool allows detailed visualization of the normal urinary tract, while information about the excretory function is obtained simultaneously. However, application of a diuretic seems to be essential to prevent lengthy examination duration.
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Affiliation(s)
- C Nolte-Ernsting
- Department of Diagnostic Radiology, University of Technology, Aachen, Germany.
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Li W, Chavez D, Edelman RR, Prasad PV. Magnetic resonance urography by breath-hold contrast-enhanced three-dimensional FISP. J Magn Reson Imaging 1997; 7:309-11. [PMID: 9090583 DOI: 10.1002/jmri.1880070209] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The purpose of this study was to present our initial experience with contrast-enhanced MR urography with a breath-hold three-dimensional imaging technique. We performed MR urographic studies in two pigs (four studies) and five human subjects using gadopentetate dimeglumine. The FISP sequence we used was the same as the one used for contrast-enhanced three-dimensional breath-hold angiography. MR three-dimensional urograms were obtained 7-24 minutes after the contrast injection with a dose as low as .03 mmol/kg. The calyces, renal pelves, and ureters were very well visualized. Three-dimensional MR urography can be acquired within a single breath-hold after administration of gadolinium chelates. This technique could become part of a protocol that could potentially lead to a single comprehensive diagnostic workup for suspected ureteral obstruction and gross hematuria.
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Affiliation(s)
- W Li
- Department of Radiology, Beth Israel Hospital, Boston, MA, USA
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