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Torres ER, Tumey TA, Dean DC, Kassahun-Yimer W, Lopez-Lambert ED, Hitchcock ME. Non-pharmacological strategies to obtain usable magnetic resonance images in non-sedated infants: Systematic review and meta-analysis. Int J Nurs Stud 2020; 106:103551. [PMID: 32294563 DOI: 10.1016/j.ijnurstu.2020.103551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Although the use of sedation is commonly practiced to keep infants still while receiving magnetic resonance imaging, non-pharmacological strategies are a potential alternative. OBJECTIVES The purpose of this study was to determine the success rate of obtaining usable magnetic resonance images in infants with the sole use of non-pharmacological strategies. DESIGN Systematic literature review and meta-analysis SETTING: A search was conducted in PubMed, CINAHL and Cochrane Library. PARTICIPANTS Human infants from birth to 24 months of age who did not receive any sedation or anesthesia during magnetic resonance imaging METHOD: Articles that reported the success rate of obtaining usable images were included. RESULTS Of the 521 non-duplicate articles found, 58 articles were included in the systematic review with sample sizes ranging from 2-457, an average success rate of 87.8%, and an average scan time of 30 min. The most common non-pharmacological technique included feeding and swaddling infants before imaging to encourage infants to sleep during the scan. Meta-analysis performed on 53 articles comprising 3,410 infants found a success rate of 87%, but significant heterogeneity was found (I2 = 98.30%). It was more difficult to obtain usable images solely with non-pharmacological techniques if infants were critically ill or a structural magnetic resonance imaging of the brain was required. CONCLUSION Non-pharmacological techniques are effective for obtaining usable magnetic resonance imaging scans in most but not all infants. Tweetable abstract: Non-pharmacological techniques are effective for obtaining usable magnetic resonance imaging scans in most infants.
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Affiliation(s)
- Elisa R Torres
- School of Nursing, University of Mississippi Medical Center, 2500 North State Street, Jackson 39216, MS, United States.
| | - Tyler A Tumey
- Burrell College of Osteopathic Medicine, 3501 Arrowhead Dr Las Cruces, NM 88001, United States.
| | - Douglas C Dean
- Waisman Center, University of Wisconsin-Madison, 1500 Highland Ave, Madison WI 53705, United States.
| | - Wondwosen Kassahun-Yimer
- Department of Data Science, University of Mississippi Medical Center, School of Population Health,2500 North State Street, Jackson, MS 39216, United States.
| | - Eloise D Lopez-Lambert
- School of Nursing, University of Mississippi Medical Center, 2500 North State Street, Jackson 39216, MS, United States
| | - Mary E Hitchcock
- Ebling Library, University of Wisconsin-Madison, 750 Highland Ave, Madison WI 53705, United States.
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Yoruk U, Saranathan M, Loening AM, Hargreaves BA, Vasanawala SS. High temporal resolution dynamic MRI and arterial input function for assessment of GFR in pediatric subjects. Magn Reson Med 2015; 75:1301-11. [PMID: 25946307 DOI: 10.1002/mrm.25731] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/26/2015] [Accepted: 03/20/2015] [Indexed: 11/08/2022]
Abstract
PURPOSE To introduce a respiratory-gated high-spatiotemporal-resolution dynamic-contrast-enhanced MRI technique and a high-temporal-resolution aortic input function (HTR-AIF) estimation method for glomerular filtration rate (GFR) assessment in children. METHODS A high-spatiotemporal-resolution DCE-MRI method with view-shared reconstruction was modified to incorporate respiratory gating, and an AIF estimation method that uses a fraction of the k-space data from each respiratory period was developed (HTR-AIF). The method was validated using realistic digital phantom simulations and demonstrated on clinical subjects. The GFR estimates using HTR-AIF were compared with estimates obtained by using an AIF derived directly from the view-shared images. RESULTS Digital phantom simulations showed that using the HTR-AIF technique gives more accurate AIF estimates (RMSE = 0.0932) compared with the existing estimation method (RMSE = 0.2059) that used view-sharing (VS). For simulated GFR > 27 mL/min, GFR estimation error was between 32% and 17% using view-shared AIF, whereas estimation error was less than 10% using HTR-AIF. In all clinical subjects, the HTR-AIF method resulted in higher GFR estimations than the view-shared method. CONCLUSION The HTR-AIF method improves the accuracy of both the AIF and GFR estimates derived from the respiratory-gated acquisitions, and makes GFR estimation feasible in free-breathing pediatric subjects.
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Affiliation(s)
- Umit Yoruk
- Department of Radiology, Stanford University, California, USA.,Department of Electrical Engineering, Stanford University, California, USA
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Jung BA, Weigel M. Spin echo magnetic resonance imaging. J Magn Reson Imaging 2013; 37:805-17. [PMID: 23526758 DOI: 10.1002/jmri.24068] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 01/11/2013] [Indexed: 11/07/2022] Open
Abstract
The spin echo sequence is a fundamental pulse sequence in MRI. Many of today's applications in routine clinical use are based on this elementary sequence. In this review article, the principles of the spin echo formation are demonstrated on which the generation of the fundamental image contrasts T1, T2, and proton density is based. The basic imaging parameters repetition time (TR) and echo time (TE) and their influence on the image contrast are explained. Important properties such as the behavior in multi-slice imaging or in the presence of flow are depicted and the basic differences with gradient echo imaging are illustrated. The characteristics of the spin echo sequence for different magnetic field strengths with respect to clinical applications are discussed.
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Affiliation(s)
- Bernd André Jung
- Department of Radiology, Medical Physics, University Medical Center, Freiburg, Germany.
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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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Silverman SG, Leyendecker JR, Amis ES. What Is the Current Role of CT Urography and MR Urography in the Evaluation of the Urinary Tract? Radiology 2009; 250:309-23. [DOI: 10.1148/radiol.2502080534] [Citation(s) in RCA: 218] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Michael R. Potential of MR-imaging in the paediatric abdomen. Eur J Radiol 2008; 68:235-44. [PMID: 18848412 DOI: 10.1016/j.ejrad.2008.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 07/16/2008] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To describe the potential and relevant applications of MR-imaging (MRI) in typical paediatric abdominal conditions and diseases. METHOD The commonly used indications, applications, and sequences as well as typical imaging findings of paediatric abdominal MRI are presented and discussed, with emphasis on specific paediatric needs and queries. Only applications as used in routine clinical work are listed, other more sophisticated and advanced techniques will only briefly be mentioned. Furthermore, some aspects of paediatric MR Urography are presented and discussed. CONCLUSION Though conventional imaging methods (ultrasound and plain film) are valuable and - particularly in the paediatric abdomen - form the mainstay of routine imaging in paediatric abdominal radiology, some conditions require sectional imaging. MRI is increasingly applied to these queries in neonates, infants and children as an alternative method to CT without any radiation burden, and - when performed adequately and skilfully - can answer most treatment relevant questions. MR will increasingly be applied with new applications and broader availability also with functional information deriving from new equipment and research offering an ideal one stop imaging approach to many conditions also in children.
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Affiliation(s)
- Riccabona Michael
- Department of Radiology, Division of Paediatric Radiology, LKH Graz, University Hospital, Auenbruggenplatz, A-8036 Graz, Austria.
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Leyendecker JR, Barnes CE, Zagoria RJ. MR urography: techniques and clinical applications. Radiographics 2008; 28:23-46; discussion 46-7. [PMID: 18203929 DOI: 10.1148/rg.281075077] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Magnetic resonance (MR) urography comprises an evolving group of techniques with the potential for allowing optimal noninvasive evaluation of many abnormalities of the urinary tract. MR urography is clinically useful in the evaluation of suspected urinary tract obstruction, hematuria, and congenital anomalies, as well as surgically altered anatomy, and can be particularly beneficial in pediatric or pregnant patients or when ionizing radiation is to be avoided. The most common MR urographic techniques for displaying the urinary tract can be divided into two categories: static-fluid MR urography and excretory MR urography. Static-fluid MR urography makes use of heavily T2-weighted sequences to image the urinary tract as a static collection of fluid, can be repeated sequentially (cine MR urography) to better demonstrate the ureters in their entirety and to confirm the presence of fixed stenoses, and is most successful in patients with dilated or obstructed collecting systems. Excretory MR urography is performed during the excretory phase of enhancement after the intravenous administration of gadolinium-based contrast material; thus, the patient must have sufficient renal function to allow the excretion and even distribution of the contrast material. Diuretic administration is an important adjunct to excretory MR urography, which can better demonstrate nondilated systems. Static-fluid and excretory MR urography can be combined with conventional MR imaging for comprehensive evaluation of the urinary tract. The successful interpretation of MR urographic examinations requires familiarity with the many pitfalls and artifacts that can be encountered with these techniques.
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Affiliation(s)
- John R Leyendecker
- Department of Radiology, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157, USA.
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Cerwinka WH, Damien Grattan-Smith J, Kirsch AJ. Magnetic resonance urography in pediatric urology. J Pediatr Urol 2008; 4:74-82; quiz 82-3. [PMID: 18631897 DOI: 10.1016/j.jpurol.2007.08.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2007] [Accepted: 08/17/2007] [Indexed: 01/25/2023]
Abstract
PURPOSE OF REVIEW Magnetic resonance urography (MRU) has emerged as a powerful diagnostic tool in the evaluation of the pediatric genitourinary tract. The purpose of this review is to familiarize the reader with the basic techniques, strengths and limitations, as well as the current and potential future applications of MRU in pediatric urology. RECENT FINDINGS MRU can provide detailed anatomical information and assess renal function and drainage in a single study. MRU does not employ ionizing radiation and may be utilized in patients with iodine-based contrast allergy or impaired renal function. MRU has been most often applied to the evaluation of hydronephrosis and provides valuable insight into a wide range of obstructive uropathies. MRU was shown to be superior to renal scintigraphy for the diagnosis of pyelonephritis and renal scarring. The use of MRU for the assessment of urolithiasis and vesicoureteral reflux is limited and technical refinements are required. Potential future applications include fetal MRU, virtual endoscopy, and MRU-guided procedures. The development of new contrast agents and new image-processing software will further enhance the diagnostic potential of MRU in pediatric urology. SUMMARY MRU is currently thought of as a problem-solving tool to define anatomy and function when conventional methods fall short. This technique is likely to emerge as the imaging modality of choice for children with complex genitourinary pathology.
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Affiliation(s)
- Wolfgang H Cerwinka
- Children's Healthcare of Atlanta, Emory University School of Medicine, 5445 Meridian Mark Road, Suite 420, Atlanta, GA 30342, USA.
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Ergen FB, Hussain HK, Carlos RC, Johnson TD, Adusumilli S, Weadock WJ, Korobkin M, Francis IR. 3D excretory MR urography: Improved image quality with intravenous saline and diuretic administration. J Magn Reson Imaging 2007; 25:783-9. [PMID: 17335024 DOI: 10.1002/jmri.20875] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To assess the effect of diuretic administration on the image quality of excretory magnetic resonance urography (MRU) obtained following intravenous hydration, and to determine whether intravenous hydration alone is sufficient to produce diagnostic quality studies of nondilated upper tracts. MATERIALS AND METHODS A total of 22 patients with nondilated upper tracts were evaluated with contrast-enhanced MRU. All patients received 250 mL of saline intravenously immediately prior to the examination. A total of 11 patients received 10-20 mg furosemide in addition to saline. Imaging was performed with a three-dimensional (3D) and two-dimensional (2D) breathhold spoiled gradient-echo sequences. Excretory MRU images were acquired five minutes after the administration of 0.1 mmol/kg gadolinium and were independently reviewed by two radiologists, who were blinded to the MRU technique. Readers evaluated the calyces, renal pelvis, and ureters qualitatively for degree of opacification, distention, and artifacts on a four-point scale. Statistical analysis was performed using a permutation test. RESULTS There was no significant disagreement between the two readers (P=0.14). Furosemide resulted in significant improvement in calyceal and renal pelvis distention (P<0.005), and significant artifact reduction in all upper tract segments (P<0.001) compared to the effect of saline alone. CONCLUSION Intravenous furosemide significantly improves the image quality of excretory MRU studies obtained following intravenous hydration. Intravenous saline alone is insufficient to produce diagnostic quality studies of the non-dilated upper tracts.
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Affiliation(s)
- F Bilge Ergen
- Department of Radiology/MRI, University of Michigan Health System, Ann Arbor, Michigan 48109-0003, USA
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Kaneyama K, Yamataka A, Someya T, Itoh S, Lane GJ, Miyano T. Magnetic Resonance Urographic Parameters for Predicting the Need for Pyeloplasty in Infants With Prenatally Diagnosed Severe Hydronephrosis. J Urol 2006; 176:1781-4; discussion 1784-5. [PMID: 16945648 DOI: 10.1016/j.juro.2006.03.122] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Indexed: 12/28/2022]
Abstract
PURPOSE Treatment in infants with prenatally diagnosed, severe hydronephrosis remains controversial. We measured anatomical parameters using magnetic resonance urography to create a pelvic index ratio, which we correlated with outcome to assess its value. MATERIALS AND METHODS We reviewed 35 cases of prenatally diagnosed severe hydronephrosis, including grade III in 19 and grade IV in 16. By 6 weeks after birth all patients had undergone repeat ultrasonography, diuretic renography and magnetic resonance urography. Magnetic resonance urography was used to measure the distance (D) from the bottom of the lowest renal calyx to the ureteropelvic junction and the total longitudinal length (L) of the caliceal system. The pelvic index ratio, defined as D/L, assesses the level at which the ureter inserts into the renal pelvis. RESULTS All cases were initially managed conservatively. Pyeloplasty was required in 16 kidneys (mean patient age +/- SD 7.5 +/- 3.9 months) because of deterioration in renal function. All patients were well at a mean followup of 3.8 years. The remaining 19 cases continued to be managed conservatively. By a mean of 5.4 years spontaneous resolution of prenatally diagnosed severe hydronephrosis had occurred in 7 of 19 cases, while 12 were downgraded to grades I-II. The mean pelvic index ratio in surgical cases was 0.26 +/- 0.13 and in nonsurgical cases it was 0.12 +/- 0.11, indicating that ureters inserted significantly higher in surgical cases (p = 0.0012). Of 9 kidneys with a pelvic index ratio of greater than 0.3 pyeloplasty was required in 8, while 10 of 12 with a pelvic index ratio of less than 0.1 were managed conservatively. CONCLUSIONS Pyeloplasty is likely to be required if the pelvic index ratio is greater than 0.3 and conservative management is likely to succeed if the ratio is less than 0.1. The pelvic index ratio can be calculated easily even in the neonatal period. It appears to be prognostic for pyeloplasty in cases of prenatally diagnosed, severe hydronephrosis.
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Affiliation(s)
- Kazuhiro Kaneyama
- Department of Pediatric General and Urogenital Surgery, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
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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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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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Riccabona M, Ruppert-Kohlmayr A, Ring E, Maier C, Lusuardi L, Riccabona M. Potential impact of pediatric MR urography on the imaging algorithm in patients with a functional single kidney. AJR Am J Roentgenol 2004; 183:795-800. [PMID: 15333372 DOI: 10.2214/ajr.183.3.1830795] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The purpose of this study was to evaluate the potential of MR urography in the assessment of children with a suspected "functional single kidney." SUBJECTS AND METHODS Sixty patients (age range, 2.7 weeks to 15.7 years) who had been referred for assessment of a suspected functional single kidney underwent MR urography in addition to detailed sonography of the urinary tract and the currently indicated standard imaging. The results of the conventional imaging ((99m)Tc-dimer captosuccinic acid scintigraphy, voiding cystourethrography, and genitography) were compared with the results of sonography and MR urography; surgical findings served as the gold standard if available. RESULTS Twenty-six patients had a single kidney. The other diagnoses were six contralateral multicystic dysplastic kidneys, two normal ectopic kidneys, one crossfused double system, and 25 ectopic or dysplastic renal buds. Scintigraphy detected all normal kidneys, two ectopic kidneys, and two dysplastic renal buds. Detailed sonography missed two ectopic kidneys and two orthotopic dysplastic renal buds, but one additional renal bud that could not be confirmed on other imaging techniques (accuracy, 91.7%; sensitivity, 88.2%; specificity, 96.2%) was suspected. MR urography results were correct in all patients and verified in all 13 with surgical correlation. CONCLUSION MR urography allows a reliable assessment of renal and ureteral anatomy and of dysplastic or ectopic renal buds, even in non- or poorly functioning systems. MR urography therefore has the potential to replace the currently used excretory urography and scintigraphy. In patients with a suspected functional single kidney a detailed sonographic study and MR urography should be considered the diagnostic algorithm of choice.
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Affiliation(s)
- Michael Riccabona
- Department of Radiology, Division of Pediatric Radiology, LKH-University Hospital, Auenbruggerplatz, Graz A-8036, Austria.
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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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Heuer R, Sommer G, Shortliffe LD. Evaluation of renal growth by magnetic resonance imaging and computerized tomography volumes. J Urol 2003; 170:1659-63; discussion 1663. [PMID: 14501685 DOI: 10.1097/01.ju.0000085676.76111.27] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Magnetic resonance imaging (MRI) and computerized tomography (CT) are commonly used to image complex medical conditions but limited data have been reported concerning normal renal volumetric measurement with these imaging techniques. We examined whether normative renal growth curves could be constructed from data derived from these imaging modalities, and from these curves assessed normal and abnormal renal development. MATERIALS AND METHODS Patients who had undergone prior renal MRI or CT were identified. Total renal volume and renal cortical fraction (CF, cortical/total volume) were calculated, and growth curves were derived. To examine the curve utility for abnormal growth assessment, renal ultrasonography of children with reflux nephropathy was examined, and MRI and radionuclide scans were compared. RESULTS A total of 60 patients 2 months to 39 years old who underwent MRI were included in the growth curve. The CF of the 120 kidneys was 75.8 +/- 4.3% and independent of sex and age. In 19 patients with vesicoureteral reflux 13 kidneys had cortical scarring, and the CF was decreased (p <0.001, 63.65 +/- 5.72%), indicating disproportionate cortical loss. No difference between CF for normal and vesicoureteral reflux unscarred kidneys was found. Differential renal function on radionuclide study correlated highly with MRI renal volume (r = 0.91). CT was performed in 70 children 1 to 15 years old (mean age 7.9) volume correlated with age and renal length, and the left kidney was larger than right kidney on MRI and CT. CONCLUSIONS Normative renal growth curves can be constructed from CT and MRI derived renal volumes. Cortical fraction is consistent, and sex and age independent. In reflux nephropathy the CF is reduced and renal differential function on nuclear scan correlates with MRI derived differential volume. This concept may be useful for predicting abnormal renal growth and differential function.
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Affiliation(s)
- Roman Heuer
- Department of Urology, Stanford University School of Medicine, California 94305, USA
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Ansari MS, Hemal AK, Gupta NP, Dogra PN. Laparoscopy for the diagnosis and treatment of radiologically occult but symptomatic hypoplastic kidneys. Urology 2003; 62:627-31. [PMID: 14550430 DOI: 10.1016/s0090-4295(03)00571-5] [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: 11/22/2022]
Abstract
OBJECTIVES To evaluate the efficacy of different imaging modalities for visualization of small poorly functioning hypoplastic and dysplastic kidneys and to assess the role of laparoscopy in localization and treatment. METHODS Between 1998 and 2002, 10 female patients who presented with urinary incontinence, flank pain, or hypertension secondary to small, poorly functioning hypoplastic or dysplastic kidneys were treated at our institute. We reviewed the results of the imaging studies, cystoscopy, and evaluation under anesthesia for these patients. After the diagnosis, all patients were treated with laparoscopic retroperitoneal or transperitoneal nephroureterectomy or nephrectomy. RESULTS Intravenous urography and ultrasonography failed to visualize the affected renal units in all 10 cases. Computed tomography could locate small dysplastic renal units in only 5 patients (50%). Dimercaptosuccinic acid renal scintigraphy was diagnostic in all 10 cases (100%). Magnetic resonance urography was done in 2 cases only, and the affected renal units were identified in both. Cystoscopy and vaginoscopy were inconclusive in all but 2 cases. Laparoscopy efficiently located the offending renal units in all 10 cases. In 9 cases, the affected renal units were located in the lumbar region, and in 1 case it was situated ectopically in the pelvis. All 10 patients underwent laparoscopic retroperitoneal or transperitoneal nephroureterectomy or nephrectomy and were asymptomatic after surgery. CONCLUSIONS Dimercaptosuccinic acid scintigraphy is an accurate and specific imaging modality for visualization of small hypoplastic renal units that are not visualized by conventional radiologic imaging techniques. Laparoscopy can be recommended as the ideal method of management, because it provides a minimally invasive technique for detecting the kidney and simultaneously correcting the problem.
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Affiliation(s)
- M S Ansari
- Department of Urology, All India Institute of Medical Sciences, New Delhi, India
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Wille S, von Knobloch R, Klose KJ, Heidenreich A, Hofmann R. Magnetic resonance urography in pediatric urology. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 2003; 37:16-21. [PMID: 12745737 DOI: 10.1080/00365590310008622] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To evaluate the efficiency of magnetic resonance urography (MRU) in pediatric urology. MATERIAL AND METHODS We report retrospectively on 12 children who underwent MRU between January 1999 and November 2001. MRU was performed to accurately evaluate the entire urinary tract because of megaureter, ectopic ureter, vesicoureteral reflux, Y-inverted duplication and hydronephrosis because of pyeloureteral stenosis. T1- and T2-weighted images were obtained in the coronal, sagittal and axial planes. The mean age of the children (8 females, 4 males) investigated was 36 months (range 2-140 months). RESULTS An accurate anatomical picture of the entire urinary tract could be obtained in all children. The obstructive nature of megaureter could be differentiated. The distal orifice of ectopic ureter could be identified in the vagina. Vesicoureteral reflux into the blind-ending ureteral bud of a duplicated system was accurately identified. Hydronephrosis was demonstrated to be the result of pyeloureteral stenosis. The location of stenoses was easily identified in the sagittal and coronal planes. CONCLUSIONS MRU is an excellent imaging modality for accurately depicting the urinary tract. MRU is superior to conventional intravenous urography because it does not use ionizing radiation, the gadolinium contrast medium used is not nephrotoxic and the imaging quality is excellent, reproducible and not interfered with by gas superposition. Considering the high costs and diagnostic benefit of MRU compared to intravenous urography, MRU should be performed in patients with impaired renal function, in those with an allergy to contrast medium and if anatomic relationships are not clear prior to reconstructive surgery.
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Affiliation(s)
- Sebastian Wille
- Department of Urology, Philipps-University Marburg, Marburg, Germany.
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Hennig J, Weigel M, Scheffler K. Multiecho sequences with variable refocusing flip angles: optimization of signal behavior using smooth transitions between pseudo steady states (TRAPS). Magn Reson Med 2003; 49:527-35. [PMID: 12594756 DOI: 10.1002/mrm.10391] [Citation(s) in RCA: 208] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A variation of the rapid acquisition with relaxation enhancement (RARE) sequence (also called turbo spin-echo (TSE) or fast spin-echo (FSE)) is presented. This technique uses variable flip angles along the echo train such that magnetization is initially prepared into the static pseudo steady state (PSS) for a low refocusing flip angle (alpha < 180 degrees ). It is shown that after such a preparation, magnetization will always stay very close to the static PSS even after significant variation of the subsequent refocusing flip angles. This allows the design of TSE sequences in which high refocusing flip angles yielding 100% of the attainable signal are applied only for the important echoes encoding for the center of k-space. It is demonstrated that a reduction of the RF power (RFP) by a factor of 2.5-6 can be achieved without any loss in signal intensity. The contribution of stimulated-echo pathways leads to a reduction of the effective TE by a factor f(t), which for typical implementations is on the order of 0.5-0.8. This allows the use of longer echo readout times, and thus longer echo trains, for acquiring images with a given T(2) contrast.
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Affiliation(s)
- Juergen Hennig
- Department of Diagnostic Radiology, Section of Medical Physics, University of Freiburg, Germany.
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20
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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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Obuchi M, Sugimoto H, Takahara T, Kubota H, Yamamoto W, Kinebuchi Y, Honda M. Moderately T2-weighted images obtained with the single-shot fast spin-echo technique: differentiating between malignant and benign urinary obstructions. Magn Reson Med Sci 2002; 1:81-7. [PMID: 16082130 DOI: 10.2463/mrms.1.81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The purpose of this study was to determine whether a distinction could be made between benign and malignant urinary obstructions in moderately T(2)-weighted images obtained with the single-shot fast spin-echo technique. Forty-four lesions in 39 patients with urinary obstruction were evaluated with the single-shot fast spin-echo (SSFSE) technique with an effective TE of 90-100 ms and without fat saturation. Benign and malignant lesions were compared for the presence of ureteral wall thickening and a signal intensity relative to the proximal ureteral wall. Statistically significant differences were found between benign and malignant lesions in both morphologic change (P<0.0001) and signal intensity of the lesions at the obstruction position (P<0.0001). The combination of wall thickening and increased signal intensity as a predictor of malignant disease yielded a sensitivity of 88% and a specificity of 100%. Neither increased signal intensity nor wall thickening as a predictor of benign disease yielded a sensitivity of 89% and a specificity of 88%. The moderately T(2)-weighted SSFSE technique without fat saturation can accurately distinguish between benign and malignant urinary obstructions.
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Affiliation(s)
- Masao Obuchi
- Department of Radiology, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, Yokohama 227-8501, Japan.
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MAGNETIC RESONANCE UROGRAPHY IN CHILDREN:. J Urol 2001. [DOI: 10.1097/00005392-200112000-00092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Staatz G, Rohrmann D, Nolte-Ernsting CC, Stollbrink C, Haage P, Schmidt T, Günther RW. Magnetic resonance urography in children: evaluation of suspected ureteral ectopia in duplex systems. J Urol 2001; 166:2346-50. [PMID: 11696782 DOI: 10.1016/s0022-5347(05)65586-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE We evaluate the diagnostic accuracy of magnetic resonance urography in children with suspected ectopic ureters and ureteroceles in duplex systems. MATERIALS AND METHODS A total of 14 children 4 weeks to 8 years old with a total of 18 duplex systems underwent magnetic resonance urography using a 1.5 tesla scanner. After injection of low dose furosemide, half-Fourier rapid acquisition with relaxation enhancement images were obtained for T2-weighted static fluid magnetic resonance urography. Respiratory gated 3-dimensional gradient echo images were acquired for T1-weighted excretory magnetic resonance urography 5 to 30 minutes after intravenously administered gadolinium. RESULTS All magnetic resonance examinations were successfully performed without sedation. The diagnostic accuracy of T1-weighted excretory magnetic resonance urography depended on the renal function. Twelve duplex systems with a normal excretory function, including 6 bifid ureters and 6 upper moieties with inferomedial ectopic ureters, were analyzed correctly with the exception of a 6 mm. ureterocele in 1 case. In 6 duplex systems with poor or nonfunctioning upper moieties ectopic ureters were only demonstrated on T2-weighted magnetic resonance urograms. CONCLUSIONS Respiratory gated excretory and static fluid magnetic resonance urography complement each other in the evaluation of duplex systems in children and provide high accuracy in the evaluation of suspected ectopic ureters and ureteroceles.
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Affiliation(s)
- G Staatz
- Department of Diagnostic Radiology, University Hospital of the RWTH Aachen, Aachen, Germany
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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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GYLYS-MORIN VICTORIAM, MINEVICH EUGENE, TACKETT LESLIED, REICHARD ELIZABETH, WACKSMAN JEFFREY, SHELDON CURTISA. MAGNETIC RESONANCE IMAGING OF THE DYSPLASTIC RENAL MOIETY AND ECTOPIC URETER. J Urol 2000. [DOI: 10.1016/s0022-5347(05)66960-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- VICTORIA M. GYLYS-MORIN
- From the Departments of Radiology and Pediatric Urology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - EUGENE MINEVICH
- From the Departments of Radiology and Pediatric Urology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - LESLIE D. TACKETT
- From the Departments of Radiology and Pediatric Urology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - ELIZABETH REICHARD
- From the Departments of Radiology and Pediatric Urology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - JEFFREY WACKSMAN
- From the Departments of Radiology and Pediatric Urology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - CURTIS A. SHELDON
- From the Departments of Radiology and Pediatric Urology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
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27
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MAGNETIC RESONANCE IMAGING OF THE DYSPLASTIC RENAL MOIETY AND ECTOPIC URETER. J Urol 2000. [DOI: 10.1097/00005392-200012000-00054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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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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29
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Maher MM, Prasad TA, Fitzpatrick JM, Corr J, Williams DH, Ennis JT, Murray JG. Spinal dysraphism at MR urography: initial experience. Radiology 2000; 216:237-41. [PMID: 10887254 DOI: 10.1148/radiology.216.1.r00jl01237] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate the role of magnetic resonance (MR) urography in the radiologic assessment of patients with spinal dysraphism. MATERIALS AND METHODS Fourteen patients with spinal dysraphism were referred for MR urography with half-Fourier rapid acquisition with relaxation enhancement (RARE) (repetition time msec/echo time msec = 11.9/95) and RARE (2,800/1,100) sequences on a 1.5-T MR machine. Six patients did not tolerate MR urography owing to claustrophobia (n = 4) or flexion deformities (n = 2), giving a final success rate of 57% (eight patients). Two patients had a single kidney (one after nephrectomy, one with a crossed-fused ectopic kidney). Images were jointly assessed by two radiologists and compared with excretory urographic studies. The signal intensity ratio and contrast-to-noise ratio were also calculated. RESULTS Visualization of the kidneys, pelvicaliceal system, and ureters was better with half-Fourier RARE than with RARE imaging, whereas visualization of the bladder was comparable with both sequences. The mean signal intensity ratios for half-Fourier RARE and RARE sequences, respectively, were 16.2 +/- 3.65 and 19.2 +/- 3.65 (P =. 58, factorial analysis of variance model), whereas the mean contrast-to-noise ratios were 55.4 +/- 5.16 and 47.8 +/- 5.16 (P =. 34). Cortical scarring was depicted more clearly at MR urography than at excretory urography, whereas a renal calculus seen at excretory urography was not detected at MR urography. CONCLUSION MR urography was feasible in 57% of patients with spinal dysraphism and is a safe, accurate method of evaluating the upper urinary tract.
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Affiliation(s)
- M M Maher
- Department of Radiology, Mater Misericordiae Hospital, Eccles St, Dublin 7, Ireland
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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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31
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Stehling MK, Liu L. Echo planar imaging's impact on modern diagnostic MR-imaging: general principles and historic facts. MAGMA (NEW YORK, N.Y.) 1999; 9:125-33. [PMID: 10628686 DOI: 10.1007/bf02594609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- M K Stehling
- Institut für moderne Radiologische Diagnostik-ImRaD, Frankfurt/Main, Germany
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Avni EF, Matos C, Rypens F, Schulman CC. Ectopic vaginal insertion of an upper pole ureter: demonstration by special sequences of magnetic resonance imaging. J Urol 1997; 158:1931-2. [PMID: 9334641 DOI: 10.1016/s0022-5347(01)64183-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- E F Avni
- Department of Radiology, University Clinics of Brussels, Erasme Hospital, Belgium
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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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Yanagisawa N, Yajima M, Takahara T, Nosaka S, Iwamoto T. Diagnostic magnetic resonance-urography in an infant girl with an ectopic ureter associated with a poorly functioning segment of a duplicated collecting system. Int J Urol 1997; 4:314-7. [PMID: 9255675 DOI: 10.1111/j.1442-2042.1997.tb00198.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We report on a case of an ectopic ureter associated with a duplicated collecting system in a 6-month-old girl. Results of conventional imaging and endoscopic studies, including intravenous pyelography, ultrasonography of the kidneys, cystoscopy, vaginoscopy, and vaginogram, were unremarkable. An ectopic ureter, extending from a poorly functioning upper pole of the ipsilateral duplicated kidney to its vaginal opening, was visible on the magnetic resonance-urogram. The imaging time was not extensive, and the need for patient sedation was minimal. Respiratory motion and intestinal gas did not interfere with the quality of the images. Magnetic resonance-urography may possibly be used as a primary diagnostic method for this anomaly when it is not detected by standard imaging techniques, or as a noninvasive substitute for some interventional studies in infants.
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Affiliation(s)
- N Yanagisawa
- Department of Urology, St. Marianna University School of Medicine, Kawasaki, Japan
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35
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36
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Roy C, Saussine C, Jahn C, Le Bras Y, Steichen G, Delepaul B, Campos M, Chambron J, Jacqmin D. Fast imaging MR assessment of ureterohydronephrosis during pregnancy. Magn Reson Imaging 1995; 13:767-72. [PMID: 8544647 DOI: 10.1016/0730-725x(95)00036-g] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE to assess the value of the fast imaging sequence called RARE-MR-Urography (RMU) for the diagnosis of pathologic ureterohydronephrosis during pregnancy. MATERIALS AND METHODS 15 pregnant women with an acute flank pain were examined with RMU. Results were compared with those of ultrasonography (US), X-rays, and the evolution of symptoms. RESULTS the accuracy of RMU in the detection of urinary tract dilatation and the localization of the level of obstruction was excellent (100%). The determination of the type of obstruction, intrinsic vs. extrinsic, was always exact. RMU alone cannot specify the exact nature of the intrinsic obstruction. Ultrasonography gave less sensitive information in terms of level (60%) and type of obstruction (53%). CONCLUSION RMU is able to differentiate a physiological from a pathologic ureterohydronephrosis during pregnancy. It could be considered as a procedure of choice for special cases when US failed to establish this differential diagnosis.
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Affiliation(s)
- C Roy
- Service de Radiologie A, Hôpitaux Universitaires de Strasbourg, Hopital Civil, Place de l'Hôpital, France
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Laubenberger J, Büchert M, Schneider B, Blum U, Hennig J, Langer M. Breath-hold projection magnetic resonance-cholangio-pancreaticography (MRCP): a new method for the examination of the bile and pancreatic ducts. Magn Reson Med 1995; 33:18-23. [PMID: 7891531 DOI: 10.1002/mrm.1910330104] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Breath-hold MR cholangio-pancreaticography using the RARE method was evaluated as a noninvasive alternative to direct cholangio-pancreaticography in 30 healthy volunteers and in 30 patients with various diseases of the respective duct systems. In contrast to 3D MR cholangiography, RARE MRCP generates projection images requiring a 4-s acquisition time and no postprocessing. Diagnostic information gained from the cholangio-pancreaticograms was fully equivalent to that of conventional x-ray imaging by invasive procedures. Additional information was gained whenever endoscopic access was impossible and/or cystic malformations were present.
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Affiliation(s)
- J Laubenberger
- Department of Diagnostic Radiology, Freiburg University Hospital, Germany
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Stöver B, Laubenberger J, Hennig J, Niemeyer C, Rückauer K, Brandis M, Langer M. Value of RARE-MRI sequences in the diagnosis of lymphangiomatosis in children. Magn Reson Imaging 1995; 13:481-8. [PMID: 7791558 DOI: 10.1016/0730-725x(94)00125-m] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Three patients suffering from extensive cavernous lymphangiomatosis are presented here. They were examined by MRI using RARE-MR hydrography (rapid acquisition with relaxation enhancement) as well as conventional spin-echo sequences. RARE sequences, which depict each fluid-filled lymphatic space, can be used for screening. RARE-sequences help to shorten investigation time, particularly in cases involving the skeleton. The imaging strategy can be changed according to the results of this sequence. It may be performed prior to spin-echo sequences and facilitates follow-up investigations. RARE sequences distinguish between lymphangiomatosis and hemangiomatosis, or a combination of the two.
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Affiliation(s)
- B Stöver
- Department of Radiology, University of Freiburg, Charité Humboldt University, Berlin, Germany
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39
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Zimmerhackl LB, Rehm M, Kaufmehl K, Kurlemann G, Brandis M. Renal involvement in tuberous sclerosis complex: a retrospective survey. Pediatr Nephrol 1994; 8:451-7. [PMID: 7947038 DOI: 10.1007/bf00856529] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In a retrospective survey performed in Germany and Switzerland, 207 patients (ranging in age from newborn to 70 years) were evaluated in order to establish the frequency, prognosis and diagnostic awareness of kidney involvement in the tuberous sclerosis complex. Renal manifestations were observed in 48% of patients: renal cysts (33 patients), renal angiomyolipoma (AML) (30 patients), a combination of both (8 patients), renal cell carcinoma (3 patients), life-threatening events such as haemorrhage (4 patients), hypertensive crisis (2 patients) and chronic renal failure (10 patients) were also documented. The diagnostic imaging techniques of ultrasonography, intravenous urography, computed tomography and magnetic resonance imaging (MRI) are important but do not always yield definitive information. Differentiation between AML and cysts can be achieved using special MRI techniques (RARE). The potential for renal involvement should be monitored in all patients with the tuberous sclerosis complex.
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Affiliation(s)
- L B Zimmerhackl
- Department of Paediatrics, Albert-Ludwigs-University, Freiburg, Germany
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40
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Abstract
Pelvic tumors in children may be large, complex and of unknown origin. Preoperative radiological information regarding tumor localization and extent becomes essential in these cases for proper staging and surgical planning. Magnetic resonance imaging (MRI) offers the ability to enhance the surgical preparation of children who present with a pelvic mass. Advantages of MRI over computerized tomography include improved soft tissue characterization, signal enhancement of neuroendocrine tumors and multiplanar imaging. These features better define the origin, size and extent of tumors. In addition, no ionizing radiation is required. Several examples of pelvic tumors are presented. The new anatomical information provided by MRI altered surgical planning previously based on computerized tomography findings alone.
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Affiliation(s)
- R Rackley
- Department of Radiology, Cleveland Clinic Foundation, Ohio 44195
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41
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Sigmund G, St�ver B, Zimmerhackl LB, Laubenberger J, Nitzsche E, Frankenschmidt A, Hennig J. Cystic diseases of the kidney in children: MRI, including RARE-MR-urography. Eur Radiol 1991. [DOI: 10.1007/bf00540099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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