Functional, Dynamic, and Anatomic MR Urography

Katzberg, Richard W.; Buonocore, Michael H.; Ivanović, Marija; Pellot‐Barakat, Claire; Ryan, John M.; Whang, Kevin; Brock, John M.; Jones, C. Darryl

doi:10.1016/s1076-6332(03)80720-1

Cited by 45 publications

(19 citation statements)

References 19 publications

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“…Recently a large-scale study by Rohrschneider et al [38] on children with congenital urinary tract dilatation showed that static-dynamic MRU was feasible for these children. Katzberg et al [24] have also reported 100% sensitivity of MRU in diagnosing urinary tract obstruction. O'Malley et al [36] evaluated the MRU results for quality, presence, degree, level, and cause of urinary tract dilatation and found a sensitivity of 100%, specificity of 96%, positive predictive value of 96% and negative predictive value of 100%.…”

Section: Discussionmentioning

confidence: 94%

Application of magnetic resonance urography in diagnosis of congenital urogenital anomalies in children

et al. 2008

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Magnetic resonance urography (MRU) has become a useful adjuvant in evaluating urogenital anomalies. In present study, we evaluated the ability of MRU in diagnosis of different congenital urogenital anomalies when the results of conventional imaging modalities were inconclusive. A total of 90 children were included in this series. The children were evaluated with T2-weighted and contrast-enhanced T1-weighted MRU sequences. The results were compared with findings obtained with ultrasonography, intravenous urography, renal nuclide scan, and voiding cystourethrography. MRU was requested in these children because conventional imaging modalities were equivocal or a co-existing urogenital anomaly was suspected. Only those cases that underwent surgery were included in this study and the surgical findings were set as the reference standard in statistical evaluation. The records of 61 boys with mean (range) age of 2.3 years (2 months-12 years) and 29 girls with mean (range) age of 3.3 years (3 months-12 years) were reviewed. The final diagnosis was ureteropelvic junction obstruction (n = 25), vesicoureteral junction obstruction (n = 16), ureterocele (n = 19), ectopic kidney (n = 11), posterior urethral valve (n = 17), and polycystic kidney (n = 2). The overall sensitivity of MRU, intravenous urography, renal nuclide scan, ultrasonography, and voiding cystourethrography in diagnosis of the aforementioned anomalies were 86, 63, 50, 44, and 41%, respectively. MRU was much more sensitive than other imaging modalities in diagnosis of end-ureteral dilation (100%) and ureterocele (89%). MRU provides a reliable noninvasive technique for imaging of the congenital anomalies in the urinary tract of children with T2-weighted MRU sequences providing unenhanced static-water images of the urinary tract as well as depicting adjacent soft-tissue lesions, and T1-weighted MRU technique imitating conventional intravenous urography. Both MRU sequences can be combined for a comprehensive examination of the urinary tract.

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Section: Discussionmentioning

confidence: 94%

Application of magnetic resonance urography in diagnosis of congenital urogenital anomalies in children

et al. 2008

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“…It can be filtered free in kidneys like Inulin. Most researches [21][22][23][24] agree that signal change and Gd-DTPA concentration have a linear relationship. Especially low dose of contrast media can ensure that the signal loss associated with concentrated gadolinium chelates can be avoided and make MR renography compatible with routine clinical contrast-enhanced imaging of the kidneys and renal arteries [9,25].…”

Section: Signal Conversionmentioning

confidence: 97%

A renal vascular compartment segmentation method based on dynamic contrast-enhanced images

Bao

et al. 2016

THC

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Abstract. BACKGROUND: Kidney function assessment from renography has great potential for clinical diagnosis. Compartment models are the main analytical models in this field and the vascular compartment is the most important one, whether in the twocompartment model or three-compartment model. Currently, there are some published research studies on renal cortex segmentation. However, there are few publications introducing the methods on how to segment the vascular compartment yet. OBJECTIVE: The objective of this paper is to segment the vascular compartment automatically.METHODS: This method was tested on multi-phase scan images. A feature image reconstructed from the original images was used to segment the vascular compartment. It used the features of the time-density curve of each voxel in the contrast-enhanced images to distinguish vascular space from other areas. RESULTS: The segmentation result was evaluated by the renal glomerular filtration rate (GFR) analysis of a two-compartment model with the Patlak-Rutland technique. The dataset contained 11 kidney subjects whose GFR ranged from 19.8 ml/min to 74.9 ml/min. The results showed that the correlation between reference GFR and model derived GFR was 0.919 (P < 0.001). CONCLUSION: Compared with segmentation performed on certain phase images, this method can avoid the problem of subjective phase selection. For a given kidney data, the proposed method can always obtain the same segmentation result automatically.

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“…Unlike 3D gadolinium (Gd)-enhanced magnetic resonance angiography, which most consider optimal for the renal vascular system, no consensus regarding magnetic resonance urography (MRU) exists [2,3]. Heavily T2-weighted sequences, such as rapid acquisition with relaxation enhancement (RARE) or half-Fourier acquisition turbo spin-echo (HASTE), and Gd-enhanced excretory MRU techniques, with and without pharmacological manipulation, have been proposed [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Successful, comprehensive, evaluation of the urinary system for renal donors has been described, both with 3D T2-weighted (T2W) fast spin-echo acquisitions and with Gd-enhanced techniques [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Magnetic resonance urography for the assessment of potential renal donors: comparison of the RARE technique with a low-dose gadolinium-enhanced magnetic resonance urography technique in the absence of pharmacological and mechanical intervention

et al. 2005

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The aim of this study was to determine whether magnetic resonance urography without pharmacological (diuretic) stimulation and mechanical compression allows conclusive evaluation of the urinary system in potential renal donors. In 28 consecutive patients magnetic resonance urography (MRU) was performed on a 1.5-T system. Two techniques, rapid acquisition with relaxation enhancement (RARE) and a gadolinium (Gd)-enhanced 3D fast low angle shot (FLASH) sequence were compared in the absence of adjunctive measures. Two reviewers assessed image quality, presence of artifacts and completeness of visualization of the collecting systems and ureters. Among the 53 MR urograms, there was no difference in image quality and presence of artifacts between RARE and Gd-MRU. Despite high image quality, visualization of the urinary collecting system was insufficient. Continuous visualization from the collecting system to the distal ureter was demonstrated bilaterally in only 14% of the RARE and 26% of Gd-enhanced MR urograms, respectively. Overall, Gd-enhanced MRU was superior to the RARE technique in displaying the segments of the urinary collecting system, but this difference was not found to be statistically significant. Neither the RARE technique nor the gadolinium-enhanced MRU technique is accurate enough to allow the evaluation of the collecting system and ureters in potential renal donors in the absence of pharmacological intervention and compression.

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Functional, Dynamic, and Anatomic MR Urography

Cited by 45 publications

References 19 publications

Application of magnetic resonance urography in diagnosis of congenital urogenital anomalies in children

Application of magnetic resonance urography in diagnosis of congenital urogenital anomalies in children

A renal vascular compartment segmentation method based on dynamic contrast-enhanced images

Magnetic resonance urography for the assessment of potential renal donors: comparison of the RARE technique with a low-dose gadolinium-enhanced magnetic resonance urography technique in the absence of pharmacological and mechanical intervention

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