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Schober JP, Ginsburg KB, Kutikov A, Cho EY, Loecher M, Strauss D, Castro Bigalli AA, Handorf E, Deng M, Anaokar J, Chen DYT, Greenberg RE, Smaldone MC, Viterbo R, Correa AF, Uzzo RG, Strother M. Real-time estimation of nephron activity with a linear measurement system (RENAL-MS) predicts postoperative estimated glomerular filtration rate. BJU Int 2024; 133:206-213. [PMID: 37667554 DOI: 10.1111/bju.16172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
OBJECTIVE To determine whether a simple point-of-care measurement system estimating renal parenchymal volume using tools ubiquitously available could be used to replace nuclear medicine renal scintigraphy (NMRS) in current clinical practice to predict estimated glomerular filtration rate (eGFR) after nephrectomy by estimating preoperative split renal function. PATIENTS AND METHODS We performed a retrospective review of patients who underwent abdominal cross-sectional imaging (computed tomography/magnetic resonance imaging) and mercaptoacetyltriglycine (MAG3) NMRS prior to total nephrectomy at a single institution. We developed the real-time estimation of nephron activity with a linear measurement system (RENAL-MS) method of estimating postoperative renal function via the following technique: renal parenchymal volume of the removed kidney relative to the remaining kidney was estimated as the product of renal length and the average of six renal parenchymal thickness measurements. The utility of this value was compared to the utility of the split renal function measured by MAG3 for prediction of eGFR and new onset Stage 3 chronic kidney disease (CKD) at ≥90 days after nephrectomy using uni- and multivariate linear and logistic regression. RESULTS A total of 57 patients met the study criteria. The median (interquartile range [IQR]) age was 69 (61-80) years. The median (IQR) pre- and postoperative eGFR was 74 (IQR 58-90) and 46 (35-62) mL/min/1.73 m2 , respectively. [Correction added on 29 December 2023, after first online publication: The data numbers in the preceding sentence have been corrected.] Correlations between actual and predicted postoperative eGFR were similar whether the RENAL-MS or NMRS methods were used, with correlation using RENAL-MS being slightly numerically but not statistically superior (R = 0.82 and 0.76; P = 0.138). Receiver operating characteristic curve analysis using logistic regression estimates incorporating age, sex, and preoperative creatinine to predict postoperative Stage 3 CKD were similar between RENAL-MS and NMRS (area under the curve 0.93 vs. 0.97). [Correction added on 29 December 2023, after first online publication: The data numbers in the preceding sentence have been corrected.] CONCLUSION: A point-of-care tool to estimate renal parenchymal volume (RENAL-MS) performed equally as well as NMRS to predict postoperative eGFR and de novo Stage 3 CKD after nephrectomy in our population, suggesting NMRS may not be necessary in this setting.
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Affiliation(s)
- Jared P Schober
- Division of Urologic Surgery, Department of Surgery, University of Nebraska Medical Center, Omaha, NE, USA
| | | | - Alexander Kutikov
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Eric Y Cho
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Matt Loecher
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - David Strauss
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | | | - Elizabeth Handorf
- Biostatistics and Bioinformatics, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Mengying Deng
- Biostatistics and Bioinformatics, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Jordan Anaokar
- Department of Diagnostic Radiology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - David Y T Chen
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Richard E Greenberg
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Marc C Smaldone
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Rosalia Viterbo
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Andres F Correa
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Robert G Uzzo
- Division of Urologic Oncology, Department of Surgical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Marshall Strother
- Department of Urology, Oregon Health and Science University, Portland, OR, USA
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Strother MC, Cho EY, Loecher M, Strauss D, Chandra A, Handorf E, Yu J, Chen DYT, Uzzo R, Levin L, Anaokar J, Kutikov A. The Delayed Nephrogram: Point-of-care Quantitative Measurement, Validation as an Indicator of Obstruction, and Novel Use as a Predictor of Renal Functional Impairment. Eur Urol Focus 2022; 8:1809-1815. [PMID: 35181283 PMCID: PMC9376190 DOI: 10.1016/j.euf.2022.01.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 01/02/2022] [Accepted: 01/29/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND The diagnostic value of delayed nephrograms on contrast-enhanced computed tomography has not been studied rigorously. OBJECTIVE To develop a method for quantitatively assessing delayed and diminished nephrograms (DDNs) easily at the point of care and to assess the association of DDNs with renal obstruction and renal function. DESIGN, SETTING, AND PARTICIPANTS Data were reviewed from 76 patients who underwent a contrast-enhanced computed tomography scan within 30 days of a technetium-99m mercaptoacetyltriglycine diuretic renal scintigraphy (MAG3-DRS) which showed at least one kidney to have normal drainage (T1/2 <10 min) between 2010 and 2021 at a tertiary academic center. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Attenuations of the renal cortex and medulla were measured using circular regions of interest. These attenuations were compared between kidneys to compute several measures of DDN in the kidney with a greater concern for obstruction. Renal parenchymal volume and anterior-posterior renal pelvis diameter (APD) were estimated using simple linear measurements. Inter-rater reliability was computed using the intraclass correlation coefficient (ICC), correlations were computed using Spearman's R, and the relationships between DDN, APD, and renal function of the subject kidney were estimated using linear regression. RESULTS AND LIMITATIONS Measures of DDN were highly reliable between raters (ICC 0.71-0.87). DDN was almost always associated with prolonged drainage on MAG3-DRS (90-100%); however, 33-52% of patients with prolonged drainage on MAG3-DRS had no appreciable DDN, depending on the measure of the DDN chosen. All measures of DDN were associated with decreased renal function (<0.001). APD did not significantly predict renal function when controlling for a DDN. CONCLUSIONS DDNs on contrast-enhanced computed tomography are associated with renal obstruction and can easily and accurately be quantified at the point of care. A DDN is more closely associated with renal dysfunction than renal pelvic dilation and therefore may be useful in assessing the severity of upper tract obstruction. PATIENT SUMMARY In this report, we confirm that a "delayed nephrogram", a classic x-ray finding thought to be associated with kidney blockage, is associated with blockage of the affected kidney. Furthermore, we show that a delayed nephrogram indicates that the affected kidney is not functioning as well as we would expect for a normal kidney of the same size. Since the severity of a delayed nephrogram predicts this decreased function better than the degree of dilation of the kidney, which is a different measurement often used to measure the severity of kidney blockage, the delayed nephrogram may be a better way of measuring the severity of kidney blockage in clinical practice.
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Affiliation(s)
- Marshall C Strother
- Department of Urology, Oregon Health and Science University, Portland, OR, USA.
| | - Eric Y Cho
- Department of Urology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Matt Loecher
- Department of Urology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - David Strauss
- Department of Urology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Akhil Chandra
- Division of Urology, Department of Surgery, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Elizabeth Handorf
- Department of Biostatistics and Bioinformatics, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Jian Yu
- Department of Diagnostic Imaging, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - David Y T Chen
- Division of Urology, Department of Surgery, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Robert Uzzo
- Division of Urology, Department of Surgery, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Laura Levin
- Department of Diagnostic Imaging, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Jordan Anaokar
- Department of Diagnostic Imaging, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Alexander Kutikov
- Division of Urology, Department of Surgery, Fox Chase Cancer Center, Philadelphia, PA, USA
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Chang W, Wu Y, Johnson K, Loecher M, Wieben O, Edjlali M, Oppenheim C, Roca P, Hald J, Aagaard-Kienitz B, Niemann D, Mistretta C, Turski P. Fast contrast-enhanced 4D MRA and 4D flow MRI using constrained reconstruction (HYPRFlow): potential applications for brain arteriovenous malformations. AJNR Am J Neuroradiol 2015; 36:1049-55. [PMID: 25698624 DOI: 10.3174/ajnr.a4245] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/29/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE HYPRFlow is a novel imaging strategy that provides fast, high-resolution contrast-enhanced time-resolved images and measurement of the velocity of the entire cerebrovascular system. Our hypothesis was that the images obtained with this strategy are of adequate diagnostic image quality to delineate the major components of AVMs. MATERIALS AND METHODS HYPRFlow and 3D TOF scans were obtained in 21 patients with AVMs with correlative DSA examinations in 14 patients. The examinations were scored for image quality and graded by using the Spetzler-Martin criteria. Mean arterial transit time and overlap integrals were calculated from the dynamic image data. Volume flow rates in normal arteries and AVM feeding arteries were measured from the phase contrast data. RESULTS HYPRFlow was equivalent to 3D-TOF in delineating normal arterial anatomy, arterial feeders, and nidus size and was concordant with DSA for AVM grading and venous drainage in 13 of the 14 examinations. Mean arterial transit time on the AVM side was 0.49 seconds, and on the normal contralateral side, 2.53 seconds with P < .001. Across all 21 subjects, the mean arterial volume flow rate in the M1 segment ipsilateral to the AVM was 4.07 ± 3.04 mL/s; on the contralateral M1 segment, it was 2.09 ± 0.64 mL/s. The mean volume flow rate in the largest feeding artery to the AVM was 3.86 ± 2.74 mL/s. CONCLUSIONS HYPRFlow provides an alternative approach to the MRA evaluation of AVMs, with the advantages of increased coverage, 0.75-second temporal resolution, 0.68-mm isotropic spatial resolution, and quantitative measurement of flow in 6 minutes.
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Affiliation(s)
- W Chang
- From the Department of Radiology (W.C.), University of California, Los Angeles, Los Angeles, California
| | - Y Wu
- Medical Physics (Y.W., K.J., M.L., O.W., C.M.), University of Wisconsin School of Medicine, Madison, Wisconsin
| | - K Johnson
- Medical Physics (Y.W., K.J., M.L., O.W., C.M.), University of Wisconsin School of Medicine, Madison, Wisconsin
| | - M Loecher
- Medical Physics (Y.W., K.J., M.L., O.W., C.M.), University of Wisconsin School of Medicine, Madison, Wisconsin
| | - O Wieben
- Medical Physics (Y.W., K.J., M.L., O.W., C.M.), University of Wisconsin School of Medicine, Madison, Wisconsin
| | - M Edjlali
- Department of Radiology (M.E., C.O., P.R.), Université Paris-Descartes, Paris, France
| | - C Oppenheim
- Department of Radiology (M.E., C.O., P.R.), Université Paris-Descartes, Paris, France
| | - P Roca
- Department of Radiology (M.E., C.O., P.R.), Université Paris-Descartes, Paris, France
| | - J Hald
- Department of Radiology (J.H.), Rikshospitalet, Oslo, Norway
| | | | | | - C Mistretta
- Medical Physics (Y.W., K.J., M.L., O.W., C.M.), University of Wisconsin School of Medicine, Madison, Wisconsin
| | - P Turski
- Departments of Radiology (B.A.-K., P.T.)
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