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Kaenkangploo D, Kampa N, Jitpean S, Seesupa S, Yongvanit K. Assessment of glomerular filtration rate measurement in dogs using dynamic contrast CT compared to serum iohexol clearance. Vet Radiol Ultrasound 2021; 63:38-46. [PMID: 34637569 DOI: 10.1111/vru.13024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/30/2022] Open
Abstract
Dynamic contrast CT with Patlak plot analysis can be used to determine the glomerular filtration rate (GFR). However, several studies have shown different GFR values and they are most likely less than the values by the standard techniques. The purpose of this prospective, experimental, and method comparison study was to evaluate the GFR using a CT technique (CT-GFR) in 12 healthy dogs compared to serum iohexol clearance (SIC-GFR). All dogs were anesthetized and placed in the right lateral recumbency position and the caudal part was lifted inside the CT gantry. A single-slice dynamic CT of the aorta and both kidneys was scanned sequentially every 2 s for 2 min after a bolus injection (3 mL/s) of iohexol (300 mg/kg). Time attenuation curves (TAC) were constructed and the GFR per volume of kidney was calculated using the Patlak plot analysis method based on 30-120 s time intervals, and results were compared to global GFR from SIC that was determined with eight blood samples for up to 240 min. The CT-GFR value (1.85 ± 0.48 mL/min/kg) was significantly less than the SIC-GFR value (3.40 ± 0.80 mL/min/kg; P < .05). The CT-GFR was correlated with SIC-GFR by the coefficient of correlation (r) at 0.61 (P = .046). In conclusion, the CT-GFR underestimated SIC-GFR and should be used carefully. We suggest that the GFR should be calculated using the equation derived from linear regression between CT-GFR and the standard GFR method. With its own particular parameters, each institute should have its own prediction equation.
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Affiliation(s)
- Duangdaun Kaenkangploo
- Division of Surgery, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Naruepon Kampa
- Division of Surgery, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Supranee Jitpean
- Division of Surgery, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Suvaluk Seesupa
- Division of Surgery, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Karn Yongvanit
- Veterinary Teaching Hospital, Khon Kaen University, Khon Kaen, Thailand
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Mariager CØ, Hansen ESS, Bech SK, Munk A, Kjaergaard U, Lyhne MD, Søberg K, Nielsen PF, Ringgaard S, Laustsen C. Graft assessment of the ex vivo perfused porcine kidney using hyperpolarized [1- 13 C]pyruvate. Magn Reson Med 2020; 84:2645-2655. [PMID: 32557782 DOI: 10.1002/mrm.28363] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/07/2020] [Accepted: 05/21/2020] [Indexed: 01/06/2023]
Abstract
PURPOSE Normothermic perfusion is an emerging strategy for donor organ preservation and therapy, incited by the high worldwide demand for organs for transplantation. Hyperpolarized MRI and MRS using [1-13 C]pyruvate and other 13 C-labeled molecules pose a novel way to acquire highly detailed information about metabolism and function in a noninvasive manner. This study investigates the use of this methodology as a means to study and monitor the state of ex vivo perfused porcine kidneys, in the context of kidney graft preservation research. METHODS Kidneys from four 40-kg Danish domestic pigs were perfused ex vivo with whole blood under normothermic conditions, using an MR-compatible perfusion system. Kidneys were investigated using 1 H MRI as well as hyperpolarized [1-13 C]pyruvate MRI and MRS. Using the acquired anatomical, functional and metabolic data, the state of the ex vivo perfused porcine kidney could be quantified. RESULTS Four kidneys were successfully perfused for 120 minutes and verified using a DCE perfusion experiment. Renal metabolism was examined using hyperpolarized [1-13 C]pyruvate MRI and MRS, and displayed an apparent reduction in pyruvate turnover compared with the usual case in vivo. Perfusion and blood gas parameters were in the normal ex vivo range. CONCLUSION This study demonstrates the ability to monitor ex vivo graft metabolism and function in a large animal model, resembling human renal physiology. The ability of hyperpolarized MRI and MRS to directly compare the metabolic state of an organ in vivo and ex vivo, in combination with the simple MR implementation of normothermic perfusion, renders this methodology a powerful future tool for graft preservation research.
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Affiliation(s)
| | | | - Sabrina Kahina Bech
- Department of Clinical Medicine, The MR Research Centre, Aarhus University, Aarhus, Denmark
| | - Anders Munk
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Uffe Kjaergaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Mads Dam Lyhne
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Karsten Søberg
- Department of Anesthesia and Intensive Care, Aarhus University Hospital, Aarhus, Denmark
| | - Peter Fast Nielsen
- Department of Anesthesia and Intensive Care, Aarhus University Hospital, Aarhus, Denmark
| | - Steffen Ringgaard
- Department of Clinical Medicine, The MR Research Centre, Aarhus University, Aarhus, Denmark
| | - Christoffer Laustsen
- Department of Clinical Medicine, The MR Research Centre, Aarhus University, Aarhus, Denmark
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Wallimann M, Richter H, Sieber-Ruckstuhl NS, Blaser A, Gent TC, Krämer SD, Santner G, Kircher PR, Dennler M. Influence of injection protocol and measurement technique on computed tomographic assessment of glomerular filtration rate in healthy Beagles. Am J Vet Res 2018; 79:1298-1305. [PMID: 30457905 DOI: 10.2460/ajvr.79.12.1298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare values of CT-derived glomerular filtration rate (GFR) determined by 3 contrast-medium injection protocols and 4 measurement techniques in healthy Beagles. ANIMALS 9 healthy Beagles (mean ± SD weight, 13.2 ± 1.6 kg). PROCEDURES Each dog underwent 3 iohexol-injection protocols (700 mg of iodine/kg administered at a constant rate over 20 seconds, 700 mg of iodine/kg administered following an exponentially decelerated injection over 20 seconds, and 350 mg of iodine/kg at a constant rate over 10 seconds) during dynamic, whole renal-volume CT in randomized order with an interval of ≥ 7 days between experiments. Values of GFR determined from Patlak plots derived by use of 4 measurement techniques (standard transverse section, optimized transverse section, dorsal reconstruction, and volume calculation techniques) were compared. RESULTS The measurement technique influenced the mean ± SD GFR results (standard transverse section technique, 2.49 ± 0.54 mL/kg/min; optimized transverse section technique, 2.72 ± 0.52 mL/kg/min; dorsal reconstruction technique, 3.00 ± 0.60 mL/kg/min, and volume calculation technique, 2.48 ± 0.51 mL/kg/min). The lower iodine dose resulted in a significantly higher GFR value (3.00 ± 0.65 mL/kg/min), compared with that achieved with either higher dose administration (constant rate injection, 2.54 ± 0.45 mL/kg/min and exponentially decelerated injection, 2.47 ± 0.48 mL/kg/min). CONCLUSIONS AND CLINICAL RELEVANCE In healthy Beagles, the CT-derived GFR measurements obtained after injection of a full dose of contrast medium were reduced, compared with measurements obtained after injection of a half dose. This finding is important with regard to potential nephrotoxicosis in dogs with impaired renal function and for GFR measurement with CT-contrast medium protocols.
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Zoller G, Langlois I, Alexander K. Glomerular filtration rate determination by computed tomography in two pet rabbits with renal disease. J Am Vet Med Assoc 2017; 250:681-687. [DOI: 10.2460/javma.250.6.681] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Bentwich ME, Dickman N, Oberman A. Autonomy and dignity of patients with dementia: Perceptions of multicultural caretakers. Nurs Ethics 2016; 25:37-53. [DOI: 10.1177/0969733016642625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: A key message in the World Health Organization’s report on dementia emphasizes the need to improve public and professional attitudes to dementia and its understanding, while acknowledging the fact that the workforce in dementia care is becoming increasingly diverse culturally. Objectives: To explore possible differences among formal caretakers from varied cultural background in their attitudes toward the autonomy and human dignity of patients with dementia. Research design: Semi-structured interviews and content analysis, utilizing two fictional vignettes for eliciting caretakers’ attitudes toward dignity and autonomy of their patients. Participants and context: A total of 20 formal caretakers of patients with dementia from three different cultural groups in Israel (“Sabras,” “Arabs,” and “Russians”), working in nursing homes and a hospital. Ethical consideration: Approvals of relevant research ethics committees were obtained and followed. Findings: In comparison with the other groups, most Arab caretakers offer markedly richer perceptions of human dignity and autonomy. Their human dignity’s conceptualization emphasizes “person-centered approach,” and their perception of patients’ autonomy includes provision of explanations and preservation and encouragement of independence. Discussion: The differences found in the attitudes toward the meaning of autonomy and human dignity between the Arab caretakers and the other caretakers stand in contrast to previous studies regarding human dignity, emphasizing the common nature of these attitudes. Offering a linkage (theoretical and empirical) between the Arab perceptions of dignity and autonomy, the study strengthen and further the importance attributed in existing literature to person-centered care in enhancing the quality of care for patients with dementia. Conclusion: The conceptualization of human dignity may vary among different cultural groups. It may also influence the extent to which the caretaker holds a full-fledged perception of the patients’ autonomy.
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Affiliation(s)
| | | | - Amitai Oberman
- The Baruch Padeh Medical Center, Poriya and Bar-Ilan University, Israel
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Tyson R, Logsdon SA, Werre SR, Daniel GB. Estimation of feline renal volume using computed tomography and ultrasound. Vet Radiol Ultrasound 2012; 54:127-32. [PMID: 23278991 DOI: 10.1111/vru.12007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 11/14/2012] [Indexed: 11/27/2022] Open
Abstract
Renal volume estimation is an important parameter for clinical evaluation of kidneys and research applications. A time efficient, repeatable, and accurate method for volume estimation is required. The purpose of this study was to describe the accuracy of ultrasound and computed tomography (CT) for estimating feline renal volume. Standardized ultrasound and CT scans were acquired for kidneys of 12 cadaver cats, in situ. Ultrasound and CT multiplanar reconstructions were used to record renal length measurements that were then used to calculate volume using the prolate ellipsoid formula for volume estimation. In addition, CT studies were reconstructed at 1 mm, 5 mm, and 1 cm, and transferred to a workstation where the renal volume was calculated using the voxel count method (hand drawn regions of interest). The reference standard kidney volume was then determined ex vivo using water displacement with the Archimedes' principle. Ultrasound measurement of renal length accounted for approximately 87% of the variability in renal volume for the study population. The prolate ellipsoid formula exhibited proportional bias and underestimated renal volume by a median of 18.9%. Computed tomography volume estimates using the voxel count method with hand-traced regions of interest provided the most accurate results, with increasing accuracy for smaller voxel sizes in grossly normal kidneys (-10.1 to 0.6%). Findings from this study supported the use of CT and the voxel count method for estimating feline renal volume in future clinical and research studies.
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Affiliation(s)
- Reid Tyson
- Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA.
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Chang J, Ahn S, Choi S, Lee H, Chang D, Choi H, Lee Y. Evaluation of glomerular filtration rate by use of dynamic computed tomography and Patlak analysis in clinically normal cats. Am J Vet Res 2011; 72:1276-82. [DOI: 10.2460/ajvr.72.9.1276] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Alexander K, Dunn M, Carmel EN, Lavoie JP, Del Castillo JRE. Clinical application of Patlak plot CT-GFR in animals with upper urinary tract disease. Vet Radiol Ultrasound 2010; 51:421-7. [PMID: 20806874 DOI: 10.1111/j.1740-8261.2010.01670.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Glomerular filtration rate (GFR), an important parameter of renal function, is difficult to assess clinically. Serum creatinine and blood urea nitrogen measurements lack sensitivity, whereas radionuclide determination of GFR is not always available and requires postinjection patient isolation. GFR can be determined using computed tomography (CT), most commonly via Patlak plot analysis. Four adult cats, two adult dogs, and a foal underwent abdominal CT under general anesthesia for various diseases of the upper urinary tract. CT-GFR was measured with a single-slice dynamic acquisition and Patlak plot analysis. In five animals, the total CT-GFR appeared to be below normal, corresponding with mild (two animals) and moderate (two animals) increases of serum creatinine in four. In the two animals with normal or increased CT-GFR, serum creatinine was within the reference values. A significant negative logarithmic relationship was found between CT-GFR and serum creatinine values (P = 0.008; r2 = 0.75). No complications occurred during or following CT-GFR. CT examination provided clinically relevant information in 3/5 patients with possible ureteral obstruction and in 3/3 patients with suspected ureteral calculi. Single-slice dynamic CT-GFR was practical and provided clinically useful information in this small series of patients undergoing CT of the upper urinary tract. There was a significant relationship between CT-GFR and serum creatinine values, which supports the clinical potential of CT-GFR and justifies further investigation of this technique.
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Affiliation(s)
- Kate Alexander
- Département de Sciences Cliniques, Faculté de médecine vétérinaire, Université de Montréal, PO Box 5000, St-Hyacinthe, QC, Canada J2S 7C6.
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Alexander K, Authier S, del Castillo JRE, Arora V, Qi S, Guillot M, Beauchamp G, Troncy E. Patlak plot analysis CT-GFR for the determination of renal function: comparison of normal dogs with autologous kidney transplant dogs. CONTRAST MEDIA & MOLECULAR IMAGING 2010; 5:133-9. [DOI: 10.1002/cmmi.372] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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