1
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Pinto DS, Clode H, Madrazo BL, Paes FM, Alessandrino F. Imaging review of spontaneous renal hemorrhage. Emerg Radiol 2024; 31:515-528. [PMID: 38703272 DOI: 10.1007/s10140-024-02233-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 04/18/2024] [Indexed: 05/06/2024]
Abstract
Spontaneous renal hemorrhage (SRH) is a diagnostic challenge and a significant cause of morbidity, and sometimes mortality. Early identification is essential to institute lifesaving and reno-protective interventions. In this review, we classify spontaneous renal hemorrhage by location, presentation and etiology. We also discuss the diagnostic approach to renal hemorrhage and optimum imaging modalities to arrive at the diagnosis. Finally, we review strategies to avoid missing a diagnosis of SRH and discuss the pitfalls of imaging in the presence of renal hemorrhage.
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Affiliation(s)
- Denver S Pinto
- Jackson Memorial Hospital, University of Miami, Miami, USA.
| | - Hannah Clode
- Jackson Memorial Hospital, University of Miami, Miami, USA
- Department of Radiology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | | | - Fabio M Paes
- Miller School of Medicine, Jackson Memorial Hospital - Ryder Trauma Center, University of Miami, Miami, FL, USA
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2
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Aly A, Burt R, Violari E, Peña C, Bryce Y. Abdominal Vascular Evaluation. Tech Vasc Interv Radiol 2022; 25:100863. [PMID: 36404064 DOI: 10.1016/j.tvir.2022.100863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The vascular lab (VL) is instrumental in diagnosing vascular diseases such as renal artery stenosis and mesenteric ischemia or following a patient after transjugular intrahepatic portal systemic shunt (TIPS) creation. This article discusses indications, protocol, and diagnostic criteria for abdominal vascular ultrasound. The vascular lab can be used to investigate pathology in the abdomen either as a preliminary screening tool to evaluate for a pathology such as mesenteric artery stenosis in a patient with food fear and weight loss, renal artery stenosis in a patient with refractory hypertension or renal failure, or as a diagnostic tool in follow up after a patient has undergone a transjugular intrahepatic portal systemic shunt (TIPS) for portal hypertension. The technical success of duplex ultrasonography of the abdomen can be compromised by respiratory motion, obesity, and intestinal gas. Therefore, duplex scanning is performed in the fasting state particularly in elective outpatient cases. In emergent cases when pathology such as acute mesenteric ischemia is suspected evaluation with CT angiography may be best.
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Affiliation(s)
- Ahmed Aly
- University of Nebraska Medical Center, Omaha, NE
| | | | | | | | - Yolanda Bryce
- Memorial Sloan Kettering Cancer Center, New York, NY.
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3
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Abstract
Ultrasound imaging is a key investigatory step in the evaluation of chronic kidney disease and kidney transplantation. It uses nonionizing radiation, is noninvasive, and generates real-time images, making it the ideal initial radiographic test for patients with abnormal kidney function. Ultrasound enables the assessment of both structural (form and size) and functional (perfusion and patency) aspects of kidneys, both of which are especially important as the disease progresses. Ultrasound and its derivatives have been studied for their diagnostic and prognostic significance in chronic kidney disease and kidney transplantation. Ultrasound is rapidly growing more widely accessible and is now available even in handheld formats that allow for bedside ultrasound examinations. Given the trend toward ubiquity, the current use of kidney ultrasound demands a full understanding of its breadth as it and its variants become available. We described the current applications and future directions of ultrasound imaging and its variants in the context of chronic kidney disease and transplantation in this review.
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Affiliation(s)
- Rohit K. Singla
- MD and PhD Program, University of British Columbia, Vancouver, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
- Address for Correspondence: Rohit Singla, MASc, The University of British Columbia, 2332 Main Mall, Vancouver, BC, Canada, V6T 1Z4.
| | - Matthew Kadatz
- Department of Nephrology, University of British Columbia, Vancouver, Canada
| | - Robert Rohling
- School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
| | - Christopher Nguan
- Department of Urologic Sciences, University of British Columbia, Vancouver, Canada
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4
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Vijayvergiya R, Kaur N, Kasinadhuni G, Sharma A, Lal A, Sood A. Endovascular stenting with a drug-eluting stent of transplanted renal artery stenosis in a dual kidney transplanted patient. J Vasc Bras 2021; 20:e20210054. [PMID: 34925473 PMCID: PMC8668082 DOI: 10.1590/1677-5449.210054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/17/2021] [Indexed: 11/21/2022] Open
Abstract
Renal transplant remains the preferred therapy for end-stage renal disease (ESRD). Given the shortage of suitable donor kidneys, use of an expanded criteria donor (ECD) allows marginal kidneys to be transplanted; albeit at risk of increased graft failure due to lower nephron mass. To reduce the risk of graft failure, double kidney transplant (DKT) is advocated, with favorable outcomes. Transplant renal artery stenosis (TRAS) is one of the most common vascular complications following renal transplant. Unlike single kidney transplants, where TRAS usually presents with fluid overload, uncontrolled hypertension, and worsening kidney functions; it may be clinically silent in DKT patients since they have two functional transplanted kidneys. We hereby report a case of TRAS in a DKT patient who had 2 years of favorable clinical outcomes following successful endovascular stenting. He however recently died of COVID-19 associated pneumonitis.
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Affiliation(s)
- Rajesh Vijayvergiya
- Post Graduate Institute of Medical Education and Research - PGIMER, Chandigarh, India
| | - Navjyot Kaur
- Post Graduate Institute of Medical Education and Research - PGIMER, Chandigarh, India
| | - Ganesh Kasinadhuni
- Post Graduate Institute of Medical Education and Research - PGIMER, Chandigarh, India
| | - Ashish Sharma
- Post Graduate Institute of Medical Education and Research - PGIMER, Chandigarh, India
| | - Anupam Lal
- Post Graduate Institute of Medical Education and Research - PGIMER, Chandigarh, India
| | - Ashwani Sood
- Post Graduate Institute of Medical Education and Research - PGIMER, Chandigarh, India
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5
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Abdominal Applications of Pediatric Body MR Angiography: Tailored Optimization for Successful Outcome. AJR Am J Roentgenol 2020; 215:206-214. [PMID: 32374667 DOI: 10.2214/ajr.19.22289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE. The purpose of this article is to summarize current common techniques and indications for pediatric abdominopelvic MR angiography and strategies for optimizing them to achieve successful outcomes. We also discuss newer MR angiography techniques, including whole-body imaging and blood pool contrast agents, as well as various approaches to reducing the need for anesthesia in pediatric MRI. CONCLUSION. Pediatric body vascular imaging presents a unique set of challenges that require a tailored approach. Emerging pediatric abdominopelvic MR angiography techniques hold promise for continued improvement in pediatric body MR angiography.
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Sugi MD, Joshi G, Maddu KK, Dahiya N, Menias CO. Imaging of Renal Transplant Complications throughout the Life of the Allograft: Comprehensive Multimodality Review. Radiographics 2020; 39:1327-1355. [PMID: 31498742 DOI: 10.1148/rg.2019190096] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The kidney is the most commonly transplanted solid organ. Advances in surgical techniques, immunosuppression regimens, surveillance imaging, and histopathologic diagnosis of rejection have allowed prolonged graft survival times. However, the demand for kidneys continues to outgrow the available supply, and there are efforts to increase use of donor kidneys with moderate- or high-risk profiles. This highlights the importance of evaluating the renal transplant patient in the context of both donor and recipient risk factors. Radiologists play an integral role within the multidisciplinary team in care of the transplant patient at every stage of the transplant process. In the immediate postoperative period, duplex US is the modality of choice for evaluating the renal allograft. It is useful for establishing a baseline examination for comparison at future surveillance imaging. In the setting of allograft dysfunction, advanced imaging techniques including MRI or contrast-enhanced US may be useful for providing a more specific diagnosis and excluding nonrejection causes of renal dysfunction. When a pathologic diagnosis is deemed necessary to guide therapy, US-guided biopsy is a relatively low-risk, safe procedure. The range of complications of renal transplantation can be organized temporally in relation to the time since surgery and/or according to disease categories, including immunologic (rejection), surgical or iatrogenic, vascular, urinary, infectious, and neoplastic complications. The unique heterotopic location of the renal allograft in the iliac fossa predisposes it to a specific set of complications. As imaging features of infection or malignancy may be nonspecific, awareness of the patient's risk profile and time since transplantation can be used to assign the probability of a certain diagnosis and thus guide more specific diagnostic workup. It is critical to understand variations in vascular anatomy, surgical technique, and independent donor and recipient risk factors to make an accurate diagnosis and initiate appropriate treatment.©RSNA, 2019.
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Affiliation(s)
- Mark D Sugi
- From the Department of Radiology, Mayo Clinic, Scottsdale, Ariz (M.D.S., N.D., C.O.M.); and Departments of Radiology and Imaging Sciences (G.J., K.K.M.) and Emergency Medicine (G.J., K.K.M.), Emory University School of Medicine, Atlanta, Ga
| | - Gayatri Joshi
- From the Department of Radiology, Mayo Clinic, Scottsdale, Ariz (M.D.S., N.D., C.O.M.); and Departments of Radiology and Imaging Sciences (G.J., K.K.M.) and Emergency Medicine (G.J., K.K.M.), Emory University School of Medicine, Atlanta, Ga
| | - Kiran K Maddu
- From the Department of Radiology, Mayo Clinic, Scottsdale, Ariz (M.D.S., N.D., C.O.M.); and Departments of Radiology and Imaging Sciences (G.J., K.K.M.) and Emergency Medicine (G.J., K.K.M.), Emory University School of Medicine, Atlanta, Ga
| | - Nirvikar Dahiya
- From the Department of Radiology, Mayo Clinic, Scottsdale, Ariz (M.D.S., N.D., C.O.M.); and Departments of Radiology and Imaging Sciences (G.J., K.K.M.) and Emergency Medicine (G.J., K.K.M.), Emory University School of Medicine, Atlanta, Ga
| | - Christine O Menias
- From the Department of Radiology, Mayo Clinic, Scottsdale, Ariz (M.D.S., N.D., C.O.M.); and Departments of Radiology and Imaging Sciences (G.J., K.K.M.) and Emergency Medicine (G.J., K.K.M.), Emory University School of Medicine, Atlanta, Ga
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7
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Schutter R, Lantinga VA, Borra RJH, Moers C. MRI for diagnosis of post-renal transplant complications: current state-of-the-art and future perspectives. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2019; 33:49-61. [PMID: 31879853 DOI: 10.1007/s10334-019-00813-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/27/2019] [Accepted: 11/30/2019] [Indexed: 02/07/2023]
Abstract
Kidney transplantation has developed into a widespread procedure to treat end stage renal failure, with transplantation results improving over the years. Postoperative complications have decreased over the past decades, but are still an important cause of morbidity and mortality. Early accurate diagnosis and treatment is the key to prevent renal allograft impairment or even graft loss. Ideally, a diagnostic tool should be able to detect post-transplant renal dysfunction, differentiate between the different causes and monitor renal function during and after therapeutic interventions. Non-invasive imaging modalities for diagnostic purposes show promising results. Magnetic resonance imaging (MRI) techniques have a number of advantages, such as the lack of ionizing radiation and the possibility to obtain relevant tissue information without contrast, reducing the risk of contrast-induced nephrotoxicity. However, most techniques still lack the specificity to distinguish different types of parenchymal diseases. Despite some promising outcomes, MRI is still barely used in the post-transplantation diagnostic process. The aim of this review is to survey the current literature on the relevance and clinical applicability of diagnostic MRI modalities for the detection of various types of complications after kidney transplantation.
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Affiliation(s)
- Rianne Schutter
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
| | - Veerle A Lantinga
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Ronald J H Borra
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Cyril Moers
- University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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8
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Abstract
Renal transplantation is the therapy of choice for patients with end-stage renal diseases. Improvement of immunosuppressive therapy has significantly increased the half-life of renal allografts over the past decade. Nevertheless, complications can still arise. An early detection of allograft dysfunction is mandatory for a good outcome. New advances in magnetic resonance imaging (MRI) have enabled the noninvasive assessment of different functional renal parameters in addition to anatomic imaging. Most of these techniques were widely tested on renal allografts in past decades and a lot of clinical data are available. The following review summarizes the comprehensive, functional MRI techniques for the noninvasive assessment of renal allograft function and highlights their potential for the investigations of different etiologies of graft dysfunction.
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9
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Abstract
PURPOSE OF REVIEW In this article, we describe the basics of how magnetic resonance urography (MRU) is performed in the pediatric population as well as the common indications and relative performance compared to standard imaging modalities. RECENT FINDINGS Although MRU is still largely performed in major academic or specialty imaging centers, more and more applications in the pediatric setting have been described in the literature. MRU is a comprehensive imaging modality for evaluating multiple pediatric urologic conditions combining excellent anatomic detail with functional information previously only available via renal scintigraphy. While generally still reserved for problem solving, MRU should be considered for some conditions as an early imaging technique.
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10
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Roustan FR, Lareyre F, Bentellis I, Haider R, Torrino S, Sedat J, Albano L, Jean-Baptiste E, Raffort J, Durand M. Endovascular Treatment of Transplant Renal Artery Stenosis: Evaluation of Postoperative Outcomes and Risk Factors for Recurrence. Angiology 2018; 70:249-256. [DOI: 10.1177/0003319718787665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Angioplasty with or without stenting has become a well-established procedure to treat transplant renal artery stenosis (TRAS). We evaluated our experience on postoperative outcomes following the intervention and identified potential predictive factors of TRAS recurrence. Consecutive patients who underwent endovascular treatment of TRAS were retrospectively reviewed. The study end points were the technical success, 30-day postoperative complications, and the estimated glomerular filtration rate (eGFR). Thirty-two patients underwent endovascular treatment for TRAS. The technical success rate was 96.6%. Complications were observed for 7 (21.9%) patients: 4 had a dissection, 2 a pseudoaneurysm, and 1 (3.1%) patient developed an acute pulmonary edema. The mean eGFR significantly increased at 7 days, 3 months, and 6 months postintervention (43.1, 44.9, and 44.3 vs 33.9 mL/min/1.73 m2 preoperatively, P < .05). The TRAS recurrence was observed in 7 (21.9%) patients. These patients had significantly higher preoperative peak systolic velocity and systolic rise time (5 vs 4 m/s, P = .0383 and 103 vs 80 milliseconds, P = .0148, respectively). Endovascular treatment of TRAS is associated with high technical success and significant improvement in renal function. Further studies are required to confirm predictive factors of TRAS recurrence following endovascular treatment.
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Affiliation(s)
- François-René Roustan
- Department of Urology, University Hospital of Nice, Nice, France
- Université Côte d’Azur, CHU, Inserm, C3M, Nice, France
| | - Fabien Lareyre
- Université Côte d’Azur, CHU, Inserm, C3M, Nice, France
- Department of Vascular Surgery, University Hospital of Nice, Nice, France
| | - Imad Bentellis
- Department of Urology, University Hospital of Nice, Nice, France
| | - Romain Haider
- Department of Urology, University Hospital of Nice, Nice, France
| | | | - Jacques Sedat
- Department of Interventional Radiology, University Hospital of Nice, Nice, France
| | - Laetitia Albano
- Department of Nephrology, University Hospital of Nice, Nice, France
| | - Elixène Jean-Baptiste
- Université Côte d’Azur, CHU, Inserm, C3M, Nice, France
- Department of Vascular Surgery, University Hospital of Nice, Nice, France
| | - Juliette Raffort
- Université Côte d’Azur, CHU, Inserm, C3M, Nice, France
- Clinical Chemistry Laboratory, University Hospital of Nice, Nice, France
| | - Matthieu Durand
- Department of Urology, University Hospital of Nice, Nice, France
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11
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Damasio MB, Ording Muller LS, Piaggio G, Marks SD, Riccabona M. Imaging in pediatric renal transplantation. Pediatr Transplant 2017; 21. [PMID: 28121050 DOI: 10.1111/petr.12885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/19/2016] [Indexed: 12/19/2022]
Abstract
Renal transplantation is the therapy of choice in children with ESKD. Radiological investigations are required in both pre- and post-transplant assessment, although there is paucity of both consensus-based statements and evidence-based imaging guidelines in pediatric renal transplantation. The phases of pediatric ESKD management that require imaging are pretransplantation recipient assessment and post-transplantation surveillance for detection of potential complications. We present suggestions for imaging algorithms for both pre- and post-transplant assessment in pediatric renal transplant recipients.
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Affiliation(s)
| | - Lil-Sofie Ording Muller
- Department of Radiology and Intervention Unit for Paediatric Radiology, Oslo University Hospital, Ullevål, Norway
| | - Giorgio Piaggio
- Department of Nephrology, Istituto Giannina Gaslini, Genoa, Italy
| | - Stephen D Marks
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Michael Riccabona
- Division of Pediatric Radiology, Department of Radiology, University Hospital Graz, Graz, Austria
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Pan FS, Liu M, Luo J, Tian WS, Liang JY, Xu M, Zheng YL, Xie XY. Transplant renal artery stenosis: Evaluation with contrast-enhanced ultrasound. Eur J Radiol 2017; 90:42-49. [PMID: 28583646 DOI: 10.1016/j.ejrad.2017.02.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/12/2017] [Accepted: 02/19/2017] [Indexed: 02/09/2023]
Abstract
OBJECTIVE To assess the efficacy of contrast-enhanced ultrasound (CEUS) in depicting transplant renal artery stenosis (TRAS). MATERIALS AND METHODS Seventy-eight patients (56 men and 22 women; aged 36±12.2years) who were suspected of TRAS due to either Doppler ultrasound (DUS) abnormalities or difficult control of blood pressure and/or persistent deterioration of renal function were enrolled to perform CEUS. The reference standard for the TRAS diagnoses was computed tomography angiography (CTA). The diagnostic performance of DUS and CEUS parameters was assessed by the area under the receiver operating characteristic curve (AUC). RESULTS TRAS was diagnosed in 32 out of 78 cases by CTA. The AUC, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CEUS in predicting TRAS were 0.92, 92.3%, 87.5%, 95.7%, 93.3%, and 91.7%, respectively. CEUS rectified 13 (28.3%) false-positive cases on DUS, which were confirmed by CTA. Compared to DUS parameters, CEUS showed the highest AUC, statistically significant differences of AUC were found (P=0.006-0.039), except for that of the PSV ratio in the main transplant renal artery to that in interlobar artery (PSV-ratio) (AUC: 0.92 versus 0.86, P=0.422). However, CEUS showed a significantly higher specificity (95.7% versus 76.1%, P=0.008) and the same sensitivity compared to PSV-ratio. CONCLUSIONS CEUS is superior to DUS in depicting TRAS. Moreover, our results suggest that CEUS might potentially be used as a noninvasive tool to spare many patients from unnecessary CTA.
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Affiliation(s)
- Fu-Shun Pan
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
| | - Ming Liu
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
| | - Jia Luo
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
| | - Wen-Shuo Tian
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
| | - Jin-Yu Liang
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
| | - Ming Xu
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
| | - Yan-Ling Zheng
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
| | - Xiao-Yan Xie
- Department of Medical Ultrasonics, Institute of Diagnostic and Interventional Ultrasound, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080, PR China.
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Can Ferumoxytol be Used as a Contrast Agent to Differentiate Between Acute and Chronic Inflammatory Kidney Disease?: Feasibility Study in a Rat Model. Invest Radiol 2016; 51:100-5. [PMID: 26352750 DOI: 10.1097/rli.0000000000000209] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVES Ferumoxytol, an intravenous iron supplement, can be used in off-label mode as a contrast agent in magnetic resonance imaging. The aim of this study was to assess whether ferumoxytol can be used as a marker of inflammation in animal models of acute and chronic inflammatory kidney diseases. MATERIAL AND METHODS The institutional animal care committee approved this study. A total of 18 rats were examined: 6 healthy Sprague Dawley rats as a control group; 6 rats with polycystic kidney disease (PKD) as a model for chronic inflammatory disease; Thy-1, an antibody triggering glomerulonephritis, was injected in 6 rats as a model for acute inflammation. Each rat was examined directly before and 24 hours after intravenous administration of ferumoxytol at a dose of 30 mg Fe/kg body weight. T2* times of renal tissue were approximated using a multiecho sequence. Changes in relative T2* times and T2 signal intensity after ferumoxytol injection were calculated. RESULTS Statistically significant differences between the 3 groups were found: the T2* times of both, Thy-1 and PKD rats were statistically significant different compared with the control group (T2* time ratio after/before: Thy-1, 0.21; PKD, 0.19, control, 0.28; P = 0.002). The highest T2 signal loss in the renal cortex was observed in the Thy-1 rats (T2 signal intensity ratio after/before: Thy-1, 0.49; PKD, 0.79; control, 0.78; P = 0.0005). CONCLUSIONS Ferumoxytol-enhanced magnetic resonance imaging allows detection and differentiation of acute and chronic inflammatory kidney disease based on different patterns of parenchymal ferumoxytol depositions. Ferumoxytol thus might help to differentiate between different types of inflammation in various kidney diseases.
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14
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Goldberg RJ, Weng FL, Kandula P. Acute and Chronic Allograft Dysfunction in Kidney Transplant Recipients. Med Clin North Am 2016; 100:487-503. [PMID: 27095641 DOI: 10.1016/j.mcna.2016.01.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Allograft dysfunction after a kidney transplant is often clinically asymptomatic and is usually detected as an increase in serum creatinine level with corresponding decrease in glomerular filtration rate. The diagnostic evaluation may include blood tests, urinalysis, transplant ultrasonography, radionuclide imaging, and allograft biopsy. Whether it occurs early or later after transplant, allograft dysfunction requires prompt evaluation to determine its cause and subsequent management. Acute rejection, medication toxicity from calcineurin inhibitors, and BK virus nephropathy can occur early or later. Other later causes include transplant glomerulopathy, recurrent glomerulonephritis, and renal artery stenosis.
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Affiliation(s)
- Ryan J Goldberg
- Renal & Pancreas Transplant Division, Saint Barnabas Medical Center, Livingston, NJ, USA.
| | - Francis L Weng
- Renal & Pancreas Transplant Division, Saint Barnabas Medical Center, Livingston, NJ, USA
| | - Praveen Kandula
- Renal & Pancreas Transplant Division, Saint Barnabas Medical Center, Livingston, NJ, USA
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15
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MR Angiography of Renal Transplant Vasculature with Ferumoxytol:: Comparison of High-Resolution Steady-State and First-Pass Acquisitions. Acad Radiol 2016; 23:368-73. [PMID: 26707344 DOI: 10.1016/j.acra.2015.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/15/2015] [Accepted: 10/15/2015] [Indexed: 01/18/2023]
Abstract
RATIONALE AND OBJECTIVES This work aimed to quantify the differences in signal-to-noise ratio (SNR) and vessel sharpness between steady-state and first-pass magnetic resonance angiography (MRA) with ferumoxytol in renal transplant recipients. MATERIALS AND METHODS We performed a retrospective study of adult patients who underwent steady-state and first-pass MRA with ferumoxytol to evaluate renal transplant vasculature. SNR was calculated in the external iliac artery, and vessel sharpness was calculated in the external iliac and renal transplant arteries for both acquisitions. Data were compared using Student's t test. RESULTS Fifteen patients were included (mean age 56.9 years, 10 males). The mean SNR of the external iliac artery was 42.2 (SD, 11.9) for the first-pass MRA and 41.8 (SD, 9.7) for the steady-state MRA (p = 0.92). The mean vessel sharpness was significantly higher for the steady-state MRA compared to first-pass MRA for both external iliac (1.24 vs. 0.80 mm(-1), p < 0.01) and renal transplant arteries (1.26 vs. 0.79 mm(-1), p < 0.01). CONCLUSION Steady-state MRA using ferumoxytol improves vessel sharpness while maintaining equivalent SNR compared to conventional first-pass MRA in renal transplant patients.
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16
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Wang YT, Li YC, Yin LL, Pu H, Chen JY. Functional assessment of transplanted kidneys with magnetic resonance imaging. World J Radiol 2015; 7:343-349. [PMID: 26516431 PMCID: PMC4620115 DOI: 10.4329/wjr.v7.i10.343] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/17/2015] [Accepted: 09/08/2015] [Indexed: 02/06/2023] Open
Abstract
Kidney transplantation has emerged as the treatment of choice for many patients with end-stage renal disease, which is a significant cause of morbidity and mortality. Given the shortage of clinically available donor kidneys and the significant incidence of allograft dysfunction, a noninvasive and accurate assessment of the allograft renal function is critical for postoperative management. Prompt diagnosis of graft dysfunction facilitates clinical intervention of kidneys with salvageable function. New advances in magnetic resonance imaging (MRI) technology have enabled the calculation of various renal parameters that were previously not feasible to measure noninvasively. Diffusion-weighted imaging provides information on renal diffusion and perfusion simultaneously, with quantification by the apparent diffusion coefficient, the decrease of which reflects renal function impairment. Diffusion-tensor imaging accounts for the directionality of molecular motion and measures fractional anisotropy of the kidneys. Blood oxygen level-dependent MR evaluates intrarenal oxygen bioavailability, generating the parameter of R2* (reflecting the concentration of deoxyhemoglobin). A decrease in R2* could happen during acute rejection. MR nephro-urography/renography demonstrates structural data depicting urinary tract obstructions and functional data regarding the glomerular filtration and blood flow. MR angiography details the transplant vasculature and is particularly suitable for detecting vascular complications, with good correlation with digital subtraction angiography. Other functional MRI technologies, such as arterial spin labeling and MR spectroscopy, are showing additional promise. This review highlights MRI as a comprehensive modality to diagnose a variety of etiologies of graft dysfunction, including prerenal (e.g., renal vasculature), renal (intrinsic causes) and postrenal (e.g., obstruction of the collecting system) etiologies.
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Zeisbrich M, Kihm LP, Drüschler F, Zeier M, Schwenger V. When is contrast-enhanced sonography preferable over conventional ultrasound combined with Doppler imaging in renal transplantation? Clin Kidney J 2015; 8:606-14. [PMID: 26413289 PMCID: PMC4581388 DOI: 10.1093/ckj/sfv070] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 07/10/2015] [Indexed: 12/18/2022] Open
Abstract
Conventional ultrasound in combination with colour Doppler imaging is still the standard diagnostic procedure for patients after renal transplantation. However, while conventional ultrasound in combination with Doppler imaging can diagnose renal artery stenosis and vein thrombosis, it is not possible to display subtle microvascular tissue perfusion, which is crucial for the evaluation of acute and chronic allograft dysfunctions. In contrast, real-time contrast-enhanced sonography (CES) uses gas-filled microbubbles not only to visualize but also to quantify renal blood flow and perfusion even in the small renal arterioles and capillaries. It is an easy to perform and non-invasive imaging technique that augments diagnostic capabilities in patients after renal transplantation. Specifically in the postoperative setting, CES has been shown to be superior to conventional ultrasound in combination with Doppler imaging in uncovering even subtle microvascular disturbances in the allograft perfusion. In addition, quantitative perfusion parameters derived from CES show predictive capability regarding long-term kidney function.
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Affiliation(s)
- Markus Zeisbrich
- Department of Nephrology , University Hospital , Heidelberg , Germany
| | - Lars P Kihm
- Department of Nephrology , University Hospital , Heidelberg , Germany
| | - Felix Drüschler
- Department of Nephrology , University Hospital , Heidelberg , Germany
| | - Martin Zeier
- Department of Nephrology , University Hospital , Heidelberg , Germany
| | - Vedat Schwenger
- Department of Nephrology , University Hospital , Heidelberg , Germany
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Chen W, Kayler LK, Zand MS, Muttana R, Chernyak V, DeBoccardo GO. Transplant renal artery stenosis: clinical manifestations, diagnosis and therapy. Clin Kidney J 2014; 8:71-8. [PMID: 25713713 PMCID: PMC4310434 DOI: 10.1093/ckj/sfu132] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 11/13/2014] [Indexed: 01/04/2023] Open
Abstract
Transplant renal artery stenosis (TRAS) is a well-recognized vascular complication after kidney transplant. It occurs most frequently in the first 6 months after kidney transplant, and is one of the major causes of graft loss and premature death in transplant recipients. Renal hypoperfusion occurring in TRAS results in activation of the renin–angiotensin–aldosterone system; patients usually present with worsening or refractory hypertension, fluid retention and often allograft dysfunction. Flash pulmonary edema can develop in patients with critical bilateral renal artery stenosis or renal artery stenosis in a solitary kidney, and this unique clinical entity has been named Pickering Syndrome. Prompt diagnosis and treatment of TRAS can prevent allograft damage and systemic sequelae. Duplex sonography is the most commonly used screening tool, whereas angiography provides the definitive diagnosis. Percutaneous transluminal angioplasty with stent placement can be performed during angiography if a lesion is identified, and it is generally the first-line therapy for TRAS. However, there is no randomized controlled trial examining the efficacy and safety of percutaneous transluminal angioplasty compared with medical therapy alone or surgical intervention.
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Affiliation(s)
- Wei Chen
- Department of Medicine , University of Rochester School of Medicine and Dentistry , Rochester, NY , USA ; Department of Medicine , Albert Einstein College of Medicine , Bronx, NY , USA
| | - Liise K Kayler
- Department of Surgery , Albert Einstein College of Medicine , Bronx, NY , USA
| | - Martin S Zand
- Department of Medicine , University of Rochester School of Medicine and Dentistry , Rochester, NY , USA
| | - Renu Muttana
- Department of Medicine , Maimonides Medical Center , Brooklyn, NY , USA
| | - Victoria Chernyak
- Department of Radiology , Albert Einstein College of Medicine , Bronx, NY , USA
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Inci MF, Ozkan F, See TC, Tatli S. Renal Transplant Complications: Diagnostic and Therapeutic Role of Radiology. Can Assoc Radiol J 2014; 65:242-52. [DOI: 10.1016/j.carj.2013.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 06/05/2013] [Accepted: 06/21/2013] [Indexed: 02/08/2023] Open
Abstract
Kidney was the first and is the most frequently transplanted organ. Despite improved surgical techniques and transplantation technology, complications do occur and, if left untreated, may lead to catastrophic consequences. Renal transplantation complications may be vascular (eg, renal artery and vein stenosis and thrombosis, arteriovenous fistula, and pseudoaneurysms); urologic (eg, urinary obstruction and leak, and peritransplantation fluid collections, including hematoma, seroma, lymphocele, and abscess formation); and nephrogenic, including acute tubular necrosis, graft rejection, chronic allograft nephropathy, and neoplasm. Early diagnosis and treatment of these complications are paramount to prevent graft failure and other significant morbidities to the patients. Radiology plays a pivotal role in the diagnosis and treatment of these complications, with minimally invasive percutaneous techniques. In this article, we reviewed renal transplantation anatomy, a wide range of complications that may occur after renal transplantation surgery, typical imaging appearances of the complications on varies imaging modalities, and percutaneous interventional techniques that are used in their treatment.
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Affiliation(s)
- Mehmet Fatih Inci
- Department of Radiology, Sütçü İmam University Medical School, Kahramanmaraş, Turkey
| | - Fuat Ozkan
- Department of Radiology, Sütçü İmam University Medical School, Kahramanmaraş, Turkey
| | - Teik Choon See
- Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Servet Tatli
- Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Onniboni M, De Filippo M, Averna R, Coco L, Zompatori M, Sverzellati N, Rossi C. Magnetic resonance imaging in the complications of kidney transplantation. Radiol Med 2012; 118:837-50. [PMID: 23090252 DOI: 10.1007/s11547-012-0891-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/28/2012] [Indexed: 11/28/2022]
Abstract
Kidney transplantation is currently the treatment of choice in most patients with end-stage chronic renal failure owing to the excellent results in terms of both graft and patient survival. However, surgical complications are still very frequent. Although urological (stricture, urinary fistulas, vesico-ureteral reflux) and lymphatic complications (lymphocoele) have a high incidence, they only rarely lead to graft loss. By contrast, vascular complications (stenosis, arterial and venous thrombosis, arterio-venous fistulas, pseudoaneurysms) are relatively rare, but potentially serious and may affect graft survival. Finally, medical complications such as acute tubular necrosis (ATN), rejection and de novo neoplasms may also arise in kidney transplantation. The purpose of this pictorial review is to illustrate the increasingly significant contribution of magnetic resonance angiography (MRA) in the management of complications of kidney transplantation, and emphasise how this method should now be considered a mandatory step in the diagnostic workup of selected cases. Moreover, the application and role in this setting of new magnetic resonance imaging (MRI) techniques, such as diffusion-weighted and blood oxygen level-dependent (BOLD) MRI, are also discussed.
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Affiliation(s)
- M Onniboni
- Scienze Radiologiche, Azienda Ospedaliero-Universitaria di Parma, Via Gramsci 14, Padiglione Barbieri, 43100, Parma, Italy.
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Diaz-Garcia C, Johannesson L, Enskog A, Tzakis A, Olausson M, Brannstrom M. Uterine transplantation research: laboratory protocols for clinical application. Mol Hum Reprod 2011; 18:68-78. [DOI: 10.1093/molehr/gar055] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Ismaeel MM, Abdel-Hamid A. Role of high resolution contrast-enhanced magnetic resonance angiography (HR CeMRA) in management of arterial complications of the renal transplant. Eur J Radiol 2011; 79:e122-7. [PMID: 21601400 DOI: 10.1016/j.ejrad.2011.04.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 04/11/2011] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Transplant renal artery (RA) stenosis (TRAS) is the most frequent posttransplantation vascular complication. Contrast enhanced magnetic resonance (CeMRA) angiography has been established as the preferred imaging technique for the evaluation of TRAS because it does not require the use of iodinated contrast material and does not expose the patient to ionizing radiation. Digital subtraction angiography (DSA) is the gold standard in the evaluation of arterial tree of the renal allograft. AIM OF THE WORK This study was carried out to assess the accuracy of CeMRA in the detection of arterial complications after renal transplantation. PATIENTS AND METHODS Thirty renal transplant patients with suspected arterial complications in which both CeMRA and DSA were performed were included in the study. The HR CeMRA shows 93.7% sensitivity, 80% specificity, 88.2% positive predictive value, 88.9% negative predictive value and 88.5% accuracy. CONCLUSION HR CeMRA is an accurate reliable tool in the assessment of arterial complications after renal transplantation. It may replace DSA as a diagnostic modality with reservation of interventional techniques for endovascular treatment of suitable cases.
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Reuben CM, Jeun B, Juluru K. Sonographic twinkling artifact in a renal graft with prolene mesh. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2010; 29:1011-1013. [PMID: 20498478 DOI: 10.7863/jum.2010.29.6.1011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Claudia M Reuben
- New York University School of Medicine, New York, New York, USA.
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Abstract
The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.
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Lanzman RS, Voiculescu A, Walther C, Ringelstein A, Bi X, Schmitt P, Freitag SM, Won S, Scherer A, Blondin D. ECG-gated nonenhanced 3D steady-state free precession MR angiography in assessment of transplant renal arteries: comparison with DSA. Radiology 2009; 252:914-21. [PMID: 19635833 DOI: 10.1148/radiol.2531082260] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate noncontrast material-enhanced steady-state free precession (SSFP) magnetic resonance (MR) angiography in the assessment of transplant renal arteries (RAs) by using digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS This prospective study was approved by the institutional review board; written informed consent was obtained from all participants. In 20 renal allograft recipients scheduled for DSA, the transplant RAs were assessed with electrocardiographically gated nonenhanced SSFP MR angiography performed at 1.5 T; the degree of stenosis was compared with that of DSA. Subjective image quality for SSFP MR angiography was assessed independently by two radiologists on a four-point scale (from 1, nondiagnostic to 4, excellent) in four predefined segments (I, the iliac artery; II, the main transplant artery; III, segmental branches; and IV, parenchymal branches). Sensitivity, specificity, and accuracy of SSFP MR angiography for the detection of relevant (> or =50%) transplant RA stenosis (TRAS) were calculated on a per-artery basis. RESULTS One patient was excluded because SSFP MR angiography failed to adequately visualize the allograft vasculature owing to low cardiac output. The mean image quality assessed by both readers was 3.98 +/- 0.16 (standard deviation), 3.5 +/- 0.68, 2.71 +/- 1.12 and 2.03 +/- 1.09 for segments I, II, III, and IV, respectively (kappa = 0.80). DSA helped identify eight relevant (> or =50%) stenoses in six transplant RAs. Kinking of the transplant artery without relevant stenosis was found in seven patients. The degree of stenosis was overestimated in three patients by using SSFP MR angiography. As compared with DSA, the sensitivity, specificity, and accuracy of SSFP MR angiography to help detect relevant TRAS were 100% (six of six), 88% (14 of 16), and 91% (20 of 22), respectively. CONCLUSION Nonenhanced SSFP MR angiography is a reliable alternative imaging technique for the assessment of transplant RAs in patients for whom contrast-enhanced MR angiography is contraindicated.
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Affiliation(s)
- Rotem S Lanzman
- Institute of Radiology, University Hospital Düsseldorf, Moorenstr 5, 40225 Düsseldorf, Germany.
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Leyendecker JR, Clingan MJ. Magnetic Resonance Urography Update—Are We There Yet? Semin Ultrasound CT MR 2009; 30:246-57. [DOI: 10.1053/j.sult.2009.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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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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Kalb B, Martin DR, Salman K, Sharma P, Votaw J, Larsen C. Kidney transplantation: structural and functional evaluation using MR Nephro-Urography. J Magn Reson Imaging 2009; 28:805-22. [PMID: 18821623 DOI: 10.1002/jmri.21562] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
End-stage-renal disease (ESRD) is a major health issue in the United States, and the Medicare costs of ESRD totaled nearly USD 21 billion in 2005. Renal transplantation has emerged as the treatment of choice in this patient population, providing improved quality of life and lower healthcare costs compared with other treatment options. Imaging evaluation of a graft kidney plays a critical role in the postoperative care of the renal transplant patient. In the past, diagnostic evaluation of the transplant kidney has depended upon a combination of ultrasonography, computed tomography, MRI, and biopsy, used in conjunction with the patient's clinical presentation. However, new and developing advances in MR technology has lead to the development of MR Nephro-Urography (MRNU), which provides both anatomic and functional evaluation of the kidney in a single examination. It is expected that the increasing use of MRNU will have a significant impact on the management of renal transplant patients. This review describes MRNU methodology, examines known posttransplant complications, and highlights the utility of MRNU as a comprehensive imaging examination to diagnose both surgical and medical complications of the transplant kidney.
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Affiliation(s)
- Bobby Kalb
- Emory University School of Medicine, 1365 Clifton Road NE, Building A - AT622, Atlanta, Georgia 30322, USA
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Miura M, Harada H, Morooka K, Tanabe T, Takada N, Seki T, Togashi M, Hirano T. Practical tests for clinical diagnosis of kidney allograft dysfunction. Clin Transplant 2008. [DOI: 10.1111/j.1399-0012.2008.00840.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Sonographic evaluation of the genitourinary system is a fast, safe, and effective means to detect renal disease. In conjunction with other modalities, Doppler can depict a variety of abnormalities. However, optimization of Doppler techniques and a solid understanding of Doppler threshold criteria are critical for success, whether in the native or transplanted kidney.
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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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Blondin D, Koester A, Andersen K, Kurz KD, Moedder U, Cohnen M. Renal transplant failure due to urologic complications: Comparison of static fluid with contrast-enhanced magnetic resonance urography. Eur J Radiol 2007; 69:324-30. [PMID: 18055152 DOI: 10.1016/j.ejrad.2007.10.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2007] [Revised: 10/22/2007] [Accepted: 10/31/2007] [Indexed: 11/26/2022]
Abstract
PURPOSE Postrenal reasons of renal transplant failure can be assessed by magnetic resonance urography. This study was designed to retrospectively compare the diagnostic accuracy of static fluid (T2-)MRU compared to contrast enhanced (CE-)MRU in patients with renal transplant failure. MATERIAL AND METHODS Thirty-five consecutive patients (14 female, 21 men; mean age 48.6 years) with renal transplant failure and sonographically detected hydronephrosis were examined both with T2-MRU as well as CE-MRU resulting in 39 MRU examinations. MRU was performed both using T2-weighted HASTE-sequence (T2-MRU) as well as Gadolinium-enhanced 3D-FLASH-sequence (CE-MRU) on a 1.5-T clinical MRI scanner (Magnetom Vision, Siemens Medical Solutions). Subjective image quality of resulting maximum intensity projection was assessed in consensus by two readers blinded to the final diagnosis, using a five point scale. MRU findings were correlated to sonography, operative results or clinical follow up. RESULTS CE-MRU yielded a sensitivity of 85.7% (T2-MRU 76.2%), and a specificity of 83.3% (T2-MRU: 73.7%), however statistical significance was not reached. The subjective image quality was significantly better in CE-MRU. CONCLUSIONS Only concerning subjective image quality CE-MRU proved superior to T2-MRU. Yet, there was no significant difference in diagnostic accuracy between T2- and CE-MRU. Thinking of incipient nephrogenic systemic fibrosis, T2-MRU can be used as reliable alternative in patients with decreased renal transplant function due to urological complications.
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Affiliation(s)
- D Blondin
- Institute of Diagnostic Radiology, University Hospital Duesseldorf, Duesseldorf, Germany.
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Banzo I, Quirce R, Martínez-Rodríguez I, Jiménez-Bonilla J, Sainz A, Carril JM. [Atlas of isotopic renography images in the renal transplant complications]. REVISTA ESPANOLA DE MEDICINA NUCLEAR 2006; 25:329-48. [PMID: 17173782 DOI: 10.1157/13092703] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- I Banzo
- Servicio de Medicina Nuclear, Hospital Universitario Marqués de Valdecilla, Universidad de Cantabria, Santander, España.
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