Retrospective study of renal images on whole bone scanning

International Nuclear Information System (INIS)

Yanagisawa, Munetoshi; Machida, Toyohei; Miki, Makoto; Ohishi, Yukihiko; Ueda, Masataka

1978-01-01

One hundred and twenty-seven cases were surveyed by sup(99m)Tc-pyrophosphate at Jikei hospital. Renal images on whole-bone scanning were observed in all cases; 75% of all renal images were normal and 25% were abnormal. Thirteen percent of these abnormal images were symmetric and 87% were asymmetric. Four of the symmetric renal images were bilaterally bad. Three of the four bilaterally bad renal images involved prostate carcinomas with general metastases and the last involved serious bilateral hydronephrosis. The reason for the high percentage of asymmetric renal images was that the materials involved many urogenital cases. Asymmetric renal images other than the urogenital cases, were recognised in 8% of all cases. This percentage is consistent with Hattner's report. Unilateral abnormal renal images involved 8 hydronephrosis cases, 2 unilateral nonfunctioning kidneys and one malrotation kidney. Among the hydronephrosis cases, serious cases gave low uptake and mild cases gave high uptake. The reason for this phenomenon was, presumably, that there were differences in renal uptake, renal excretion and renal pelvic accumulation. In nine cases, one kidney was not visualized on whole-bone scanning, 8 of them involved nephrectomy and the remainining one unilateral nonfunctioning kidney. Six cases presented locally abnormal renal images on whole-bone scanning, three of them suffered renal cell carcinomas and the rest renal solitary cyst. Eighty-eight percent of the abnormal renal images agreed with IVP findings. The renal images of whole-bone scanning faithfully reflected the original renal lesion. Two cases of renal carcinoma and renal solitary cyst recognized on whole-bone scanning are presented, to indicate the usefulness of renal images on whole-bone scanning. (auth.)

Renal angiomyoadenomatous tumour: Imaging features

Science.gov (United States)

Sahni, V. Anik; Hirsch, Michelle S.; Silverman, Stuart G.

2012-01-01

Renal angiomyoadenomatous tumour is a rare, recently described neoplasm with a distinctive histological appearance. Although reported in the pathology literature, to our knowledge, no prior reports have described its imaging appearance. We describe the computed tomography and magnetic resonance imaging features of an incidentally detected renal angiomyoadenomatous tumour that appeared as a well-marginated, solid T2-hypointense enhancing mass, in a 50-year-old woman. It is indistinguishable from a variety of benign and malignant renal neoplasms. PMID:23093565

Functional dynamic MR imaging and pharmacokinetics of Gd-DTPA in patients with renal failure

International Nuclear Information System (INIS)

Krestin, G.P.; Neufang, K.F.R.; Friedmann, G.; Clauss, W.; Schuhmann-Giampieri, G.; Stoeckl, B.

1989-01-01

This paper reports excretion of Gd-DTPA analyzed in 20 patients with renal parenchymal disease and decreased creatinine clearance (20-80 mL/min) and compared with excretion in five patients with normal renal function. All 25 underwent a dynamic MR study that employed fast gradient-echo sequences with single images during breath holding. The time between appearance of the contrast agent in the renal cortex and signal intensity drop in the medulla was an indicator of glomerular filtration rate and correlated well with creatinine clearance values. Fractionate urine collection and serum analysis up to 120 hours showed a prolonged but complete (98%) elimination of Gd-DTPA. Renal functional parameters did not change after administration of Gd-DTPA, and no nephrotoxic effects were observed. Thus, MR imaging provides a good quantitative evaluation of the glomerular filtration rate; moreover, administration of Gd-DTPA in patients with renal failure does not impair excretory function and can therefore be safely applied in patients with reduced excretory function

Role of FDG/CT in imaging of renal lesions

International Nuclear Information System (INIS)

Kochhar, R.; Manoharan, P.; Brown, R.K.; Dunnick, N.R.; Frey, K.A.; Wong, C.O.

2010-01-01

Full text: Focal incidental renal lesions are commonly encountered on positron emission tomography (PET)/computed tomography (CT) imaging. The wast majority of these lesions are benign. However, the interpretation of renal lesions can be problematic if the imaging criteria of simple cysts are not met. Limited literature exists on the characterisation of renal masses with metabolic imaging. The purpose of this article is to focus on the imaging features of benign and malignant renal masses with PET/CT. The lesions discussed include renal cyst, angiomyolipoma, oncocytoma, renal cell carcinoma, renal metastases and other infiltrating neoplastic processes affecting the kidney. Both the anatomical and metabolic features which characterise these benign and malignant entities are described. We emphasise the importance of viewing the CT component to identify the typical morphological features and discuss how to best use hybrid imaging for management of renal lesions. Metabolic imaging has a promising role in the imaging of renal lesions and can help prevent unnecessary biopsies and ensure optimal management of suspicious lesions.

Non-contrast magnetic resonance angiography in renal transplantation and renal donation

DEFF Research Database (Denmark)

Blankholm, Anne Dorte

2015-01-01

for this purpose, including US, CTA and CEMRA. CTA is based on x-ray technology, and the applied iodine-based contrast agent can cause nephropathy and, in rare cases, severe allergic reactions. Allergic reactions to Gd used in CEMRA are extremely rare. Thus, CEMRA was often used for preoperative examination before...... renal transplantation. In 2006, it was realised that the Gd used in CEMRA could cause NSF, which prompted the Danish National Board of Health to produce guidelines for the use of contrast agents in patients with severe renal disease. This thesis discusses different preoperative imaging methods without...... contrast agents before kidney transplantation and kidney donation. Study I is a review of NCMRA techniques and clinical applications. In study II, we searched for an NCMRA method with consistently good image quality for the examination of the pelvic vessels in patients with severe renal disease. Five...

Imaging chronic renal disease and renal transplant in children

International Nuclear Information System (INIS)

Carmichael, Jim; Easty, Marina

2010-01-01

At Great Ormond Street Hospital we have the highest number of paediatric renal transplant patients in Europe, taking cases from across the United Kingdom and abroad. Our caseload includes many children with rare complicating medical problems and chronic renal failure related morbidity. This review aims to provide an overview of our experience of imaging children with chronic renal failure and transplants. (orig.)

Differentiation of Solid Renal Tumors with Multiparametric MR Imaging.

Science.gov (United States)

Lopes Vendrami, Camila; Parada Villavicencio, Carolina; DeJulio, Todd J; Chatterjee, Argha; Casalino, David D; Horowitz, Jeanne M; Oberlin, Daniel T; Yang, Guang-Yu; Nikolaidis, Paul; Miller, Frank H

2017-01-01

Characterization of renal tumors is critical to determine the best therapeutic approach and improve overall patient survival. Because of increased use of high-resolution cross-sectional imaging in clinical practice, renal masses are being discovered with increased frequency. As a result, accurate imaging characterization of these lesions is more important than ever. However, because of the wide array of imaging features encountered as well as overlapping characteristics, identifying reliable imaging criteria for differentiating malignant from benign renal masses remains a challenge. Multiparametric magnetic resonance (MR) imaging based on various anatomic and functional parameters has an important role and adds diagnostic value in detection and characterization of renal masses. MR imaging may allow distinction of benign solid renal masses from several renal cell carcinoma (RCC) subtypes, potentially suggest the histologic grade of a neoplasm, and play an important role in ensuring appropriate patient management to avoid unnecessary surgery or other interventions. It is also a useful noninvasive imaging tool for patients who undergo active surveillance of renal masses and for follow-up after treatment of a renal mass. The purpose of this article is to review the characteristic MR imaging features of RCC and common benign renal masses and propose a diagnostic imaging approach to evaluation of solid renal masses using multiparametric MR imaging. © RSNA, 2017.

Renal imaging in paediatrics

International Nuclear Information System (INIS)

Porn, U.; Hahn, K.; Fischer, S.

2003-01-01

The most frequent renal diseases in paediatrics include urinary tract infections, hydronephrosis, kidney anomalies and reflux. The main reason for performing DMSA scintigraphy in paediatrics is the detection of cortical abnormalities related to urinary tract infection. Because the amount of tracer retained in the tubular cells is associated with the distribution of functioning renal parenchyma in the kidney, it is possible, to evaluate the split renal function. In comparison to ultrasound and intravenous urography the sensitivity in the detection of acute as well as chronic inflammatory changes is very high, however less specific. An indication for a renography in neonates and children is beside an estimation of the total renal function and the calculation of the split renal function, the assessment of renal drainage in patients with unclear dilatation of the collecting system in ultrasound. The analysis of the time activity curve provides, especially for follow-up studies, a reproducible method to assess the urinary outflow. The diuretic scintigraphy allows the detection of urinary obstruction. Subsequently it is possible to image the micturition phase to detect vesico-ureteric reflux (indirect MCU) after drainage of tracer from the renal pelvis. An reflux in the ureters or the pelvicalyceal system is visible on the scintigraphic images and can be confirmed by time activity curves. A more invasive technique is the direct isotope cystography with bladder catheterization. The present paper should give an overview about the role of nuclear medicine in paediatric urology. (orig.) [de

Prevention of radiographic-contrast-agent-induced reductions in renal function by acetylcysteine

DEFF Research Database (Denmark)

Tepel, Martin; van der Giet, M; Schwarzfeld, C

2000-01-01

Radiographic contrast agents can cause a reduction in renal function that may be due to reactive oxygen species. Whether the reduction can be prevented by the administration of antioxidants is unknown.......Radiographic contrast agents can cause a reduction in renal function that may be due to reactive oxygen species. Whether the reduction can be prevented by the administration of antioxidants is unknown....

Evaluation of (o)-[77Br]bromohippuran as renal tubular function agent

International Nuclear Information System (INIS)

Aswegen, A. van; Roodt, J.P.; Pieters, H.; Herbst, C.P.; Otto, A.C.; Loetter, M.G.; Minnaar, P.C.; Haasbroek, F.J.

1985-01-01

(o)-[ 77 Br]bromohippuran (BHIP) was developed as renal tubular function agent due to its favourable chemical and physical properties and compared to (o)-[ 131 I]iodohippuran (IHIP). Renograms obtained from baboons were compared and absorbed radiation dose calculations performed. Although BHIP showed a delayed kidney uptake and washout pattern, good kidney clearance of the radionuclide was obtained after 30 min. Radiation dose values for BHIP were markedly lower than for IHIP indicating that larger activities of BHIP could be administered to increase counting statistics. BHIP imaging in normal volunteers did however not substantiate the favourable behaviour obtained in the primate. (author)

Renal imaging with a new agent sup(99m)Tc-d1-DMS

International Nuclear Information System (INIS)

Tanaka, A.

1980-01-01

By using sup(99m)-Tc-d1 DMS labeled with 99 m-Tc using stannous chloride and prepared with freeze-dried d1-DMS containing a 3:1 molar ratio of DMS and Sn +2 the effect of stereochemical factor of DMS on kidney affinity, renal images, blood clearance, urinary excretion was studied in experimental animals and two normal volunteers and 75 patients. The comparation revealed a quite similar formation of complex II from d1-DMS to that from the meso-form, judge from its absorption spectra and absorption behavior into the gel. The stereochemical difference of DMS is not a critical factor for the formation of the sup(99m)-Tc-DMS complex with high affinity for the kidney, although it is believed that the renal accumulation of Tc-complex will depend greatly on chemical configuration of the complex. (APR)

Pediatric renal leukemia: spectrum of CT imaging findings

International Nuclear Information System (INIS)

Hilmes, Melissa A.; Dillman, Jonathan R.; Mody, Rajen J.; Strouse, Peter J.

2008-01-01

The kidneys are a site of extramedullary leukemic disease that can be readily detected by CT. To demonstrate the spectrum of CT findings in children with renal leukemic involvement. Twelve children were identified retrospectively as having renal leukemic involvement by contrast-enhanced CT of the abdomen. Contrast-enhanced CT images through the kidneys of each patient were reviewed by two pediatric radiologists. Pertinent imaging findings and renal lengths were documented. The electronic medical record was accessed to obtain relevant clinical and pathologic information. Five patients with renal leukemic involvement presented with multiple bilateral low-attenuation masses, while three patients demonstrated large areas of wedge-shaped and geographic low attenuation. Four other patients presented with unique imaging findings, including a solitary unilateral low-attenuation mass, solitary bilateral low-attenuation masses, multiple bilateral low-attenuation masses including unilateral large conglomerate masses, and bilateral areas of ill-defined parenchymal low attenuation. Two patients showed unilateral nephromegaly, while eight other patients showed bilateral nephromegaly. Two patients had normal size kidneys. Two patients had elevated serum creatinine concentrations at the time of imaging. Renal leukemic involvement in children can present with a variety of CT imaging findings. Focal renal abnormalities as well as nephromegaly are frequently observed. Most commonly, renal leukemic involvement does not appear to impair renal function. (orig.)

Pediatric renal leukemia: spectrum of CT imaging findings

Energy Technology Data Exchange (ETDEWEB)

Hilmes, Melissa A. [University of Michigan Health System, C.S. Mott Children' s Hospital, Section of Pediatric Radiology, Ann Arbor, MI (United States); Vanderbilt University Children' s Hospital, Section of Pediatric Radiology, Nashville, TN (United States); Dillman, Jonathan R. [University of Michigan Health System, C.S. Mott Children' s Hospital, Section of Pediatric Radiology, Ann Arbor, MI (United States); University of Michigan Health System, Department of Radiology, Ann Arbor, MI (United States); Mody, Rajen J. [University of Michigan Health System, C.S. Mott Children' s Hospital, Division of Pediatric Hematology-Oncology and Bone Marrow Transplantation, Ann Arbor, MI (United States); Strouse, Peter J. [University of Michigan Health System, C.S. Mott Children' s Hospital, Section of Pediatric Radiology, Ann Arbor, MI (United States)

2008-04-15

The kidneys are a site of extramedullary leukemic disease that can be readily detected by CT. To demonstrate the spectrum of CT findings in children with renal leukemic involvement. Twelve children were identified retrospectively as having renal leukemic involvement by contrast-enhanced CT of the abdomen. Contrast-enhanced CT images through the kidneys of each patient were reviewed by two pediatric radiologists. Pertinent imaging findings and renal lengths were documented. The electronic medical record was accessed to obtain relevant clinical and pathologic information. Five patients with renal leukemic involvement presented with multiple bilateral low-attenuation masses, while three patients demonstrated large areas of wedge-shaped and geographic low attenuation. Four other patients presented with unique imaging findings, including a solitary unilateral low-attenuation mass, solitary bilateral low-attenuation masses, multiple bilateral low-attenuation masses including unilateral large conglomerate masses, and bilateral areas of ill-defined parenchymal low attenuation. Two patients showed unilateral nephromegaly, while eight other patients showed bilateral nephromegaly. Two patients had normal size kidneys. Two patients had elevated serum creatinine concentrations at the time of imaging. Renal leukemic involvement in children can present with a variety of CT imaging findings. Focal renal abnormalities as well as nephromegaly are frequently observed. Most commonly, renal leukemic involvement does not appear to impair renal function. (orig.)

Are T2-weighted images necessary in renal mass characterization?

International Nuclear Information System (INIS)

Dann, Phoebe; Thakur, Ravi; Chin, Deanne; Krinsky, Glenn; Israel, Gary M.

2006-01-01

Objective: To determine what role T2-weighted images play in characterizing renal masses. Methods: Forty-four pathologically proven renal masses (34 renal cell carcinomas, 8 oncocytomas, 1 metanephric adenoma, 1 angiomyolipoma without macroscopic fat) and 38 simple renal cysts were evaluated with T1- and T2-weighted images at 1.5 T. Two independent and blinded readers initially characterized all masses using only the T1-weighed images (in- and opposed-phase chemical shift, unenhanced frequency-selective fat-suppressed, gadolinium-enhanced frequency-selective fat-suppressed and subtraction images) and placed each mass into one of three categories: nonsurgical, in need of follow-up, or surgical. The masses were then re-evaluated with the addition of the T2-weighted images. It was determined if the T2-weighted images changed the initial classification. Results: Forty-three of the 44 (98%) pathologically proven renal masses were characterized as a surgical mass using only the T1-weighted images. The remaining renal mass (a renal cell carcinoma) was characterized as a mass in which follow-up exams would be suggested. Thirty-eight of 38 (100%) simple renal cysts were correctly characterized using only the T1-weighted images. The T2-weighted images did not change the initial interpretation of the T1-weighted images in any of the cases. Conclusion: The results of this study suggest that T2-weighted images are not necessary in the evaluation of all renal masses and are specifically not necessary in the differentiation of solid and cystic renal neoplasms from simple renal cysts

Viscosity of iodinated contrast agents during renal excretion

International Nuclear Information System (INIS)

Jost, Gregor; Lengsfeld, Philipp; Lenhard, Diana C.; Pietsch, Hubertus; Huetter, Joachim; Sieber, Martin A.

2011-01-01

Objective: Modern iodinated non-ionic contrast agents (CAs) can be classified based on their molecular structure into monomeric and dimeric CAs and have at comparable iodine concentrations a different viscosity and osmolality. During their renal excretion, CAs are concentrated in the renal tubuli which might enhance the viscosity difference between monomeric and dimeric CAs. The viscosity of a CA might have an underestimated importance for renal safety, as suggested by recent publications. In this study, we investigated the viscosities of CAs at the concentrations expected to be present in renal tubules. This concentration process was simulated in vitro using dialysis. Furthermore, we investigated urine viscosity and urine flow in rodents after administration of several non-ionic monomeric and dimeric CAs. Materials and methods: To estimate the viscosity of the CAs in vivo, we performed an in vitro dialysis of monomeric and dimeric CAs at various physiological osmolalities of the renal tubulus (290, 400, 500, 700 and 1000 mOsm/kg H 2 O). Following the dialysis, the iodine concentrations and the viscosities of the CAs were determined. Furthermore, to investigate the concentration process in vivo, we measured the urine viscosity and the urine flow in Han Wister rats after the administration of Iopromide, Iohexol, Ioversol, Iomeprol, Iodixanol, and Iosimenol at comparable iodine concentrations. As a control, saline was injected at the same volume. Results: In vitro dialysis of the dimeric CA increased the iodine concentration and strongly increased the viscosity at all tested osmolalities. In contrast, for the monomeric agents an increase in concentration and viscosity was observed only at 700 as well 1000 mOsm/kg H 2 O but to a lesser extent. In summary, dialysis strongly enhanced the viscosity differences between the non-ionic monomeric and dimeric CAs. The administration of dimeric CAs leads to a strong increase in urine viscosity; this was not observed for the

Viscosity of iodinated contrast agents during renal excretion

Energy Technology Data Exchange (ETDEWEB)

Jost, Gregor, E-mail: Gregor.Jost@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Lengsfeld, Philipp, E-mail: Philipp.Lengsfeld@bayer.com [Global Medical Affairs Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Lenhard, Diana C., E-mail: Diana.Lenhard@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Pietsch, Hubertus, E-mail: Hubertus.Pietsch@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Huetter, Joachim, E-mail: Joachim.Huetter@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany); Sieber, Martin A., E-mail: Martin.Sieber@bayer.com [TRG Diagnostic Imaging, Bayer Schering Pharma AG, Berlin (Germany)

2011-11-15

Objective: Modern iodinated non-ionic contrast agents (CAs) can be classified based on their molecular structure into monomeric and dimeric CAs and have at comparable iodine concentrations a different viscosity and osmolality. During their renal excretion, CAs are concentrated in the renal tubuli which might enhance the viscosity difference between monomeric and dimeric CAs. The viscosity of a CA might have an underestimated importance for renal safety, as suggested by recent publications. In this study, we investigated the viscosities of CAs at the concentrations expected to be present in renal tubules. This concentration process was simulated in vitro using dialysis. Furthermore, we investigated urine viscosity and urine flow in rodents after administration of several non-ionic monomeric and dimeric CAs. Materials and methods: To estimate the viscosity of the CAs in vivo, we performed an in vitro dialysis of monomeric and dimeric CAs at various physiological osmolalities of the renal tubulus (290, 400, 500, 700 and 1000 mOsm/kg H{sub 2}O). Following the dialysis, the iodine concentrations and the viscosities of the CAs were determined. Furthermore, to investigate the concentration process in vivo, we measured the urine viscosity and the urine flow in Han Wister rats after the administration of Iopromide, Iohexol, Ioversol, Iomeprol, Iodixanol, and Iosimenol at comparable iodine concentrations. As a control, saline was injected at the same volume. Results: In vitro dialysis of the dimeric CA increased the iodine concentration and strongly increased the viscosity at all tested osmolalities. In contrast, for the monomeric agents an increase in concentration and viscosity was observed only at 700 as well 1000 mOsm/kg H{sub 2}O but to a lesser extent. In summary, dialysis strongly enhanced the viscosity differences between the non-ionic monomeric and dimeric CAs. The administration of dimeric CAs leads to a strong increase in urine viscosity; this was not observed for

Assessment of renal function with 99Tcm-DTPA renal dynamic imaging in neonatal hydronephrosis

International Nuclear Information System (INIS)

Jiang Lixin; Guo Zongyuan; Wu Rongde; Yu Qihai; Liu Zhanfeng

2004-01-01

Objective: To assess the renal function in neonatal hydronephrosis with 99 Tc m -DTPA renal imaging. Methods: Eighteen unilateral hydronephrotic kidneys and 12 normal kidneys were studied by 99 Tc m -DTPA renal dynamic imaging , and glomerular filtration rate (GFR) quantitative analysis was also performed. Blood urea nitrogen (BUN), serum creatinine (SCr) and hemoglobin (Hb) were determined simultaneously and the correlations between GFR and each of these parameters were analyzed. Results: Positive correlation was discovered between GFR and Hb in neonates with moderate or severe hydronephrosis (r=0.414, 0.667, P 0.05). The renal function was decreased significantly in moderate and severe neonatal hydronephrosis (P 99 Tc m -DTPA renal dynamic imaging GFR is an ideal marker for estimating renal function in neonatal hydronephrosis; SCr could be a marker for renal damage especially in moderate and severe neonatal hydronephrosis; BUN could not be a marker for evaluating renal function in neonatal hydronephrosis. Neonates with hydronephrosis should be referred for surgical procedures as soon as possible in the early stage

Radiology of renal failure

International Nuclear Information System (INIS)

Griffiths, H.J.

1990-01-01

This book covers most aspects of imaging studies in patients with renal failure. The initial chapter provides basic information on contrast agents, intravenous urography, and imaging findings in the urinary tract disorders responsible for renal failure and in patients who have undergone transplantation. It illustrates common gastro-intestinal abnormalities seen on barium studies in patients with renal failure. It illustrates the cardiopulmonary complications of renal failure and offers advice for radiologic differentiation. It details different aspects of skeletal changes in renal failure, including a basic description of the pathophysiology of the changes; many excellent illustrations of classic bone changes, arthritis, avascular necrosis, and soft-tissue calcifications; and details of bone mineral analysis

Diagnostic imaging in pediatric renal inflammatory disease

International Nuclear Information System (INIS)

Sty, J.R.; Wells, R.G.; Schroeder, B.A.; Starshak, R.J.

1986-01-01

Some form of imaging procedure should be used to document the presence of infection of the upper urinary tract in troublesome cases in children. During the past several years, sonography, nuclear radiology, and computed tomography (CT) have had a significant influence on renal imaging. The purpose of this article is to reevaluate the noninvasive imaging procedures that can be used to diagnose pediatric renal inflammatory disease and to assess the relative value of each modality in the various types of renal infection. The authors will not discuss the radiologic evaluation of the child who has had a previous renal infection, in whom cortical scarring or reflux nephropathy is a possibility; these are different clinical problems and require different diagnostic evaluation

The usefulness of cardiofocal collimator in static renal imaging

International Nuclear Information System (INIS)

Evren, I.; Durak, H.; Degirmenci, B.; Derebek, E.; Oezbilek, E.; Capa, G.

2001-01-01

Static renal imaging is best performed using pinhole collimator. But this technique takes too much time and generally parallel hole collimators are preferred for static renal imaging in nuclear medicine departments. The purpose of this study was to investigate the usefulness of the cardio-focal collimator used for myocardial perfusion imaging in static renal scintigraphy

Evaluation of a liquid embolization agent (Onyx) for transcatheter embolization for renal vascular lesions

Energy Technology Data Exchange (ETDEWEB)

Rennert, Janine; Herold, T.; Schreyer, A.G.; Jung, E.M.; Mueller-Wille, R.; Zorger, N. [Inst. fuer Roentgendiagnostik, Klinikum der Univ. Regensburg (Germany); Banas, B.; Feuerbach, S. [Medizinische Klinik, Nephrologie, Univ. Regensburg (Germany); Lenhart, M. [Klinik fuer Diagnostische und Interventionelle Radiologie, Sozialstiftung Bamberg (Germany)

2009-10-15

Purpose: to evaluate the therapeutic outcome after endovascular treatment of renal vascular lesions using the liquid embolization agent, Onyx. Materials and methods: between 2004 and 2008 nine patients with renal vascular lesions were treated with transcatheter arterial embolization using Onyx. The renal vascular lesions consisted of 4 AV-fistulas, a pseudoaneurysm, bleeding from a single subsegmental artery, diffuse parenchymal bleeding after trauma, septic embolizations and multiple aneurysms in endocarditis. All patients underwent selective angiography of the renal artery. A dimethyl sulfoxide (DMSO)-compatible microcatheter was used and Onyx was injected. The technical and clinical success rate, examination time and procedure-related complications were documented. Results: the overall technical and clinical success rate was 100%. One patient had to be treated twice due to recurrent bleeding after an accidental puncture with a drainage catheter. No loss of viable renal tissue occurred in 4 cases. In 4 patients mild to moderate parenchyma loss was noted. In one patient having diffuse renal bleeding, occlusion of the main renal artery was performed. No procedure-related complications were noted. The mean examination time was 16.17 min when treating with Onyx alone and 60 min when using a combination of Onyx and coils. Within an average follow-up period of 21 months, no recurrent renal bleeding or recurrent AV-fistulas occurred. Conclusion: Onyx is an effective embolization agent for the treatment of renal vascular lesions. It allows controlled and quick application with low complication rates and a short examination time as a standalone agent or in combination with coils. (orig.)

MR imaging of renal transplant rejection

International Nuclear Information System (INIS)

Hanna, S.; Helenon, O.; Legendre, C.; Chichie, J.F.; Di Stefano, D.; Kreis, H.; Moreau, J.F.; Hopital Necker, 75 - Paris

1991-01-01

The results of 62 consecutive MR examinations were correlated with the subsequent clinical course and histologic results. Twenty-six cases of rejection showed a marked diminution of cortico-medullary differentiation (CMD). The renal parenchymal vascular pattern and visibility of renal sinus fat were not markedly altered in rejection and there was no difference between normal and rejected allograft shape. The ability of MR imaging to diagnose renal transplant rejection is only based on CMD, which, however, is non-specific. In 2 cases of severe rejection, T2 weighted images showed an abnormal signal intensity of the cortex due to renal infarction. Our preliminary results in 8 patients with Gd-DOTA injection showed 2 cases with necrosis seen as areas with absent contrast enhancement. This technique seems to be promising in the detection of perfusion defects. (orig.)

CT imaging spectrum of infiltrative renal diseases.

Science.gov (United States)

Ballard, David H; De Alba, Luis; Migliaro, Matias; Previgliano, Carlos H; Sangster, Guillermo P

2017-11-01

Most renal lesions replace the renal parenchyma as a focal space-occupying mass with borders distinguishing the mass from normal parenchyma. However, some renal lesions exhibit interstitial infiltration-a process that permeates the renal parenchyma by using the normal renal architecture for growth. These infiltrative lesions frequently show nonspecific patterns that lead to little or no contour deformity and have ill-defined borders on CT, making detection and diagnosis challenging. The purpose of this pictorial essay is to describe the CT imaging findings of various conditions that may manifest as infiltrative renal lesions.

Imaging diagnosis in various renal sinus lesions

International Nuclear Information System (INIS)

Yoon, Yeo Dong; Byun, Jae Young; Jee, Won Hee; Hwang, Tae Gon; Park, Sok Hee; Shinn, Kyung Sub; Kim, Seung Hyup; Kim, Myeong Jin

1997-01-01

The renal sinus extends from the perinephric space into the deep recess situatede on the tuated on the medial border of the kidney. Contained within the space are the pelvocalyceal system, fat and lymph nodes. Arteries, veins, lymphatic channels and nerves of the autonomic nervous system traverse the sinus, and various pathological conditions may occur in this area. These various sinusal lesions may present a similar imaging appearance, and diagnostic errors may frequently occur, especially if diagnosis is attempted without first clearly understanding the several possibilities. This pictorial essay demonstrates various renal sinus lesions and emphasizes the proper combination of multimodal imaging. For evaluation of the extent of the lesious, CT is the preferred imaging modality, since this best depicts the anatomy of the renal sinus. Using a proper combination of multimodal imaging, specific diagnosis was in most cases possible.=20

Imaging diagnosis in various renal sinus lesions

Energy Technology Data Exchange (ETDEWEB)

Yoon, Yeo Dong; Byun, Jae Young; Jee, Won Hee; Hwang, Tae Gon; Park, Sok Hee; Shinn, Kyung Sub [Catholic Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Seung Hyup [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Myeong Jin [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

1997-09-01

The renal sinus extends from the perinephric space into the deep recess situatede on the tuated on the medial border of the kidney. Contained within the space are the pelvocalyceal system, fat and lymph nodes. Arteries, veins, lymphatic channels and nerves of the autonomic nervous system traverse the sinus, and various pathological conditions may occur in this area. These various sinusal lesions may present a similar imaging appearance, and diagnostic errors may frequently occur, especially if diagnosis is attempted without first clearly understanding the several possibilities. This pictorial essay demonstrates various renal sinus lesions and emphasizes the proper combination of multimodal imaging. For evaluation of the extent of the lesious, CT is the preferred imaging modality, since this best depicts the anatomy of the renal sinus. Using a proper combination of multimodal imaging, specific diagnosis was in most cases possible.=20.

Magnetic resonance imaging of large chromophobe renal cell carcinomas

International Nuclear Information System (INIS)

Sasaguri, Kohei; Irie, Hiroyuki; Kamochi, Noriyuki; Nakazono, Takahiko; Yamaguchi, Ken; Uozumi, Jiro; Kudo, Sho

2010-01-01

The objective of this study was to clarify the magnetic resonance imaging (MRI) findings of large chromophobe renal cell carcinomas. Five patients diagnosed pathologically with chromophobe renal cell carcinoma are included. MRI findings were retrospectively evaluated for the tumor contour, uniformity and hypointensity of the rim of the tumor on T2-weighted images, ''micro-scopic fat'', enhancement degree and pattern on dynamic study, and necrosis in the tumor, among other findings. The tumor size ranged from 4.8 to 13.7 cm (mean 7.9 cm). The tumor contour was well defined in four patients. All but one tumor showed a hypointensity rim, and all tumors had a heterogeneous appearance on T2-weighted images. ''Microscopic fat'' was detected in one case. All tumors demonstrated low enhancement compared to that of the renal cortex. All tumors showed heterogeneous enhancement on postcontrast images. Necrosis was seen in four. Hemorrhage and renal vein thrombosis was seen in one. Chromophobe renal cell carcinomas of large size tend to have a heterogeneous appearance on post-contrast and T2-weighted images, a well-defined tumor contour with a hypointensity rim on T2-wighted images, and lower enhancement than that of the renal cortex. Tumor necrosis is easily apparent, and ''microscopic fat'' may be observed. (author)

Changes of renal blood flow after ESWL: Assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index

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Abd Ellah, Mohamed, E-mail: dr_m_hamdy2006@hotmail.co [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Kremser, Christian, E-mail: christian.kremser@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pallwein, Leo, E-mail: leo.pallwein-prettner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Aigner, Friedrich, E-mail: friedrich.Aigner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Schocke, Michael, E-mail: michael.schocke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Peschel, Reinhard, E-mail: reinhard.peschel@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pedross, Florian, E-mail: florian.pedross@i-med.ac.a [Innsbruck Medical University, Medical Statistics Dept., Anich St. 35, 6020 Innsbruck (Austria); Pinggera, Germar-Michael, E-mail: germar.pinggera@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Wolf, Christian, E-mail: christian.wolf@bkh-reutte.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Alsharkawy, Mostafa A.M., E-mail: drmostafamri@yahoo.co [Assiut University, Radiology Dept., Assiut (Egypt); Jaschke, Werner, E-mail: werner.jaschke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Frauscher, Ferdinand, E-mail: ferdinand.frauscher@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria)

2010-10-15

The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12 h before and 12 h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p < 0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p < 0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

Clinical aspects of dynamic renal imaging with radiochlormerodrin, /sup 99m/Tc pertechnetate, and 131I orthoiodohippurate

International Nuclear Information System (INIS)

Freeman, L.M.

1972-01-01

Three major radionuclide imaging studies are available for assistance in the diagnostic evaluation of renal disorders. Morphology and functional tubular mass may be depicted with mercury-197 chlormerodrin or one of the new technetium-99m renal imaging agents (iron ascorbate or chelate). Excretion data as well as visualization in severely diseased kidneys are obtained with iodine-131 ortho-iodohippurate (hippuran). Vascular patterns of the kidney and lesions within it are obtained using a small volume, high activity bolus of a short-lived radiopharmaceutical, such as technetium-99m pertechnetate. These procedures are to be complementary and not competitive with radiographic studies such as urography, nephrotomography, and selective renal angiography. Each clinical situation must be evaluated individually so that the optimal study or combination of studies is utilized to help supply whatever information is sought. Familiarity with the available imaging techniques and their limitations will help one approach such situations more intelligently. (U.S.)

Changes of renal blood flow after ESWL: assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index.

Science.gov (United States)

Abd Ellah, Mohamed; Kremser, Christian; Pallwein, Leo; Aigner, Friedrich; Schocke, Michael; Peschel, Reinhard; Pedross, Florian; Pinggera, Germar-Michael; Wolf, Christian; Alsharkawy, Mostafa A M; Jaschke, Werner; Frauscher, Ferdinand

2010-10-01

The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12h before and 12h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (pESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Studies on renal function in the elderly by analysis of radioisotope renal images

International Nuclear Information System (INIS)

Ohishi, Yukihiko

1990-01-01

This study was carried out to evaluate the potential of radionuclide renal imagings for examining senile renal function in a total of 178 subjects. Single photon emission computed tomography (SPECT) with Tc-99m-dimercaptosuccinic acid (Tc-DMSA) was performed in the senile group (60-87 years) and in the adult group to determine renal uptake rate of Tc-DMSA and renal volume. Renography studies with I-131 hippuran (n=100) and Tc-99m diethylentriaminepentaacetic acid (Tc-DTPA) (n=20) were also performed for deconvolution analysis. Mean transit time (MTT) was mainly assessed as one of the retention function parameters. Blood residual rates (R15%) at fifteen minutes were also investigated. Renal volume and renal uptake rate for healthy persons were significantly lower in the senile group (n=17) than the adult group (n=24), 205±50 ml vs 225±27 ml; and 22±5% vs 26±2%. I-133 hippuran renography in healthy persons (n=35) showed a tendency toward higher MTT values with aging; however, there was no significant difference among age groups. R15%, obtained by I-133 hippuran renograms, tended to be higher with aging in age groups of persons younger than 70 years. A decreased number of effective nephrons was considered to result in higher R15% values even when aged persons had normal MTT values of I-131 hippuran. Split renal function values for healthy persons, calculated by the two radionuclide imagings, were lower in the senile group than the adult group, suggesting the usefulness of radionuclide imagings in renal function examination. (N.K.)

Clinical value of renal images obtained incidentally to bone scintigraphy

International Nuclear Information System (INIS)

Ohishi, Y.; Machida, T.; Miki, M.; Kido, A.; Tanaka, A.

1982-01-01

Various studies were made on 400 renal (including 325 clinical cases) observed during whole-body bone scintigraphy using 99mTc-MDP. Asymmetrical renal images in bone scintigrams were obtained from 40% of the urologic patients and 7.5% of the nonurologic patients. Out of the asymmetrical images of the urologic patients, 50% provided nonvisualized kidneys and 35% showed unilateral renal high accumulation. It can be said from the above that renal images incidentally obtained during whole-body bone scintigraphy should not be overlooked

Renal function study using I-123-OIH

International Nuclear Information System (INIS)

Yamashita, Masato; Osaka, Yosio; Aikawa, Ichiro

1989-01-01

Twenty-eight renal function studies were performed in 24 patients with renal diseases with I-123 orthoiodohippurate (I-123 OIH). Neither side effects nor abnormal laboratory values were attributable to I-123 OIH. Imaging with Tc-99m diethylene triaminepentaacetic acid (DTPA) was also performed in 20 patients within one week after I-123 imaging. Findings with I-123 OIH and Tc-99m DTPA were similar in all except for two patients. The two patients had received cadaveric renal transplantation. One patient presented with acute tubular necrosis and the other with chronic renal rejection. In these patients, I-123 imaging showed vascular stricture and Tc-99m imaging showed a decreased glomerular function. Because I-123 OIH and Tc-99m DTPA had different pharmacodynamics, combined use of the two imaging agents may be useful in evaluating renal rejection or acute tubular necrosis. (N.K.)

Magnetic resonance imaging (MRI) of the renal sinus.

Science.gov (United States)

Krishna, Satheesh; Schieda, Nicola; Flood, Trevor A; Shanbhogue, Alampady Krishna; Ramanathan, Subramaniyan; Siegelman, Evan

2018-04-09

This article presents methods to improve MR imaging approach of disorders of the renal sinus which are relatively uncommon and can be technically challenging. Multi-planar Single-shot T2-weighted (T2W) Fast Spin-Echo sequences are recommended to optimally assess anatomic relations of disease. Multi-planar 3D-T1W Gradient Recalled Echo imaging before and after Gadolinium administration depicts the presence and type of enhancement and relation to arterial, venous, and collecting system structures. To improve urographic phase MRI, concentrated Gadolinium in the collecting systems should be diluted. Diffusion-Weighted Imaging (DWI) should be performed before Gadolinium administration to minimize T2* effects. Renal sinus cysts are common but can occasionally be confused for dilated collecting system or calyceal diverticula, with the latter communicating with the collecting system and filling on urographic phase imaging. Vascular lesions (e.g., aneurysm, fistulas) may mimic cystic (or solid) lesions on non-enhanced MRI but can be suspected by noting similar signal intensity to the blood pool and diagnosis can be confirmed with MR angiogram/venogram. Multilocular cystic nephroma commonly extends to the renal sinus, however, to date are indistinguishable from cystic renal cell carcinoma (RCC). Solid hilar tumors are most commonly RCC and urothelial cell carcinoma (UCC). Hilar RCC are heterogeneous, hypervascular with epicenter in the renal cortex compared to UCC which are centered in the collecting system, homogeneously hypovascular, and show profound restricted diffusion. Diagnosis of renal sinus invasion in RCC is critically important as it is the most common imaging cause of pre-operative under-staging of disease. Fat is a normal component of the renal sinus; however, amount of sinus fat correlates with cardiovascular disease and is also seen in lipomatosis. Fat-containing hilar lesions include lipomas, angiomyolipomas, and less commonly other tumors which engulf sinus

Biological evaluation of 99mTC cis-Pt iminoacetic acid complexes as tumour imaging agents

International Nuclear Information System (INIS)

Awaluddin, A.; Jacobs, J.J.; Bourne, D.W.; Maddalena, D.J.; Wilson, J.G.; Boyd, D.W.

1987-01-01

The biodistributions of three new 99m Tc labelled cis-platinum bifunctional tumour imaging agents were examined in mice bearing a certain type of sarcoma between 15 minutes and 24 hours post injection. The three complexes were excreted primarily via the renal pathway into the urine but at quite different rates. All complexes had some affinity for the tumour, but complexes III had the greatest, with tumour to blood and tumour to muscle rates at 24 hours in excess of 10:1 and 18:1. Biodistribution results were calculated using Tiscon Program. Suggesting that the three complexes may be useful as tumour imaging agents. (M.E.L.) [es

In vivo MR perfusion imaging of renal artery stenosis

International Nuclear Information System (INIS)

Powers, T.; Lorenz, C.H.; Bain, R.; Holburn, G.; Price, R.R.

1989-01-01

Various techniques have been developed for noninvasive evaluation of renal blood flow. More important in the assessment of potential renal ischemia may be actual perfusion of the nephron mass. MR pulse sequences have been devised that allow perfusion imaging (PI) in a dog model of renal artery stenosis. Unilateral renal artery stenosis was created in mongrel dogs and quantitation of renal blood flow was obtained with radioactive microspheres. Perfusion imaging was performed on a 1.5-T system to obtain the apparent diffusion coefficient. During initial studies, it was found that the usual gradient factor used in brain PI was too high for renal studies; a factor of < 50 was found to be optimal. Additionally, respiratory gating with acquisition at end expiration was necessary to prevent renal motion. Recent studies have shown that PI reflects the asymmetry of flow in this model

Radionuclide dynamic renal imaging for renal function study in patients with NIDDM

International Nuclear Information System (INIS)

Yang Ruiping; Qu Wanying; Gao Wenping

1996-01-01

Radionuclide dynamic renal imaging was performed to gain evidence for further treatment and evaluation of prognosis in patients with non-insulin-dependent diabetes mellitus (NIDDM). 99m Tc-DTPA dynamic renal imaging was performed in 137 NIDDM patients and 44 normal controls (NC). Glomerular filtration rate (GFR) and renogram were acquired simultaneously. Renal tubular secretion function was measured with 99m Tc-EC in 126 of the 137 diabetics and 17 NC. GFR decreased in all patients with different duration of NIDDM and the difference was remarkably significance in comparison with NC (t = 7.17∼13.73, P 99m Tc-EC. This study showed that the function of glomerular filtration and tubular secretion were both damaged in all diabetics. Their magnitude was aggravated with the prolongation of the course of disease

99mTc-MAG3 as a single modality investigative agent for evaluation of renal diseases in children

International Nuclear Information System (INIS)

Bal, C.S.; Padhy, A.K.; Handa, R.; Bajpai, M.

1998-01-01

Optimal assessment of a child with congenital or acquired renal disease consists of quantitation of renal cortical and excretory function. This at present is routinely done with a 99m Tc-GHA/DMSA and 99m Tc-DTPA scans, respectively. This study was undertaken to assess if 99m Tc-MAG 3 can be utilized as a single modality investigation to provide adequate information about these functions. Sixteen children attending the pediatric urology clinic at All India Institute of Medical Sciences (AIIMS), New Delhi with a variety of renal disorders like posterior urethral valves, hydronephrosis vesicoureteral reflux etc. were included in the study. All the cases were subjected to 99m Tc-MAG 3 , 99m -DTPA and 99m Tc-GHA scans on separate occasions, but as close to one other as possible. The time required for the completion of a 99m Tc-MAG 3 renogram was only twenty minutes. 99m Tc-MAG 3 produced significantly better scintigraphic images of the kidneys and ureters, enabling differentiation between pelviureteric and vesicoureteric junction obstruction. Because of the abundance of photons in 99m Tc-MAG 3 , antegrade ureteric visualization was possible in nine renal units with active ureteric peristalsis appreciable in three renal units. Being a renal tubular agent, it gave a better assessment of renal health of the involved renal unit as compared to 99m Tc-DTPA, a glomerular filtration agent. Detection of renal scars as compared to 99m Tc-GHA showed a sensitivity of 69% and specificity of 93%. Amount of radioactivity required was consistently less than either GHA or DTPA scans. Use of 99m Tc-MAG 3 for renal functional evaluation may result in decreased radiation exposure and optional gamma camera utilization. Besides it is more cost-effective and may reduce the number of investigations that a child needs to be subjected to. It may be of immense value in a country like India where patients have to travel long distances to avail such investigations in a few, overworked nuclear

Renal trauma imaging: Diagnosis and management. A pictorial review

International Nuclear Information System (INIS)

Szmigielski, Wojciech; Kumar, Rajendra; Al Hilli, Shatha; Ismail, Mostafa

2013-01-01

The purpose of this review is to illustrate and discuss the spectrum of imaging findings, particularly computed tomography (CT), of blunt and penetrating renal trauma, based on our own materials, according to the American Association for Surgery of Trauma (AAST) renal injury grading scale. The article also indicates the conditions in which interventional radiology procedures can be applied for the management of renal trauma. Cases for this pictorial review were selected from the imaging material collected at the Radiology Department of Hamad Medical Corporation during a 14-year period from 1999 to 2012. The material includes 176 cases (164 males and 12 females) with confirmed blunt or penetrating renal trauma. Following abdominal trauma, all patients had a CT examination performed on admission to the hospital and/or during hospitalization. The most representative and illustrative cases of renal trauma were reviewed according to CT findings and were categorized according to the AAST grading system. The review describes a spectrum of imaging presentations with special emphasis on the 5 grades of renal injury on a CT according to the AAST scale. The most representative cases were illustrated and discussed with indications of possible interventional radiology treatment. Two groups of patients not included in the AAST grading system were presented separately: those with preexisting renal abnormalities and those with sustained iatrogenic renal injury. Proper application of renal trauma grading scale is essential for selecting the patients for conservative treatment, surgery or interventional radiology procedure

Blood oxygenation level dependent (BOLD). Renal imaging. Concepts and applications; Blood Oxygenation Level Dependent (BOLD). Bildgebung der Nieren. Konzepte und Anwendungen

Energy Technology Data Exchange (ETDEWEB)

Nissen, Johanna C.; Haneder, Stefan; Schoenberg, Stefan O.; Michaely, Henrik J. [Heidelberg Univ. Medizinische Fakultaet Mannheim (Germany). Inst. fuer Klinische Radiologie und Nuklearmedizin; Mie, Moritz B.; Zoellner, Frank G. [Heidelberg Univ. Medizinische Fakultaet Mannheim (DE). Inst. fuer Computerunterstuetzte Klinische Medizin (CKM)

2010-07-01

Many renal diseases as well as several pharmacons cause a change in renal blood flow and/or renal oxygenation. The blood oxygenation level dependent (BOLD) imaging takes advantage of local field inhomogeneities and is based on a T2{sup *}-weighted sequence. BOLD is a non-invasive method allowing an estimation of the renal, particularly the medullary oxygenation, and an indirect measurement of blood flow without administration of contrast agents. Thus, effects of different drugs on the kidney and various renal diseases can be controlled and observed. This work will provide an overview of the studies carried out so far and identify ways how BOLD can be used in clinical studies. (orig.)

Gadolinium-enhanced turbo FLASH MR imaging of renal perfusion and excretion

International Nuclear Information System (INIS)

Watanabe, A.; Teresi, L.M.; Herbst, M.; O'Sullivan, R.M.; Lee, R.; Smith, C.; Renner, J.; Rappaport, A.; Bradley, W.G. Jr.

1990-01-01

This paper describes a novel approach to MR imaging of renal perfusion and excretion using gadolinium-enhanced, T1-weighted TURBP, fast low-angle shot (FLASH) imaging. Five normal volunteers and four patients were studied on a 1.5-T imaging system. Time-intensity curves of the appearance of gadolinium in each kidney and the bladder were then generated. In normal volunteers, marked first-pass enhancement of renal cortex followed by renal pyramids and collecting systems could be demonstrated on the first-pass gadolinium images. Delayed images showed hyperintense gadolinium within the bladder

A clinical study and the diagnosis in magnetic resonance imaging of renal scarring

International Nuclear Information System (INIS)

Tsugaya, Masayuki; Hirao, Noriaki; Ohtaguro, Kazuo; Kato, Jiro.

1989-01-01

Twenty-nine kidneys of seventeen patients (nine boys and eight girls) with vesicoureteral reflux and repeated urinary tract infection were studied by magnetic resonance imaging for diagnosis of renal scarring and correlation between clinical data and the degree renal scarring. Renal scarring is classified into three types according to findings in magnetic resonance imaging. The degree of renal scarring are classified into five grades according to traditional grading of intravenous pyelogram. If a fine deformity of calyx is shown on intravenous pyelogram, magnetic resonance imaging demonstrates renal scarring. Magnetic resonance imaging without irradiation is exceedingly valuable for the diagnosis of renal scarring. The appearances of magnetic resonance imaging were supported by X-ray computed tomography. There is a substantial correlation between serum creatinine and the grades of renal scarring by magnetic resonance imaging. There is a substantial correlation between fever attacks and the grade of renal scarring, and there is a significant reverse correlation between the age of the onset of upper urinary tract infection and the grade of renal scarring. It is suggested that upper urinary tract infection is the most significant factor in scar formation. (author)

Chronological alterations of diagnostic imaging of renal cell carcinoma

International Nuclear Information System (INIS)

Arima, Kiminobu; Sugimura, Yoshiki; Yanagawa, Makoto; Tochigi, Hiromi; Kawamura, Juichi

1994-01-01

A review of 156 cases of renal cell carcinoma diagnosed during a 20-year period demonstrated the changes of initial signs/symptoms and imaging modalities for detection and definition. According to the imaging modality used for diagnosing renal cell carcinoma, clinical pictures were chronologically examined over 4 periods: 1973 to 1979 (before CT era), 1980 to 1984 (early CT era), 1985 to 1987 (CT era) and 1988 to 1992 (CT/MRI era). With regards to initial signs or symptoms, the proportion of classical trials has gradually decreased, while that of tumors noted incidentally has increased. As for imaging modalities for detection, the proportion of IVP has gradually decreased and that of CT and US has increased over the periods. With regard to imaging modalities for definition, the proportion of angiography has decreased and that of CT has increased. From chronological changes in clinical pictures and imaging modalities, we suggested a decision tree of imaging modalities for detection and definition of renal cell carcinoma. (author)

Diffusion-weighted imaging versus contrast-enhanced MR imaging for the differentiation of renal oncocytomas and chromophobe renal cell carcinomas

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Zhong, Yan; Wang, Haiyi; Shen, Yanguang; Ma, Lu; Pan, Jingjing; Ye, Huiyi [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Guo, Aitao [Chinese PLA General Hospital, Department of Pathology, Beijing (China); Wang, Jia [Handan Central Hosptical, Department of Radiology, Hebei (China); Kang, Suhai [264 Hospital of PLA, X-ray Department, Taiyuan (China)

2017-12-15

To compare the performance of diffusion-weighted imaging (DWI) with that of contrast-enhanced MRI in differentiating renal oncocytomas from chromophobe renal cell carcinomas (RCCs). We recruited 48 patients with histopathologically confirmed renal oncocytomas (n=16) and chromophobe RCCs (n=32). All patients underwent preoperative DWI and contrast-enhanced MRI. Apparent diffusion coefficient (ADC) and signal intensity were measured in each patient. ADC ratio and percentage of signal intensity change were calculated. Mean ADC values for renal oncocytomas were significantly higher than those for chromophobe RCCs (1.59±0.21 vs. 1.09±0.29 x 10{sup -3} mm{sup 2}/s, p < 0.001). Area under the ROC curve, sensitivity and specificity were 0.931, 87.5% and 84.4%, respectively, for ADC measurement of DW imaging; 0.825, 87.5% and 75%, respectively, for enhancement ratio (p > 0.05). Adding ADC values to the enhancement ratios in the ROC, analysis to differentiate renal oncocytoma from chromophobe RCCs increased specificity from 75 to 87.5% at 87.5% sensitivity without significantly increasing the AUC (0.930). Both DWI and contrast-enhanced MRI may assist in differentiating renal oncocytomas from chromophobe RCCs, with DWI showing higher diagnostic value. The combination of the two parameters could potentially provide better performance in distinguishing these two tumours. (orig.)

Effect of indomethacin and salt depletion on renal proton MR imaging

International Nuclear Information System (INIS)

Heyman, S.N.; Mammen, M.

1991-01-01

Blockade of the synthesis of vasodilating prostaglandins with non-steroidal anti-inflammatory drugs (NSAID) renders the renal medulla susceptible to hypoxic injury with reduced renal function, especially in clinical conditions characterized by volume depletion. Alterations in renal hemodynamics and urine production may effect renal MR imaging under these circumstances. We injected salt-depleted and control rats undergoing proton MR imaging with indomethacin 10 mg/kg. Indomethacin abolished the cortico-medullary T2-gradient and markedly diminished the overall renal signal in salt-depleted rats only. These changes, which progressed over a period of 40 min after indomethacin was injected, probably result from renal oligemia and decreased urine production, with an associated decrease in T2-values. We suggest that a history of consumption of non-steroidal anti-inflammatory drugs should be obtained and taken into account in the evaluation of renal proton MR imaging, especially in the presence of salt and volume depletion. (orig.)

Adrenal imaging agents

International Nuclear Information System (INIS)

Davis, M.A.; Hanson, R.N.; Holman, B.L.

1980-01-01

The goals of this proposal are the development of selenium-containing analogs of the aromatic amino acids as imaging agents for the pancreas and of the adrenal cortex enzyme inhibitors as imaging agents for adrenal pathology. The objects for this year include (a) the synthesis of methylseleno derivatives of phenylalanine and tryptophan, and (b) the preparation and evaluation of radiolabeled iodobenzoyl derivatives of the selenazole and thiazole analogs of metyrapone and SU-9055

Comparisons of clinic effects between DTPA renal dynamic imaging and B-ultrasound examination in diagnosis and treatment of infantile hydronephrosis

International Nuclear Information System (INIS)

Zhang Lixia; Qi Lili; Shen Wenhua; Luo Yunxiao

2011-01-01

Objective: To study the clinic value of DTPA renal dynamic imaging in the functional evaluation of infantile hydronephrosis and clarify its application value, and lay the foundation for DTPA renal dynamic imaging in diagnosis and treatment of infantile hydronephrosis. Methods: 70 infants with hydronephrosis in our hospital whose mean age was (2.32±2.1) years (rang from 37 d to 6 years) were selected. There were 56 males and 14 females. 18 normal infants with mean age (2.66±2.01) years (rang from 41 d to 6 years, 15 males and 3 females) were selected as control group during the same period. Technetium-99m-labelled DTPA ( 99m Tc-DTPA) was taken as agent, and the dose of 99m Tc was 18.5 MBq per infant. GE Infinia SPECT was used as imaging equipment. The time-activity curve was generated in the imaging system automatically. The glomerular filtration rate (GFR) was detected by DTPA renal dynamic imaging through drawing the region of interest (ROI). Results: 83 kidneys were suffered from hydronephrosis diagnosed by B-ultrasound among 70 infant patients, while 104 abnormal kidneys were diagnosed by renal dynamic imaging. The detection rate of renal dysfunction by renal dynamic imaging was higher than that of B-ultrasound (t=7.751, P=0.005). Among 83 kidneys suffered from hydronephrosis diagnosed by B-ultrasound, the continued rising type was 56 cases (67.47% ); the parabolic type was cases (7.23% ); the high linear extension type was 14 cases (16.87% ); and the low linear extension type was 7 cases (8.43% ). The GFR value of linear extension type was lower than normal control group, the difference was significant (P<0.05), and the another three types had no significant differences compared with control group. Conclusion: For infantile hydronephrosis, DTPA renal dynamic imaging can observe not only the abnormal morphology of kidney, but also the function of split kidney; and it can provide objective basis for diagnosis and treatment of infantile hydronephrosis. (authors)

Detection of renal arteries with fast spin-echo magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Tello, R.; Mitchell, P.J.; Witte, D.J.; Thomson, K.R. [University of Melbourne, Parkville, VIC (Australia). Department of Radiology

1998-08-01

With the increasing use of non-invasive imaging with MR and volumetric CT to evaluate renal arteries, the ability to accurately detect the number and state of native renal arteries becomes critical if conventional angiography is to be supplanted in these settings. The present study evaluated the utility of a fast spin-echo (FSE) T2-weighted sequence to detect the number and course of renal arteries and their ostia compared to conventional angiography. Ten patients underwent conventional catheter angiography either for renal artery stenosis evaluation or as potential renal donors. Each patient then had an MR study of the renal arteries and kidneys with FSE MR (TR = 4000 ms, TE = 102 ms, eight- echo train length, 5-mm-thick interleaved 128 phase encodes, superior and inferior saturation pulses, number of excitations (NEX) = 4, on a 1.5-T superconducting magnet). Images were reviewed by two `blinded` radiologists and renal arteries were counted and their ostia were evaluated. Results were compared with angiography and inter- and intra-observer statistics were calculated. All 10 patients underwent MR successfully, nine for renal artery stenosis (RAS) evaluation and one was a renal donor. A total of 24 renal arteries were imaged in 19 kidneys. Fast spin-echo MR is 95% accurate (95%CI: 88-100%) in detection of renal arteries, with no statistical difference between FSE MR and catheter angiography (McNemar P = 0.0). Inter- and intra-observer statistics demonstrate good-to-excellent agreement in renal artery detection (kappa: 0.63-0.90). In one case of RAS evaluation an incidental adrenal mass was detected as the aetiology of the patient`s hypertension. Fast spin-echo MR can be a useful adjunct as part of the imaging for renal arteries with MRI. Copyright (1998) Blackwell Science Pty Ltd 16 refs., 1 fig.

Detection of renal arteries with fast spin-echo magnetic resonance imaging

International Nuclear Information System (INIS)

Tello, R.; Mitchell, P.J.; Witte, D.J.; Thomson, K.R.

1998-01-01

With the increasing use of non-invasive imaging with MR and volumetric CT to evaluate renal arteries, the ability to accurately detect the number and state of native renal arteries becomes critical if conventional angiography is to be supplanted in these settings. The present study evaluated the utility of a fast spin-echo (FSE) T2-weighted sequence to detect the number and course of renal arteries and their ostia compared to conventional angiography. Ten patients underwent conventional catheter angiography either for renal artery stenosis evaluation or as potential renal donors. Each patient then had an MR study of the renal arteries and kidneys with FSE MR (TR = 4000 ms, TE = 102 ms, eight- echo train length, 5-mm-thick interleaved 128 phase encodes, superior and inferior saturation pulses, number of excitations (NEX) = 4, on a 1.5-T superconducting magnet. Images were reviewed by two 'blinded' radiologists and renal arteries were counted and their ostia were evaluated. Results were compared with angiography and inter- and intra-observer statistics were calculated. All 10 patients underwent MR successfully, nine for renal artery stenosis (RAS) evaluation and one was a renal donor. A total of 24 renal arteries were imaged in 19 kidneys. Fast spin-echo MR is 95% accurate (95%CI: 88-100%) in detection of renal arteries, with no statistical difference between FSE MR and catheter angiography (McNemar P = 0.0). Inter- and intra-observer statistics demonstrate good-to-excellent agreement in renal artery detection (kappa: 0.63-0.90). In one case of RAS evaluation an incidental adrenal mass was detected as the aetiology of the patient's hypertension. Fast spin-echo MR can be a useful adjunct as part of the imaging for renal arteries with MRI. Copyright (1998) Blackwell Science Pty Ltd

An analysis of 'obstructive type' renography cases in 99mTc-DTPA renal dynamic imaging

International Nuclear Information System (INIS)

Wang Xinhui

1991-01-01

99m Tc-DTPA renal dynamic imaging and computed renography were performed in 61 cases. Renal blood perfusion imaging was also performed in some cases. Renography curves, which did not decrease in 20 min on all 61 cases (90 kidneys), are analysed in combination with renal dynamic imaging and renal perfusion imaging. 11 cases (12 kidneys) are only obstructive. 24 cases (32 kidneys) are obstructive and renal function impaired. Other 26 cases (46 kidneys) are renal function impaired or blood perfusion insufficient, but are not obstructive. The result demonstrated that the obstructive type renography may be obstructive or may be renal function impaired or blood supply insufficient. An analysis of renography in combination with renal dynamic imaging and blood perfusion imaging is more accurate than renography alone

The fabrication of novel nanobubble ultrasound contrast agent for potential tumor imaging

Energy Technology Data Exchange (ETDEWEB)

Xing Zhanwen; Ke Hengte; Yue Xiuli; Dai Zhifei [Nanobiotechnology Division, State Key Laboratory of Urban Water Resources and Environment, School of Sciences, Harbin Institute of Technology, Harbin 150080 (China); Wang Jinrui; Zhao Bo [Department of Ultrasonography, Peking University Third Hospital, Beijing 100083 (China); Liu Jibin, E-mail: zhifei.dai@hit.edu.cn, E-mail: ji-bin.liu@jefferson.edu [Ultrasound Research and Education Institute, Thomas Jefferson University, Philadelphia, PA 19107 (United States)

2010-04-09

Novel biocompatible nanobubbles were fabricated by ultrasonication of a mixture of Span 60 and polyoxyethylene 40 stearate (PEG40S) followed by differential centrifugation to isolate the relevant subpopulation from the parent suspensions. Particle sizing analysis and optical microscopy inspection indicated that the freshly generated micro/nanobubble suspension was polydisperse and the size distribution was bimodal with large amounts of nanobubbles. To develop a nano-sized contrast agent that is small enough to leak through tumor pores, a fractionation to extract smaller bubbles by variation in the time of centrifugation at 20g (relative centrifuge field, RCF) was suggested. The results showed that the population of nanobubbles with a precisely controlled mean diameter could be sorted from the initial polydisperse suspensions to meet the specified requirements. The isolated bubbles were stable over two weeks under the protection of perfluoropropane gas. The acoustic behavior of the nano-sized contrast agent was evaluated using power Doppler imaging in a normal rabbit model. An excellent power Doppler enhancement was found in vivo renal imaging after intravenous injection of the obtained nanobubbles. Given the broad spectrum of potential clinical applications, the nano-sized contrast agent may provide a versatile adjunct for ultrasonic imaging enhancement and/or treatment of tumors.

The fabrication of novel nanobubble ultrasound contrast agent for potential tumor imaging

International Nuclear Information System (INIS)

Xing Zhanwen; Ke Hengte; Yue Xiuli; Dai Zhifei; Wang Jinrui; Zhao Bo; Liu Jibin

2010-01-01

Novel biocompatible nanobubbles were fabricated by ultrasonication of a mixture of Span 60 and polyoxyethylene 40 stearate (PEG40S) followed by differential centrifugation to isolate the relevant subpopulation from the parent suspensions. Particle sizing analysis and optical microscopy inspection indicated that the freshly generated micro/nanobubble suspension was polydisperse and the size distribution was bimodal with large amounts of nanobubbles. To develop a nano-sized contrast agent that is small enough to leak through tumor pores, a fractionation to extract smaller bubbles by variation in the time of centrifugation at 20g (relative centrifuge field, RCF) was suggested. The results showed that the population of nanobubbles with a precisely controlled mean diameter could be sorted from the initial polydisperse suspensions to meet the specified requirements. The isolated bubbles were stable over two weeks under the protection of perfluoropropane gas. The acoustic behavior of the nano-sized contrast agent was evaluated using power Doppler imaging in a normal rabbit model. An excellent power Doppler enhancement was found in vivo renal imaging after intravenous injection of the obtained nanobubbles. Given the broad spectrum of potential clinical applications, the nano-sized contrast agent may provide a versatile adjunct for ultrasonic imaging enhancement and/or treatment of tumors.

The fabrication of novel nanobubble ultrasound contrast agent for potential tumor imaging

Science.gov (United States)

Xing, Zhanwen; Wang, Jinrui; Ke, Hengte; Zhao, Bo; Yue, Xiuli; Dai, Zhifei; Liu, Jibin

2010-04-01

Novel biocompatible nanobubbles were fabricated by ultrasonication of a mixture of Span 60 and polyoxyethylene 40 stearate (PEG40S) followed by differential centrifugation to isolate the relevant subpopulation from the parent suspensions. Particle sizing analysis and optical microscopy inspection indicated that the freshly generated micro/nanobubble suspension was polydisperse and the size distribution was bimodal with large amounts of nanobubbles. To develop a nano-sized contrast agent that is small enough to leak through tumor pores, a fractionation to extract smaller bubbles by variation in the time of centrifugation at 20g (relative centrifuge field, RCF) was suggested. The results showed that the population of nanobubbles with a precisely controlled mean diameter could be sorted from the initial polydisperse suspensions to meet the specified requirements. The isolated bubbles were stable over two weeks under the protection of perfluoropropane gas. The acoustic behavior of the nano-sized contrast agent was evaluated using power Doppler imaging in a normal rabbit model. An excellent power Doppler enhancement was found in vivo renal imaging after intravenous injection of the obtained nanobubbles. Given the broad spectrum of potential clinical applications, the nano-sized contrast agent may provide a versatile adjunct for ultrasonic imaging enhancement and/or treatment of tumors.

Complications from the use of intravenous gadolinium-based contrast agents for magnetic resonance imaging

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Elias Junior, Jorge; Santos, Antonio Carlos dos; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Koenigkam-Santos, Marcel [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Centro de Ciencias das Imagens e Fisica Medica]. E-mail: jejunior@fmrp.usp.br

2008-07-15

Gadolinium-based contrast agents are much safer than the iodinated ones; however complications may occur and should be recognized for appropriate orientation and management. The total incidence of adverse reactions to contrast agents in magnetic resonance imaging ranges between 2% and 4%. Cases of severe acute reactions to gadolinium, such as laryngospasm and anaphylactic shock, are rare. Chronic complications secondary to the use of gadolinium also can occur and, recently an association between its use and a rare dermatologic disease occurring in patients with renal failure has been reported. Nephrogenic systemic fibrosis was the subject of an official health notification issued by the American Food and Drug Administration. This progressive disease is characterized by hardened skin with fibrotic nodules and plaques which may involve other parts of the body. Patients who have been affected by this disorder presented chronic renal failure, with metabolic acidosis and had been submitted to magnetic resonance angiography, probably involving exposure to large amounts of intravenous paramagnetic contrast. This review is aimed at presenting a succinct description of the gadolinium-based contrast agent types, possible secondary complications, their preventive measures and management. (author)

Arterial spin labeling blood flow magnetic resonance imaging for evaluation of renal injury.

Science.gov (United States)

Liu, Yupin P; Song, Rui; Liang, Chang hong; Chen, Xin; Liu, Bo

2012-08-15

A multitude of evidence suggests that iodinated contrast material causes nephrotoxicity; however, there have been no previous studies that use arterial spin labeling (ASL) blood flow functional magnetic resonance imaging (fMRI) to investigate the alterations in effective renal plasma flow between normointensive and hypertensive rats following injection of contrast media. We hypothesized that FAIR-SSFSE arterial spin labeling MRI may enable noninvasive and quantitative assessment of regional renal blood flow abnormalities and correlate with disease severity as assessed by histological methods. Renal blood flow (RBF) values of the cortex and medulla of rat kidneys were obtained from ASL images postprocessed at ADW4.3 workstation 0.3, 24, 48, and 72 h before and after injection of iodinated contrast media (6 ml/kg). The H&E method for morphometric measurements was used to confirm the MRI findings. The RBF values of the outer medulla were lower than those of the cortex and the inner medulla as reported previously. Iodinated contrast media treatment resulted in decreases in RBF in the outer medulla and cortex in spontaneously hypertensive rats (SHR), but only in the outer medulla in normotensive rats. The iodinated contrast agent significantly decreased the RBF value in the outer medulla and the cortex in SHR compared with normotensive rats after injection of the iodinated contrast media. Histological observations of kidney morphology were also consistent with ASL perfusion changes. These results demonstrate that the RBF value can reflect changes of renal perfusion in the cortex and medulla. ASL-MRI is a feasible and accurate method for evaluating nephrotoxic drugs-induced kidney damage.

Imaging in acute renal infection in children

International Nuclear Information System (INIS)

Sty, J.R.; Wells, R.G.; Starshak, R.J.; Schroeder, B.A.

1987-01-01

Infection is the most common disease of the urinary tract in children, and various imaging techniques have been used to verify its presence and location. On retrospective analysis, 50 consecutive children with documented upper urinary tract infection had abnormal findings on renal cortical scintigraphy with 99mTc-glucoheptonate. The infection involved the renal poles only in 38 and the poles plus other renal cortical areas in eight. Four had abnormalities that spared the poles. Renal sonograms were abnormal in 32 of 50 children. Excretory urograms were abnormal in six of 23 children in whom they were obtained. Vesicoureteral reflux was found in 34 of 40 children in whom voiding cystourethrography was performed. These data show the high sensitivity of renal cortical scintigraphy with 99mTc-glucoheptonate in documenting upper urinary tract infection. The location of the abnormalities detected suggests that renal infections spread via an ascending mode and implies that intrarenal reflux is a major contributing factor

Acute renal failure secondary to rhabdomyolysis; MR imaging of the kidney

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Kim, S.H.; Han, M.C.; Kim, S.; Lee, J.S. (Dept. of Radiology and Dept. of Internal Medicine, Seoul National Univ., Coll. of Medicine (Korea, Republic of))

1992-11-01

MR imaging of the kidney was performed in 6 patients with acute renal failure (ARF) secondary to rhabdomyolysis caused by snake bite (n = 4), crush injury (n = 1), and carbon monoxide poisoning (n = 1). A test for urine myoglobin was positive in all 6 patients and MR imaging was done 6 to 18 days after the causative event of the rhabdomyolysis. MR images in all 6 patients showed globular swelling of the kidneys, preserved corticomedullary contrast on T1-weighted images, and obliteration of corticomedullary contrast on T2-weighted images. Unlike other medical renal diseases in which corticomedullary contrast is lost on T1-weighted images, preservation of the corticomedullary contrast on T1-weighted MR images with globular renal swelling was a constant finding in patients with ARF secondary to rhabdomyolysis. (orig.).

PET/CT in renal, bladder and testicular cancer

Science.gov (United States)

Bouchelouche, Kirsten; Physician, Chief; Choyke, Peter L.

2015-01-01

Imaging plays an important role in the clinical management of cancer patients. Hybrid imaging with PET/CT is having a broad impact in oncology, and in recent years PET/CT is beginning to have an impact in uro-oncology as well. In both bladder and renal cancer there is a need to study the efficacy of other tracers than F-18 fluorodeoxyglucose (FDG), particularly tracers with only limited renal excretion. Thus, new tracers are being introduced in these malignancies. This review focuses on the clinical role of FDG and other PET agents in renal, bladder and testicular cancer. PMID:26099672

Functional MR urography in patients with renal transplants

International Nuclear Information System (INIS)

Knopp, M.V.; Doersam, J.; Oesingmann, N.; Piesche, S.; Hawighorst, H.; Wiesel, M.; Schad, L.R.; Kaick, G. van

1997-01-01

Purpose: To assess the value of functional magnetic resonance urography for the noninvasive postoperative evaluation of renal transplants. Methods: A saturation inversion projection sequence allows the selective imaging of strongly T1 weighted signal from the MR contrast agent. A coronal slab leads to images comparable to conventional urography which can be acquired as a sequence with four images per minute. Results: 15 patients with urologic questionable findings after renal transplantation were studied. FMRU revealed in 6 patients normal findings, in 6 moderate dilatation of the renal pelvis without any urodynamic relevant obstruction. 3 pathologic findings, ureteral leak, ureteropelvic-junction obstruction and ureteral stenosis were diagnosed and consequently surgically treated. The imaging quality in all studies was diagnostic and urologically relevant. Conclusion: FMRU can be used as a noninvasive technique for the assessment of renal transplant in cases with suspicion of complication in the excretory system. (orig.) [de

Nephrogenic Systemic Fibrosis Risk After Liver Magnetic Resonance Imaging With Gadoxetate Disodium in Patients With Moderate to Severe Renal Impairment

Science.gov (United States)

Lauenstein, Thomas; Ramirez-Garrido, Francisco; Kim, Young Hoon; Rha, Sung Eun; Ricke, Jens; Phongkitkarun, Sith; Boettcher, Joachim; Gupta, Rajan T.; Korpraphong, Pornpim; Tanomkiat, Wiwatana; Furtner, Julia; Liu, Peter S.; Henry, Maren; Endrikat, Jan

2015-01-01

Objective The objective of this study was to assess the risk of gadoxetate disodium in liver imaging for the development of nephrogenic systemic fibrosis (NSF) in patients with moderate to severe renal impairment. Materials and Methods We performed a prospective, multicenter, nonrandomized, open-label phase 4 study in 35 centers from May 2009 to July 2013. The study population consisted of patients with moderate to severe renal impairment scheduled for liver imaging with gadoxetate disodium. All patients received a single intravenous bolus injection of 0.025-mmol/kg body weight of liver-specific gadoxetate disodium. The primary target variable was the number of patients who develop NSF within a 2-year follow-up period. Results A total of 357 patients were included, with 85 patients with severe and 193 patients with moderate renal impairment, which were the clinically most relevant groups. The mean time period from diagnosis of renal disease to liver magnetic resonance imaging (MRI) was 1.53 and 5.46 years in the moderate and severe renal impairment cohort, respectively. Overall, 101 patients (28%) underwent additional contrast-enhanced MRI with other gadolinium-based MRI contrast agents within 12 months before the start of the study or in the follow-up. No patient developed symptoms conclusive of NSF within the 2-year follow-up. Conclusions Gadoxetate disodium in patients with moderate to severe renal impairment did not raise any clinically significant safety concern. No NSF cases were observed. PMID:25756684

Evaluation of the renal venous system on late arterial and venous phase images with MDCT angiography in potential living laparoscopic renal donors

International Nuclear Information System (INIS)

Kawamoto, S.; Lawler, L.P.; Fishman, E.K.

2005-01-01

Objective: The objective of our study was to assess whether both renal arteries and renal veins can be evaluated using single-phase MDCT data sets alone to eliminate the need for both arterial and venous phase data sets. Materials and methods: One hundred consecutive potential living renal donors who underwent 4- MDCT were evaluated. CT was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Both late arterial and venous phase acquisitions were obtained at 25 and 55 sec from the start of IV contrast injection, respectively. The number of the right and left renal veins and its anatomic variations were assessed by two reviewers. Late arterial phase images were evaluated initially, and then venous phase images were analyzed to assess opacification of the renal vein and to see whether venous phase data sets changed or added information about the venous anatomy as seen on late arterial phase images. Results: The retroaortic left renal vein was found in two subjects, and the circumaortic left renal vein was detected in three subjects. The renal veins were adequately opacified on late arterial phase images in all subjects. There were six subjects who had a normal left renal vein with a small posterior branch coursing posterior to the aorta and draining into the inferior vena cava, which were difficult to differentiate from the lumbar vein or ascending lumbar vein; in three of these six subjects, the small posterior branch was opacified only on venous phase images. Conclusion: Late arterial phase images obtained at 25 sec after the start of contrast injection can reveal the renal vein anatomy except for a small posterior branch of the left renal vein difficult to differentiate from the lumbar or ascending lumbar vein, as seen in three subjects. The data suggest that venous phase imaging is not necessary for the evaluation of renal vein anatomy. (author)

Evaluation of the renal venous system on late arterial and venous phase images with MDCT angiography in potential living laparoscopic renal donors

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Kawamoto, S.; Lawler, L.P.; Fishman, E.K. [Johns Hopkins Hospital, Baltimore, MD (United States). The Russell H. Morgan Department of Radiology and Radiological Science

2005-03-15

Objective: The objective of our study was to assess whether both renal arteries and renal veins can be evaluated using single-phase MDCT data sets alone to eliminate the need for both arterial and venous phase data sets. Materials and methods: One hundred consecutive potential living renal donors who underwent 4- MDCT were evaluated. CT was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Both late arterial and venous phase acquisitions were obtained at 25 and 55 sec from the start of IV contrast injection, respectively. The number of the right and left renal veins and its anatomic variations were assessed by two reviewers. Late arterial phase images were evaluated initially, and then venous phase images were analyzed to assess opacification of the renal vein and to see whether venous phase data sets changed or added information about the venous anatomy as seen on late arterial phase images. Results: The retroaortic left renal vein was found in two subjects, and the circumaortic left renal vein was detected in three subjects. The renal veins were adequately opacified on late arterial phase images in all subjects. There were six subjects who had a normal left renal vein with a small posterior branch coursing posterior to the aorta and draining into the inferior vena cava, which were difficult to differentiate from the lumbar vein or ascending lumbar vein; in three of these six subjects, the small posterior branch was opacified only on venous phase images. Conclusion: Late arterial phase images obtained at 25 sec after the start of contrast injection can reveal the renal vein anatomy except for a small posterior branch of the left renal vein difficult to differentiate from the lumbar or ascending lumbar vein, as seen in three subjects. The data suggest that venous phase imaging is not necessary for the evaluation of renal vein anatomy. (author)

Attenuation values of renal parenchyma in virtual noncontrast images acquired from multiphase renal dual-energy CT: Comparison with standard noncontrast CT.

Science.gov (United States)

Lin, Yuan-Mao; Chiou, Yi-You; Wu, Mei-Han; Huang, Shan-Su; Shen, Shu-Huei

2018-04-01

To compare the renal parenchyma attenuation of virtual noncontrast (VNC) images derived from multiphase renal dual-energy computed tomography (DECT) with standard noncontrast (SNC) images, and to determine the optimum phase for VNC images. Twenty-nine men and 16 women (mean age, 61 ± 13 years; range, 37-89 years) underwent dynamic renal DECT (100/Sn140 kVp) were included in this institutional review board-approved retrospective study. There were four phases of the scan, which included noncontrast, corticomedullary (CMP), nephrographic (NP), and excretory phases (EP). The VNC images was generated from CMP, NP and EP. CT numbers of SNC images and VNC images of each phases were measured in the renal cortex and medulla. Mean standard deviation of subcutaneous fat was measured as image noise on SNC and VNC images. Radiation dose was recorded and potential radiation dose reduction was estimated. Results were tested for statistical significance using the unpaired t-test and agreement using Bland-Altman plot analysis. The difference in mean attenuation between SNC and each phase of VNC images were ≤4 HU. The mean attenuation of renal cortex and medulla was 33.2 ± 4.4 HU, and 34.2 ± 4.8 HU in SNC, 33.6 ± 7.6 HU and 31.1 ± 8.3 HU in VNC of CMP, 34.8 ± 8.6 HU and 35.6 ± 8.5 HU in VNC of NP, 31.5 ± 7.6 HU and 32.4 ± 7.5 HU in VNC of EP. In VNC of CMP, the attenuation of the cortex was higher than the medulla (p VNC of NP, the attenuation of renal cortex was higher than SNC (p VNC of EP, the attenuation of cortex and medulla were lower than SNC (p VNC images from multiphase renal DECT were similar to SNC images. Using the nephrographic phase can gives more comparable VNC images to SNC images in renal parenchyma than other phases. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of high-fat diet and losartan on renal cortical blood flow using contrast ultrasound imaging.

Science.gov (United States)

Declèves, Anne-Emilie; Rychak, Joshua J; Smith, Dan J; Sharma, Kumar

2013-11-01

Obesity-related kidney disease occurs as a result of complex interactions between metabolic and hemodynamic effects. Changes in microvascular perfusion may play a major role in kidney disease; however, these changes are difficult to assess in vivo. Here, we used perfusion ultrasound imaging to evaluate cortical blood flow in a mouse model of high-fat diet-induced kidney disease. C57BL/6J mice were randomized to a standard diet (STD) or a high-fat diet (HFD) for 30 wk and then treated either with losartan or a placebo for an additional 6 wk. Noninvasive ultrasound perfusion imaging of the kidney was performed during infusion of a microbubble contrast agent. Blood flow within the microvasculature of the renal cortex and medulla was derived from imaging data. An increase in the time required to achieve full cortical perfusion was observed for HFD mice relative to STD. This was reversed following treatment with losartan. These data were concurrent with an increased glomerular filtration rate in HFD mice compared with STD- or HFD-losartan-treated mice. Losartan treatment also abrogated fibro-inflammatory disease, assessed by markers at the protein and messenger level. Finally, a reduction in capillary density was found in HFD mice, and this was reversed upon losartan treatment. This suggests that alterations in vascular density may be responsible for the elevated perfusion time observed by imaging. These data demonstrate that ultrasound contrast imaging is a robust and sensitive method for evaluating changes in renal microvascular perfusion and that cortical perfusion time may be a useful parameter for evaluating obesity-related renal disease.

99Tcm-DTPA renal dynamic imaging in judgment of renal functions in patients with diabetes mellitus

International Nuclear Information System (INIS)

Yao Lixin; Guo Leiming; Li Zuofei; Liu Bo

2009-01-01

Objective: To evaluate 99 Tc m -diethylenetriamine-pentaacetic acid ( 99 T m -DTPA) renal dynamic imaging in judgment of the renal function inpatients with diabetes mellitus (DM) so as to provide reference for clinical treatment and prognosis predicting. Methods: Ninety patients with DM were divided into four groups according to values of urinary albumin excretion rate (UAER). 1) Group DM 1 : UAER -1 , 25 cases. 2) Group DM 2 : UAER 20 ∼200 μg ·min -1 , 24 cases. 3) Group DM 3 : UAER>200 μg ·min -1 , 23 cases. 4) a renal function failure group (DM 4 ), 18 cases. Fourty healthy people were chosen as normal control (NC) group. 99 Tc m -DTPA radionuclide renal dynamic imaging of glomerular filtration rate (GFR) was performed and the levels of serum creatinine (Scr), blood urea nitrogen (Bun) and blood β 2 -microglobulin (β 2 -Mg) were measured in the five groups. Results: GFR were significantly increased in group DM 1 than those in Nc (t=12.5, P 2 GFR was not different from Nc. The half activity time (T 1/2 ) of the renogram was significantly prolonged. The 20 min retention rate (C 20 ) of the renogram increased compared with Nc. In group DM 3 and DM 4 , GCFR was remarkably decreased. The peak time (Tp) of the renogram delayed. T 1/2 distinctly prolonged and C 20 increased, comparing with Nc (r=-0.497, P<0.05). Conclusion: Radionuclide renal dynamic imaging is helpful for the evaluation of renal damage in early stage of diabetic nephropathy (D N), judge the injury of the renal function and provide reference for clinical treatment and follow-up. (authors)

Image-guided radiofrequency ablation of renal cell carcinoma

International Nuclear Information System (INIS)

Boss, Andreas; Clasen, Stephan; Pereira, Philippe L.; Kuczyk, Markus; Schick, Fritz

2007-01-01

The incidence of renal cell carcinoma is rising with the increased number of incidental detection of small tumours. During the past few years, percutaneous imaging-guided radiofrequency ablation has evolved as a minimally invasive treatment of small unresectable renal tumours offering reduced patient morbidity and overall health care costs. In radiofrequency ablation, thermal energy is deposited into a targeted tumour by means of a radiofrequency applicator. In recent studies, radiofrequency ablation was shown to be an effective and safe modality for local destruction of renal cell carcinoma. Radiofrequency applicator navigation can be performed via ultrasound, computed tomography or magnetic resonance guidance; however, ultrasound seems less favourable because of the absence of monitoring capabilities during ablation. On-line monitoring of treatment outcome can only be performed with magnetic resonance imaging giving the possibility of eventual applicator repositioning to ablate visible residual tumour tissue. Long-term follow-up is crucial to assess completeness of tumour ablation. New developments in ablation technology and radiological equipment will further increase the indication field for radiofrequency ablation of renal cell carcinoma. Altogether, radiofrequency ablation seems to be a promising new modality for the minimally invasive treatment of renal cell carcinoma, which was demonstrated to exhibit high short-term effectiveness. (orig.)

Multilocular cystic renal cell carcinoma: imaging and clinical correlation

International Nuclear Information System (INIS)

Xu Yong; Zhang Sheng

2013-01-01

Multilocular cystic renal cell carcinoma (MCRCC) is a subtype of clear cell renal cell carcinoma and has mild clinical symptoms and a favorable prognosis. Accordingly, nephron-sparing surgery is recommended as a therapeutic strategy. If histologic subtype of MCRCC can be predicted preoperatively with an acceptable level of accuracy, it may be important in predicting prognosis and make clinical management. Most MCRCCs show characteristic cross-sectional imaging findings and permit accurate diagnosis before the treatment. Cross -sectional imaging of MCRCC reveals a well -defined multilocular cystic mass with irregularly enhanced thickened septa and without enhanced intracystic solid nodule. It is often classified as Bosniak classification Ⅲ , which is significantly different from that of other renal cystic masses. The clinical, pathologic, and radiologic features of MCRCC were discussed and illustrated in this article. The role of the imaging preoperative evaluation for MCRCC, and management implications were emphasized. (authors)

Multidetector row CT angiography of living related renal donors: Is there a need for venous phase imaging?

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Namasivayam, Saravanan [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Kalra, Mannudeep K. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Waldrop, Sandra M. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Mittal, Pardeep K. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Small, William C. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States)]. E-mail: wsmall@emory.edu

2006-09-15

Objective: To prospectively evaluate whether renal venous anatomy can be detected from arterial phase images of multidetector row CT (MDCT) of renal donors. Material and methods: Institutional review board approved our study protocol with waiver of consent. Forty-eight consecutive renal donors (age range, 21-56 years; M:F, 20:28) referred for MDCT evaluation were included. Two sub-specialty radiologists performed an independent and separate evaluation of renal venous anatomy in arterial and venous phase images. Opacification of renal venous structures was scored on a five-point scale (1-not seen; 3-minimal opacification; 5-excellent opacification). Arterial and venous phase opacification scores were compared by Wilcoxon signed rank test. Results: Both readers detected all renal venous anomalies in arterial as well as venous phase images. Each reader detected accessory right renal veins (n = 14), retroaortic left renal vein (n = 2), circumaortic left renal vein (n = 1), and left renal hilar arteriovenous malformation (n = 1) in arterial phase images. Retroaortic left renal venous branch was difficult to differentiate from lumbar vein (reader-1, n = 1; reader-2, n = 2) in both arterial and venous phase images. Sensitivity of detection of renal veins, left adrenal, gonadal and lumbar veins in arterial phase images was 100, 83-88, 100, and 85-90%, respectively. As expected, venous phase images showed significantly greater opacification of renal veins, left gonadal, adrenal and lumbar veins (p < .05). However, this did not substantially limit the evaluation of renal venous anatomy in arterial phase images. Both readers had substantial interobserver agreement (kappa coefficient, 0.7; p < 0.05). Conclusions: Arterial phase MDCT images alone can be used to detect renal venous anomalies, and to identify small left renal venous branches namely, the left gonadal, adrenal and lumbar veins in renal donors. Venous phase MDCT acquisition is not necessary for evaluation of renal

Multidetector row CT angiography of living related renal donors: Is there a need for venous phase imaging?

International Nuclear Information System (INIS)

Namasivayam, Saravanan; Kalra, Mannudeep K.; Waldrop, Sandra M.; Mittal, Pardeep K.; Small, William C.

2006-01-01

Objective: To prospectively evaluate whether renal venous anatomy can be detected from arterial phase images of multidetector row CT (MDCT) of renal donors. Material and methods: Institutional review board approved our study protocol with waiver of consent. Forty-eight consecutive renal donors (age range, 21-56 years; M:F, 20:28) referred for MDCT evaluation were included. Two sub-specialty radiologists performed an independent and separate evaluation of renal venous anatomy in arterial and venous phase images. Opacification of renal venous structures was scored on a five-point scale (1-not seen; 3-minimal opacification; 5-excellent opacification). Arterial and venous phase opacification scores were compared by Wilcoxon signed rank test. Results: Both readers detected all renal venous anomalies in arterial as well as venous phase images. Each reader detected accessory right renal veins (n = 14), retroaortic left renal vein (n = 2), circumaortic left renal vein (n = 1), and left renal hilar arteriovenous malformation (n = 1) in arterial phase images. Retroaortic left renal venous branch was difficult to differentiate from lumbar vein (reader-1, n = 1; reader-2, n = 2) in both arterial and venous phase images. Sensitivity of detection of renal veins, left adrenal, gonadal and lumbar veins in arterial phase images was 100, 83-88, 100, and 85-90%, respectively. As expected, venous phase images showed significantly greater opacification of renal veins, left gonadal, adrenal and lumbar veins (p < .05). However, this did not substantially limit the evaluation of renal venous anatomy in arterial phase images. Both readers had substantial interobserver agreement (kappa coefficient, 0.7; p < 0.05). Conclusions: Arterial phase MDCT images alone can be used to detect renal venous anomalies, and to identify small left renal venous branches namely, the left gonadal, adrenal and lumbar veins in renal donors. Venous phase MDCT acquisition is not necessary for evaluation of renal

A review of equine renal imaging techniques

International Nuclear Information System (INIS)

Matthews, H.K.; Toal, R.L.

1996-01-01

Radiography has a limited role in the evaluation of the kidneys in foals and adult horses. Ultrasonography is the current method of choice for structural evaluation of the kidneys in horses as it provides additional information to standard serum chemistry and urinalysis evaluation. A variety of structural abnormalities have been identified in diseased equine kidneys with the use of ultrasound. Ultrasound guided renal biopsy is the preferred method for performing renal biopsy in the horse. The use of Duplex Doppler ultrasound may allow for the characterization of regional hemodynamics of the equine kidney, but is currently an untapped method for evaluation of equine renal hemodynamics. Radionuclide methods including scintigraphy and quantitative renal function measurement can be used to provide further information about equine renal function. Scintigraphy can provide structural and possibly functional information. Quantitative methods using radiopharmaceuticals can provide precise measurement of glomerular filtration rate and effective renal blood flow. This method is especially helpful in identifying acute renal failure and in guiding response to treatment. All equine renal imaging techniques should be a supplement to the physical examination and standard laboratory tests. Additional diagnostic aids such as urinary tract endoscopy should also be considered in horses with hematuria, hydroureter, and suspected calculi. Taken together, all these modalities provide a thorough evaluation of the equine renal system and provide a basis for the clinician to select treatment options and provide prognostic information to the owner

Double agents and secret agents: the emerging fields of exogenous chemical exchange saturation transfer and T2-exchange magnetic resonance imaging contrast agents for molecular imaging.

Science.gov (United States)

Daryaei, Iman; Pagel, Mark D

2015-01-01

Two relatively new types of exogenous magnetic resonance imaging contrast agents may provide greater impact for molecular imaging by providing greater specificity for detecting molecular imaging biomarkers. Exogenous chemical exchange saturation transfer (CEST) agents rely on the selective saturation of the magnetization of a proton on an agent, followed by chemical exchange of a proton from the agent to water. The selective detection of a biomarker-responsive CEST signal and an unresponsive CEST signal, followed by the ratiometric comparison of these signals, can improve biomarker specificity. We refer to this improvement as a "double-agent" approach to molecular imaging. Exogenous T 2 -exchange agents also rely on chemical exchange of protons between the agent and water, especially with an intermediate rate that lies between the slow exchange rates of CEST agents and the fast exchange rates of traditional T 1 and T 2 agents. Because of this intermediate exchange rate, these agents have been relatively unknown and have acted as "secret agents" in the contrast agent research field. This review exposes these secret agents and describes the merits of double agents through examples of exogenous agents that detect enzyme activity, nucleic acids and gene expression, metabolites, ions, redox state, temperature, and pH. Future directions are also provided for improving both types of contrast agents for improved molecular imaging and clinical translation. Therefore, this review provides an overview of two new types of exogenous contrast agents that are becoming useful tools within the armamentarium of molecular imaging.

Radiopharmaceuticals for renal studies

International Nuclear Information System (INIS)

Verdera, Silvia

1994-01-01

Between the diagnostic techniques using radiopharmaceuticals in nuclear medicine it find renal studies.A brief description about renal glomerular filtration(GFR) and reliability renal plasma flux (ERPF),renal blood flux measurement agents (RBF),renal scintillation agents and radiation dose estimates by organ physiology was given in this study.tabs

MR Imaging of papillary renal neoplasms: potential application for characterization of small renal masses

International Nuclear Information System (INIS)

Roy, Catherine; Sauer, Benoit; Lindner, Veronique; Lang, Herve; Saussine, Christian; Jacqmin, Didier

2007-01-01

The purpose of our study was to evaluate the role of MRI in demonstrating the precise nature of papillary renal tumors (P RCC) and its potential application to select patients for partial surgery. Ninety-seven tumors less than or equal to 3 cm in size [55 papillary renal cell carcinoma - 42 clear cell renal carcinoma (CC RCC)] were preoperatively evaluated by MRI. Imaging findings were assessed with a special focus on the aspect of the tumoral process. Correlations were performed with pathologic staging after surgery. At pathology, 92 tumors were established to be staged p T1 and 5 were p T3 (3 cases of CC RCC and 2 cases of P RCC). Ninety-four percent of papillary tumors exhibited low signal intensity with homogeneous pattern on T2-weighted images. All clear cell carcinoma were hyperintense and heterogeneous on T2-weighted sequence. Enhancement was lower and delayed in the papillary type in comparison with the clear cell type. MRI is accurate enough to predict the 'histologic' nature of papillary renal carcinoma. It is an additional argument to propose that the tumor can be removed by partial surgery. (orig.)

Blunt renal trauma in children: healing of renal injuries and recommendations for imaging follow-up

International Nuclear Information System (INIS)

Abdalati, H.; Bulas, D.I.; Sivit, C.J.; Majd, M.; Rushton, H.G.; Eichelberger, M.R.

1994-01-01

Initial CT grading of renal injury was correlated with the frequency of complications and the time course of healing in 35 children. All renal contusions (grade 1, 8) and small parenchymal lacerations (grade 2, 8) healed without complications. All lacerations extending to the collecting system (grade 3, 9) resulted in mild to severe loss of renal function with progressive healing over 4 months. One of four segmental infarcts (grade 4 A), and five of six vascular pedicle injuries (grade 4 B) resulted in severe loss of renal function. Complications, including urinoma (2), sepsis (1), hydronephrosis (1), and persistent hypertension (2), were limited to grade 3 and 4 injuries. Our results suggest that mild renal injuries do not require follow-up imaging. Major renal lacerations and vascular pedicle injuries, however, often result in loss of renal function and should be followed up closely due to the risk of delayed complications. Follow-up examinations should continue for 3-4 months until healing is documented. (orig.)

Evaluation of renal transplants with Gd-DOTA dynamic MR imaging with factor analysis

International Nuclear Information System (INIS)

Chabrials, J.; Frouin, F.; Helenon, O.; Benall, H.; Kreis, H.; Moreau, J.F.; Di Paola, R.

1990-01-01

This paper reports on renal and urinary excretion factors by means of Gd-DOTA dynamic MR imaging and using factor analysis of dynamic structure (FADS) to follow-up renal transplants. We examined 60 patients with renal transplants by use of dynamic MR imaging after administration of a Gd-DOTA bolus (0.2 ml/kg) on a 0.5-T system; 10--12 fast gradient-echo sequences (TR/TE = 40/14, flip angle = 45 degree, acquisition time = 13 seconds) with single images and a 32-second intersequence delay were used. Of these, 13 dynamic MR imaging sequences were processed with an extension to dynamic MR images of FADS, previously developed to analyze nuclear medicine dynamic studies. The results were compared with the results of biologic dosages, renal biopsy and Seldinger digital arteriography

Renal 99M-technetium dimercaptosuccinic acid scintigraphy

International Nuclear Information System (INIS)

Ajdinovic, B.; Jaukovic, L.; Jankovic, Z.; Krstic, Z.

2004-01-01

99m-Technetium dimercaptosuccinic acid (99mTc-DMSA) whose ligand was used as a radioprotective agent and as a chelating compound for metal poisoning was reported to be an excellent renal imaging agent. As 99mTc-DMSA concentrates actively in the proximal convoluted tubule, it gives an image functional renal mass. Its integrity is dependent upon several factors, predominently intrarenal blood flow and intact enzyme function.Considering low radiation dose delivered by 99mTc DMSA and wide pediatric use of this radiopharmaceutical we calculate abnormal findings incidence (%).Results of 592 99m Tc-DMSA renal scintigraphy (348 children), which were classified as: 1. normal, 2. probably normal, 3. equivocal, 4. probably abnormal, 5. abnormal, are presented.Normal results were found in 269 patients (45,4%), 25% of whom was normal and 75% probably normal. Equivocal findings were found in 47 patients (7,9%). Abnormal results were presented in 276 patients (82% abnormal, 18% probably abnormal).The highest abnormal findings incidence was found in patients with congenital anomaly (88%), calculosis (87%) and policystic renal disease (79,3%). The lowest abnormal findings percentage was present in patients with urinary tract infection (12,9%) and arterial hypertension (17,3%)The role 99mTc-DMSA renal scintigraphy in pathology is clear in pyelonephrifis, hydronephrotic kidneys, and pediatric disease (urinary tract infections, congenital anomalies) and is confirmed by our results. (authors)

Prostate Activated Prodrugs and Imaging Agents

National Research Council Canada - National Science Library

Jones, Graham B

2004-01-01

.... The substrate chosen was a 3 component system composed of a peptide sequence with affinity for PSA, an imaging agent and a deactivating bridge-linker, which electronically incapacitates the imaging agent...

Advances in radiological imaging of the renal arteries and veins

International Nuclear Information System (INIS)

Miao Xiaofan; Tang Lijun; Yang Bing

2013-01-01

Familiarity with the normal anatomy of the renal vessels and common variants is of particular importance for the operator who performs renal transplantation or therapeutic interventions in the renal vessels. Because of the recent major advances in multislice spiral computed tomography angiography (MSCTA) techniques, our ability has been considerably improved to determine the patterns and characters of renal arteries and veins. This article summarizes the research situation and progress in the area of renal vessel imaging anatomy. Some regularity in the distribution of renal vessel positions, dimensions and variations among patients who received MSCTA examinations, and these anatomical measurements are of great value for clinical diagnosis and treatment. (authors)

Renal tolerance for iopromide (ultravist) in patients with chronic renal failure. Preliminary report

International Nuclear Information System (INIS)

Golebiowski, M.; Pruszynski, B.

1993-01-01

The authors present the renal tolerance for nonionic low-osmotic contrast agent iopromide (ultravist) on the ground of literature and of angiographic examinations in 10 patients with chronic renal failure. One patient only had significant temporary deterioration of renal function. The presented results showed that analyzed agent is less nephrotoxic than high osmolality contrast agents. The use of iopromide is strongly recommended in patients with chronic renal failure. The risk of depression of renal function after administration of contrast material is minimized. (author)

Bilateral renal masses in a 10-year-old girl with renal failure and urinary tract infection: the importance of functional imaging

Energy Technology Data Exchange (ETDEWEB)

Urbania, Thomas H. [University of California, San Francisco, Department of Radiology and Biomedical Imaging, 505 Parnassus Ave., Box 0628, San Francisco, CA (United States); Kammen, Bamidele F.; Nancarrow, Paul A. [Children' s Hospital and Research Center Oakland, Department of Diagnostic Imaging, Oakland, CA (United States); Morrell, Rose Ellen [Children' s Hospital and Research Center Oakland, Department of Nephrology, Oakland, CA (United States)

2009-02-15

Renal sonography is a routine step in the evaluation of new onset renal failure. When renal masses are discovered in this setting, functional imaging may be critical. We report a case of bilateral renal masses in a girl with urinary tract infection and renal insufficiency found to have vesicoureteral reflux. Renal scintigraphy revealed these masses to be the only remaining functional renal tissue, preventing potentially harmful resection. (orig.)

Bilateral renal masses in a 10-year-old girl with renal failure and urinary tract infection: the importance of functional imaging

International Nuclear Information System (INIS)

Urbania, Thomas H.; Kammen, Bamidele F.; Nancarrow, Paul A.; Morrell, Rose Ellen

2009-01-01

Renal sonography is a routine step in the evaluation of new onset renal failure. When renal masses are discovered in this setting, functional imaging may be critical. We report a case of bilateral renal masses in a girl with urinary tract infection and renal insufficiency found to have vesicoureteral reflux. Renal scintigraphy revealed these masses to be the only remaining functional renal tissue, preventing potentially harmful resection. (orig.)

Magnetic resonance imaging with liver-specific contrast agent in primary amyloidosis and intrahepatic cholestasis

Energy Technology Data Exchange (ETDEWEB)

Moeller, J.M.; Santoni-Rugiu, E.; Chabanova, E.; Logager, V.; Hansen, A.B.; Thomsen, H.S. [Depts. of Radiology and Pathology, Copenhagen Univ. Hospital, Herlev (Denmark)

2007-02-15

Magnetic resonance imaging (MRI) findings in hepatic amyloidosis are not well defined. Here, we report on a patient with renal failure caused by primary amyloidosis (AL type) who developed jaundice. Ultrasound and computed tomography were normal except for some ascites. MRI with oral manganese-containing contrast agent revealed several focal areas without contrast uptake in the hepatocytes and no bile secretion after 8 hours. No extrahepatic bile obstructions were found. Liver biopsy showed severe intraportal, vascular, and parenchymal amyloidosis causing severe cholestasis and atrophy of hepatocytes.

Consideration on the diagnostic ability of various imaging techniques in relation to renal tumor

International Nuclear Information System (INIS)

Ike, Katsushi

1984-01-01

Radiological diagnosis of renal tumors is being improved with the increased imaging accuracy which has resulted from advancement in the various equipment used and improvement in techniques. However, at the clinical level, diagnostic procedures based on the characteristics of the delineated images are not yet established and the diverse diagnostic procedures are being conducted currently in a stereotyped manner. In this study, the images of 61 cases diagnosed as renal tumor were analysed retrospectively with the purpose of establishing the imaging accuracy, capacity for diagnosis based on image characteristics and a subseguent proper diagnostic procedure. It was found that CT and Angio gave similar diagnostic accuracy. It was further revealed that US images enabled to differentiate renal tumors from the more commonly experienced renal cystic disease. For determination of tunica involucrum infiltration, which is essential to diagnose Stage I and II renal tumors, CT was proved to be superior to Angio. CT and US were also to be so in the determination of metastasis to para-aortic lymph nodes which is a Stage III criterion. In recent years, CT and US imaging accuracies have increased, hence the improvement in the capacity to diagnose non-observable renal tumors is highly expected. (author)

99mTc-Alafosfalin: an antibiotic peptide infection imaging agent

International Nuclear Information System (INIS)

Tsopelas, C.; Penglis, S.; Ruszkiewicz, A.; Bartholomeusz, F.D.L.

2003-01-01

The radiolabeled antibiotic peptide 99m Tc-alafosfalin was assessed as an infection imaging agent in a rat model by comparison with 99m Tc-DTPA and 99m Tc-leukocytes. 99m Tc-alafosfalin was prepared via an instant cold kit and 99m Tc-leukocytes were prepared using 99m Tc-stannous fluoride colloid in an ex vivo labeling procedure of whole blood. In separate experiments, the three radiotracers were administered to rats infected with staphylococcus aureus. Quantitative biodistribution studies were performed as well as scintigraphic images and histopathology. 99m Tc-alafosfalin is a stable product, obtained in high radiochemical purity (>95%). This agent was mainly renally excreted, with low liver, spleen and bone uptake, and resulted in a mean ratio of infected/non-infected thighs of 4.3/1.0 at 4 hr post radiotracer injection. 99m Tc-DTPA gave a corresponding ratio of 1.9/1.0 and 99m Tc-leukocytes gave 20.0/1.0 at the same time point. An in vitro assay found the level of 99m Tc-alafosfalin binding to staphylococcus aureas higher than 99m Tc-DTPA (10% versus 1% respectively). 99m Tc-alafosfalin accumulates at sites of infection in a rat model better than the perfusion molecule 99m Tc-DTPA, yet less than 99m Tc-leukocytes. The distribution characteristics of this 99m Tc-antibiotic peptide would be an advantage in imaging abdominal and soft tissue infection

Impact of Impaired Renal Function on Gadolinium Retention After Administration of Gadolinium-Based Contrast Agents in a Mouse Model.

Science.gov (United States)

Kartamihardja, A Adhipatria P; Nakajima, Takahito; Kameo, Satomi; Koyama, Hiroshi; Tsushima, Yoshito

2016-10-01

The aim of this study was to investigate the impact of impaired renal function on gadolinium (Gd) retention in various organs after Gd-based contrast agent injection. After local animal care and review committee approval, 23 normal mice and 26 with renal failure were divided into 4 treatment groups (Gd-DTPA-BMA, 5 mmol/kg; Gd-DOTA, 5 mmol/kg; GdCl3, 0.02 mmol/kg; and saline, 250 μL). Each agent was intravenously administered on weekdays for 4 weeks. Samples were collected on days 3 (short-term) and 45 (long-term) after the last injection. Gadolinium concentrations were quantified by inductively coupled plasma-mass spectrometry. Three mice with renal failure and 2 normal mice in the GdCl3 group and 1 mouse with renal failure in the Gd-DTPA-BMA group died. In the Gd-DTPA-BMA group, impaired renal function increased short-term Gd retention in the liver, bone, spleen, skin, and kidney (P DTPA-BMA showed higher Gd retention than Gd-DOTA. Although Gd retention in the Gd-DOTA group was generally low, impaired renal function increased only long-term hepatic Gd retention. Hepatic and splenic Gd retentions were significantly higher than other organs' Gd retention in the GdCl3 group (P DTPA-BMA administration, long-term Gd retention for Gd-based contrast agents was almost unaffected by renal function, suggesting that the chemical structures of retained Gd may not be consistent and some Gd is slowly eliminated after initially being retained.

Value of T2-weighted MR imaging in differentiating low-fat renal angiomyolipomas from other renal tumors

International Nuclear Information System (INIS)

Choi, Hyuck Jae; Kim, Jeong Kon; Kim, Mi-Hyun; Cho, Kyoung-Sik; Ahn, Hanjong; Kim, Choung-Soo

2011-01-01

Background: Accurate preoperative diagnosis of fat scanty angiomyolipomas is an important clinical issue. By evaluating the low signal intensity of angiomyolipomas in MR T2-weighted images the diagnostic accuracy can be elevated. Purpose: To retrospectively assess the usefulness of T2-weighted MR imaging for differentiating low-fat angiomyolipomas (AMLs) from other renal tumors. Material and Methods: We retrospectively evaluated 71 patients with surgically proven renal masses (10 AMLs, 57 renal cell carcinomas [RCCs], and four oncocytomas), all of which showed no visible fat as well as gradual enhancement patterns on contrast-enhanced CT. Signal intensity was measured in each renal mass and in the spleen on T2-weighted images, and each signal intensity ratio (SIR) was calculated; SIR values were then compared in the AML and non-AML groups. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of the two parameters for differentiating the two groups. Results: The SIR values (77 ± 24% vs. 162 ± 79%, p = 0.002) were significantly lower in the AML than in the non-AML group. The area under the ROC curve was 0.926 for SIR. The sensitivity and specificity in the diagnosis of AMLs were 90% and 90.2%, using SIR cut-off of 92.5%. Conclusion: Signal intensity measurements on T2-weighted MR images can differentiate AML from non-AML in the kidney

Contrast Agent in Magnetic Resonance Imaging

DEFF Research Database (Denmark)

Vu-Quang, Hieu

2015-01-01

Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... cancer cells for cancer diagnosis in MRI. F127-Folate coated SPION were stable in various types of suspension medium for over six months. They could specifically target folate receptor of cancer cells in vitro and in vivo thus enhancing the contrast in MRI T2/T2* weighted images. These are preliminary...

An analysis of 99mTc-DTPA renal dynamic imaging in patients with diabetes mellitus

International Nuclear Information System (INIS)

Cao Guoxiang; Zhang Yongxue

2000-01-01

To investigate the regularity of renal dynamic imaging in the various courses of diabetes mellitus, and then to provide the important evidence variety for diagnosis and treatment. The data of renal dynamic imaging was analyzed on 276 kidneys of 40 normal and 98 diabetic patients, and according to course of disease, the diabetic patients was divided into three groups: ≤1 year, 1-5 year and ≥5 year respectively. Based upon was grouped 99m Tc-DTPA renal dynamic imaging and others, the renal functions into normal, approximately normal, I, II and III injury respectively, and the statistics and analysis of these data were carried out. The extent of renal function injury was related to the course of disease significantly, and it showed that the longer the course, the heavier the damage of renal function, and there was a significant difference between them (P 99m Tc-DTPA renal dynamic imaging can effectively evaluate the extent of renal functions injury and was also valuable for the clinical. Also, the study indicated that in diabetic patients susceptible to urinary tract infection could aggravate the injury of renal function

Intelligent Design of Nano-Scale Molecular Imaging Agents

Directory of Open Access Journals (Sweden)

Takeaki Ozawa

2012-12-01

Full Text Available Visual representation and quantification of biological processes at the cellular and subcellular levels within living subjects are gaining great interest in life science to address frontier issues in pathology and physiology. As intact living subjects do not emit any optical signature, visual representation usually exploits nano-scale imaging agents as the source of image contrast. Many imaging agents have been developed for this purpose, some of which exert nonspecific, passive, and physical interaction with a target. Current research interest in molecular imaging has mainly shifted to fabrication of smartly integrated, specific, and versatile agents that emit fluorescence or luminescence as an optical readout. These agents include luminescent quantum dots (QDs, biofunctional antibodies, and multifunctional nanoparticles. Furthermore, genetically encoded nano-imaging agents embedding fluorescent proteins or luciferases are now gaining popularity. These agents are generated by integrative design of the components, such as luciferase, flexible linker, and receptor to exert a specific on–off switching in the complex context of living subjects. In the present review, we provide an overview of the basic concepts, smart design, and practical contribution of recent nano-scale imaging agents, especially with respect to genetically encoded imaging agents.

MR imaging findings of renal capsular leiomyoma : a case report

Energy Technology Data Exchange (ETDEWEB)

Yang, Dal Mo; Yoon, Myung Hwan; Kim, Hak Soo; Kim, Hyung Sik; Chung, Jin Woo; Cho, Hyun I; Lee, Jong Bouk [Gachon Medical college Gil Medical Center, Seoul (Korea, Republic of)

1999-06-01

In the literature, descriptions of the MR findings of renal leiomyoma are rare. We present the MR findings of a capsular leiomyoma of the kidney in which hypointensity relative to normal renal parenchyma was seen on both T1-and T2-weighted MR images.

MR imaging findings of renal capsular leiomyoma : a case report

International Nuclear Information System (INIS)

Yang, Dal Mo; Yoon, Myung Hwan; Kim, Hak Soo; Kim, Hyung Sik; Chung, Jin Woo; Cho, Hyun I; Lee, Jong Bouk

1999-01-01

In the literature, descriptions of the MR findings of renal leiomyoma are rare. We present the MR findings of a capsular leiomyoma of the kidney in which hypointensity relative to normal renal parenchyma was seen on both T1-and T2-weighted MR images

MR imaging of renal carcinoma: A comparison of techniques

International Nuclear Information System (INIS)

Choyke, P.L.; Frank, J.A.; Dwyer, A.J.; Doppman, J.L.; Sank, V.J.; Robertson, C.J.; Linehan, W.M.; Rosenberg, S.A.

1986-01-01

The design of an optimal MR imaging protocol for renal cell carcinomas is complicated by the number of available pulse sequences and imaging planes. The authors evaluated nine different pulse sequences (SE, TR/TE = 200-300/80-120, 500-700/26, and IR 1,500/100/30) in the axial, coronal, and sagittal planes in 26 patients with stage IV renal carcinoma at 0.5T. The IR 100 provided the greatest tumor-to-background signal ratio for both primary and secondary lesions in 24 of 24 of the patients. It alone allowed detection of 10% of the lesions. Anatomic and vascular data were provided best by the T1-weighted SE sequences. The least useful were the T2-weighted SE sequences, which had considerable motion artifact and little anatomic detail. Axial planes were best for displaying adenopathy and soft-tissue involvement. Coronal IR images provided a clear overview of the abdomen and lower thorax, paravertebral and vertebral metastases and impending cord compression. Imaging with an IR sequence of 1,500/100/30 in the axial and coronal planes and a T1-weighted SE sequence in the axial and coronal planes is an efficient, sensitive strategy for staging renal carcinoma

Imaging efficacy of a targeted imaging agent for fluorescence endoscopy

Science.gov (United States)

Healey, A. J.; Bendiksen, R.; Attramadal, T.; Bjerke, R.; Waagene, S.; Hvoslef, A. M.; Johannesen, E.

2008-02-01

Colorectal cancer is a major cause of cancer death. A significant unmet clinical need exists in the area of screening for earlier and more accurate diagnosis and treatment. We have identified a fluorescence imaging agent targeted to an early stage molecular marker for colorectal cancer. The agent is administered intravenously and imaged in a far red imaging channel as an adjunct to white light endoscopy. There is experimental evidence of preclinical proof of mechanism for the agent. In order to assess potential clinical efficacy, imaging was performed with a prototype fluorescence endoscope system designed to produce clinically relevant images. A clinical laparoscope system was modified for fluorescence imaging. The system was optimised for sensitivity. Images were recorded at settings matching those expected with a clinical endoscope implementation (at video frame rate operation). The animal model was comprised of a HCT-15 xenograft tumour expressing the target at concentration levels expected in early stage colorectal cancer. Tumours were grown subcutaneously. The imaging agent was administered intravenously at a dose of 50nmol/kg body weight. The animals were killed 2 hours post administration and prepared for imaging. A 3-4mm diameter, 1.6mm thick slice of viable tumour was placed over the opened colon and imaged with the laparoscope system. A receiver operator characteristic analysis was applied to imaging results. An area under the curve of 0.98 and a sensitivity of 87% [73, 96] and specificity of 100% [93, 100] were obtained.

Prospective MR image alignment between breath-holds: Application to renal BOLD MRI.

Science.gov (United States)

Kalis, Inge M; Pilutti, David; Krafft, Axel J; Hennig, Jürgen; Bock, Michael

2017-04-01

To present an image registration method for renal blood oxygen level-dependent (BOLD) measurements that enables semiautomatic assessment of parenchymal and medullary R2* changes under a functional challenge. In a series of breath-hold acquisitions, three-dimensional data were acquired initially for prospective image registration of subsequent BOLD measurements. An algorithm for kidney alignment for BOLD renal imaging (KALIBRI) was implemented to detect the positions of the left and right kidney so that the kidneys were acquired in the subsequent BOLD measurement at consistent anatomical locations. Residual in-plane distortions were corrected retrospectively so that semiautomatic dynamic R2* measurements of the renal cortex and medulla become feasible. KALIBRI was tested in six healthy volunteers during a series of BOLD experiments, which included a 600- to 1000-mL water challenge. Prospective image registration and BOLD imaging of each kidney was achieved within a total measurement time of about 17 s, enabling its execution within a single breath-hold. KALIBRI improved the registration by up to 35% as found with mutual information measures. In four volunteers, a medullary R2* decrease of up to 40% was observed after water ingestion. KALIBRI improves the quality of two-dimensional time-resolved renal BOLD MRI by aligning local renal anatomy, which allows for consistent R2* measurements over many breath-holds. Magn Reson Med 77:1573-1582, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Image diagnosis of parathyroid glands in chronic renal failure

International Nuclear Information System (INIS)

Takagi, H.; Tominaga, Y.; Uchida, K.; Yamada, N.; Morimoto, T.; Yasue, M.

1983-01-01

Twenty-two out of 31 patients with chronic renal failure and secondary hyperparathyroidism who underwent parathyroidectomy before operation underwent non-invasive image diagnosis of parathyroid glands by computed tomography (CT), scintigraphy with 201 TlCl and /sup 99m/TcO 4+ , and/or ultrasonography. CT visualized 39 of 45 parathyroid glands (86.7%), weighing more than 500 mg. Scintigraphy with a subtraction method using a computer performed the diagnosis in 19 of 27 glands (70.4%). Ultrasonography detected 21 of 27 glands (77.8%). Image diagnosis was also useful in the postoperative follow-up study. The non-invasive image diagnosis of parathyroid glands in patients with chronic renal failure is thus valuable for 1) definite diagnosis of secondary hyperparathyroidism, 2) localization, and 3) diagnosis for effectiveness of conservative treatment

Improved radionuclide bone imaging agent injection needle withdrawal method can improve image quality

International Nuclear Information System (INIS)

Qin Yongmei; Wang Laihao; Zhao Lihua; Guo Xiaogang; Kong Qingfeng

2009-01-01

Objective: To investigate the improvement of radionuclide bone imaging agent injection needle withdrawal method on whole body bone scan image quality. Methods: Elbow vein injection syringe needle directly into the bone imaging agent in the routine group of 117 cases, with a cotton swab needle injection method for the rapid pull out the needle puncture point pressing, pressing moment. Improvement of 117 cases of needle injection method to put two needles into the skin swabs and blood vessels, pull out the needle while pressing two or more entry point 5min. After 2 hours underwent whole body bone SPECT imaging plane. Results: The conventional group at the injection site imaging agents uptake rate was 16.24%, improved group was 2.56%. Conclusion: The modified bone imaging agent injection needle withdrawal method, injection-site imaging agent uptake were significantly decreased whole body bone imaging can improve image quality. (authors)

Evaluation of renal first pass blood flow with a functional image technique in hypertensive patients

International Nuclear Information System (INIS)

Ishibashi, Masatoshi; Morita, Seiichiro; Umezaki, Noriyoshi; Ohtake, Hisashi

1988-01-01

The renal circulation of patients with essential hypertension and renovascular hypertension was evaluated using 99m Tc-DTPA. The first renal peak count (the first C max ; FC max ), time phase distribution (the first T max ; FT max ), and blood velocity (the FC max /FT max ) were calculated by digital imaging. This yields a visual image of the renal circulation. We consider that the increase in the renal first pass blood flow in patients with essential hypertension is best observed pixel by pixel. The FC max and FC max /FT max images before and after treatment by percutaneous transluminal renal angioplasty in patients with renovascular hypertension clearly show its therapeutic effect. The FI technique, therefore, has the advantage that it can be performed at the same time as the conventional routine examinations of renal function. This makes it very useful clinically. (orig.)

Renal contrast-enhanced MR angiography: timing errors and accurate depiction of renal artery origins.

Science.gov (United States)

Schmidt, Maria A; Morgan, Robert

2008-10-01

To investigate bolus timing artifacts that impair depiction of renal arteries at contrast material-enhanced magnetic resonance (MR) angiography and to determine the effect of contrast agent infusion rates on artifact generation. Renal contrast-enhanced MR angiography was simulated for a variety of infusion schemes, assuming both correct and incorrect timing between data acquisition and contrast agent injection. In addition, the ethics committee approved the retrospective evaluation of clinical breath-hold renal contrast-enhanced MR angiographic studies obtained with automated detection of contrast agent arrival. Twenty-two studies were evaluated for their ability to depict the origin of renal arteries in patent vessels and for any signs of timing errors. Simulations showed that a completely artifactual stenosis or an artifactual overestimation of an existing stenosis at the renal artery origin can be caused by timing errors of the order of 5 seconds in examinations performed with contrast agent infusion rates compatible with or higher than those of hand injections. Lower infusion rates make the studies more likely to accurately depict the origin of the renal arteries. In approximately one-third of all clinical examinations, different contrast agent uptake rates were detected on the left and right sides of the body, and thus allowed us to confirm that it is often impossible to optimize depiction of both renal arteries. In three renal arteries, a signal void was found at the origin in a patent vessel, and delayed contrast agent arrival was confirmed. Computer simulations and clinical examinations showed that timing errors impair the accurate depiction of renal artery origins. (c) RSNA, 2008.

Renal cell carcinoma: histological classification and correlation with imaging findings

Energy Technology Data Exchange (ETDEWEB)

Muglia, Valdair F., E-mail: fmuglia@fmrp.usp.br [Universidade de Sao Paulo (CCIFM/FMRP/USP), Ribeirao Preto, SP (Brazil). Centro de Ciencias das Imagens e Fisica Medica. Faculdade de Medicina; Prando, Adilson [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Hospital Vera Cruz, Campinas, SP (Brazil). Dept. de Imaginologia

2015-05-15

Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes. (author)

Parametric Imaging Of Digital Subtraction Angiography Studies For Renal Transplant Evaluation

Science.gov (United States)

Gallagher, Joe H.; Meaney, Thomas F.; Flechner, Stuart M.; Novick, Andrew C.; Buonocore, Edward

1981-11-01

A noninvasive method for diagnosing acute tubular necrosis and rejection would be an important tool for the management of renal transplant patients. From a sequence of digital subtraction angiographic images acquired after an intravenous injection of radiographic contrast material, the parametric images of the maximum contrast, the time when the maximum contrast is reached, and two times the time at which one half of the maximum contrast is reached are computed. The parametric images of the time when the maximum is reached clearly distinguish normal from abnormal renal function. However, it is the parametric image of two times the time when one half of the maximum is reached which provides some assistance in differentiating acute tubular necrosis from rejection.

Usefulness of parametric renal clearance images in the assessment of basic risk factors for renalnal clearance images in the assessment of basic risk factors for renal scarring in children with recurrent urinary tract infections.

Science.gov (United States)

Pietrzak-Stelasiak, Ewa; Bieńkiewicz, Małgorzata; Woźnicki, Wojciech; Bubińska, Krystyna; Kowalewska-Pietrzak, Magdalena; Płachcińska, Anna; Kuśmierek, Jacek

2017-01-01

Clinically confirmed incidents of acute pyelonephritis (APN) following recurrent infections of urinary tract (UTI) form basic risk factors for renal scarring in children. Vesico-uretheral reflux (VUR) of higher grade is additional risk factor for this scarring. Opinions on diagnostic value of summed sequential images of renal uptake phase (SUM) of dynamic renal scintigraphy in detection of renal scars are diverse. However, several publications point to higher diagnostic efficacy of clearance parametric images (PAR) generated from this study. To establish a clinical value of parametric renal clearance images in detection of renal scarring. A prospective study was performed in a group of 91 children at the age of 4 to 18 years with recurrent UTI. Clinically documented incidents of APN were noted in 32 children: in 8 cases - one and in the remaining 24 - 2 to 5 (mean 3) incidents. In the remaining 59 patients only infections of the lower part of urinary tract were diagnosed. Static renal 99mTc-DMSA SPECT study and after 2-4 days dynamic renal studies (99mTc-EC) were performed in every patient not earlier than 6 months after the last documented incident of UTI. PAR images generated from a dynamic study by in-house developed software and SUM images were compared with a gold standard SPECT study. Percentages of children with detected renal scar(s) with SPECT and PAR methods amounted to 55% and 54%, respectively and were statistically significantly higher (p children with history of APN detected with SPECT and PAR methods were significantly more frequent than with infections of only lower part of urinary tract (72% vs. 46%; p = 0.017 and 69% vs. 46%; p = 0.036, respectively). A SUM method did not reveal statistically significant differences between frequencies of detection of scars in groups specified above - 38% vs. 27% (p = 0.31). Both SPECT and PAR methods showed also that frequencies of occurrence of renal scars in children with higher grades of VUR were higher than

Multimodal nanoparticle imaging agents: design and applications

Science.gov (United States)

Burke, Benjamin P.; Cawthorne, Christopher; Archibald, Stephen J.

2017-10-01

Molecular imaging, where the location of molecules or nanoscale constructs can be tracked in the body to report on disease or biochemical processes, is rapidly expanding to include combined modality or multimodal imaging. No single imaging technique can offer the optimum combination of properties (e.g. resolution, sensitivity, cost, availability). The rapid technological advances in hardware to scan patients, and software to process and fuse images, are pushing the boundaries of novel medical imaging approaches, and hand-in-hand with this is the requirement for advanced and specific multimodal imaging agents. These agents can be detected using a selection from radioisotope, magnetic resonance and optical imaging, among others. Nanoparticles offer great scope in this area as they lend themselves, via facile modification procedures, to act as multifunctional constructs. They have relevance as therapeutics and drug delivery agents that can be tracked by molecular imaging techniques with the particular development of applications in optically guided surgery and as radiosensitizers. There has been a huge amount of research work to produce nanoconstructs for imaging, and the parameters for successful clinical translation and validation of therapeutic applications are now becoming much better understood. It is an exciting time of progress for these agents as their potential is closer to being realized with translation into the clinic. The coming 5-10 years will be critical, as we will see if the predicted improvement in clinical outcomes becomes a reality. Some of the latest advances in combination modality agents are selected and the progression pathway to clinical trials analysed. This article is part of the themed issue 'Challenges for chemistry in molecular imaging'.

In vivo 3-dimensional photoacoustic imaging of the renal vasculature in preclinical rodent models

OpenAIRE

Ogunlade, O.; Connell, J. J.; Huang, J. L.; Zhang, E.; Lythgoe, M. F.; Long, D. A.; Beard, P.

2017-01-01

Non-invasive imaging of the kidney vasculature in preclinical murine models is important for studying renal development, diseases and evaluating new therapies, but is challenging to achieve using existing imaging modalities. Photoacoustic imaging is a promising new technique that is particularly well suited to visualising the vasculature and could provide an alternative to existing preclinical imaging methods for studying renal vascular anatomy and function. To investigate this, an all-optica...

The role of imaging in the diagnosis and management of renal stone disease in pregnancy

International Nuclear Information System (INIS)

Masselli, G.; Weston, M.; Spencer, J.

2015-01-01

The distinction of pain in pregnancy due to urolithiasis from that related to physiological dilation of the renal tract is a common conundrum as renal colic is one of the commonest causes for non-obstetric pain in pregnancy. Ultrasound is the first-line imaging test but although it may demonstrate renal dilation, it may not show the cause. Magnetic resonance imaging (MRI) is able to make the distinction. Physiological dilation will show smooth tapering of the ureter in the middle third as it is compressed between the gravid uterus and the retroperitoneum. Obstruction due to calculi causes renal enlargement and perinephric oedema. When a stone is lodged in the lower ureter, a standing column of dilated ureter will be seen below the physiological constriction. The stone itself may be shown. Computed tomography (CT) is an acceptable alternative if there is a contraindication to MRI, but even low-dose regimes involve some ionising radiation. This paper serves to highlight the role of MRI compared to US and CT in the imaging of renal colic in pregnancy. Multidisciplinary collaboration between obstetricians, urologists, and radiologists is required for effective management. - Highlights: • Ultrasound and MR imaging are the preferred investigations for renal colic during pregnancy. • MR imaging helps differentiate physiologic from obstructive hydronephrosis when ultrasound is inconclusive. • If MR imaging cannot be performed, low-dose CT may be necessary.

Liposomes as carriers of imaging agents

International Nuclear Information System (INIS)

Caride, V.J.

1985-01-01

This review discusses the utilization of liposomes as imaging agents or as vehicles for contrast materials. The initial approach was the use of radiolabeled liposomes for scintigraphy. To this end liposomes were either labeled in the lipid membrane or aqueous radiotracers were incorporated inside the lipid vesicles. The lipid labeling provides a more stable association of the radioactive tracer and the lipid vesicles, while the use of water-soluble radiotracers provides a wider selection of compounds. Early attempts at selective tumor imaging using radiolabeled liposomes were unsuccessful. The use of monoclonal antibodies attached to liposomes offers new hopes. Several strategies have been proposed in this respect and several others can be envisioned. The use of liposomes permits the use of several administration routes for imaging agents. Of particular interest is the subcutaneous administration for lymph node visualization. Liposomes offer clear advantages over most radiocontrast agents for prolonged hepatosplenic contrast enhancement. This is particularly relevant in the diagnostic evaluation of the abdomen with computed tomography. Important research efforts are being conducted in this area. Two different approaches have been advanced: the incorporation of contrast agents into liposomes and the preparation of radiopaque liposomes from radiodense lipids. Nuclear magnetic resonance imaging can also benefit from contrast agents. Several centers are investigating this exciting field using liposomes loaded with paramagnetic elements.152 references

99m Tc-tazobactam, a novel infection imaging agent: Radiosynthesis, quality control, biodistribution, and infection imaging studies.

Science.gov (United States)

Rasheed, Rashid; Naqvi, Syed Ali Raza; Gillani, Syed Jawad Hussain; Zahoor, Ameer Fawad; Jielani, Asif; Saeed, Nidda

2017-05-15

The radiolabeled drug 99m Tc-tazobactam ( 99m Tc-TZB) was developed and assessed as an infection imaging agent in Pseudomonas aeruginosa and Salmonella enterica infection-induced animal models by comparing with inflammation induced animal models. Radiosynthesis of 99m Tc-TZB was assessed while changing ligand concentration, reducing agent concentration, pH, and reaction time while keeping radioactivity constant (~370 MBq). Percent labeling of the resulting complex was measured using paper chromatography and instant thin layer chromatography. The analysis of the 99m Tc-TZB complex indicated >95% labeling yield and electrophoresis revealed complex is neutral in nature. The biodistribution study also showed predominantly renal excretion; however liver, stomach, and intestine also showed slight tracer agent uptake. The agent significantly accumulated in Pseudomonas aeruginosa and Salmonella enterica infection induced tissues 3.58 ± 0.26% and 2.43 ± 0.42% respectively at 1 hour postinjection. The inflamed tissue failed to uptake noticeable activity at 1 hour time point. The scintigraphic study results were found in accordance with biodistribution pattern. On the basis of our preliminary results, the newly developed 99m Tc-TZB can be used to diagnose bacterial infection and to discriminate between infected and inflamed tissues. Copyright © 2017 John Wiley & Sons, Ltd.

In vivo estimation of renal volume using a rotating gamma camera for sup(99m)Tc-dimercaptosuccinic acid renal imaging

Energy Technology Data Exchange (ETDEWEB)

Kawamura, J; Itoh, H; Yoshida, O; Fujita, T; Torizuka, K

1984-03-01

The in vivo renal volume was determined using SPECT for sup(99m)Tc-DMSA renal imaging. The total renal volume was derived by summing the DMSA distribution volumes of the transaxial slices in the whole kidney. In 20 healthy subjects the renal volume in the right kidney was 220 ml for men and 195.2 ml for women, while that in the left kidney was 213 ml for men and 193.7 ml for women. Differences in those values were not statistically significant. A good correlation was found between renal volumes in both kidneys and body surface area. In 106 kidneys including solitary and pathological kidneys, individual renal volume correlated well with individual DMSA renal uptake rate which demonstrates cortical functioning mass, depending on the cortical blood flow. Thus, SPECT enables an accurate noninvasive means of estimating in vivo functioning renal volume.

Quantitative Renal Cortical Perfusion in Human Subjects with Magnetic Resonance Imaging Using Iron-Oxide Nanoparticles: Influence of T1 Shortening

Energy Technology Data Exchange (ETDEWEB)

Morell, A.; Ahlstrom, H.; Schoenberg, S.O.; Abildgaard, A.; Bock, M.; Bjoernerud, A. (Dept. of Diagnostic Radiology, Uppsala Univ. Hospital, Uppsala (Sweden))

2008-10-15

Background: Using conventional contrast agents, the technique of quantitative perfusion by observing the transport of a bolus with magnetic resonance imaging (MRI) is limited to the brain due to extravascular leakage. Purpose: To perform quantitative perfusion measurements in humans with an intravascular contrast agent, and to estimate the influence of the T1 relaxivity of the contrast agent on the first-pass response. Material and Methods: Renal cortical perfusion was measured quantitatively in six patients with unilateral renal artery stenosis using a rapid gradient double-echo sequence in combination with an intravenous bolus injection of NC100150 Injection, an intravascular contrast agent based on iron-oxide nanoparticles. The influence of T1 relaxivity was measured by comparing perfusion results based on single- and double-echo data. Results: The mean values of cortical blood flow, cortical blood volume, and mean transit time in the normal kidneys were measured to 339+-60 ml/min/100 g, 41+-8 ml/100 g, and 7.3+-1.0 s, respectively, based on double-echo data. The corresponding results based on single-echo data, which are not compensated for the T1 relaxivity, were 254+-47 ml/min/100 g, 27+-3 ml/100 g, and 6+-1.2 s, respectively. Conclusion: The use of a double-echo sequence enabled elimination of confounding T1 effects and consequent systematic underestimation of the perfusion.

Renal volume assessed by magnetic resonance imaging volumetry correlates with renal function in living kidney donors pre- and postdonation: a retrospective cohort study.

Science.gov (United States)

Lange, Daniel; Helck, Andreas; Rominger, Axel; Crispin, Alexander; Meiser, Bruno; Werner, Jens; Fischereder, Michael; Stangl, Manfred; Habicht, Antje

2018-07-01

Renal function of potential living kidney donors is routinely assessed with scintigraphy. Kidney anatomy is evaluated by imaging techniques such as magnetic resonance imaging (MRI). We evaluated if a MRI-based renal volumetry is a good predictor of kidney function pre- and postdonation. We retrospectively analyzed the renal volume (RV) in a MRI of 100 living kidney donors. RV was correlated with the tubular excretion rate (TER) of MAG3-scintigraphy, a measured creatinine clearance (CrCl), and the estimated glomerular filtration rate (eGFR) by Cockcroft-Gault (CG), CKD-EPI, and modification of diet in renal disease (MDRD) formula pre- and postdonation during a follow-up of 3 years. RV correlated significantly with the TER (total: r = 0.6735, P volumetry might be an alternative technique for the evaluation of split renal function and prediction of renal function postdonation in living kidney donors. © 2018 Steunstichting ESOT.

Smart Contrast Agents for Magnetic Resonance Imaging.

Science.gov (United States)

Bonnet, Célia S; Tóth, Éva

2016-01-01

By visualizing bioactive molecules or biological parameters in vivo, molecular imaging is searching for information at the molecular level in living organisms. In addition to contributing to earlier and more personalized diagnosis in medicine, it also helps understand and rationalize the molecular factors underlying physiological and pathological processes. In magnetic resonance imaging (MRI), complexes of paramagnetic metal ions, mostly lanthanides, are commonly used to enhance the intrinsic image contrast. They rely either on the relaxation effect of these metal chelates (T(1) agents), or on the phenomenon of paramagnetic chemical exchange saturation transfer (PARACEST agents). In both cases, responsive molecular magnetic resonance imaging probes can be designed to report on various biomarkers of biological interest. In this context, we review recent work in the literature and from our group on responsive T(1) and PARACEST MRI agents for the detection of biogenic metal ions (such as calcium or zinc), enzymatic activities, or neurotransmitter release. These examples illustrate the general strategies that can be applied to create molecular imaging agents with an MRI detectable response to biologically relevant parameters.

Imaging of renal metastases

International Nuclear Information System (INIS)

Bruneton, J.N.; Normand, F.; Balu-Maestro, C.; Rogopoulos, A.; Drouillard, J.; Laurent, F.

1988-01-01

Metastases are the most frequent malignant tumors of the kidney, but these lesions are of late onset in neoplastic disease. The 19 cases reported here were all investigated with various imaging techniques (CT 12 cases, ultrasonography 12 cases, urography 8 cases, angiography 2 cases, MRI 1 case). The most common primary malignancies were lung cancer, melanoma and cancer of the controlateral kidney. In this series, 8 of the lesions were solitary, and 9 were unilateral. Tumor vascularity was evaluated in 15 cases: 14 of these lesions were hypovascular. The differential diagnosis includes small cysts, lymphoma, bilateral renal cancer, multiple small abscesses and multiple small infarcts [fr

Effect on renal function of an iso-osmolar contrast agent in patients with monoclonal gammopathies

International Nuclear Information System (INIS)

Preda, Lorenzo; Agazzi, Alberto; Martinelli, Giovanni; Raimondi, Sara; Lanfranchi, Carla Federica; Passerini, Rita; Calvetta, Albania; Bellomi, Massimo

2011-01-01

To assess the safety of the non-ionic iso-osmolar contrast agent iodixanol on renal function in patients with monoclonal gammopathies undergoing CT. We explored the effect of iodixanol on renal function in 30 patients with monoclonal gammopathies and 20 oncological patients with a normal electrophoretic profile (control group). The parameters used to estimate renal function were: serum creatinine, eGFR (determined 24 h before and 48 h after the administration of iodixanol), and urinary excretion of Neutrophil Gelatinase-Associated Lipocalin (NGAL) determined 2 h and 24 h after. Serum creatinine was also determined 1 month after the administration of iodixanol. No significant increase in serum creatinine values were observed in the monoclonal gammopathies group and in 19/20 patients in the control group. Only 1 patient in the control group developed a transient contrast agent-induced nephropathy. We found no statistically significant difference between the two groups regarding the percentage variation from baseline values of serum creatinine, creatinine clearance, NGAL 2 h after, and eGFR. Whereas NGAL at 24 h showed a statistically significant increase in patients with Monoclonal gammopathies. The use of iodixanol appears to be safe in patients with monoclonal gammopathies and an eGFR ≥ 60 ml/min/1.73 mq. (orig.)

Age-Related Renal Microvascular Changes: Evaluation by Three-Dimensional Digital Imaging of the Human Renal Microcirculation Using Virtual Microscopy.

Science.gov (United States)

Uesugi, Noriko; Shimazu, Yoshihito; Kikuchi, Kazunori; Nagata, Michio

2016-11-02

The renal microvasculature is targeted during aging, sometimes producing chronic kidney disease (CKD). Overdiagnosis of CKD in older persons is concerning. To prevent it, a new concept of "healthy aging" is arising from a healthy renal donor study. We investigated the renal microcirculatory changes of three older persons and compared them with that of one patient with nephrosclerosis using a three-dimensional (3D) reconstruction technique that we previously developed. This method uses a virtual slide system and paraffin-embedded serial sections of surgical material that was double-immunostained by anti-CD34 and anti-α smooth muscle actin (SMA) antibodies for detecting endothelial cells and medial smooth muscle cells, respectively. In all cases, the 3D images proved that arteriosclerotic changes in large proximal interlobular arteries did not directly induce distal arterial change or glomerulosclerosis. The nephrosclerotic patient showed severe hyalinosis with luminal narrowing of small arteries directly inducing glomerulosclerosis. We also visualized an atubular glomerulus and intraglomerular dilatation of an afferent arteriole during healthy aging on the 3D image and showed that microcirculatory changes were responsible for them. Thus, we successfully visualized healthy aged kidneys on 3D images and confirmed the underlying pathology. This method has the ability to investigate renal microcirculatory damage during healthy aging.

Dynamic Contrast-Enhanced MR Imaging of Renal Ischemia-Reperfusion Injury

Energy Technology Data Exchange (ETDEWEB)

Baik, Jun Hyun; Ahn, Myeong Im; Park, Young Ha; Chung, Soo Kyo [Catholic University, Seoul (Korea, Republic of)

2010-02-15

To evaluate the usefulness of magnetic resonance imaging (MRI) in a renal ischemia-reperfusion injury. Twenty-four rabbits were randomly divided into four groups, including a sham operated group (n=3). Renal ischemia was induced for 30 minutes (group 1), 60 minutes (group 2) and 120 minutes (group 3). MR imaging was performed before ischemia as well as one hour, 24 hours, and 72 hours after reperfusion. A 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy was performed before ischemia, as well as 24 hours and 72 hours after reperfusion. The signal-to-noise ratio (SNR) on the T2WI, time-relative signal intensity (%RSI) curve on dynamic enhanced images, and relative left renal uptake (%) on DMSA scan were obtained and compared to the histologic findings. The SNR of the cortex on the T2WI changed significantly over the course of the reperfusion time (p<0.001), but was not significantly different among the ischemia groups. The area under the time-%RSI curve gradually decreased from cortex to inner medulla before ischemia, which was reversed and gradually increased after reperfusion. The areas under the time-%RSI curve of outer and inner medulla were significantly different among the ischemia groups (p=0.04, p=0.008). The relative renal uptake (%) of left kidney decreased significantly over the reperfusion time (p=0.03), and was also significantly different among the ischemia groups (p=0.005). Tubular cell necrosis was observed in 16 rabbits (76.2%). The histologic grades of group 3 were higher than those of group 1 and group 2 (p=0.002). Even in rabbits without tubular cell necrosis, the areas under the time-%RSI curves of the cortex, outer, and inner medulla after a 72 hour reperfusion time were significantly lower than those before ischemia (p=0.007, p=0.005, p=0.004). The results of this study suggest that dynamic enhanced MR imaging could be a useful tool for the evaluation of renal ischemia and reperfusion injury.

Liposome imaging agents in personalized medicine

DEFF Research Database (Denmark)

Petersen, Anncatrine Luisa; Hansen, Anders Elias; Gabizon, Alberto

2012-01-01

In recent years the importance of molecular and diagnostic imaging has increased dramatically in the treatment planning of many diseases and in particular in cancer therapy. Within nanomedicine there are particularly interesting possibilities for combining imaging and therapy. Engineered liposomes...... that selectively localize in tumor tissue can transport both drugs and imaging agents, which allows for a theranostic approach with great potential in personalized medicine. Radiolabeling of liposomes have for many years been used in preclinical studies for evaluating liposome in vivo performance and has been...... start to consider how to use imaging for patient selection and treatment monitoring in connection to nanocarrier based medicines. Nanocarrier imaging agents could furthermore have interesting properties for disease diagnostics and staging. Here, we review the major advances in the development...

Diffusion-weighted MR imaging of kidneys in renal artery stenosis

International Nuclear Information System (INIS)

Yildirim, Erkan; Kirbas, Ismail; Teksam, Mehmet; Karadeli, Elif; Gullu, Hakan; Ozer, Ismail

2008-01-01

Objective: The purpose of our study was to evaluate perfusion and diffusion of kidneys in renal artery stenosis (RAS) and any correlation between stenosis and ADC values and whether this imaging modality may be a noninvasive complementary assessment technique to MR angiography before interventional procedures. Materials and methods: Twenty consecutive patients suspected of having renal artery stenosis were evaluated with renal MR angiography to exclude stenosis and were then included in the study. Transverse DW multisection echo-planar MR imaging was performed. In the transverse ADC map, rectangular regions of interest were placed in the cortex on 3 parts (upper, middle, and lower poles) in each kidney. ADCs of the kidneys were calculated separately for the low, average, and high b-values to enable differentiation of the relative influence of the perfusion fraction and true diffusion. The ADC values of 39 kidneys (13 with renal artery stenosis and 26 normal renal arteries) were compared, and the relationship between stenosis degree and ADC values was calculated. Results: RAS was detected in 11 of 20 (55%) patients with MRA. Thirteen of 39 kidneys demonstrated RAS, and 26 were normal. The ADC low (1.9 ± 0.2 versus 2.1 ± 0.2; P = .020), ADC average (1.7 ± 0.2 versus 1.9 ± 0.1; P = .006), and ADC high (1.8 ± 0.2 versus 2.0 ± 0.1; P = .012) values were significantly lower in patients with kidneys with arterial stenosis than that in patients with kidneys with normal arteries. Statistical analysis revealed that stenosis degree correlated strongly with ADC low (r = -.819; P = .001), ADC average (r = -.754; P = .003), and ADC high (r = -.788; P = .001). The ADC low , ADC average , and ADC high values were significantly lower in patients with kidneys with arterial stenosis than that in patients with kidneys with normal arteries. Conclusion: We think that DW MR imaging of kidneys with RAS can help determine the functional status of a renal artery stenosis

Preparation of Ga-68-NOTA as a renal PET agent and feasibility tests in mice

International Nuclear Information System (INIS)

Lee, Ji Youn; Jeong, Jae Min; Kim, Young Ju; Jeong, Hyuk-Jin; Lee, Yun-Sang; Lee, Dong Soo

2014-01-01

Introduction: Positron emission tomography (PET) may provide more accurate quantification of kidney function such as glomerular filtration rate (GFR) than gamma imaging. The purpose of these experiments was to prepare and evaluate Ga-68 complexes as potential PET agents for measurement of GFR. Methods: We labeled EDTA, DTPA, DOTA, and NOTA with Ga-68 obtained from a Ge-68/Ga-68-generator and measured the binding to serum and red blood cells. Biodistribution study was performed in male BALB/c mice after intravenous injection together with Cr-51-EDTA as the standard for glomerular filtration rate (GFR) measurement. Animal-PET study was performed using BALB/c mice. Results: All the tested chelating agents except DTPA showed quantitative labeling yields (> 99%). Among them, Ga-68-NOTA showed consistently low binding to both human and mouse RBC and serum protein. Biodistribution study showed no significant difference between Ga-68-NOTA and Cr-51-EDTA groups by one-way analysis of variance (ANOVA) (p > 0.05). Furthermore, the GFR values obtained by Ga-68-NOTA and Cr-51-EDTA were almost same (0.26 ± 0.04 and 0.25 ± 0.04 mL/min, respectively). Animal-PET study showed almost the same GFR (0.25 mL/min) with the values obtained by biodistribution study. Conclusion: We proved that an easy-to-prepare agent Ga-68-NOTA is ideal for renal PET as well as for GFR measurement

Contribution of MR imaging to the diagnosis of neonatal adrenal hemorrhage and renal vein thrombosis

International Nuclear Information System (INIS)

Brill, P.W.; Jogannath, A.S.; Winchester, P.H.; Markisz, J.A.; Zirinsky, K.

1988-01-01

Three newborns with flank masses underwent MR imaging after adrenal hemorrhage and/or renal vein and inferior vena cava (IVC) thromboses were suspected at US. The infants underwent a total of six MR examinations with the head coil of a 0.6-T unit. Relatively T1- and T2-weighted images were obtained in axial, sagittal, and coronal planes. MR imaging was found to be valuable in defining the hemorrhagic nature of suprarenal masses and in delineating the full extent of thrombi in the renal veins and IVC. Two infants with clinical and radionuclide scan evidence of renal parenchymal damage had abnormal corticomedullary distinction on MR images

Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors.

Science.gov (United States)

Bhatti, Aftab A; Chugtai, Aamir; Haslam, Philip; Talbot, David; Rix, David A; Soomro, Naeem A

2005-11-01

To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors. Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery. CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively. Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.

Comparing the difference of measured GFR of ectopic pelvic kidney between anterior and posterior imaging processing in renal dynamic imaging

International Nuclear Information System (INIS)

Li Baojun; Zhao Deshan

2014-01-01

Objective: To compare and analyze the difference of measured glomerular filtration rate (GFR) of ectopic pelvic kidney between anterior and posterior imaging processing in renal dynamic imaging. Methods: There were 10 patients collected retrospectively, with ectopic kidneys in pelvic cavity confirmed by ultrasound, CT, renal dynamic imaging and other imaging modalities. All images of ectopic kidneys in renal dynamic imaging were processed by anterior and posterior methods respectively. The ectopic kidney was only processed in anterior imaging, ectopic kidney and contralateral normal kidney were processed in posterior imaging. Total GFR equalled the sum of GFR of normal kidney in posterior imaging and GFR of ectopic kidney in anterior imaging, was compared with total GFR of two kidneys in posterior imaging and GFR in two-sample method. All correlation analysis were completed between GFRs from three methods and all patients were followed up. Statistically paired t-test and bivariate correlation analysis test were used. Results: The mean GFR of ectopic kidney in anterior imaging equal to (27.48±12.24) ml/(min · 1.73 m 2 ). It was more than GFR [(10.71 ±4.74) ml/ (min · 1.73 m 2 )] in posterior imaging above 46% (t=5.481, P<0.01). There was no significant difference (t=-2.238, P>0.05), but better correlation (r=0.704, P<0.05) between total GFR in anterior imaging and GFR in two-sample method. There was significant difference (t=4.629, P<0.01)and worse correlation (r=0.576, P>0.05) between total GFR in posterior imaging and GFR in two-sample method. Conclusion: Comparing with GFR in posterior imaging, GFR in anterior imaging can more truly reflect function condition of ectopic pelvic kidney in renal dynamic imaging. (authors)

Arterial spin labeling MR imaging for characterisation of renal masses in patients with impaired renal function: initial experience

International Nuclear Information System (INIS)

Pedrosa, Ivan; Rafatzand, Khashayar; Robson, Philip; Alsop, David C.; Wagner, Andrew A.; Atkins, Michael B.; Rofsky, Neil M.

2012-01-01

To retrospectively evaluate the feasibility of arterial spin labeling (ASL) magnetic resonance imaging (MRI) for the assessment of vascularity of renal masses in patients with impaired renal function. Between May 2007 and November 2008, 11/67 consecutive patients referred for MRI evaluation of a renal mass underwent unenhanced ASL-MRI due to moderate-to-severe chronic or acute renal failure. Mean blood flow in vascularised and non-vascularised lesions and the relation between blood flow and final diagnosis of malignancy were correlated with a 2-sided homogeneous variance t-test and the Fisher Exact Test, respectively. A p value 2 (range 7-39). The average blood flow of 11 renal masses interpreted as ASL-positive (134 +/- 85.7 mL/100 g/min) was higher than that of 6 renal masses interpreted as ASL-negative (20.5 +/- 8.1 mL/100 g/min)(p = 0.015). ASL-positivity correlated with malignancy (n = 3) or epithelial atypia (n = 1) at histopathology or progression at follow up (n = 7). ASL detection of vascularity in renal masses in patients with impaired renal function is feasible and seems to indicate neoplasia although the technique requires further evaluation. (orig.)

T2' imaging of native kidneys and renal allografts. A feasibility study

International Nuclear Information System (INIS)

Mathys, C.; Blondin, D.; Wittsack, H.J.; Miese, F.R.; Rybacki, K.; Walther, C.; Holstein, A.; Lanzman, R.S.

2011-01-01

Purpose: To evaluate the feasibility of T2' mapping in native kidneys and renal allografts. Materials and Methods: Following approval of the local ethics committee, 24 renal allograft recipients and 10 control subjects (healthy volunteers) were included in this study. Multi-echo T2 and T2 * imaging was performed on a 1.5 Tesla scanner. Allograft recipients were assigned to two groups: group (a), 8 patients with good (glomerular filtration rate of more than 40 ml/min) allograft function and no evidence of transplant rejection, transplant renal artery stenosis or ureteral obstruction; group (b), 16 patients with deterioration of renal graft function (glomerular filtration rate (GFR) of 40 ml/min or less). Two different imaging protocols were tested. Results: The mean T2' relaxation parameters were 108.33 msec ± 13.34, 100.00 msec ± 18.89 and 124.57 msec ± 6.51 for groups (a), (b) and for control subjects, respectively. The reduction of T2' values in patient group (b) was not statistically significant. However, significant correlations could be demonstrated between T2' values and the glomerular filtration rate (GFR) of renal allograft function. The reproducibility was tested and the coefficients of variation of T2' values in the cortex of transplanted kidneys were 11.1 % within subjects and 11.3 % between subjects. Conclusion: Our results indicate that T2' imaging is a promising non-enhanced technique, which seems to reveal information on transplant function. Further studies are required to determine the clinical value of T2' mapping for monitoring renal allograft recipients. (orig.)

Advances in the staging of renal cell carcinoma with high-resolution imaging

International Nuclear Information System (INIS)

Hallscheidt, P.; Noeldge, G.; Schawo, S.; Kauffmann, G.; Palmowski, M.; Bartling, S.; Pfitzenmaier, J.

2007-01-01

Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches. (orig.)

Renal damage after extracorporeal shock-wave lithotripsy detected by magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Torii, Shinichiro; Machida, Toyohei; Ooishi, Yukihiko; Tashiro, Kazuya; Mochizuki, Atsushi; Yoshigoe, Fukuo

1988-08-01

The acute effects of extracorporeal Shock-wave lithotripsy (ESWL) on morphology of the renal parenchyma were evaluated by Magnetic Resonance Imaging (MRI) in 15 kidneys, before and immediately after (within 24 hours) ESWL in 11 cases. The renal parenchymal damages were observed by MRI as the changes of signal itensity of renal cortex and medulla, perirenal fluid, loss of corticomedullar differentiation, and other renal traumas. Loss of corticomedullar differentiation was seen in 9/11 cases and peripheral fluid of the kidney was seen in 4/11 cases. Irregular and edematous changes of renal capsula were seen in 5/11 cases. Obvious abnormal findings indicated renal trauma were not observed in this study. Several MRI findings may transient and reversible changes and the morpholigic changes detected by MRI may attributed to renal parenchymal obstruction and edema and decreasing of renal capillary flow, such as in renal contusion. It is concluded that MRI is very sensitive and the best technique to detect the effects and clinical trouble of ESWL.

CT imaging and histopathological features of renal epithelioid angiomyolipomas

International Nuclear Information System (INIS)

Cui, L.; Zhang, J.-G.; Hu, X.-Y.; Fang, X.-M.; Lerner, A.; Yao, X.-J.; Zhu, Z.-M.

2012-01-01

Aim: To describe computed tomography (CT) imaging and histopathological manifestations of renal epithelioid angiomyolipomas (EAMLs) for better understanding and cognition in the diagnosis of this new category of renal tumours. Materials and methods: Clinical data and CT images from 10 cases of EAML were retrospectively analysed. All patients underwent CT with and without contrast medium administration, with multiplanar reconstruction (MPR) when needed. Results: Plain CT manifestations of EAMLs were a higher density of mass (10–25 HU) than renal parenchyma, bulging contour of the involved kidney, absence of fat, distinct edges without a lobulate appearance. Contrast-enhanced CT features were markedly heterogeneous enhancement (from rapid wash-in to slow wash-out), large tumour size without lobular appearance, complete capsule with distinct margins and frequent mild necrotic areas. Histopathological features were epithelioid cells with eosinophilic cytoplasm, large and deeply stained nuclei, and dense arrangement of tumour cells with patchy necrosis; diffuse sheets of epithelioid cells were positive for HMB-45 (melanoma-associated antigen) and negative for epithelial membrane antigen (EMA) staining. Conclusion: Multiple specific CT features correlated well with the histopathology and may play an important role in the primary diagnosis of EAMLs.

Computer-assisted static/dynamic renal imaging: a screening test for renovascular hypertension

International Nuclear Information System (INIS)

Keim, H.J.; Johnson, P.M.; Vaughan, E.D. Jr.; Beg, K.; Follett, D.A.; Freeman, L.M.; Laragh, J.H.

1979-01-01

Computer-assisted static/dynamic renal imaging with [ 197 Hg] chlormerodrin and [/sup 99m/Tc] pertechnetate was evaluated prospectively as a screening test for renovascular hypertension. Results are reported for 51 patients: 33 with benign essential hypertension and 18 with renovascular hypertension, and for 21 normal controls. All patients underwent renal arteriography. Patients with significant obesity, renal insufficiency, or renoparenchymal disease were excluded from this study. Independent visual analyses of renal gamma images and time-activity transit curves identified 17 of the 18 patients with renovascular hypertension; one study was equivocal. There were five equivocal and three false-positive results in the essential hypertension and normal control groups. The sensitivity of the method was 94% and the specificity 85%. Since the prevalence of the renovascular subset of hypertension is approximately 5%, the predictive value is only 25%. Inclusion of computer-generated data did not improve this result. Accordingly, this method is not recommended as a primary screening test for renovascular hypertension

Magnetization Transfer Magnetic Resonance Imaging Noninvasively Detects Renal Fibrosis in Swine Atherosclerotic Renal Artery Stenosis at 3.0 T.

Science.gov (United States)

Jiang, Kai; Ferguson, Christopher M; Woollard, John R; Zhu, Xiangyang; Lerman, Lilach O

2017-11-01

Renal fibrosis is a useful biomarker for diagnosis and evaluation of therapeutic interventions of renal diseases but often requires invasive testing. Magnetization transfer magnetic resonance imaging (MT-MRI), which evaluates the presence of macromolecules, offers a noninvasive tool to probe renal fibrosis in murine renal artery stenosis (RAS) at 16.4 T. In this study, we aimed to identify appropriate imaging parameters for collagen detection at 3.0 T MRI and to test the utility of MT-MRI in measuring renal fibrosis in a swine model of atherosclerotic RAS (ARAS). To select the appropriate offset frequency, an MT-MRI study was performed on a phantom containing 0% to 40% collagen I and III with offset frequencies from -1600 to +1600 Hz and other MT parameters empirically set as pulse width at 16 milliseconds and flip angle at 800 degrees. Then selected MT parameters were used in vivo on pigs 12 weeks after sham (n = 8) or RAS (n = 10) surgeries. The ARAS pigs were fed with high-cholesterol diet to induce atherosclerosis. The MT ratio (MTR) was compared with ex vivo renal fibrosis measured using Sirius-red staining. Offset frequencies at 600 and 1000 Hz were selected for collagen detection without direct saturation of free water signal, and subsequently applied in vivo. The ARAS kidneys showed mild cortical and medullary fibrosis by Sirius-red staining. The cortical and medullary MTRs at 600 and 1000 Hz were both increased. Renal fibrosis measured ex vivo showed good linear correlations with MTR at 600 (cortex: Pearson correlation coefficient r = 0.87, P 3.0 T. Therefore, MT-MRI may potentially be clinically applicable and useful for detection and monitoring of renal pathology in subjects with RAS.

Radiographic imaging study of pneumocystis carinii pneumonia in renal transplantation recipient

International Nuclear Information System (INIS)

Chen Chengshui; Li Yuping; Ye Min; Zhang Dongqing; Zheng Shaoling; Xing Lingling; Chen Shaoxian

2005-01-01

Objective: To improve the understanding of the imaging features of pneumocystis carinii pneumonia (PCP) in renal transplantation recipient. Methods: Twenty-four renal transplantation recipients suffered from PCP. There were 19 males and 5 females, the age ranged from 23 to 62 years (mean 39.2 years). The mean time duration from renal transplantation to onset of illness was 5.6 months, and the mean time from onset of illness to consultation was 5.5 days. All patients had fever and dyspnea. The chest radiographic imaging was reviewed and the dynamic imaging changes were followed up. Results: Pathology showed alveolar exudation, inflammation in the interstitium and alveolar lumen, fibrosis in lung interstitium, and erosion of alveolar epithelium. Initial chest X-ray demonstrated diffuse changes in only 10 patients. Of the 10 patients, 3 showed ground-glass changes, 2 showed ground-glass and reticular changes, and 4 showed consolidation. But all patients had abnormal ill-defined ground-glass findings on thoracic CT images, 9 of them showed reticulum among ground-glass changes, and 12 of them showed consolidation among ground-glass changes. Among patients with clinical deterioration, chest radiographs and CT showed progression of pulmonary infiltrations, and it reached the top level within 1 to 2 weeks. With successful response to therapy, chest radiographs and CT showed resolution of the lung opacities, but the resolution was retarded for about 1 week, complete resolution would need 4 weeks. Conclusion: The radiographic imaging features of PCP in renal transplantation recipient were diffuse interstitial alterations and consolidations, and with fast progression. With successful response to therapy, it showed resolution of the lung opacities, but the resolution was retarded for about 1 week, and complete resolution would need 4 weeks. Chest CT was more sensitive than radiographs. (authors)

Effect of indomethacin and salt depletion on renal proton MR imaging; An experimental study in the rat

Energy Technology Data Exchange (ETDEWEB)

Heyman, S.N.; Mammen, M. (Harvard Medical School, Boston, MA (United States). Charles A Dana Research Inst. Beth Israel Hospital, Boston, MA (United States))

1991-11-01

Blockade of the synthesis of vasodilating prostaglandins with non-steroidal anti-inflammatory drugs (NSAID) renders the renal medulla susceptible to hypoxic injury with reduced renal function, especially in clinical conditions characterized by volume depletion. Alterations in renal hemodynamics and urine production may effect renal MR imaging under these circumstances. We injected salt-depleted and control rats undergoing proton MR imaging with indomethacin 10 mg/kg. Indomethacin abolished the cortico-medullary T2-gradient and markedly diminished the overall renal signal in salt-depleted rats only. These changes, which progressed over a period of 40 min after indomethacin was injected, probably result from renal oligemia and decreased urine production, with an associated decrease in T2-values. We suggest that a history of consumption of non-steroidal anti-inflammatory drugs should be obtained and taken into account in the evaluation of renal proton MR imaging, especially in the presence of salt and volume depletion. (orig.).

Duplex sonography and magnetic resonance imaging in the clarification of nephrological complications after renal transplant

International Nuclear Information System (INIS)

Gueckel, C.; Krestin, G.P.; Wienand, P.

1989-01-01

A prospective study compared Duplex sonography and magnetic resonance imaging in evaluating renal transplant. Hundred and two Duplex sonographic and 24 MR examinations were performed and correlated with clinical course or biopsy. All normal renal allografts, 6 transplants with acute tubular necrosis and 2 cases of cyclosporin toxicity had normal Doppler waveforms, whereas 9 renal transplants with evidence of interstitial rejection by biopsy showed an obliteration or reversal of diastolic flow. MR imaging was less specific in identifying allograft rejection. There were false positive results in normal renal transplants, allografts with acute tubular necrosis and after rejection therapy. With regard to cost, accessibility and specificity, Duplex sonography is the method of choice for the evaluation of renal allografts. (orig.) [de

Prevalence and patterns of renal involvement in imaging of malignant lymphoproliferative diseases

International Nuclear Information System (INIS)

Bach, Andreas Gunter; Behrmann, Curd; Spielmann, Rolf Peter; Surov, Alexey; Holzhausen, Hans Jurgen; Katzer, Michaela; Arnold, Dirk

2012-01-01

Background: Renal involvement in patients with lymphoproliferative disease is an uncommon radiological finding. Purpose: To determine its prevalence and radiological appearances in a patient population. Material and Methods: All forms of lymphoproliferative disease (ICD: C81-C96) were considered. From January 2005 to January 2010, 668 consecutive patients with lymphoproliferative disease were identified with the help of the radiological database and patient records. Inclusion criteria were complete staging including appropriate CT scan and/or MRI. All stored images (initial staging and follow-up examinations) were reviewed. Results: Review of all stored images revealed renal infiltration in patients with non-Hodgkin lymphoma (11 of 364 = 3.0%; median age = 65 years, m:f = 6:5) but also multiple myeloma (2 of 162 = 1.2%; median age = 72 years; m:f = 1:1) and leukemia (5 of 101 4.9%; median age = 12 years; m:f = 2:3). There were no cases of renal infiltration in 41 patients with Hodgkin's disease. In total there were six patients with solitary lesions, five patients with diffuse renal enlargement, four patients with perirenal lesions, and two patients with direct invasion of the kidney. Conclusion: In leukemia the most common imaging pattern is diffuse enlargement. In the other subtypes of lymphoproliferative disease no specific correlation between typical CT patterns and subtype of lymphoproliferative disease can be found. The prevalence of renal involvement is in line with earlier studies. Contrary to earlier reports, multiple lesions were not found to be a common pattern

Analysis of renal nuclear medicine images

International Nuclear Information System (INIS)

Jose, R.M.J.

2000-01-01

Nuclear medicine imaging of the renal system involves producing time-sequential images showing the distribution of a radiopharmaceutical in the renal system. Producing numerical and graphical data from nuclear medicine studies requires defining regions of interest (ROIs) around various organs within the field of view, such as the left kidney, right kidney and bladder. Automating this process has several advantages: a saving of a clinician's time; enhanced objectivity and reproducibility. This thesis describes the design, implementation and assessment of an automatic ROI generation system. The performance of the system described in this work is assessed by comparing the results to those obtained using manual techniques. Since nuclear medicine images are inherently noisy, the sequence of images is reconstructed using the first few components of a principal components analysis in order to reduce the noise in the images. An image of the summed reconstructed sequence is then formed. This summed image is segmented by using an edge co-occurrence matrix as a feature space for simultaneously classifying regions and locating boundaries. Two methods for assigning the regions of a segmented image to organ class labels are assessed. The first method is based on using Dempster-Shafer theory to combine uncertain evidence from several sources into a single evidence; the second method makes use of a neural network classifier. The use of each technique in classifying the regions of a segmented image are assessed in separate experiments using 40 real patient-studies. A comparative assessment of the two techniques shows that the neural network produces more accurate region labels for the kidneys. The optimum neural system is determined experimentally. Results indicate that combining temporal and spatial information with a priori clinical knowledge produces reasonable ROIs. Consistency in the neural network assignment of regions is enhanced by taking account of the contextual

Renal artery stenosis: comparative assessment by unenhanced renal artery mra versus contrast-enhanced MRA

International Nuclear Information System (INIS)

Khoo, Michael M.Y.; Deeab, Dhafer; Gedroyc, Wladyslaw M.W.; Dick, Elizabeth A.; Duncan, Neil; Taube, David

2011-01-01

To evaluate steady-state free precession (SSFP) non-contrast-enhanced MR angiography (Unenhanced-MRA) versus conventional contrast-enhanced MR angiography (CE-MRA) in the detection of renal artery stenosis (RAS). Retrospective analysis of 70 consecutive patients referred for suspected RAS, examined by SSFP Unenhanced-MRA and CE-MRA. Image quality, quality of visible renal arterial segments, presence and grade of RAS were evaluated. The Unenhanced-MRA were compared against reference standard CE-MRA results. 149 renal arteries were assessed with 21 haemodynamically significant stenoses (≥50% stenosis) demonstrated by CE-MRA. Combined sensitivity and specificity for RAS detection by Unenhanced-MRA was 72.8% and 97.8% respectively. There is substantial correlation for RAS detection between Unenhanced-MRA and CE-MRA with kappa values of between 0.64 and 0.74. There was excellent inter-observer correlation for RAS on Unenhanced-MRA (kappa values 0.82-1.0). Our study has shown Unenhanced-MRA to be a viable alternative to CE-MRA, yielding images equal in quality without the requirement for gadolinium contrast agents. The sensitivity and specificity for the detection of haemodynamically significant stenoses are comparable to CE-MRA. Potentially, Unenhanced-MRA could be used as an initial investigation to avoid performing CE-MRA in patients with normal renal arteries, however we suggest that its real value will lie in being complementary to CE-MRA. (orig.)

Arterial spin labeling MR imaging for characterisation of renal masses in patients with impaired renal function: initial experience

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Pedrosa, Ivan [Beth Israel Deaconess Medical Center and Harvard Medical School, Department of Radiology, Boston, MA (United States); UT Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Rafatzand, Khashayar; Robson, Philip; Alsop, David C. [Beth Israel Deaconess Medical Center and Harvard Medical School, Department of Radiology, Boston, MA (United States); Wagner, Andrew A. [Beth Israel Deaconess Medical Center and Harvard Medical School, Surgery, Division of Urology, Boston, MA (United States); Atkins, Michael B. [Beth Israel Deaconess Medical Center and Harvard Medical School, Hematology/Oncology, Boston, MA (United States); Rofsky, Neil M. [University of Texas Southwestern Medical Center, Departments of Radiology, Dallas, TX (United States)

2012-02-15

To retrospectively evaluate the feasibility of arterial spin labeling (ASL) magnetic resonance imaging (MRI) for the assessment of vascularity of renal masses in patients with impaired renal function. Between May 2007 and November 2008, 11/67 consecutive patients referred for MRI evaluation of a renal mass underwent unenhanced ASL-MRI due to moderate-to-severe chronic or acute renal failure. Mean blood flow in vascularised and non-vascularised lesions and the relation between blood flow and final diagnosis of malignancy were correlated with a 2-sided homogeneous variance t-test and the Fisher Exact Test, respectively. A p value <0.05 was considered statistically significant. Seventeen renal lesions were evaluated in 11 patients (8 male; mean age = 70 years) (range 57-86). The median eGFR was 24 mL/min/1.73 m{sup 2} (range 7-39). The average blood flow of 11 renal masses interpreted as ASL-positive (134 +/- 85.7 mL/100 g/min) was higher than that of 6 renal masses interpreted as ASL-negative (20.5 +/- 8.1 mL/100 g/min)(p = 0.015). ASL-positivity correlated with malignancy (n = 3) or epithelial atypia (n = 1) at histopathology or progression at follow up (n = 7). ASL detection of vascularity in renal masses in patients with impaired renal function is feasible and seems to indicate neoplasia although the technique requires further evaluation. (orig.)

Magnetic resonance imaging contrast agents: Overview and perspectives

International Nuclear Information System (INIS)

Yan Guoping; Robinson, Leslie; Hogg, Peter

2007-01-01

Magnetic resonance imaging (MRI) is a non-invasive clinical imaging modality, which has become widely used in the diagnosis and/or staging of human diseases around the world. Some MRI examinations include the use of contrast agents. The categorizations of currently available contrast agents have been described according to their effect on the image, magnetic behavior and biodistribution in the body, respectively. In this field, superparamagnetic iron oxide particles and soluble paramagnetic metal chelates are two main classes of contrast agents for MRI. This review outlines the research and development of MRI contrast agents. In future, the ideal MRI contrast agent will be focused on the neutral tissue- or organ-targeting materials with high relaxivity and specificity, low toxicity and side effects, suitable long intravascular duration and excretion time, high contrast enhancement with low dose in vivo, and with minimal cost

Genitourinary imaging

International Nuclear Information System (INIS)

Anon.

1987-01-01

The application of radionuclide studies in nephrology, urology, and gynecology has reached a measurable degree of maturity in recent years. However, the utilization of these techniques continues to be less frequent than the clinical advantages would seem to warrant, probably because of the complexities of renal physiology. This complexity has been resulted in the availability of large number of agents for renal studies. It is the functional nature of nuclear medicine studies that provides their tremendous potential for use in evaluation of the kidney, where the pathology of which is so often related to functional derangements rather than to anatomic problems. A familiarity with various measures of renal function and with the effects of these parameters on the handling of the commonly used radiopharmaceuticals is essential to the appropriate use of radionuclide studies. The types of studies commonly used include renal perfusion studies, renal imaging solely for anatomic information, and renal imaging combined with an estimate of renal function. Radionuclide techniques serve a complementary role to radiography, ultrasonography, and computed tomography in the morphologic diagnosis of renal diseases. Urethral abnormalities, bladder diverticula, and minimal distal urethral reflux are better demonstrated with radiographic than nuclear technique, but radionuclide cystography can be helpful for follow-up evaluations. Radionuclide testicular imaging is extremely useful in the differential diagnosis of testicular torsion

Establishment of frame image in dynamic function renal studies

International Nuclear Information System (INIS)

Guedes, Germano P.; Brunetto, Sergio Q.

1996-01-01

Statistical procedures applied to a set of images of renal function study are described to define a region of interest (ROI) on the kidneys's contours. The kidneys geometry is considered to adapt to the emitting area in every frames

Renal damage after extracorporeal shock-wave lithotripsy detected by magnetic resonance imaging

International Nuclear Information System (INIS)

Torii, Shinichiro; Machida, Toyohei; Ooishi, Yukihiko; Tashiro, Kazuya; Mochizuki, Atsushi; Yoshigoe, Fukuo

1988-01-01

The acute effects of extracorporeal Shock-wave lithotripsy (ESWL) on morphology of the renal parenchyma were evaluated by Magnetic Resonance Imaging (MRI) in 15 kidneys, before and immediately after (within 24 hours) ESWL in 11 cases. The renal parenchymal damages were observed by MRI as the changes of signal itensity of renal cortex and medulla, perirenal fluid, loss of corticomedullar differentiation, and other renal traumas. Loss of corticomedullar differentiation was seen in 9/11 cases and peripheral fluid of the kidney was seen in 4/11 cases. Irregular and edematous changes of renal capsula were seen in 5/11 cases. Obvious abnormal findings indicated renal trauma were not observed in this study. Several MRI findings may transient and reversible changes and the morpholigic changes detected by MRI may attributed to renal parenchymal obstruction and edema and decreasing of renal capillary flow, such as in renal contusion. It is concluded that MRI is very sensitive and the best technique to detect the effects and clinical trouble of ESWL. (author)

Gradient field echo imaging and Gd-DTPA for the assessment of renal function in humans

International Nuclear Information System (INIS)

Von Schulthess, G.K.; Kikinis, R.; Durr, R.; Bino, M.; Jager, P.; Kubler, O.

1986-01-01

To evaluate renal parenchymal function, 1.5 T gradient field echo imaging using a sequence of repetitive 10-second scans was performed in apneic patients after injection of Gd-DTPA (0.1 mmol/kg body weight). During the 10-second pauses the patients were allowed to breathe. Angled coronal images (TR=40 msec, TE =20 msec, flip angle = 40 0 ) were obtained in four volunteers and four patients with hydronephrosis. Image quality was excellent, suggesting unprecedented spatial resolution for renal function studies. Initially, cortical perfusion was observed. Then the papilae became isointense; after 70 seconds they became hypointense; and finally the renal pelvic signal dropped. No papillary signal drop was seen in hydronephrosis, as confirmed by region-of-interest analysis. These results strongly suggest that in MR renal ''function'' studies with Gd-DTPA, T1 and T2 paramagnetic effects are operative

Benign renal complex cysts: MR imaging

International Nuclear Information System (INIS)

Levy, P.; Helenon, O.; Melki, P.; Paraf, F.; Chauveau, D.; Chretien, Y.; Moreau, J.F.

1994-01-01

The aim of this study was to assess the magnetic resonance imaging (MRI) characteristics of 13 benign complex renal cysts using T1 and T2-weighted images and contrast-enhanced images. The results have been compared to CT and ultrasonographic findings in all cases and correlated with histopathologic datas in 12 cases. Five groups have been defined according to the MR features. Group 1: homogeneous low signal intensity on T1-weighted images and homogeneous high signal intensity on T2-weighted images mimicking simple cyst (n = 2); group 2: homogeneous high signal intensity on both T1 and T2-weighted images mimicking hemorrhagic cyst (n = 1); group 3: characterized by high signal intensity on T1-weighted images and fluid-iron level on T2-weighted images (n = 3); group 4: characterized by fluid-iron level on both T1 and T2-weighted images (n = 3); group 5: pseudotumoral feature: heterogeneous signal intensity and/or wall contrast enhancement (n = 3). Among the 13 indeterminate lesions on ultrasonography and CT, MRI was of diagnostic value in 8 cases, whereas the 5 remaining cases remained indeterminate on MR images. Our results suggest that MRI can be useful in the diagnosis of benign complex cyst of the kidney presenting as indeterminate cystic lesion on other modalities. (authors). 40 refs., 7 figs., 2 tabs

Sonographic patterns of renal lymphoma in B-mode imaging and in contrast-enhanced ultrasound (CEUS)—A retrospective evaluation

International Nuclear Information System (INIS)

Trenker, C.; Neesse, A.; Görg, C.

2015-01-01

Introduction: Retrospective analysis of sonographic patterns of renal lymphoma in B-mode imaging and contrast-enhanced ultrasound (CEUS). Patients/methods: From January 2000 to June 2014, 27 patients with clinical or histologically confirmed renal lymphoma were examined with B-mode imaging, followed by CEUS in 8 cases. Results: In B-mode imaging renal lymphoma were hypoechoic in all 27 cases (100%). 9 patients (33.3%) had a bilateral, 18 (66.7%) patients had an unilateral lymphoma infiltration of the kidneys. 8 (29.6%) cases of small nodular, 5 (18.5%) cases of large nodular and 6 (22.2%) cases of perirenal lymphoma infiltration of the kidney were observed in B-mode imaging. Bulky-formation of renal lymphoma was detected in 6 (22.2%) patients and 2 (7.4%) patients had a diffuse lymphoma infiltration of the kidneys. In CEUS an arterial isoechoic enhancement was observed in 5 (62.5%)- and, an arterial hypoechoic enhancement was observed in 3 (37.5%) cases of renal lymphoma. A hypoechoic enhancement in the parenchymal phase was observed in 8 (100%) cases of renal lymphoma infiltration. Conclusion: In B-mode-imaging, nodular lymphoma infiltration of the kidneys is the most common of all renal lymphoma patterns in B-mode imaging. In CEUS, renal lymphoma presented an arterial iso- or hypoechoic enhancement, followed by a hypoechoic enhancement in the parenchymal phase. In regard to the differentiation of renal lymphoma to benign lesions of the kidney, CEUS may be helpful. However, the differentiation of renal lymphoma from other malignant lesions of the kidney like renal cell carcinoma is not feasible by CEUS

Renal Arteriovenous Shunts: Clinical Features, Imaging Appearance, and Transcatheter Embolization Based on Angioarchitecture.

Science.gov (United States)

Maruno, Miyuki; Kiyosue, Hiro; Tanoue, Shuichi; Hongo, Norio; Matsumoto, Shunro; Mori, Hiromu; Sagara, Yoshiko; Kashiwagi, Junji

2016-01-01

Renal arteriovenous (AV) shunt, a rare pathologic condition, is divided into two categories, traumatic and nontraumatic, and can cause massive hematuria, retroperitoneal hemorrhage, pain, and high-output heart failure. Although transcatheter embolization is a less-invasive and effective treatment option, it has a potential risk of complications, including renal infarction and pulmonary embolism, and a potential risk of recanalization. The successful embolization of renal AV shunt requires a complete occlusion of the shunted vessel while preventing the migration of embolic materials and preserving normal renal arterial branches, which depends on the selection of adequate techniques and embolic materials for individual cases, based on the etiology and imaging angioarchitecture of the renal AV shunts. A classification of AV malformations in the extremities and body trunk could precisely correspond with the angioarchitecture of the nontraumatic renal AV shunts. The selection of techniques and choice of adequate embolic materials such as coils, vascular plugs, and liquid materials are determined on the basis of cause (eg, traumatic vs nontraumatic), the classification, and some other aspects of the angioarchitecture of renal AV shunts, including the flow and size of the fistulas, multiplicity of the feeders, and endovascular accessibility to the target lesions. Computed tomographic angiography and selective digital subtraction angiography can provide precise information about the angioarchitecture of renal AV shunts before treatment. Color Doppler ultrasonography and time-resolved three-dimensional contrast-enhanced magnetic resonance angiography represent useful tools for screening and follow-up examinations of renal AV shunts after embolization. In this article, the classifications, imaging features, and an endovascular treatment strategy based on the angioarchitecture of renal AV shunts are described. (©)RSNA, 2016.

Intensity ratio curve analysis of small renal masses on T2-weighted magnetic resonance imaging: Differentiation of fat-poor angiomyolipoma from renal cell carcinoma.

Science.gov (United States)

Moriyama, Shingo; Yoshida, Soichiro; Tanaka, Hajime; Tanaka, Hiroshi; Yokoyama, Minato; Ishioka, Junichiro; Matsuoka, Yoh; Saito, Kazutaka; Kihara, Kazunori; Fujii, Yasuhisa

2018-03-25

To assess the diagnostic ability of a pixel intensity-based analysis in evaluating the magnetic resonance imaging characteristics of small renal masses, especially in differentiating fat-poor angiomyolipoma from renal cell carcinoma. T2-weighted images from 121 solid small renal masses (ratio curve was plotted using intensity ratios, which were ratios of signal intensities of tumor pixels (each pixel along a linear region of interest drawn across the renal tumor on T2-weighted image) to the signal intensity of a normal renal cortex. The diagnostic ability of the intensity ratio curve analysis was evaluated. The tumors were classified into three types: intensity ratio fat-poor angiomyolipoma (n = 19) with no pseudocapsule, iso-low intensity and no heterogeneity; intensity ratio clear cell renal cell carcinoma (n = 76) with a pseudocapsule, iso-high intensity and heterogeneity; and other type of intensity ratio (n = 26), including tumors that did not fall into the above two categories. The sensitivity/specificity/accuracy of the intensity ratio curve analysis in diagnosing fat-poor angiomyolipoma was 93%/94%/94%, respectively. When the intensity ratio curve analysis was applied only to the tumor with undetermined radiological diagnosis, the sensitivity for diagnosing fat-poor angiomyolipoma compared with subjective reading alone significantly improved (93% vs 50%; P = 0.014). Our novel semiquantitative model for combined assessment of key features of fat-poor angiomyolipoma, including low intensity, homogeneity and absence of a pseudocapsule on T2-weighted image, might make diagnosis of fat-poor angiomyolipoma more accurate. © 2018 The Japanese Urological Association.

An analysis of motion correction for 99Tcm DMSA renal imaging in paediatrics

International Nuclear Information System (INIS)

Meadows, A.; Hogg, P.

2007-01-01

Movement artefact during paediatric 99 Tc m DMSA renal imaging can reduce image quality and therefore render images non-diagnostic. This research assessed software used for the correction of movement artefact in children. The software comprised a count rate dependent dynamic acquisition with a 256 x 256 pixel frame-shift motion correction algorithm. A Williams' phantom was used to generate data during dynamic (experimental) and static (control) image acquisitions. During image acquisition, the Williams' phantom was moved to simulate seven typical paediatric patient movements; acquisitions also considered no movement (Gold Standard). Seven image data sets with motion artefact were corrected using the frame-shift software. The corrected, uncorrected, and static images were rated for quality by suitably qualified and experienced nuclear medicine professionals. The images were scored using an image quality assessment instrument, based on a Likert rating scale. Inferential statistics were applied to these data. The image quality ratings demonstrated a statistically significant (P 99 Tc m DMSA renal scans

New MR contrast agent

International Nuclear Information System (INIS)

Grossman, C.D.; Subramanian, G.; Schneider, R.; Szeverenyi, N.E.; Rosenbaum, A.M.; Gagne, G.; Tillapaugh-Fay, G.; Berlin, R.; Ritter-Hrncirik, C.; Yu, S.

1990-01-01

This paper evaluates an MR contrast agent-meglumine tris-(2,6-dicarboxypyridine) gadolinium (III) or gadolinium dipicolinate (Gd-DPC)-produced in-house. Rats were anesthetized with pentobarbital. For renal imaging, bowel motion artifact was minimized with glucagon (0.014 mg/kg, intravenous (IV)). Enhanced images were generated on a 2-T chemical shift imaging system with a 31-cm horizontal bore magnet after IV injection of Gd-DPC (100 μM/kg). Coronal sections of the kidneys and sagittal sections of the brain, 2 mm thick, were made. Six to eight excitations and 128 or 356 phase-encoding steps were used for each image. Control animals were injected with equivalent doses of gadopentetate dimeglumine

Small renal mass cryosurgery: Imaging and vascular changes

NARCIS (Netherlands)

Lagerveld, B.W.

2014-01-01

The combined use of a fluorescent casting technique, cryomicrotome imaging, and 3-D computer analysis as a new static method for visualizing and reconstructing the vascular anatomy in a porcine renal model was studied. The arterial blood supply in 3-D at a resolution of up to 50μm of the whole could

Imaging features of renal complications after crizotinib treatment for non–small-cell lung cancer: a case report

Directory of Open Access Journals (Sweden)

Wan Ying Chan, MBBS

2016-09-01

Full Text Available Crizotinib has been approved for the treatment of advanced ALK-positive non–small cell lung cancer. Its use is associated with the development of complex renal cysts. However, there is limited literature regarding imaging features of renal cystic disease during crizotinib therapy and its complications or progression. Here, we describe a case of a patient with ALK-positive advanced non–small cell lung cancer who developed complex renal cyst during crizotinib treatment. The renal cyst is complicated by infection and abscess formation. Subsequent renal biopsy, antibiotics treatment, and open drainage of loculated renal abscess showed no malignant cells and contributed to the diagnosis. The imaging features should be recognized as renal cystic disease of crizotinib treatment and not to be mistaken as new metastasis and disease progression.

99mTc-DMSA renal uptake in urological diseases measured from renal tomographic images using single photon emission computed tomography (SPECT)

International Nuclear Information System (INIS)

Oishi, Yukihiko; Tashiro, Kazuya; Kishimoto, Koichi; Wada, Tetsuro; Torii, Shinichiro; Yoshigoe, Fukuo; Machida, Toyohei; Yamada, Hideo; Toyama, Hinako.

1987-01-01

To determine renal function, 99m Tc-DMSA renal uptake was measured from renal tomographic images obtained by single photon emission computed tomography (SPECT). A total of 77 tests was conducted on 73 patients with various diseases in the kidneys and urinary tract to determine renal uptake. The correlation coefficient(r) between total renal volume and total renal uptake was 0.3509 and that between renal volume and uptake of 143 kidneys was 0.5433. In 62 patients whose creatinine clearance could be measured, the correlation coefficient between creatinine clearance and total renal volume was 0.2352, and that between creatinine clearance and total renal uptake was 0.8854, that is, creatinine clearance correlated well with renal uptake. Renal volume and uptake determined in 10 normal male and 10 normal female adults were 220 ml and 26.8 % for the right kidney and 239 ml and 27.6 % for the left kidney for the males and 206 ml and 26.4 % (right) and 237 ml and 27.9 % (left) for the females. This method, which requires no blood or urine collection, is very useful as an individual kidney function test to evaluate individual kidney function and to understand kidney function before and after operation in patients with renal and urinary diseases. (author)

Cranial nerve contrast using nerve-specific fluorophores improved by paired-agent imaging with indocyanine green as a control agent

Science.gov (United States)

Torres, Veronica C.; Vuong, Victoria D.; Wilson, Todd; Wewel, Joshua; Byrne, Richard W.; Tichauer, Kenneth M.

2017-09-01

Nerve preservation during surgery is critical because damage can result in significant morbidity. This remains a challenge especially for skull base surgeries where cranial nerves (CNs) are involved because visualization and access are particularly poor in that location. We present a paired-agent imaging method to enhance identification of CNs using nerve-specific fluorophores. Two myelin-targeting imaging agents were evaluated, Oxazine 4 and Rhodamine 800, and coadministered with a control agent, indocyanine green, either intravenously or topically in rats. Fluorescence imaging was performed on excised brains ex vivo, and nerve contrast was evaluated via paired-agent ratiometric data analysis. Although contrast was improved among all experimental groups using paired-agent imaging compared to conventional, solely targeted imaging, Oxazine 4 applied directly exhibited the greatest enhancement, with a minimum 3 times improvement in CNs delineation. This work highlights the importance of accounting for nonspecific signal of targeted agents, and demonstrates that paired-agent imaging is one method capable of doing so. Although staining, rinsing, and imaging protocols need to be optimized, these findings serve as a demonstration for the potential use of paired-agent imaging to improve contrast of CNs, and consequently, surgical outcome.

Excretory urogramm with angiotomography: Imaging of the renal arteries by excretory urogramm

International Nuclear Information System (INIS)

Binder, G.

1982-01-01

Excretory urography permits imaging of the renal arteries up to the intrarenal ramification if the contrast medium is injected as a bolus and the time of circulation between arm vein and abdominal aorta is determined with sufficient accuracy. Imaging of the vessel phase is done using simultaneous tomography. In the experimental part of the paper phantom tests are carried through to establish the contrast medium concentration to be expected in the renal arteries by means of microdensitometry. With the aid of 100 computerized tomograms of the abdomen the layer thickness required was determined to 4.5 cm; further phantom tests provided the necessary layer distances to image renal arteries that do not run in parallel to the plain of the film. The circulation time between arm vein and abdominal aorta was measured in 180 patients using the radioisotope method. It ranges between 9 and 22 seconds. Comparisons with the Decholin-method were made. 739 renal arteries were seen during the evaluation of 343 excretory urographies with angiotomograms, in 83 per cent of the cases these arteries were presented entirely. Provided perfect execution, simultaneous tomography is a very informative method. For 212 patients the side-effects of the bolar contrast medium injection were recorded. The importance of excretory urography with combined angiotomography for the diagnosis of arterial hypertension is discussed. (orig.) [de

sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

Energy Technology Data Exchange (ETDEWEB)

Hosokawa, S; Daijo, K; Okabe, T; Kawamura, J; Hara, A [Kyoto Univ. (Japan). Hospital

1979-08-01

Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1.

sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

International Nuclear Information System (INIS)

Hosokawa, Shin-ichi; Daijo, Kazuyuki; Okabe, Tatsushiro; Kawamura, Juichi; Hara, Akira

1979-01-01

Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1. (author)

Characterization of nanoparticle-based contrast agents for molecular magnetic resonance imaging

International Nuclear Information System (INIS)

Shan, Liang; Chopra, Arvind; Leung, Kam; Eckelman, William C.; Menkens, Anne E.

2012-01-01

The development of molecular imaging agents is currently undergoing a dramatic expansion. As of October 2011, ∼4,800 newly developed agents have been synthesized and characterized in vitro and in animal models of human disease. Despite this rapid progress, the transfer of these agents to clinical practice is rather slow. To address this issue, the National Institutes of Health launched the Molecular Imaging and Contrast Agents Database (MICAD) in 2005 to provide freely accessible online information regarding molecular imaging probes and contrast agents for the imaging community. While compiling information regarding imaging agents published in peer-reviewed journals, the MICAD editors have observed that some important information regarding the characterization of a contrast agent is not consistently reported. This makes it difficult for investigators to evaluate and meta-analyze data generated from different studies of imaging agents, especially for the agents based on nanoparticles. This article is intended to serve as a guideline for new investigators for the characterization of preclinical studies performed with nanoparticle-based MRI contrast agents. The common characterization parameters are summarized into seven categories: contrast agent designation, physicochemical properties, magnetic properties, in vitro studies, animal studies, MRI studies, and toxicity. Although no single set of parameters is suitable to define the properties of the various types of contrast agents, it is essential to ensure that these agents meet certain quality control parameters at the preclinical stage, so that they can be used without delay for clinical studies.

The application of 99mTc-EC renal dynamic imaging in urinary system calculus

International Nuclear Information System (INIS)

Dai Ruqi; Li Shiyun; Liu Xueshu; Huang Wei

2002-01-01

Objective: To evaluate the clinical value of 99m Tc-EC renal dynamic imaging (RDI) for diagnosis of urinary system calculus. Methods: 135 case with confirmed urinary system calculus by ultrasound and IVP were examined by 99m Tc-EC renal dynamic imaging and to analyze the degree of hydronephrosis and the remaining renal function. The quantitative indexes used were effective renal plasma flow (ERPF) and peak uptake rate (PUR). Results: RDI almost accorded with IVP in renal calculus complicated by mild and moderate hydronephrosis cases. On other cases of the severe hydronephrosis and serious renal insufficiency, RDI was more sensitive than IVP which had no excretion in 6 patients with hydronephrosis. ERPF and PUR showed the remaining function of the morbid kidney more accurately than other methods. In severe and mild hydronephrosis the ERPF were 84.3 ± 49 ml/min and 202.2 ± 52.4 ml/min, the PUR were 20.4 ± 11.5% and 48.5 ± 13.6% respectively. Conclusion: RDI can correctly reflect the degree of hydronephrosis and the remaining function of the morbid kidney in urinary system calculus, which would be helpful for the clinical surgical planning

Treatment of renal anemia: Erythropoiesis stimulating agents and beyond

Directory of Open Access Journals (Sweden)

Patrick Biggar

2017-09-01

Full Text Available Anemia, complicating the course of chronic kidney disease, is a significant parameter, whether interpreted as subjective impairment or an objective prognostic marker. Renal anemia is predominantly due to relative erythropoietin (EPO deficiency. EPO inhibits apoptosis of erythrocyte precursors. Studies using EPO substitution have shown that increasing hemoglobin (Hb levels up to 10-11 g/dL is associated with clinical improvement. However, it has not been unequivocally proven that further intensification of erythropoiesis stimulating agent (ESA therapy actually leads to a comprehensive benefit for the patient, especially as ESAs are potentially associated with increased cerebro-cardiovascular events. Recently, new developments offer interesting options not only via stimulating erythropoeisis but also by employing additional mechanisms. The inhibition of activin, a member of the transforming growth factor superfamily, has the potential to correct anemia by stimulating liberation of mature erythrocyte forms and also to mitigate disturbed mineral and bone metabolism as well. Hypoxia-inducible factor prolyl hydroxylase inhibitors also show pleiotropic effects, which are at the focus of present research and have the potential of reducing mortality. However, conventional ESAs offer an extensive body of safety evidence, against which the newer substances should be measured. Carbamylated EPO is devoid of Hb augmenting effects whilst exerting promising tissue protective properties. Additionally, the role of hepcidin antagonists is discussed. An innovative new hemodialysis blood tube system, reducing blood contact with air, conveys a totally different and innocuous option to improve renal anemia by reducing mechanical hemolysis.

Meeting Report: High-Throughput Technologies for In Vivo Imaging Agents

Directory of Open Access Journals (Sweden)

Robert J. Gillies

2005-04-01

Full Text Available Combinatorial chemistry and high-throughput screening have become standard tools for discovering new drug candidates with suitable pharmacological properties. Now, those same technologies are starting to be applied to the problem of discovering novel in vivo imaging agents. Important differences in the biological and pharmacological properties needed for imaging agents, compared to those for a therapeutic agent, require new screening methods that emphasize those characteristics, such as optimized residence time and tissue specificity, that make for a good imaging agent candidate.

Using BOLD imaging to measure renal oxygenation dynamics in rats injected with diuretics

International Nuclear Information System (INIS)

Kusakabe, Yoshinori; Matsushita, Taro; Honda, Saori; Okada, Sakie; Murase, Kenya

2010-01-01

We used blood oxygenation level-dependent magnetic resonance imaging (BOLD MRI) to measure renal oxygenation dynamics in rats injected with diuretics and evaluated diuretic effect on renal oxygenation. We performed BOLD MRI studies in 32 rats using a 1.5-tesla MR imaging system for animal experiments. We intravenously injected rats with saline (n=7), furosemide (n=7), acetazolamide (n=6), or mannitol (n=6). For controls, 6 rats were not injected with drugs. We estimated the apparent transverse relaxation rate (R 2 *) from the apparent transverse relaxation time (T 2 *)-weighted images and measured the time course of R 2 * at 4-min intervals over approximately 30 min. Compared with preadministration values, the R 2 * value did not change significantly in either the cortex or medulla in the control and mannitol groups but decreased significantly in the saline group; the R 2 * value significantly decreased in the medulla but did not change significantly in the cortex in the furosemide group; and the R 2 * value significantly increased in the medulla and significantly decreased in the cortex in the acetazolamide group. Our study results suggest that BOLD MRI is useful for evaluating the dynamics of renal oxygenation in response to various diuretics in the renal cortex and in the medulla. (author)

Methods of Blood Oxygen Level-Dependent Magnetic Resonance Imaging Analysis for Evaluating Renal Oxygenation

Directory of Open Access Journals (Sweden)

Fen Chen

2018-03-01

Full Text Available Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI has recently been utilized as a noninvasive tool for evaluating renal oxygenation. Several methods have been proposed for analyzing BOLD images. Regional ROI selection is the earliest and most widely used method for BOLD analysis. In the last 20 years, many investigators have used this method to evaluate cortical and medullary oxygenation in patients with ischemic nephropathy, hypertensive nephropathy, diabetic nephropathy, chronic kidney disease (CKD, acute kidney injury and renal allograft rejection. However, clinical trials of BOLD MRI using regional ROI selection revealed that it was difficult to distinguish the renal cortico-medullary zones with this method, and that it was susceptible to observer variability. To overcome these deficiencies, several new methods were proposed for analyzing BOLD images, including the compartmental approach, fractional hypoxia method, concentric objects (CO method and twelve-layer concentric objects (TLCO method. The compartmental approach provides an algorithm to judge whether the pixel belongs to the cortex or medulla. Fractional kidney hypoxia, measured by using BOLD MRI, was negatively correlated with renal blood flow, tissue perfusion and glomerular filtration rate (GFR in patients with atherosclerotic renal artery stenosis. The CO method divides the renal parenchyma into six or twelve layers of thickness in each coronal slice of BOLD images and provides a R2* radial profile curve. The slope of the R2* curve associated positively with eGFR in CKD patients. Indeed, each method invariably has advantages and disadvantages, and there is generally no consensus method so far. Undoubtedly, analytic approaches for BOLD MRI with better reproducibility would assist clinicians in monitoring the degree of kidney hypoxia and thus facilitating timely reversal of tissue hypoxia.

Fundamental study of DSA images using gadolinium contrast agent

International Nuclear Information System (INIS)

Nagashima, Hiroyuki; Shiraishi, Akihisa; Igarashi, Hitoshi; Sakamoto, Hajime; Sano, Yoshitomo

2002-01-01

Most contrast agents used in digital subtraction angiography (DSA) are non-ionic iodinated contrast agents, which can cause severe side effects in patients with contraindications for iodine or allergic reactions to iodine. Therefore, DSA examinations using carbon dioxide gas or examinations done by magnetic resonance imaging (MRI) and ultrasound (US) were carried out in these patients. However, none of these examinations provided mages as clear as those of DSA with an iodinated contrast agent. We experienced DSA examination using a gadolinium contrast agent in a patient contraindicated for iodine. The patient had undergone MRI examination with a gadolinium contrast agent previously without side effects. The characteristics of gadolinium and the iodinated contrast agent were compared, and the DSA images obtained clinically using these media were also evaluated. The signal-to-noise (SN) ratio of the gadolinium contrast agent was the highest at tube voltages of 70 to 80 kilovolts and improved slightly when the image intensifier (I.I.) entrance dose was greater than 300 μR (77.4 nC/kg). The dilution ratios of five iodinated contrast agents showed the same S/N value as the undiluted gadolinium contrast agent. Clinically, the images obtained showed a slight decrease in contrast but provided the data necessary to make a diagnosis and made it possible to obtain interventional radiology (IVR) without any side effects. DSA examinations using a gadolinium contrast agent have some benefit with low risk and are thought to be useful for patients contraindicated for iodine. (author)

WE-D-204-07: Development of An ImageJ Plugin for Renal Function Quantification: RenalQuant

Energy Technology Data Exchange (ETDEWEB)

Marques da Silva, A; Narciso, L [PUCRS, Porto Alegre, RS (Brazil)

2015-06-15

Purpose: Commercial workstations usually have their own software to calculate dynamic renal functions. However, usually they have low flexibility and subjectivity on delimiting kidney and background areas. The aim of this paper is to present a public domain software, called RenalQuant, capable to semi-automatically draw regions of interest on dynamic renal scintigraphies, extracting data and generating renal function quantification parameters. Methods: The software was developed in Java and written as an ImageJ-based plugin. The preprocessing and segmentation steps include the user’s selection of one time frame with higher activity in kidney’s region, compared with background, and low activity in the liver. Next, the chosen time frame is smoothed using a Gaussian low pass spatial filter (σ = 3) for noise reduction and better delimitation of kidneys. The maximum entropy thresholding method is used for segmentation. A background area is automatically placed below each kidney, and the user confirms if these regions are correctly segmented and positioned. Quantitative data are extracted and each renogram and relative renal function (RRF) value is calculated and displayed. Results: RenalQuant plugin was validated using retrospective 20 patients’ 99mTc-DTPA exams, and compared with results produced by commercial workstation software, referred as reference. The renograms intraclass correlation coefficients (ICC) were calculated and false-negative and false-positive RRF values were analyzed. The results showed that ICC values between RenalQuant plugin and reference software for both kidneys’ renograms were higher than 0.75, showing excellent reliability. Conclusion: Our results indicated RenalQuant plugin can be trustingly used to generate renograms, using DICOM dynamic renal scintigraphy exams as input. It is user friendly and user’s interaction occurs at a minimum level. Further studies have to investigate how to increase RRF accuracy and explore how to solve

Renal perfusion scintiscan

Science.gov (United States)

... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

Comparative analysis of maximum renal longitudinal length with positional changes on ultrasound with multiplanar reconstructed MR image in Korea Adults

International Nuclear Information System (INIS)

Jang, Yun Hee; Cho, Bum Sang; Kang, Min Ho; Kang, Woo Young; Lee, Jisun; Kim, Yook; Lee, Soo Hyun; Lee, Soo Jung; Lee, Jin Yong

2016-01-01

The purpose of this study was to determine a suitable position in which the measured length on ultrasound is close to the true renal length obtained through a multiplanar reconstructed MR image. A total of 33 individuals (males: 15, females: 18) without any underlying renal disease were included in the present study. Renal length was measured as the longest axis at the level of the renal hilum in three positions-supine, lateral decubitus, and prone, respectively. With a 3.0 T MR scanner, 3D eTHRIVE was acquired. Subsequently, the maximum longitudinal length of both the kidneys was measured through multiplanar reconstructed MR images. Paired t-test was used to compare the renal length obtained from ultrasonographic measurement with the length obtained through multiplanar reconstructed MR images. Our study demonstrated significant difference between sonographic renal length in three positions and renal length through MRI (p < 0.001). However, the longest longitudinal length of right kidney among the measured three values by ultrasound was statistically similar to the renal length measured by reconstructed MR image. Among them, the lateral decubitus position showed the strongest correlation with true renal length (right: 0.887; left: 0.849). We recommend measurement of the maximum renal longitudinal length in all possible positions on ultrasonography. If not allowed, the best measurement is on the lateral decubitus showing the strongest correlation coefficient with true renal length

Comparative analysis of maximum renal longitudinal length with positional changes on ultrasound with multiplanar reconstructed MR image in Korea Adults

Energy Technology Data Exchange (ETDEWEB)

Jang, Yun Hee; Cho, Bum Sang; Kang, Min Ho; Kang, Woo Young; Lee, Jisun; Kim, Yook; Lee, Soo Hyun; Lee, Soo Jung [Dept. of Radiology, Chungbuk National University Hospital, Cheongju (Korea, Republic of); Lee, Jin Yong [Public Health Medical Service, Seoul National University Boramae Medical Center, Seoul (Korea, Republic of)

2016-07-15

The purpose of this study was to determine a suitable position in which the measured length on ultrasound is close to the true renal length obtained through a multiplanar reconstructed MR image. A total of 33 individuals (males: 15, females: 18) without any underlying renal disease were included in the present study. Renal length was measured as the longest axis at the level of the renal hilum in three positions-supine, lateral decubitus, and prone, respectively. With a 3.0 T MR scanner, 3D eTHRIVE was acquired. Subsequently, the maximum longitudinal length of both the kidneys was measured through multiplanar reconstructed MR images. Paired t-test was used to compare the renal length obtained from ultrasonographic measurement with the length obtained through multiplanar reconstructed MR images. Our study demonstrated significant difference between sonographic renal length in three positions and renal length through MRI (p < 0.001). However, the longest longitudinal length of right kidney among the measured three values by ultrasound was statistically similar to the renal length measured by reconstructed MR image. Among them, the lateral decubitus position showed the strongest correlation with true renal length (right: 0.887; left: 0.849). We recommend measurement of the maximum renal longitudinal length in all possible positions on ultrasonography. If not allowed, the best measurement is on the lateral decubitus showing the strongest correlation coefficient with true renal length.

Magnetic Resonance Imaging Contrast Agents: A Review of Literature

Directory of Open Access Journals (Sweden)

Zahra Sahraei

2015-10-01

Full Text Available  Magnetic Resonance Imaging (MRI contrast agents most commonly agents used in diagnosing different diseases. Several agents have been ever introduced with different peculiar characteristics. They vary in potency, adverse reaction and other specification, so it is important to select the proper agent in different situations. We conducted a systematic literature search in MEDLINE/PUBMED, Web of Science (ISI, Scopus,Google Scholar by using keywords "gadolinium" and "MRI contrast Medias", "Gadofosvest", "Gadobenate" and "Gadoxetate". The most frequent contrast media agents made based on gadolinium (Gd. These are divided into two categories based on the structure of their chelating parts, linear agents and macrocyclic agents. All characteristics of contrast media factors, including efficiency, kinetic properties, stability, side effects and the rate of resolution are directly related to the structure of chelating part of that formulation.In vitro data has shown that the macrocyclic compounds are the most stable Gd-CA as they do not bind to serum proteins, they all possess similar and relatively low relaxivity and the prevalence of Nephrogenic Systemic Fibrosis (NSF has decreased by increasing the use of macrocyclic agents in recent years. No cases of NSF have been recorded after the administration of any of the high-relaxivity protein interacting agents, the vascular imaging agent gadofosveset trisodium (Ablavar, the hepatic imaging agent gadoxetate meglumine (Eovist, and the multipurpose agent gadobenate dimeglumine (MultiHance. In pregnancy and lactating women, stable macrocyclic agent is recommended.

Preparation and biological characteristics of 99mTc-diol a renal agent

International Nuclear Information System (INIS)

Castanheira, I.; Paulo, A.; Neves, M.; Patricio, L.; Sawas-Dimopoulou, C.

1993-01-01

The present work concerns the production of 1,2-dihydroxypropyl-1-phosphonic acid (diol) by acid hydrolysis of (-cis) 1,2-epoxypropylphosphonic acid (phosphomycin), and its formation as a kit easily labeled with [ 99m Tc]pertechnetate. Biodistribution studies and whole-body autoradiographies in mice show that 99m Tc-diol has a specific affinity for the kidneys: it is rapidly cleared from the blood and excreted in urine. Part of the injected activity remains in the kidney cortex sufficiently long to permit kidney imaging. In comparison with other agents which also localize in the kidney cortex, such as 99m Tc-DMSA and 99m Tc-glucoheptonate ( 99m Tc-GHA), the main differences are the following: the peak of renal activity is reached early in the 5 min post-injection period for 99m Tc-diol, only at about 10 min post-injection for 99m Tc-GHA and after 3 h post-injection for 99m Tc-DMSA. The uptake of 99m Tc-diol by other organs, especially by bones, is much smaller than in the case of 99m Tc-DMSA. Unlike 99m Tc-DMSA, the biodistribution of 99m Tc-diol is not significantly influenced by acid-base imbalance. Moreover, the retention effect of hyperuricemia on 99m Tc-diol blood clearance and kidney excretion could be the result of a competition mechanism between this radiopharmaceutical and uric acid for a common transport system. The above biological characteristics suggest that 99m Tc-diol is a kidney radiopharmaceutical with an ability for functional and imaging studies. (author)

Prognostic value of intravenous dipyridamole thallium imaging in patients with diabetes mellitus considered for renal transplantation

International Nuclear Information System (INIS)

Camp, A.D.; Garvin, P.J.; Hoff, J.; Marsh, J.; Byers, S.L.; Chaitman, B.R.

1990-01-01

Patients with diabetes and end-stage renal failure are known to have a high risk for cardiac morbidity and mortality associated with renal transplantation. The most efficient method to determine preoperative cardiac risk has not been established. To determine the effectiveness of intravenous dipyridamole thallium imaging in predicting cardiac events, 40 diabetic renal transplant candidates were studied preoperatively in a prospective trial. The study group consisted of 40 patients whose average age was 42 years (range 27 to 64); 34 (85%) were hypertensive and 21 (53%) were cigarette smokers. Cardiac history included chest pain in 6 patients and prior myocardial infarction in 3 patients. Dipyridamole thallium imaging showed reversible defects in 9 patients, fixed defects in 8 patients and normal scans in 23 patients. Dipyridamole thallium imaging was performed using 0.56 mg/kg of dipyridamole infused intravenously over 4 minutes. Cardiac events occurred only in patients with reversible thallium defects, of which there were 6. Of these 6 patients, 3 had cardiac events before transplantation and 3 had them in the early postoperative phase (within 6 weeks of surgery). Of 21 patients who underwent renal transplantation, 3 had cardiac events within 6 weeks of transplantation. The average duration of follow-up was 11 months (range 1 to 21). Thus, dipyridamole thallium imaging is an effective method of identifying renal transplant candidates likely to develop cardiac complications. Routine coronary angiography may not be necessary to screen all renal transplant candidates for coronary artery disease before surgery

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

International Nuclear Information System (INIS)

Pedersen, Michael; Aarhus Univ.; Univ. Victor Segalen Bordeaux 2; Laustsen, Christoffer; Perot, Vincent; Grenier, Nicolas; Basseau, Fabrice; Moonen, Chrit

2010-01-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2 * , and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2 * was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

Energy Technology Data Exchange (ETDEWEB)

Pedersen, Michael [Aarhus Univ. Hospital (Denmark). MR Research Centre; Aarhus Univ. (Denmark). Inst. of Experimental Clinical Medicine; Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231; Laustsen, Christoffer [Aarhus Univ. Hospital (Denmark). MR Research Centre; Perot, Vincent; Grenier, Nicolas [Hopital Pellegrin, CHU Bordeaux (France). Service d' Imagerie Diagnostique et Therapeutique de l' Adulte; Basseau, Fabrice; Moonen, Chrit [Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231

2010-07-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2{sup *}, and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2{sup *} was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

Imaging and management of atherosclerotic renal artery stenosis

International Nuclear Information System (INIS)

Sarkodieh, J.E.; Walden, S.H.; Low, D.

2013-01-01

Renal artery stenosis (RAS) causes chronic, progressive ischaemic nephropathy and is the most common cause of secondary hypertension. Radiology plays a large part in the diagnosis, with a variety of imaging techniques available. Each has relative advantages and disadvantages depending on each unique clinical setting. We discuss and illustrate the range of diagnostic methods and interventional techniques for diagnosis and management of RAS and review the current evidence base for endovascular therapy compared with optimal medical management. Knowledge of the relative merits of the various forms of imaging and treatment will guide decision making in the multidisciplinary setting

Nanogels as imaging agents for modalities spanning the electromagnetic spectrum.

Science.gov (United States)

Chan, Minnie; Almutairi, Adah

2016-01-21

In the past few decades, advances in imaging equipment and protocols have expanded the role of imaging in in vivo diagnosis and disease management, especially in cancer. Traditional imaging agents have rapid clearance and low specificity for disease detection. To improve accuracy in disease identification, localization and assessment, novel nanomaterials are frequently explored as imaging agents to achieve high detection specificity and sensitivity. A promising material for this purpose are hydrogel nanoparticles, whose high hydrophilicity, biocompatibility, and tunable size in the nanometer range make them ideal for imaging. These nanogels (10 to 200 nm) can circumvent uptake by the reticuloendothelial system, allowing longer circulation times than small molecules. In addition, their size/surface properties can be further tailored to optimize their pharmacokinetics for imaging of a particular disease. Herein, we provide a comprehensive review of nanogels as imaging agents in various modalities with sources of signal spanning the electromagnetic spectrum, including MRI, NIR, UV-vis, and PET. Many materials and formulation methods will be reviewed to highlight the versatility of nanogels as imaging agents.

Dynamic renal and static bone imaging after a single foot injection of Tc-99m methylene diphosphonate

International Nuclear Information System (INIS)

Siddiqui, A.R.; Cohen, M.; Moran, D.P.

1982-01-01

Much better information regarding the renal anatomy and physiology can be obtained by imaging the kidneys immediately after the injection of Tc-99m MDP, rather than on the bone scan a few hours later. Evaluation of inferior vena cava is possible if the radiotracer is injected in the foot and dynamic images of the abdomen are obtained. It is possible to differentiate renal from extra-renal masses during bone scanning without any additional radiation to the patient

Quantification of renal cortical blood flow using factor analysis of O-15 water dynamic PET images

International Nuclear Information System (INIS)

Seo, Kang Jun; Ahn, Ji Young; Lee, Jae Sung; Paeng, Jin Chul; Cheon, Gi Jeong; Lee, Dong Soo; Noh, Tae Won; Chung, June Key; Lee, Myung Chul

2000-01-01

To obtain spatial distribution of renal factor images, input function, and regional tissue time-activity curve (TAC) from O-15 water dynamic PET images non-invasively, factor analysis (FA) was used. O-15 water dynamic PET scans were performed on 3 normal dogs (22 ∼ 29 kg) with the bolus injection of O-15 water (555 ∼ 740 Mbq). We performed FA on the masked dynamic images and obtained the pure TACs and the corresponding factor images. Microsphere experiment also was performed. 37MBq of microsphere labeled with Sc-46 was injected into the left ventricle. Arterial input functions derived from the PET images using FA were compared with the invasively derived arterial blood samples. The renal cortical blood flow using the TACs by FA was within the normal range of 1.23 ∼ 2.46 ml/min/g. In microsphere study, the renal cortical blood flow of left kidney by FA was 2.49±0.47 ml/min/g (1.81∼2.90 ml/min/g) and by microsphere was 2.52 ±0.19 ml/min/g (2.34 ∼2.68 ml/min/g). In right kidney, flow by FA was 2.02 ±0.32 ml/min/g (1.82∼2.49 ml/min/g) and by microsphere was 2.49 ±0.27 ml/min/g (2.02∼2.7). FA is a useful and robust method to extract input functions and tissue TACs from O-15 dynamic renal PET. Renal cortical blood flow can be estimated non-invasively using FA and it will be helpful for the assessment of renal functional disease

Metabolomic Analysis of N-acetylcysteine Protection of Injury from Gadolinium-DTPA Contrast Agent in Rats with Chronic Renal Failure.

Science.gov (United States)

Wan, Chuanling; Xue, Rong; Zhan, Youyang; Wu, Yijie; Li, Xiaojing; Pei, Fengkui

2017-09-01

Gadolinium-based contrast agents (GBCAs) are frequently used to enhance the diagnostic efficacy of magnetic resonance imaging. On the other hand, the association between GBCA administration in patients with advanced renal disease and nephrogenic systemic fibrosis (NSF) was also noted. NSF is a systemic disorder characterized by widespread tissue fibrosis that may lead to death. N-acetylcysteine (NAC) protects rats from injury induced by gadolinium-based contrast agents, but the underlying mechanisms remain unclear. In this study, a nuclear magnetic resonance-based metabolomic approach was used to systematically investigate the protective effects of NAC on Gd-DTPA-induced injury. Thirty-two male Sprague-Dawley rats were given adenine (200 mg·kg -1 body weight) by oral gavage once a day for 3 weeks to induce chronic renal failure (CRF). NAC (600 mg/L in drinking water for 9 days) pretreatment was initiated 2 days before Gd-DTPA injection (a single tail vein injection, 2 mmol/kg body weight). Serum and liver samples were collected on day 7 after Gd-DTPA injection. By study design, the serum and hepatic metabolic changes of rats were measured in four groups of eight each: CRF, CRF-Gd, CRF-Gd-NAC, and CRF-NAC. Gd-DTPA administration to rats with CRF resulted in disturbances of several metabolic pathways, including glucose, lipid, glutamate, choline, gut microbiota, one-carbon, and purine metabolism. NAC pretreatment reversed the abundance changes of high-density lipoprotein, low-density lipoprotein, very low-density lipoprotein, glutamate, glutamine, oxidized glutathione, choline, phosphocholine, glycerophosphocholine, trimethylamine, and trimethylamine-N-oxide induced by Gd-DTPA. It is noteworthy, however, that the ameliorating effects of NAC on the disturbance of glutamate, choline, and gut microbiota metabolism may be specific to Gd-DTPA. In all, these findings could be potentially useful to decipher the underlying mechanisms of NAC protective effects from the

Power Doppler Imaging in Acute Renal Vein Occlusion and Recanalization: a Canine Model

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Yoo, So-Young; Kim, In-One; Kim, Young-Il; Lee, Kyoung Ho; Lee, Min Woo; Youn, Byung Jae; Kim, Woo Sun; Yeon, Kyung Mo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2008-04-15

Objective : To evaluate the dynamic changes of the power Doppler (PD) in acute renal vein occlusion and recanalization in a canine model. Materials and Methods : We performed a PD of the kidney during graded renal vein occlusion and recanalization induced by balloon inflation and deflation in nine dogs. The PD images were transferred to a personal computer, and the PD signals were quantified. Result : We observed the temporal change of the PD signal during renal vein occlusion and recanalization, with a decrease in the PD signal during occlusion and an increase during recanalization. The mean PD signal decreased gradually as the renal vein was occluded, and conversely increased gradually with sequential relief of occlusion. The sequential change of the mean value of the PD signal was statistically significant. Conclusion : The PD can detect a change in renal blood flow during acute renal vein occlusion and recanalization in a canine model. The PD may be used as a helpful tool for the early detection of acute renal vein thrombosis and the monitoring of renal perfusion.

Power Doppler Imaging in Acute Renal Vein Occlusion and Recanalization: a Canine Model

International Nuclear Information System (INIS)

Yoo, So-Young; Kim, In-One; Kim, Young-Il; Lee, Kyoung Ho; Lee, Min Woo; Youn, Byung Jae; Kim, Woo Sun; Yeon, Kyung Mo

2008-01-01

Objective : To evaluate the dynamic changes of the power Doppler (PD) in acute renal vein occlusion and recanalization in a canine model. Materials and Methods : We performed a PD of the kidney during graded renal vein occlusion and recanalization induced by balloon inflation and deflation in nine dogs. The PD images were transferred to a personal computer, and the PD signals were quantified. Result : We observed the temporal change of the PD signal during renal vein occlusion and recanalization, with a decrease in the PD signal during occlusion and an increase during recanalization. The mean PD signal decreased gradually as the renal vein was occluded, and conversely increased gradually with sequential relief of occlusion. The sequential change of the mean value of the PD signal was statistically significant. Conclusion : The PD can detect a change in renal blood flow during acute renal vein occlusion and recanalization in a canine model. The PD may be used as a helpful tool for the early detection of acute renal vein thrombosis and the monitoring of renal perfusion

Measurement of renal blood flow by phase-contrast magnetic resonance imaging during septic acute kidney injury: a pilot investigation.

Science.gov (United States)

Prowle, John R; Molan, Maurice P; Hornsey, Emma; Bellomo, Rinaldo

2012-06-01

In septic patients, decreased renal perfusion is considered to play a major role in the pathogenesis of acute kidney injury. However, the accurate measurement of renal blood flow in such patients is problematic and invasive. We sought to overcome such obstacles by measuring renal blood flow in septic patients with acute kidney injury using cine phase-contrast magnetic resonance imaging. Pilot observational study. University-affiliated general adult intensive care unit. Ten adult patients with established septic acute kidney injury and 11 normal volunteers. Cine phase-contrast magnetic resonance imaging measurement of renal blood flow and cardiac output. The median age of the study patients was 62.5 yrs and eight were male. At the time of magnetic resonance imaging, eight patients were mechanically ventilated, nine were on continuous hemofiltration, and five required vasopressors. Cine phase-contrast magnetic resonance imaging examinations were carried out without complication. Median renal blood flow was 482 mL/min (range 335-1137) in septic acute kidney injury and 1260 mL/min (range 791-1750) in healthy controls (p = .003). Renal blood flow indexed to body surface area was 244 mL/min/m2 (range 165-662) in septic acute kidney injury and 525 mL/min/m2 (range 438-869) in controls (p = .004). In patients with septic acute kidney injury, median cardiac index was 3.5 L/min/m2 (range 1.6-8.7), and median renal fraction of cardiac output was only 7.1% (range 4.4-10.8). There was no rank correlation between renal blood flow index and creatinine clearance in patients with septic acute kidney injury (r = .26, p = .45). Cine phase-contrast magnetic resonance imaging can be used to noninvasively and safely assess renal perfusion during critical illness in man. Near-simultaneous accurate measurement of cardiac output enables organ blood flow to be assessed in the context of the global circulation. Renal blood flow seems consistently reduced as a fraction of cardiac output in

Molecular Imaging to Predict Response to Targeted Therapies in Renal Cell Carcinoma

Directory of Open Access Journals (Sweden)

Ingrid Leguerney

2017-01-01

Full Text Available Molecular magnetic resonance imaging targeted to an endothelial integrin involved in neoangiogenesis was compared to DCE-US and immunochemistry to assess the early response of three different therapeutic agents in renal cell carcinoma. Human A498 renal cells carcinoma was subcutaneously inoculated into 24 nude mice. Mice received either phosphate-buffered saline solution, sunitinib, everolimus, or bevacizumab during 4 days. DCE-US and molecular MRI targeting αvβ3 were performed at baseline and 4 days after treatment initiation. PI, AUC, relaxation rate variations ΔR2⁎, and percentage of vessels area quantified on CD31-stained microvessels were compared. Significant decreases were observed for PI and AUC parameters measured by DCE-US for bevacizumab group as early as 4 days, whereas molecular αvβ3-targeted MRI was able to detect significant changes in both bevacizumab and everolimus groups. Percentage of CD31-stained microvessels was significantly correlated with DCE-US parameters, PI (R=0.87, p=0.0003 and AUC (R=0.81, p=0.0013. The percentage of vessel tissue area was significantly reduced (p<0.01 in both sunitinib and bevacizumab groups. We report an early detection of neoangiogenesis modification after induction of targeted therapies, using DCE-US or αvβ3-targeted MRI. We consider these outcomes should encourage clinical trial developments to further evaluate the potential of this molecular MRI technique.

Effect of alpha-interferon alone and combined with other antineoplastic agents on renal cell carcinoma determined by the tetrazolium microculture assay.

Science.gov (United States)

Homma, Y; Aso, Y

1994-01-01

The antiproliferative effect of various alpha-interferons (alpha-IFNs), alone or combined with other agents, on a renal cell carcinoma cell line was evaluated by the tetrazolium microculture assay to examine the rationale for combination therapies. Cells incubated in 96-week microculture plates at 5 x 10(3)/well were exposed to various agents for 3 days. There were no obvious differences in the growth inhibition caused by the 5 kinds of alpha-IFN examined as single agents. The combination of alpha-IFN with the following agents was also assessed: 5-fluorouracil (5FU), methotrexate (MTX), mitomycin C, bleomycin, cis-diaminedichloroplatinum (CDDP), vinblastine, etoposide (ETOP), alpha-IFN, tumor necrosis factor-alpha (TNF), and alpha-difluoromethylornithine. Synergism was observed for the combination of alpha-IFN+TNF, while the other combinations had additive or subadditive effects. No interference or antagonism was found. Trimodal combinations of alpha-IFN+MTX with either 5FU, ETOP, or CDDP all showed subadditive effects. These results indicated that an increased antiproliferative effect, although not necessarily synergistic, was obtained by the combination of alpha-IFN with a variety of antineoplastic agents, providing a rationale to seek for combination therapies including alpha-IFN for treating renal cell carcinoma.

Diagnostic accuracy of dynamic contrast-enhanced MR imaging of renal masses with rapid-acquisition spin-echo technique

International Nuclear Information System (INIS)

Eilenberg, S.S.; Lee, J.K.T.; Brown, J.J.; Heiken, J.P.; Mirowitz, S.A.

1990-01-01

This paper compares the diagnostic accuracy of Gd-DTPA-enhanced rapid-acquisition spin-echo (RASE) imaging with standard spin-echo techniques for detecting renal cysts and solid renal neoplasms. RASE imaging combines a short TR (275 msec)/short TE (10 msec), single excitation pulse sequence with half-Fourier data sampling. Eighteen patients with CT evidence of renal masses were first evaluated with standard T1-and T2-weighted SE sequences. Pre- and serial postcontrast (Cd-DTPA, 0.1 mmol./kg) RASE sequences were then performed during suspended respiration. A final set of postcontrast images was obtained with the standard T1-weighted SE sequence. Each set of MR images was first reviewed separately (ie, T1, T2, pre- and post-contrast RASE, etc)

The Role of Compounds Derived from Natural Supplement as Anticancer Agents in Renal Cell Carcinoma: A Review.

Science.gov (United States)

Haque, Inamul; Subramanian, Arvind; Huang, Chao H; Godwin, Andrew K; Van Veldhuizen, Peter J; Banerjee, Snigdha; Banerjee, Sushanta K

2017-12-31

Renal Cell Carcinoma (RCC) is the most prominent kidney cancer derived from renal tubules and accounts for roughly 85% of all malignant kidney cancer. Every year, over 60,000 new cases are registered, and about 14,000 people die from RCC. The incidence of this has been increasing significantly in the U.S. and other countries. An increased understanding of molecular biology and the genomics of RCC has uncovered several signaling pathways involved in the progression of this cancer. Significant advances in the treatment of RCC have been reported from agents approved by the Food and Drug Administration (FDA) that target these pathways. These agents have become drugs of choice because they demonstrate clinical benefit and increased survival in patients with metastatic disease. However, the patients eventually relapse and develop resistance to these drugs. To improve outcomes and seek approaches for producing long-term durable remission, the search for more effective therapies and preventative strategies are warranted. Treatment of RCC using natural products is one of these strategies to reduce the incidence. However, recent studies have focused on these chemoprevention agents as anti-cancer therapies given they can inhibit tumor cell grow and lack the severe side effects common to synthetic compounds. This review elaborates on the current understanding of natural products and their mechanisms of action as anti-cancer agents. The present review will provide information for possible use of these products alone or in combination with chemotherapy for the prevention and treatment of RCC.

Technetium-99m pyrophosphate imaging in acute renal failure associated with nontraumatic rhabdomyolysis

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Patel, R.; Mishkin, F.S.

1986-10-01

Technetium-99m pyrophosphate (Tc-PYP) imaging was performed in five patients with acute renal failure associated with nontraumatic rhabdomyolysis. Four patients had phencyclidine intoxication and one had viral pneumonia. During the acute phase, marked uptake of pyrophosphate was seen in all patients in several muscle groups, but always in the thigh adductors. The results show that phencyclidine intoxication can result in diffuse muscle uptake of Tc-PYP without overt evidence of muscle injury. Tc-PYP imaging may provide a clue to the cause of acute renal failure in patients with suspected rhabdomyolysis in whom elevations of serum creatine phosphokinase concentrations are equivocal.

Technetium-99m pyrophosphate imaging in acute renal failure associated with nontraumatic rhabdomyolysis

International Nuclear Information System (INIS)

Patel, R.; Mishkin, F.S.

1986-01-01

Technetium-99m pyrophosphate (Tc-PYP) imaging was performed in five patients with acute renal failure associated with nontraumatic rhabdomyolysis. Four patients had phencyclidine intoxication and one had viral pneumonia. During the acute phase, marked uptake of pyrophosphate was seen in all patients in several muscle groups, but always in the thigh adductors. The results show that phencyclidine intoxication can result in diffuse muscle uptake of Tc-PYP without overt evidence of muscle injury. Tc-PYP imaging may provide a clue to the cause of acute renal failure in patients with suspected rhabdomyolysis in whom elevations of serum creatine phosphokinase concentrations are equivocal

Anatomic distribution of renal artery stenosis in children: implications for imaging.

Science.gov (United States)

Vo, Nghia J; Hammelman, Ben D; Racadio, Judy M; Strife, C Frederic; Johnson, Neil D; Racadio, John M

2006-10-01

Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty.

Anatomic distribution of renal artery stenosis in children: implications for imaging

Energy Technology Data Exchange (ETDEWEB)

Vo, Nghia J.; Racadio, Judy M.; Johnson, Neil D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Division of Pediatric Interventional Radiology, Cincinnati, OH (United States); Hammelman, Ben D. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Strife, C.F. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Division of Nephrology and Hypertension, Cincinnati, OH (United States); Racadio, John M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Division of Pediatric Interventional Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital, Department of Radiology, Cincinnati, OH (United States)

2006-10-15

Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty. (orig.)

Anatomic distribution of renal artery stenosis in children: implications for imaging

International Nuclear Information System (INIS)

Vo, Nghia J.; Racadio, Judy M.; Johnson, Neil D.; Hammelman, Ben D.; Strife, C.F.; Racadio, John M.

2006-01-01

Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty. (orig.)

Dendrimer-based Macromolecular MRI Contrast Agents: Characteristics and Application

Directory of Open Access Journals (Sweden)

Hisataka Kobayashi

2003-01-01

Full Text Available Numerous macromolecular MRI contrast agents prepared employing relatively simple chemistry may be readily available that can provide sufficient enhancement for multiple applications. These agents operate using a ~100-fold lower concentration of gadolinium ions in comparison to the necessary concentration of iodine employed in CT imaging. Herein, we describe some of the general potential directions of macromolecular MRI contrast agents using our recently reported families of dendrimer-based agents as examples. Changes in molecular size altered the route of excretion. Smaller-sized contrast agents less than 60 kDa molecular weight were excreted through the kidney resulting in these agents being potentially suitable as functional renal contrast agents. Hydrophilic and larger-sized contrast agents were found better suited for use as blood pool contrast agents. Hydrophobic variants formed with polypropylenimine diaminobutane dendrimer cores created liver contrast agents. Larger hydrophilic agents are useful for lymphatic imaging. Finally, contrast agents conjugated with either monoclonal antibodies or with avidin are able to function as tumor-specific contrast agents, which also might be employed as therapeutic drugs for either gadolinium neutron capture therapy or in conjunction with radioimmunotherapy.

MR Imaging of renal transplants

International Nuclear Information System (INIS)

Gremo, L.; Avataneo, T.; Potenzoni, F.; Colla, L.; Segoloni, G.

1988-01-01

The authors report their experience in the study of renal transplant recipients by MR, in order to determine its clinical potentials. The main purpose of this work is to focus on MR patterns in relation to clinical findings of rejector or normally fuctioning kidney. Twenty-four patients were examined with a 0.5 T superconductive magnete, body coil, spin-echo pulse sequence (SE) and inversion-recovery (IR). MRI patterns could be seen in normally functioning kidneys and transplant rejections, while variable MRI findings were observed in transplants with acute tubular necrosis (ATN). In the normally functioning transplanted kidney there is a clear corticomedullary differentiation (CMD), and the extent of vascular penetration into the renal parenchyma is clearly seen. In transplant rejection, CMD is either diminished or absent, and there is no vascular penetration into the parenchyma; to differentiate acute from chronic rejections, the increase/decrease in renal size and the change in renal shape (spherical shape in acute transplant rejection) respectively must be observed. MRI proves thus to be useful in the study of renal transplants, even in case of questionable clinical findings, and in patients in whom renal biopsy is contraindicated

Dynamic renal transplant imaging with /sup 99m/Tc DTPA (Sn) supplemented by a transplant perfusion index in the management of renal transplants

International Nuclear Information System (INIS)

Hilson, A.J.W.; Maisey, M.N.; Brown, C.B.; Ogg, C.S.; Bewick, M.S.

1978-01-01

We have performed 955 studies on 152 patients with 167 renal transplants. Images were recorded following bolus injection of 12 to 15 mCi Tc-99m DTPA (Sn). The data were stored on a computer and analyzed by generation of region-of-interest curves from (a) the iliac artery distal to the transplant, (b) the kidney, and (c) a background area. A perfusion index was adopted: arterial counts per cell, integrated to peak/concurrent renal counts per cell x 100. In 276 studies the patient clearly had acute tubular necrosis (ATN), rejection, or a normal kidney on retrospective analysis. The normal perfusion index has a value below 150, and it increases with falling perfusion, such as is seen in rejection and in renal-artery stenosis. The use of this index in addition to sequential images and changes in the region-of-interest curves usually allows separation of rejection from ATN and, particularly, rejection from normals. When serial studies are performed, the separation of rejecting from nonrejecting transplants is excellent, although renal-artery stenosis may cause similar changes in perfusion

Photoacoustic imaging at 1064nm wavelength with exogenous contrast agents

Science.gov (United States)

Upputuri, Paul Kumar; Jiang, Yuyan; Pu, Kanyi; Pramanik, Manojit

2018-02-01

Photoacoustic (PA) imaging is a promising imaging modality for both preclinical research and clinical practices. Laser wavelengths in the first near infrared window (NIR-I, 650-950 nm) have been widely used for photoacoustic imaging. As compared with NIR-I window, scattering of photons by biological tissues is largely reduced in the second NIR (NIR-II) window, leading to enhanced imaging fidelity. However, the lack of biocompatible NIR-II absorbing exogenous agents prevented the use of this window for in vivo imaging. In recent years, few studies have been reported on photoacoustic imaging in NIR-II window using exogenous contrast agents. In this work, we discuss the recent work on PA imaging using 1064 nm wavelength, the fundamental of Nd:YAG laser, as an excitation wavelength. The PA imaging at 1064 nm is advantageous because of the low and homogeneous signal from tissue background, enabling high contrast in PA imaging when NIR-II absorbing contrast agents are employed.

Arterial spin labelling MRI for detecting pseudocapsule defects and predicting renal capsule invasion in renal cell carcinoma.

Science.gov (United States)

Zhang, H; Wu, Y; Xue, W; Zuo, P; Oesingmann, N; Gan, Q; Huang, Z; Wu, M; Hu, F; Kuang, M; Song, B

2017-11-01

To evaluate prospectively the performance of combining morphological and arterial spin labelling (ASL) magnetic resonance imaging (MRI) for detecting pseudocapsule defects in renal cell carcinoma (RCC), and to predict renal capsule invasion confirmed histopathologically. Twenty consecutive patients with suspicious renal tumours underwent MRI. Renal ASL imaging was performed and renal blood flow was measured quantitatively. The diagnostic performance of T2-weighted images alone, and a combination of T2-weighted and ASL images for predicting renal capsule invasion were assessed. Twenty renal lesions were evaluated in 20 patients. All lesions were clear cell RCCs (ccRCCs) confirmed at post-surgical histopathology. Fifteen ccRCCs showed pseudocapsule defects on T2-weighted images, of which 12 cases showed existing blood flow in defect areas on perfusion images. To predict renal capsule invasion, the sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 71.4%, 86.7%, 100%, respectively, for T2-weighted images alone, and 92.3%, 100%, 100%, 87.5%, respectively, for the combination of T2-weighted and ASL images. ASL images can reflect the perfusion of pseudocapsule defects and as such, the combination of T2-weighted and ASL images produces promising diagnostic accuracy for predicting renal capsule invasion. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Tc-99m imaging agents

International Nuclear Information System (INIS)

Weininger, J.; Trumper, J.

1984-01-01

A wide range of pharmaceuticals for labeling with Tc-99m, developed by the Soreq Radiopharmaceuticals Department, is described. Details of the production and quality control of 13 kits are given, as well as the range of results required for consistently high quality imaging agents

Studies of renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) by diagnostic imaging methods

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Ohishi, Yukihiko; Machida, Toyohei; Tashiro, Kazuya; Wada, Tetsuro; Mochizuki, Atsushi; Torii, Shinichiro; Yoshigoe, Fukuo; Kawashima, Yoshio; Asano, Koji (Jikei Univ., Tokyo (Japan). School of Medicine)

1989-05-01

Renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) were studied by diagnostic imaging methods. The subjects were 25 patients with renal stones, and EDAP LT-01 (piezoelectric system) was used for the equipment of ESWL. The examination by MRI, X-ray CT and /sup 99m/Tc-DMSA scintigraphy using SPECT were performed before and after ESWL. To the 24 kidneys of 12 adult dogs, shock waves were fired in order to examine the experimental renal parenchymal impairments. After the treatment with ESWL, renal abnormal findings were obtained with MRI in 6 patients out of 11 (54.5%), with X-ray CT in 1 patient out of 12 (8.3%), and with the /sup 99m/Tc-DMSA renal scintigraphy in 4 patients out of 6 (66.7%). In the inspections with X-ray CT and renal scintigraphy conducted in 4 weeks, it was noted that the conditions of patients were recovered to the states before ESWL was performed. Using the therapeutic doses of shock wave for humans, the renal parenchymal impairments in the kidney in dogs were normalized in 7 days. Although it has been considered that the degree of renal parenchymal impairments with ESWL treatment may be influenced by the kind of the equipment, frequency of shock waves and their strength, the extent of impairments were rather mild, and it was presumed that the impairments might be recovered on the images in 3 to 4 weeks at the latest. (author).

Studies of renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) by diagnostic imaging methods

International Nuclear Information System (INIS)

Ohishi, Yukihiko; Machida, Toyohei; Tashiro, Kazuya; Wada, Tetsuro; Mochizuki, Atsushi; Torii, Shinichiro; Yoshigoe, Fukuo; Kawashima, Yoshio; Asano, Koji

1989-01-01

Renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) were studied by diagnostic imaging methods. The subjects were 25 patients with renal stones, and EDAP LT-01 (piezoelectric system) was used for the equipment of ESWL. The examination by MRI, X-ray CT and 99m Tc-DMSA scintigraphy using SPECT were performed before and after ESWL. To the 24 kidneys of 12 adult dogs, shock waves were fired in order to examine the experimental renal parenchymal impairments. After the treatment with ESWL, renal abnormal findings were obtained with MRI in 6 patients out of 11 (54.5%), with X-ray CT in 1 patient out of 12 (8.3%), and with the 99m Tc-DMSA renal scintigraphy in 4 patients out of 6 (66.7%). In the inspections with X-ray CT and renal scintigraphy conducted in 4 weeks, it was noted that the conditions of patients were recovered to the states before ESWL was performed. Using the therapeutic doses of shock wave for humans, the renal parenchymal impairments in the kidney in dogs were normalized in 7 days. Although it has been considered that the degree of renal parenchymal impairments with ESWL treatment may be influenced by the kind of the equipment, frequency of shock waves and their strength, the extent of impairments were rather mild, and it was presumed that the impairments might be recovered on the images in 3 to 4 weeks at the latest. (author)

Phantom and animal studies of a new hepatobiliary agent for MR imaging: comparison of Gd-DTPA-DeA with Gd-EOB-DTPA.

Science.gov (United States)

Yoshikawa, Kohki; Inoue, Yusuke; Akahane, Masaaki; Shimada, Morio; Itoh, Sayaka; Seno, Atsushi; Hayashi, Sanshin

2003-08-01

To investigate the characteristics of Gd-DTPA-DeA as a hepatobiliary contrast agent for MR imaging in comparison with those of Gd-EOB-DTPA. We undertook phantom experiments to assess T1 relaxivity for Gd-DTPA-DeA, Gd-EOB-DTPA, and Gd-DTPA in human plasma. For Gd-DTPA-DeA and Gd-EOB-DTPA, we evaluated the contrast effect in rats using an SPGR sequence. The contrast ratios of liver and abdominal aorta were measured up to 21 minutes after intravenous administration of the agents. Visualization of the bile duct and renal pelvis was also assessed. In human plasma, T1 relaxivity was similar for Gd-DTPA-DeA and Gd-EOB-DTPA, and higher than those for Gd-DTPA. Whereas the contrast ratio of liver peaked about five minutes after the injection of Gd-EOB-DTPA and was followed by a subsequent decline, a continuous rise was shown for Gd-DTPA-DeA, resulting in a larger maximal contrast effect. Contrast ratios of the abdominal aorta were larger for Gd-DTPA-DeA. Biliary excretion was observed for both agents but occurred earlier with Gd-EOB-DTPA. While renal excretion was shown for all rats three minutes after the injection of Gd-EOB-DTPA, it was not observed for Gd-DTPA-DeA. Gd-DTPA-DeA may be used as a hepatobiliary contrast agent and shows different pharmacokinetics from Gd-EOB-DTPA. Copyright 2003 Wiley-Liss, Inc.

Nanoparticles as image enhancing agents for ultrasonography

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Liu Jun [Biomedical Engineering Department, Ohio State University, 270 Bevis Hall, 1080 Carmack Rd, Columbus, OH 43210 (United States); Levine, Andrea L [Department of Veterinary Biosciences, Ohio State University, 1925 Coffey Rd, Columbus, OH 43210 (United States); Mattoon, John S [Department of Veterinary Clinical Sciences, Ohio State University, 1151 Veterinary Hospital, 601 Vernon Tharp St., Columbus, OH 43210 (United States); Yamaguchi, Mamoru [Department of Veterinary Biosciences, Ohio State University, 1925 Coffey Rd, Columbus, OH 43210 (United States); Lee, Robert J [Division of Pharmaceutics, College of Pharmacy, NCI Comprehensive Cancer Center, and NSF Nanoscale Science and Engineering Center, Ohio State University, 500 West 12th Avenue, Columbus, OH 43210 (United States); Pan Xueliang [Department of Statistics, Ohio State University, 1958 Neil Avenue, Columbus, OH 43210 (United States); Rosol, Thomas J [Department of Veterinary Biosciences, Ohio State University, 1925 Coffey Rd, Columbus, OH 43210 (United States)

2006-05-07

Nanoparticles have drawn great attention as targeted imaging and/or therapeutic agents. The small size of the nanoparticles allows them to target cells that are beyond capillary vasculature, such as cancer cells. We investigated the effect of solid nanoparticles for enhancing ultrasonic grey scale images in tissue phantoms and mouse livers in vivo. Silica nanospheres (100 nm) were dispersed in agarose at 1-2.5% mass concentration and imaged by a high-resolution ultrasound imaging system (transducer centre frequency: 30 MHz). Polystyrene particles of different sizes (500-3000 nm) and concentrations (0.13-0.75% mass) were similarly dispersed in agarose and imaged. Mice were injected intravenously with nanoparticle suspensions in saline. B-mode images of the livers were acquired at different time points after particle injection. An automated computer program was used to quantify the grey scale changes. Ultrasonic reflections were observed from nanoparticle suspensions in agarose gels. The image brightness, i.e., mean grey scale level, increased with particle size and concentration. The mean grey scale of mouse livers also increased following particle administration. These results indicated that it is feasible to use solid nanoparticles as contrast enhancing agents for ultrasonic imagin000.

Contrast-enhanced three-dimensional MR imaging using a volumetric interpolated breath-hold examination (VIBE): clinical utility in the evaluation of renal tumors

International Nuclear Information System (INIS)

Lee, Young Hwan; Kim, Chong Soo; Lee, Jeong Min

2002-01-01

To compare, in terms of technical feasibility, image quality and clinical efficacy, contrast-enhanced three-dimensional (3D) MR imaging using volumetric interpolated breath-hold examination (VIBE) with two-dimensional gradient-echo MR imaging for the evaluation of renal messes. Twenty-three patients with 25 renal masses underwent dynamic MR imaging using a 1.5-T MR system and the 3D VIBE, 2D fast low angle shot (FLASH), and combined fat saturation techniques after the injection of 20 ml of Gd-DTPA. We compared postcontrast 2D FLASH and 3D VIBE images with precontrast 2D FLASH images. For quantitative analysis, the signal-to-noise and lesion to kidney contrast-to-noise ratio of the images were calculated using the three different techniques. For qualitative analysis, two experienced radiologists analyzed the images in terms of artifacts, lesion conspicuity and delineation, and general image quality. Delineation of the anatomy of renal vasculature and pelvocalyceal systems on reconstructed 3D VIBE MIP images was also assessed. Quantitative analysis showed that the SNR of a renal mass was slightly higher at postcontrast 2D FLASG than at 3D VIBE imaging, and the SNR of renal cortex was higher at 3D VIBE than at postcontrast 2D FLASF imaging. The differences were, though, statistically insignificant (p>0.05). The CNR of al renal mass was, however, significantly higher at 3D VIBE than at 2D FLASH imaging (p<0.05). Qualitative analysis showed that general image quality was best at postcontrast 3D VIBE, followed by 2D FLASH and precontrast 2D FLASH imaging, and image artifacts were worst at post-contrast 2D FLASH image (p<0.05). In terms of lesion conspicuity and delineation, 3D VIBE gave the best results and postcontrast images were better than precontrast (p<0.05). Reconstructed angiographic and urographic images using the VIBE technique provided information about the anatomy of the renal vasculature and pelvocalyceal system. 3D VIBE MR imaging offers comparable or

Contrast-enhanced three-dimensional MR imaging using a volumetric interpolated breath-hold examination (VIBE): clinical utility in the evaluation of renal tumors

International Nuclear Information System (INIS)

Lee, Young Hwan; Lee, Jeong Min; Kim, Chong Soo

2002-01-01

To compare, in terms of technical feasibility, image quality and clinical efficacy, contrast-enhanced three-dimensional (3D) MR imaging using volumetric interpolated breath-hold examination (VIBE) with two-dimensional gradient-echo MR imaging for the evaluation of renal masses. Twenty-three patients with 25 renal masses underwent dynamic MR imaging using a 1.5-T MR system and the 3D VIBE, 2D fast low angle shot (FLASH), and combined fat saturation techniques after the injection of 20 ml of Gd-DTPA. We compared postcontrast 2D FLASH and 3D VIBE images with precontrast 2D FLASH images. For quantitative analysis, the signal-to-noise and lesion to kidney contrast-to-noise ratio of the images were calculated using the three different techniques. For qualitative analysis, two experienced radiologists analyzed the images in terms of artifacts, lesion conspicuity and delineation, and general image quality. Delineation of the anatomy of renal vasculature and pelvocalyceal system on reconstructed 3D VIBE MIP images was also assessed. Quantitative analysis showed that the SNR of a renal mass was slightly higher at postcontrast 2D FLASH than at 3D VIBE imaging, and the SNR of renal cortex was higher at 3D VIBE than at postcontrast 2D FLASH imaging. The differences were, though, statistically insignificant (p>0.05). The CNR of a renal mass was, however, significantly higher at 3D VIBE than at 2D FLASH imaging (p<0.05). Qualitative analysis showed that general image quality was best at postcontrast 3D VIBE, followed by 2D FLASH and precontrast 2D FLASH imaging, and image artifacts were worst at post-contrast 2D FLASH image (p<0.05). In terms of lesion conspicuity and delineation, 3D VIBE gave the best results and postcontrast images were better than precontrast (p<0.05). Reconstructed angiographic and urographic images using the VIBE technique provided information about the anatomy of the renal vasculature and pelvocalyceal system. 3D VIBE MR imaging offers comparable or

Contrast-enhanced three-dimensional MR imaging using a volumetric interpolated breath-hold examination (VIBE): clinical utility in the evaluation of renal tumors

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Hwan; Kim, Chong Soo [Chonbuk National University Hospita, Chungju (Korea, Republic of); Lee, Jeong Min [Seoul National University Hospital, Seoul (Korea, Republic of)

2002-12-01

To compare, in terms of technical feasibility, image quality and clinical efficacy, contrast-enhanced three-dimensional (3D) MR imaging using volumetric interpolated breath-hold examination (VIBE) with two-dimensional gradient-echo MR imaging for the evaluation of renal messes. Twenty-three patients with 25 renal masses underwent dynamic MR imaging using a 1.5-T MR system and the 3D VIBE, 2D fast low angle shot (FLASH), and combined fat saturation techniques after the injection of 20 ml of Gd-DTPA. We compared postcontrast 2D FLASH and 3D VIBE images with precontrast 2D FLASH images. For quantitative analysis, the signal-to-noise and lesion to kidney contrast-to-noise ratio of the images were calculated using the three different techniques. For qualitative analysis, two experienced radiologists analyzed the images in terms of artifacts, lesion conspicuity and delineation, and general image quality. Delineation of the anatomy of renal vasculature and pelvocalyceal systems on reconstructed 3D VIBE MIP images was also assessed. Quantitative analysis showed that the SNR of a renal mass was slightly higher at postcontrast 2D FLASG than at 3D VIBE imaging, and the SNR of renal cortex was higher at 3D VIBE than at postcontrast 2D FLASF imaging. The differences were, though, statistically insignificant (p>0.05). The CNR of al renal mass was, however, significantly higher at 3D VIBE than at 2D FLASH imaging (p<0.05). Qualitative analysis showed that general image quality was best at postcontrast 3D VIBE, followed by 2D FLASH and precontrast 2D FLASH imaging, and image artifacts were worst at post-contrast 2D FLASH image (p<0.05). In terms of lesion conspicuity and delineation, 3D VIBE gave the best results and postcontrast images were better than precontrast (p<0.05). Reconstructed angiographic and urographic images using the VIBE technique provided information about the anatomy of the renal vasculature and pelvocalyceal system. 3D VIBE MR imaging offers comparable or

Evaluation of renal function with dynamic Gd-DTPA enhanced magnetic resonance imaging after shock wave lithotripsy

International Nuclear Information System (INIS)

Izumi, Hirokazu; Shiokawa, Hidefumi; Kurokawa, Jun; Murata, Koichiro; Mashimo, Setsuo; Koshiba, Ken.

1992-01-01

It has already been reported that MR imaging is a superior imaging technique to detect minute anatomical changes in the kidney after extracorporeal shock wave lithotripsy (ESWL). However, the morphological abnormalities found by MR imaging do not necessarily mean deterioration of the renal function. The purpose of this study is to assess the morphological changes in the kidney and changes in renal function after ESWL treatment by dynamic MR imaging. A total of 16 patients underwent axial MR imaging before and after ESWL. Dynamic MR was also performed on 11 patients of them within 24 hours after ESWL, and both before and after ESWL in the remaining 5 patients. Eight kidneys showed morphological abnormalities on T1-weighted images, and 4 of them showed loss of corticomedullary demarcation. Furthermore, the first MR imaging after injection of Gd-DTPA revealed focal areas of decreased signal intensity in only 2 of these 4 patients who showed loss of corticomedullary demarcation on previous MR images. However, the second MR imaging 6 months after ESWL showed no abnormality in either of them. The percent contrast of signal intensity increase to fat signal intensity was one minute after Gd-DTPA injection compared before and after ESWL in 5 of the 16 patients. The values before and after ESWL revealed no statistically significant difference, and no patient showed any remarkable decrease of signal intensity after ESWL. These results suggest that loss of corticomedullary demarcation after ESWL does not necessarily reflect damage to the renal function and that the shock-wave exposure causes no premanent damage to the renal function but only temporary impairment. (author)

Evaluation of renal function with dynamic Gd-DTPA enhanced magnetic resonance imaging after shock wave lithotripsy

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Izumi, Hirokazu; Shiokawa, Hidefumi; Kurokawa, Jun; Murata, Koichiro (Kitasato Inst., Saitama (Japan). Medical Center Hospital); Mashimo, Setsuo; Koshiba, Ken

1992-03-01

It has already been reported that MR imaging is a superior imaging technique to detect minute anatomical changes in the kidney after extracorporeal shock wave lithotripsy (ESWL). However, the morphological abnormalities found by MR imaging do not necessarily mean deterioration of the renal function. The purpose of this study is to assess the morphological changes in the kidney and changes in renal function after ESWL treatment by dynamic MR imaging. A total of 16 patients underwent axial MR imaging before and after ESWL. Dynamic MR was also performed on 11 patients of them within 24 hours after ESWL, and both before and after ESWL in the remaining 5 patients. Eight kidneys showed morphological abnormalities on T1-weighted images, and 4 of them showed loss of corticomedullary demarcation. Furthermore, the first MR imaging after injection of Gd-DTPA revealed focal areas of decreased signal intensity in only 2 of these 4 patients who showed loss of corticomedullary demarcation on previous MR images. However, the second MR imaging 6 months after ESWL showed no abnormality in either of them. The percent contrast of signal intensity increase to fat signal intensity was one minute after Gd-DTPA injection compared before and after ESWL in 5 of the 16 patients. The values before and after ESWL revealed no statistically significant difference, and no patient showed any remarkable decrease of signal intensity after ESWL. These results suggest that loss of corticomedullary demarcation after ESWL does not necessarily reflect damage to the renal function and that the shock-wave exposure causes no premanent damage to the renal function but only temporary impairment. (author).

A comparison of positron-emitting blood pool imaging agents

International Nuclear Information System (INIS)

Hnatowich, D.J.; Kulprathipanja, S.; Evans, G.; Elmaleh, D.

1979-01-01

The three agents, 11 C-carboxyhaemoglobin, 68 Ga-transferrin and 68 Ga-labelled red cells have been compared in dogs to assess their relative merits for blood-pool imaging. For 1 h following administration of each agent, periodic blood samples were withdrawn for counting in a NaI (Tl) well counter while conventional two-dimensional images were obtained simultaneously on the Massachusetts General Hospital positron camera. Count rates in regions about the heart, liver and spleen were obtained for each image. The disappearance of blood activity as shown from the results of counting the blood samples and from the counting rates in regions about the heart was found to be identical within experimental error for the three agents. In the liver and spleen regions, the highest count rates were obtained with 68 Ga-transferrin and the lowest with 68 Ga-labelled red cells; count rates in these regions with labelled red cells were virtually constant throughout the 1 h study. It may be concluded that with the exceptions noted above, the three agents are approximately equivalent for blood-pool imaging. (author)

Renal imaging in paediatrics; Nuklearmedizinische Nierendiagnostik in der Paediatrie

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Porn, U.; Hahn, K.; Fischer, S. [Klinik und Poliklinik fuer Nuklearmedizin, Ludwig-Maximilians-Univ. Muenchen (Germany)

2003-09-01

The most frequent renal diseases in paediatrics include urinary tract infections, hydronephrosis, kidney anomalies and reflux. The main reason for performing DMSA scintigraphy in paediatrics is the detection of cortical abnormalities related to urinary tract infection. Because the amount of tracer retained in the tubular cells is associated with the distribution of functioning renal parenchyma in the kidney, it is possible, to evaluate the split renal function. In comparison to ultrasound and intravenous urography the sensitivity in the detection of acute as well as chronic inflammatory changes is very high, however less specific. An indication for a renography in neonates and children is beside an estimation of the total renal function and the calculation of the split renal function, the assessment of renal drainage in patients with unclear dilatation of the collecting system in ultrasound. The analysis of the time activity curve provides, especially for follow-up studies, a reproducible method to assess the urinary outflow. The diuretic scintigraphy allows the detection of urinary obstruction. Subsequently it is possible to image the micturition phase to detect vesico-ureteric reflux (indirect MCU) after drainage of tracer from the renal pelvis. An reflux in the ureters or the pelvicalyceal system is visible on the scintigraphic images and can be confirmed by time activity curves. A more invasive technique is the direct isotope cystography with bladder catheterization. The present paper should give an overview about the role of nuclear medicine in paediatric urology. (orig.) [German] Die haeufigsten nephrourologischen Erkrankungen in der Paediatrie umfassen die entzuendlichen Veraenderungen des Nierenparenchyms, Harnstauungen, Nierenanomalien und Refluxerkrankungen. Die statische Nierenszintigraphie mit {sup 99m}Tc-DMSA hat in der Paediatrie vor allem zur Evaluierung von Narbenbildungen bei Pyelonephritis ihren Stellenwert. Da die tubulaere Speicherung von DMSA

Computer analysis of the X-ray images of renal concretions

International Nuclear Information System (INIS)

Naumov, N.; Zozikov, B.; Yanakiev, I.; Varlev, H.; Dimitrov, I.; Baltadjiev, D.; Dimitrova, St.; Shimanov, V.; Sultanov, A.; Pazderov, R.

1997-01-01

An investigation aimed to assessing the possibilities of computerized analysis of renal concretions is described. The results of comparative study of digitized X-ray images of concretions and data retrieved from radio-spectral microprobe analysis are presented. The obtained data confirm the author's hypothesis set forth, claiming that it is possible to define the composition and structure of renal concretions using specially developed software (Videoexpert 2.0). Excellent results are obtained even from native X-rays where the concernment is still within the patient's body. Roentgen computerized analysis is recommended in making decision on therapeutic approach towards calculi in urological and radiographic practice. 5 refs., 5 figs

Evaluation of renal allograft rejection by Doppler sonography and MR imaging

International Nuclear Information System (INIS)

Steinberg, H.V.; Nelson, R.C.; Murphy, F.B.; Baumgartner, B.R.; Bourke, E.; Delaney, V.B.; Whelchel, J.B.; Bernardino, M.E.

1986-01-01

The authors prospectively studies the efficacy of Doppler sonography and MR imaging in evaluating renal allografts, with specific attention to transplant rejection. Based on study findings, we were unable to make a statement with respect to the appearance or accuracy of diagnosing cyclosporin toxicity or acute tubular necrosis by either modality due to concomitant rejection in the few patients so afflicted. Moreover, the ability to predict and diagnose the presence or absence of allograft rejection was not affected by different serum creatinine values. Most important, however, Doppler sonography was shown to be superior to MR imaging in evaluating for allograft rejection, as evidenced by its higher sensitivity (100% vs. 71%), specificity (88% vs. 75%), and accuracy (96% vs. 73%). Thus, because of its low cost and ease of accessibility, Doppler sonography should become the primary modality for renal transplant screening

The Role of Compounds Derived from Natural Supplement as Anticancer Agents in Renal Cell Carcinoma: A Review

Science.gov (United States)

Haque, Inamul; Subramanian, Arvind; Huang, Chao H.; Godwin, Andrew K.; Van Veldhuizen, Peter J.; Banerjee, Snigdha; Banerjee, Sushanta K.

2017-01-01

Renal Cell Carcinoma (RCC) is the most prominent kidney cancer derived from renal tubules and accounts for roughly 85% of all malignant kidney cancer. Every year, over 60,000 new cases are registered, and about 14,000 people die from RCC. The incidence of this has been increasing significantly in the U.S. and other countries. An increased understanding of molecular biology and the genomics of RCC has uncovered several signaling pathways involved in the progression of this cancer. Significant advances in the treatment of RCC have been reported from agents approved by the Food and Drug Administration (FDA) that target these pathways. These agents have become drugs of choice because they demonstrate clinical benefit and increased survival in patients with metastatic disease. However, the patients eventually relapse and develop resistance to these drugs. To improve outcomes and seek approaches for producing long-term durable remission, the search for more effective therapies and preventative strategies are warranted. Treatment of RCC using natural products is one of these strategies to reduce the incidence. However, recent studies have focused on these chemoprevention agents as anti-cancer therapies given they can inhibit tumor cell grow and lack the severe side effects common to synthetic compounds. This review elaborates on the current understanding of natural products and their mechanisms of action as anti-cancer agents. The present review will provide information for possible use of these products alone or in combination with chemotherapy for the prevention and treatment of RCC. PMID:29301217

The potential of dual-energy virtual monochromatic imaging in reducing renal cyst pseudoenhancement. A phantom study

International Nuclear Information System (INIS)

Yamada, Sachiko; Ueguchi, Takashi; Ukai, Isao; Nagai, Yumiko; Yamakawa, Masanobu; Shimosegawa, Eku; Shimazu, Takeshi; Hatazawa, Jun

2012-01-01

Renal cyst pseudoenhancement, an artifactual increase of computed tomography (CT) attenuation for cysts with increased iodine concentrations in the renal parenchyma, complicates the classification of cysts and may thus lead to the mischaracterization of a benign non-enhancing lesion as an enhancing mass. The purpose of this study was to use a phantom model to assess the ability of dual-energy virtual monochromatic imaging to reduce renal pseudoenhancement. A water-filled cylindrical cyst model suspended in varying concentrations of iodine solution, to simulate varying levels of parenchymal enhancement, was scanned with a dual-energy CT scanner using the following three scanning protocols with different combinations of tube voltage: 80 and 140 kV; 80 and 140 kV with tin filter; and 100 and 140 kV with tin filter. Virtual monochromatic images were then synthesized for each dual-energy scan. Single-energy scan with a tube voltage of 120 kV was also performed to obtain polychromatic images as controls. Mean attenuation values (in Hounsfield units) of cyst proxies were measured on both polychromatic and virtual monochromatic images. Pseudoenhancement was considered to be present when the cyst attenuation level increased by more than 10 HU (Hounsfield Unit) as the background iodine concentration increased from 0.0% to 0.4%, 1.5%, or 2.5%. Our results revealed that pseudoenhancement was not observed on any of the monochromatic images, but appeared on polychromatic images at a background iodine concentration of 2.5%. We thus conclude that dual-energy virtual monochromatic images have a potential to reduce renal pseudoenhancement. (author)

3D Texture Analysis in Renal Cell Carcinoma Tissue Image Grading

Science.gov (United States)

Cho, Nam-Hoon; Choi, Heung-Kook

2014-01-01

One of the most significant processes in cancer cell and tissue image analysis is the efficient extraction of features for grading purposes. This research applied two types of three-dimensional texture analysis methods to the extraction of feature values from renal cell carcinoma tissue images, and then evaluated the validity of the methods statistically through grade classification. First, we used a confocal laser scanning microscope to obtain image slices of four grades of renal cell carcinoma, which were then reconstructed into 3D volumes. Next, we extracted quantitative values using a 3D gray level cooccurrence matrix (GLCM) and a 3D wavelet based on two types of basis functions. To evaluate their validity, we predefined 6 different statistical classifiers and applied these to the extracted feature sets. In the grade classification results, 3D Haar wavelet texture features combined with principal component analysis showed the best discrimination results. Classification using 3D wavelet texture features was significantly better than 3D GLCM, suggesting that the former has potential for use in a computer-based grading system. PMID:25371701

3D Texture Analysis in Renal Cell Carcinoma Tissue Image Grading

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Tae-Yun Kim

2014-01-01

Full Text Available One of the most significant processes in cancer cell and tissue image analysis is the efficient extraction of features for grading purposes. This research applied two types of three-dimensional texture analysis methods to the extraction of feature values from renal cell carcinoma tissue images, and then evaluated the validity of the methods statistically through grade classification. First, we used a confocal laser scanning microscope to obtain image slices of four grades of renal cell carcinoma, which were then reconstructed into 3D volumes. Next, we extracted quantitative values using a 3D gray level cooccurrence matrix (GLCM and a 3D wavelet based on two types of basis functions. To evaluate their validity, we predefined 6 different statistical classifiers and applied these to the extracted feature sets. In the grade classification results, 3D Haar wavelet texture features combined with principal component analysis showed the best discrimination results. Classification using 3D wavelet texture features was significantly better than 3D GLCM, suggesting that the former has potential for use in a computer-based grading system.

Evaluation of potential gastrointestinal contrast agents for echoplanar MR imaging

International Nuclear Information System (INIS)

Reimer, P.; Schmitt, F.; Ladebeck, R.; Graessner, J.; Schaffer, B.

1993-01-01

The purpose of this study was to investigate approved aqueous gastrointestinal contrast agents for use in abdominal EPI. Conventional and echoplanar MR imaging experiments were performed with 1.0 Tesla whole body systems. Phantom measurements of Gastrografin, barium sulfate suspension, oral gadopentetate dimeglumine, water, and saline were performed. Signal intensity (SI) of aqueous oral barium sulfate and iodine based CT contrast agents was lower on conventional spin-echo (SE), Flash, and Turbo-Flush images than on EP images. The contrast agents exhibited higher SI on T2-weighted SE PE images and TI-time dependence on inversion recovery EP-images. The barium sulfate suspension was administered in volunteers to obtain information about bowel lumen enhancement and susceptibility artifacts. Oral administration of the aqueous barium sulfate suspension increased bowel lumen signal and reduced susceptibility artifacts. (orig.)

Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

International Nuclear Information System (INIS)

Borelli, Flavio Antonio de Oliveira; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R.

2013-01-01

Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m 2 . Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction

Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

Energy Technology Data Exchange (ETDEWEB)

Borelli, Flavio Antonio de Oliveira, E-mail: fborelli@cardiol.br; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R. [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

2013-11-15

Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m{sup 2}. Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction.

Comparative study between 99Tcm-MDP renal dynamic imaging and measurement of serum cystatin C in evaluation of glomerular function

International Nuclear Information System (INIS)

Ji Zeqiang; Miao Weibing

2010-01-01

Objective: To compare the difference between 99 Tcm-diethylenetriaminepentaacetic acid ( 99 Tc m -DTPA) renal dynamic imaging and measurement of serum cystatin C in evaluation of glomerular filtration rate (GFR). Methods: One hundred patients were selected at random, 38 cases with hypertension, 35 with nephrosis, 10 with arteriosclerosis obliterans, 9 with diabetes and 8 with other diseases. Evaluation of patients' GFR was made separately by 99 Tc m -DTPA renal dynamic imaging and measurement of serum cystatin C. Results: No significant difference of GFR was found between the two methods (t=1.591, P>0.05 ), and linear correlation was showed as well (r=0.809, P 99 Tc m -DTPA renal dynamic imaging could reveal the individual renal function and provide a more comprehensive evaluation of renal function while the measurement of serum cystatin C was simple and convenient, timesaving, economic, and more suit-able for screening patients' renal function clinically. (authors)

Modular strategies for PET imaging agents

International Nuclear Information System (INIS)

Hooker, J.M.

2010-01-01

In recent years, modular and simplified chemical and biological strategies have been developed for the synthesis and implementation of positron emission tomography (PET) radiotracers. New developments in bioconjugation and synthetic methodologies, in combination with advances in macromolecular delivery systems and gene-expression imaging, reflect a need to reduce radiosynthesis burden in order to accelerate imaging agent development. These new approaches, which are often mindful of existing infrastructure and available resources, are anticipated to provide a more approachable entry point for researchers interested in using PET to translate in vitro research to in vivo imaging.

Acetic acid sclerotheraphy of renal cysts

International Nuclear Information System (INIS)

Hong, Hoon Pyo; Oh, Joo Hyeong; Yoon, Yup; Kong, Keun Young; Kim, Eui Jong; Goo, Jang Sung

1998-01-01

Sclerotherapy for renal cysts was performed, using 50% acetic acid as new sclerosing agent. We report the methods and results of this procedure. Fifteen patients underwent sclerotherapy for renal cyst, using 50% acetic acid. Because four patients were lost to follow-up, only 11 of the 15 were included in this study. The renal cysts, including one infected case, were diagnosed by ultrasonograpy (n=3D10) ormagnetic resonance imaging (n=3D1). The patient group consisted of four men and seven women(mean age, 59 years; range, 23-77). At first, the cyst was completely aspirated, and 25 volume% of aspirated volume was replaced with 50% sterile acetic acid through the drainage catheter. During the follwing 20 minutes, the patient changed position, and the acetic acid was then removed from the cyst. Finally, the drainage catheter was removed, after cleaning the cyst with saline. After treatment of infection by antibiotics and catheter drainage for 7 days, sclerotherapy in the infected case followed the same procedure. In order to observe changes in the size of renal cysts and recurrence, all patients were followed up by ultrasound between 2 and 8 months. We defined response to therapy as follows:complete regression as under 5 volume%, partial regression as 5-50 volume% and no response as more than 50 volume% of initial cyst volume. No clinically significant complication occured during the procedures or follow-up periods. All cysts regressed completely during follow-up of 8 months. Complete regression occurred as follows: two cysts at 2 months, seven cysts at 4 months, two cysts at 6 months. Two cysts showed residues at the last follow-up, at 4 and 6 months, respectively. The volume of residual cysts decreased to under 5 volume% of initial volume, however. Completely regressed cysts did not recurr during follow-up. Acetic acid sclerotherapy for renal cysts showed good results, regardless of the dilution of sclerosing agent with residual cyst fluid, and no significant

Nanoparticle Contrast Agents for Computed Tomography: A Focus on Micelles

Science.gov (United States)

Cormode, David P.; Naha, Pratap C.; Fayad, Zahi A.

2014-01-01

Computed tomography (CT) is an X-ray based whole body imaging technique that is widely used in medicine. Clinically approved contrast agents for CT are iodinated small molecules or barium suspensions. Over the past seven years there has been a great increase in the development of nanoparticles as CT contrast agents. Nanoparticles have several advantages over small molecule CT contrast agents, such as long blood-pool residence times, and the potential for cell tracking and targeted imaging applications. Furthermore, there is a need for novel CT contrast agents, due to the growing population of renally impaired patients and patients hypersensitive to iodinated contrast. Micelles and lipoproteins, a micelle-related class of nanoparticle, have notably been adapted as CT contrast agents. In this review we discuss the principles of CT image formation and the generation of CT contrast. We discuss the progress in developing non-targeted, targeted and cell tracking nanoparticle CT contrast agents. We feature agents based on micelles and used in conjunction with spectral CT. The large contrast agent doses needed will necessitate careful toxicology studies prior to clinical translation. However, the field has seen tremendous advances in the past decade and we expect many more advances to come in the next decade. PMID:24470293

[Diffusion weighted imaging and perfusion weighted imaging in the differential diagnosis of benign and malignant renal masses on 3.0 T MRI].

Science.gov (United States)

Xu, Xiaowen; Wang, Peijun; Ma, Liang; Shao, Zhihong; Zhang, Min

2015-01-20

To explore the value of diffusion weighted imaging (DWI) and perfusion weighted imaging (PWI) in identifying benign and malignant renal masses and differentiating the histological types of renal masses. Fifteen healthy volunteers and 46 patients with renal masses proven by pathology, including clear cell carcinomas (n = 18), papillary carcinomas (n = 8), chromophobe carcinomas (n = 7) and angiomyolipomas (n = 13), were examined with DWI and PWI scan at 3.0 T MRI. ANOVA was employed to compare the values of transfer constant (K(trans)), rate constant of backflux (Kep) and extra-vascular extra-cellular space fractional volume (Ve) proceeded by PWI and the value of ADC resulted from DWI between normal kidney and different histological types of renal masses. Receiver operating characteristics (ROC) curve was used to analyze and compare the diagnostic value of the methods of PWI and DWI in differentiating benign and malignant renal masses. The ADC value of normal renal parenchyma was (2.10 ± 0.24) × 10⁻³ mm²/s, which was statistically higher than benign and malignant renal masses (P 0.05).Values of K(trans), Kep and Ve between normal renal parenchyma and different histological types of renal masses had statistical differences.Values of K(trans) and Ve in three histological types of malignant renal masses were statistically higher than those of benign renal masses.Kep value of clear cell carcinoma was significantly higher than that of benign renal masses (P benign and malignant renal masses. The K(trans) of benign and malignant renal masses had the largest AUC (AUC = 0.937) at a threshold of 0.38/min. And there were a sensitivity of 87.9% and a specificity of 85.7%. The AUC of ADC was 0.823, sensitivity 72.7% and specificity 92.9%. The ADC threshold for differentiating benign from malignant masses was 1.40 × 10⁻³ mm²/s; AUC of Ve 0.803, sensitivity 78.8% and specificity 71.4%, a threshold of 0.29/min; Kep showed lower diagnostic value. 3.0 T MRI DWI and PWI

Advanced Contrast Agents for Multimodal Biomedical Imaging Based on Nanotechnology.

Science.gov (United States)

Calle, Daniel; Ballesteros, Paloma; Cerdán, Sebastián

2018-01-01

Clinical imaging modalities have reached a prominent role in medical diagnosis and patient management in the last decades. Different image methodologies as Positron Emission Tomography, Single Photon Emission Tomography, X-Rays, or Magnetic Resonance Imaging are in continuous evolution to satisfy the increasing demands of current medical diagnosis. Progress in these methodologies has been favored by the parallel development of increasingly more powerful contrast agents. These are molecules that enhance the intrinsic contrast of the images in the tissues where they accumulate, revealing noninvasively the presence of characteristic molecular targets or differential physiopathological microenvironments. The contrast agent field is currently moving to improve the performance of these molecules by incorporating the advantages that modern nanotechnology offers. These include, mainly, the possibilities to combine imaging and therapeutic capabilities over the same theranostic platform or improve the targeting efficiency in vivo by molecular engineering of the nanostructures. In this review, we provide an introduction to multimodal imaging methods in biomedicine, the sub-nanometric imaging agents previously used and the development of advanced multimodal and theranostic imaging agents based in nanotechnology. We conclude providing some illustrative examples from our own laboratories, including recent progress in theranostic formulations of magnetoliposomes containing ω-3 poly-unsaturated fatty acids to treat inflammatory diseases, or the use of stealth liposomes engineered with a pH-sensitive nanovalve to release their cargo specifically in the acidic extracellular pH microenvironment of tumors.

Ultrasound contrast-agent improves imaging of lower limb occlusive disease

DEFF Research Database (Denmark)

Eiberg, J P; Hansen, M A; Jensen, F

2003-01-01

to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA).......to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA)....

Quantitative Differences Between the First and Second Injection of Contrast Agent in Contrast-Enhanced Ultrasonography of Feline Kidneys and Spleen.

Science.gov (United States)

Stock, Emmelie; Vanderperren, Katrien; Haers, Hendrik; Duchateau, Luc; Hesta, Myriam; Saunders, Jimmy H

2017-02-01

Contrast-enhanced ultrasound is a valuable and safe technique for the evaluation of organ perfusion. Repeated injections of ultrasound contrast agent are often administered during the same imaging session. However, it remains unclear if quantitative differences are present between the consecutive microbubble injections. Therefore, the first and second injection of contrast agent for the left renal cortex, renal medulla and the splenic parenchyma in healthy cats were compared. A lower peak intensity and area under the curve were observed for the first injection of contrast agent in the feline kidney, both for the renal cortex and medulla, and spleen. Moreover, for the renal cortex, the time-intensity curve was steeper after the second injection. Findings from the present study demonstrate that a second injection of contrast agent provides stronger enhancement. The exact mechanism behind our findings remains unclear; however, saturation of the lung macrophages is believed to play an important role. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Living renal donors: optimizing the imaging strategy--decision- and cost-effectiveness analysis

NARCIS (Netherlands)

Y.S. Liem (Ylian Serina); M.C.J.M. Kock (Marc); W. Weimar (Willem); K. Visser (Karen); M.G.M. Hunink (Myriam); J.N.M. IJzermans (Jan)

2003-01-01

textabstractPURPOSE: To determine the most cost-effective strategy for preoperative imaging performed in potential living renal donors. MATERIALS AND METHODS: In a decision-analytic model, the societal cost-effectiveness of digital subtraction angiography (DSA), gadolinium-enhanced

Diffusion-Weighted Magnetic Resonance Imaging in Renal Lesion Characterization

Directory of Open Access Journals (Sweden)

Elif Karadeli

2012-03-01

Conclusion: The technique has the advantage that it is non-invasive without need for gadolinium administration, takes about 2 minute. This method provides qualitative and quantitative infomation on tissue characterization. DA-MRI and ADC values are important for characterization of renal lesions. Especially, utility of diffusion-weighted magnetic resonance imaging in the patients with risk for nephrogenic systemic fibrosis (NSF could be beneficial. [Cukurova Med J 2012; 37(1: 27-36

Renal computed angiography. Part I: Renal CT phlebography. Renal veins variants

International Nuclear Information System (INIS)

Al-Amin, M.; Krupev, M.; Hadjidekov, V.; Plachkov, I.

2012-01-01

The changing trend in renal surgery, transplantation and minimal invasive urology implies preprocedure evaluation of renal veins. Development of imaging methods offers new possibilities for venographic visualization. The goal of this study is to present authors experience in visualization of renal veins using 64 MDCT and to evaluate the utility in assessments of their variants. 128 patients (68 females and 60 males, mean age 53,3) with urological complaints underwent 64MDCT examination including CT angiography. Contrast enhancement includes 3-4ml/sec injection flow of 90 ml contrast medium followed by 20 ml saline at the same rate. In 23 out of 128 examined patients some of the common variants of the renal vein is found. 64 MDCT angiography visualize very well renal veins and becomes method of choice in preoperative assessment of renal vein anatomy. (authors)

Use of Erythropoietin-Stimulating Agents (ESA) in Patients With End-Stage Renal Failure Decided to Forego Dialysis: Palliative Perspective.

Science.gov (United States)

Cheng, Hon Wai Benjamin; Chan, Kwok Ying; Lau, Hoi To; Man, Ching Wah; Cheng, Suk Ching; Lam, Carman

2017-05-01

Normochromic normocytic anemia is a common complication in chronic kidney disease (CKD) and is associated with many adverse clinical consequences. Erythropoiesis-stimulating agents (ESAs) act to replace endogenous erythropoietin for patients with end-stage renal disease having anemia. Today, ESAs remain the main tool for treating anemia associated with CKD. In current practice, the use of ESA is not limited to the patients on renal replacement therapy but has extended to nondialysis patients under palliative care (PC). Current evidence on ESA usage in patients with CKD decided to forego dialysis often have to take reference from studies conducted in other groups of patients with CKD, including pre-dialysis patients and those on renal replacement therapy. There is paucity of studies targeting use of ESAs in renal PC patients. Small-scale retrospective study in renal PC patients had suggested clinical advantage of ESAs in terms of hemoglobin improvement, reduction in fatigue, and hospitalization rate. With the expected growth in elderly patients with CKD decided to forego dialysis and manage conservatively, there remains an urgent need to call for large-scale prospective trial in exploring efficacy of ESAs in this population, targeting on quality of life and symptoms improvement outcome. This article also reviews the mechanism of action, pharmacology, adverse effects, and clinical trial evidence for ESA in patients with CKD under renal PC.

Comparison of renal dynamic imaging and modified MDRD equation in determining the stage of chronic kidney disease patients

International Nuclear Information System (INIS)

Xie Peng; Liu Xiaomei; Huang Jianmin; Zhang Fang; Pan Liping; Wu Weijie; Gao Jianqing

2013-01-01

Objective: To compare the accuracy of 99 Tc m -diethylene triamine pentaacetic acid ( 99 Tc m -DTPA) renal dynamic imaging and modified modification of diet in renal disease trail (MDRD) equation in determining the stage of the chronic kidney disease (CKD) patients in clinical practice. Methods: A total of 169 patients were enrolled whose glomerular filtration rate (GFR) were determined simultaneously by 3 methods: dual plasma sample clearance method, renal dynamic imaging and modified MDRD equation. The dual plasma sample clearance method was employed as the reference method. The accuracy of the other methods in determining the stage of CKD patients was compared and the comparison was repeated based on the different stages. Results: The accuracy of renal dynamic imaging and modified MDRD equation was 56.80% and 68.64%, respectively (P=0.019<0.05). And only in the stage of uremia, the difference of the above-mentioned two method reached statistical significance (P=0.012<0.05), while in other stages they showed similar performance (P=0.180, 0.424, 0.629 and 0.754, all P>0.05). Conclusion: Modified MDRD equation showed better performance than renal dynamic imaging or as good as the second one in determining the stage of CKD patients and the former one should be the first choice in clinical practice because of its simplicity and economy. (authors)

Technetium SPECT agents for imaging heart and brain

International Nuclear Information System (INIS)

Linder, K.E.

1990-01-01

One major goal of radiopharmaceutical research has been the development of technetium-based perfusion tracers for SPECT imaging of the heart and brain. The recent clinical introduction of the technetium complexes HM-PAO, ECD and DMG-2MP for brain imaging, and of CDO-MEB and MIBI for heart imaging promises to revolutionize the field of nuclear medicine. All of these agents appear to localize in the target tissue in proportion to blood flow, but their mechanisms of localization and/or retention may differ quite widely. In this talk, a survey of the new technetium SPECT agents will be presented. The inorganic and biological chemistry of these complexes, mechanisms of uptake and retention, QSAR studies, and potential clinical applications are discussed

Evaluation of Renal Blood Flow and Oxygenation in CKD Using Magnetic Resonance Imaging.

Science.gov (United States)

Khatir, Dinah S; Pedersen, Michael; Jespersen, Bente; Buus, Niels H

2015-09-01

Animal studies suggest that progression of chronic kidney disease (CKD) is related to renal hypoxia. With renal blood supply determining oxygen delivery and sodium absorption being the main contributor to oxygen consumption, we describe the relationship between renal oxygenation, renal artery blood flow, and sodium absorption in patients with CKD and healthy controls. Cross-sectional study. 62 stable patients with CKD stages 3 to 4 (mean age, 61±13 [SD] years) and 24 age- and sex-matched controls. CKD versus control status. Renal artery blood flow, tissue oxygenation (relative changes in deoxyhemoglobin concentration of the renal medulla [MR2*] and cortex [CR2*]), and sodium absorption. Renal artery blood flow was determined by phase-contrast magnetic resonance imaging (MRI); MR2* and CR2* were determined by blood oxygen level-dependent MRI. Ultrafiltered and reabsorbed sodium were determined from measured glomerular filtration rate (mGFR) and 24-hour urine collections. mGFR in patients was 37% that of controls (36±15 vs 97±23 mL/min/1.73 m(2); P renal artery blood flow was 72% that of controls (319 vs 443 mL/min; P renal artery blood flow or sodium absorption. Increasing arterial blood oxygen tension by breathing 100% oxygen had very small effects on CR2*, but reduced MR2* in both groups. Only renal artery blood flow was determined and thus regional perfusion could not be related to CR2* or MR2*. In CKD, reductions of mGFR and reabsorbed sodium are more than double that of renal artery blood flow, whereas cortical and medullary oxygenation are within the range of healthy persons. Reduction in glomerular filtration fraction may prevent renal hypoxia in CKD. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Renal venogram

Science.gov (United States)

... be black. Other structures will be shades of gray. Veins are not normally seen in an x- ... Venogram - kidney; Renal vein thrombosis - venogram Images Kidney anatomy Kidney - blood and urine flow Renal veins References ...

Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

Energy Technology Data Exchange (ETDEWEB)

Pua, Uei; Tan, Cher Heng [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong [Tan Tock Seng Hospital, Department of Cardiology, Singapore (Singapore)

2014-08-28

Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

International Nuclear Information System (INIS)

Pua, Uei; Tan, Cher Heng; Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong

2015-01-01

Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

BOLD magnetic resonance imaging in nephrology

Science.gov (United States)

Hall, Michael E; Jordan, Jennifer H; Juncos, Luis A; Hundley, W Gregory; Hall, John E

2018-01-01

Magnetic resonance (MR) imaging, a non-invasive modality that provides anatomic and physiologic information, is increasingly used for diagnosis of pathophysiologic conditions and for understanding renal physiology in humans. Although functional MR imaging methods were pioneered to investigate the brain, they also offer powerful techniques for investigation of other organ systems such as the kidneys. However, imaging the kidneys provides unique challenges due to potential complications from contrast agents. Therefore, development of non-contrast techniques to study kidney anatomy and physiology is important. Blood oxygen level-dependent (BOLD) MR is a non-contrast imaging technique that provides functional information related to renal tissue oxygenation in various pathophysiologic conditions. Here we discuss technical considerations, clinical uses and future directions for use of BOLD MR as well as complementary MR techniques to better understand renal pathophysiology. Our intent is to summarize kidney BOLD MR applications for the clinician rather than focusing on the complex physical challenges that functional MR imaging encompasses; however, we briefly discuss some of those issues. PMID:29559807

Inherent characteristics of metachronous metastatic renal cell carcinoma in the era of targeted agents.

Science.gov (United States)

Han, Jang Hee; Lee, Seung Hwan; Ham, Won Sik; Han, Woong Kyu; Rha, Koon Ho; Choi, Young Deuk; Hong, Sung Joon; Yoon, Young Eun

2017-10-03

To assess the prognostic and predictive factors of time to treatment failure (TTF) and overall survival (OS), respectively, in patients with metachronous metastatic renal cell carcinoma (mRCC) who were treated with targeted agents. We retrospectively reviewed metachronous mRCC patients, defined as individuals diagnosed with metastatic disease >3 months after initial nephrectomy, treated at an institute since 2005. Cox proportional hazard regression analysis was performed to discover the most determinant variables associated with TTF and OS. Sarcomatoid features, absence of metastasectomy, multiple site metastasis, time to metastasis risk group (0-1 risk factors) did not reach the median OS, whereas the OS for the intermediate (2 risk factors) and high risk groups (3-5 risk factors) were 58.6 and 23.6 months, respectively (prisk criteria models. Initial tumor size or T stage did not affect TTF or OS. Patients who could not undergo metastasectomy and rapidly developed multiple metastases with higher corrected calcium and initial tumors with sarcomatoid features were less likely to benefit from targeted therapy; thus, the new agents under development or clinical trials could be more helpful than the use of standard targeted agents.

Chemical renal denervation in the rat.

Science.gov (United States)

Consigny, Paul M; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, Deanne

2014-02-01

The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose-response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography-mass spectrometry. Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10(-5) M through 10(-2) M paclitaxel. We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

In vivo Photoacoustic Imaging of Prostate Cancer Using Targeted Contrast Agent

Science.gov (United States)

2016-11-01

AD______________ AWARD NUMBER: W81XWH-14-1-0242 TITLE: In Vivo Photoacoustic Imaging of Prostate Cancer Using Targeted Contrast Agent PRINCIPAL...TITLE AND SUBTITLE In vivo Photoacoustic Imaging of Prostate Cancer Using T argeted Contrast Agent 5a. CONTRACT NUMBER W81XWH-14-1-0242 5b. GRANT...diagnose prostate cancer based on the near-infrared optical absorption of either endogenous tissue constituents or exogenous contrast agents . Although

The value of dynamic renal 99Tcm-diethylene triamine penta acetic acid imaging in rabbits with acute upper urinary tract obstruction

International Nuclear Information System (INIS)

Yan Jun; Li Xianfeng; Wang Jin; Li Sijin; Liu Jianzhong; Cheng Yan; Wu Zhifeng

2008-01-01

Objective: To research the degression of renal function of 99 Tc m -diethylene triamine pentaaceticacid ( 99 Tc m -DTPA) renal imaging in rabbits with acute upper urinary tract obstruction and its early recovery after relief. Methods: Twenty-four health rabbit models with left acute upper urinary tract obstruction were built up. 99 Tc m -DTPA renal imaging was performed before making model and after obstruction 1, 3, 5-7 and more than 8 weeks respectively and 4 weeks after relief of obstruction. Results: After obstnrction 1 and 3 weeks, 99 Tc m -DTPA imaging showed development in left renal. Values of glomemlar filtration rate (GFR) and uptake ratio decreased, while time to reach the peak increased. These are obviously different compared with those before obstruction (t=2.916, t=7.034, P 99 Tc m -DTPA imagingshowed cortex developert. Values of GFR and uptake ratio decreased obvious, while time to reach the peak increased obviously. These are obviously different compared with those before obstruction (t=6.722, t=7.470, t=3.678, P 99 Tc m -DTPA imaging showed no obvious development. In those rabbits with durations of 1-3 weeks obstructions, the renal function could almost recover within 4 weeks after relief of obstruction. GRF is 31.23 ± 14.4 (t=2.627, P 0.05). With obstruction of 5-7 weeks, the GRF and uptake ratio, could recover partly to some extent. But with obstruction for more than 8 weeks, the renal function could not recover. Conclusions: For the acute upper urinary tract obstruction, the renal function is most remarkable decreased in the early time, and can be restored after lelief. For long time obstruction, even if relieved, the renal function is not easily to restore. The dynamic renal imaging can reflect the extent of the renal damage and its recovery, and could be used as a reliable indicator. (authors)

Prognosis for recovery of function in acute renal failure

International Nuclear Information System (INIS)

Harwood, T.H. Jr.; Hiesterman, D.R.; Robinson, R.G.; Cross, D.E.; Whittier, F.C.; Diederich, D.A.; Grantham, J.J.

1976-01-01

Twenty-four survivors of acute, nonobstructive, nonnephritic renal failure had a renal scan using iodohippurate sodium I 131 performed early in the acute illness. Scans were judged according to whether the renal images were prominent, faint, or absent during the first 30 minutes after intravenous injection of 100 to 250 microcuries of iodohippurate sodium I 131. All ten patients with prominent renal images attained life-sustaining renal function with an average postrecovery creatinine clearance of 80 ml/min. Of the seven patients with faint renal images, six recovered life-sustaining renal function (average creatinine clearance of 39 ml/min), and one required chronic hemodialysis. Seven patients had no renal image initially; four recovered life-sustaining renal function with an average creatinine clearance of 25 ml/min; three required chronic hemodialysis. We conclude that, for patients with acute renal failure, the appearance of the renal image obtained using this substance is an important indicator of renal viability and of the likelihood for functional recovery

Arterial Transit Time-corrected Renal Blood Flow Measurement with Pulsed Continuous Arterial Spin Labeling MR Imaging.

Science.gov (United States)

Shimizu, Kazuhiro; Kosaka, Nobuyuki; Fujiwara, Yasuhiro; Matsuda, Tsuyoshi; Yamamoto, Tatsuya; Tsuchida, Tatsuro; Tsuchiyama, Katsuki; Oyama, Nobuyuki; Kimura, Hirohiko

2017-01-10

The importance of arterial transit time (ATT) correction for arterial spin labeling MRI has been well debated in neuroimaging, but it has not been well evaluated in renal imaging. The purpose of this study was to evaluate the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-labeling delay (PLD) acquisition for measuring ATT-corrected renal blood flow (ATC-RBF). A total of 14 volunteers were categorized into younger (n = 8; mean age, 27.0 years) and older groups (n = 6; 64.8 years). Images of pcASL were obtained at three different PLDs (0.5, 1.0, and 1.5 s), and ATC-RBF and ATT were calculated using a single-compartment model. To validate ATC-RBF, a comparative study of effective renal plasma flow (ERPF) measured by 99m Tc-MAG3 scintigraphy was performed. ATC-RBF was corrected by kidney volume (ATC-cRBF) for comparison with ERPF. The younger group showed significantly higher ATC-RBF (157.68 ± 38.37 mL/min/100 g) and shorter ATT (961.33 ± 260.87 ms) than the older group (117.42 ± 24.03 mL/min/100 g and 1227.94 ± 226.51 ms, respectively; P renal ASL-MRI as debated in brain imaging.

ESPR uroradiology task force and ESUR Paediatric Work Group--Imaging recommendations in paediatric uroradiology, part VI: childhood renal biopsy and imaging of neonatal and infant genital tract. Minutes from the task force session at the annual ESPR Meeting 2012 in Athens on childhood renal biopsy and imaging neonatal genitalia.

Science.gov (United States)

Riccabona, Michael; Lobo, Maria Luisa; Willi, Ulrich; Avni, Fred; Damasio, Beatrice; Ording-Mueller, Lil-Sofie; Blickman, Johan; Darge, Kassa; Papadopoulou, Frederika; Vivier, Pierre-Hugues

2014-04-01

The European Society of Paediatric Radiology Uroradiology Task Force and the ESUR Paediatric Work Group jointly publish guidelines for paediatric urogenital imaging. Two yet unaddressed topics involving patient safety and imaging load are addressed in this paper: renal biopsy in childhood and imaging of the neonatal genital tract, particularly in girls. Based on our thorough review of literature and variable practice in multiple centers, procedural recommendations are proposed on how to perform renal biopsy in children and how to approach the genital tract in (female) neonates. These are statements by consensus due to lack of sufficient evidence-based data. The procedural recommendation on renal biopsy in childhood aims at improving patient safety and reducing the number of unsuccessful passes and/or biopsy-related complications. The recommendation for an imaging algorithm in the assessment of the neonatal genital tract focuses on the potential of ultrasonography to reduce the need for more invasive or radiating imaging, however, with additional fluoroscopy or MRI to be used in selected cases. Adherence to these recommendations will allow comparable data and evidence to be generated for future adaptation of imaging strategies in paediatric uroradiology.

High prevalence of nephrogenic systemic fibrosis in chronic renal failure patients exposed to gadodiamide, a gadolinium-containing magnetic resonance contrast agent

DEFF Research Database (Denmark)

Rydahl, Casper; Thomsen, Henrik S; Marckmann, Peter

2008-01-01

OBJECTIVE: Nephrogenic systemic fibrosis (NSF) is a serious disease affecting renal failure patients. It may be caused by some gadolinium (Gd)-containing contrast agents, including gadodiamide. The study aimed at estimating the prevalence of NSF after gadodiamide exposure for patients with chronic...

Examining multi-component DNA-templated nanostructures as imaging agents

Science.gov (United States)

Jaganathan, Hamsa

2011-12-01

Magnetic resonance imaging (MRI) is the leading non-invasive tool for disease imaging and diagnosis. Although MRI exhibits high spatial resolution for anatomical features, the contrast resolution is low. Imaging agents serve as an aid to distinguish different types of tissues within images. Gadolinium chelates, which are considered first generation designs, can be toxic to health, while ultra-small, superparamagnetic nanoparticles (NPs) have low tissue-targeting efficiency and rapid bio-distribution, resulting to an inadequate detection of the MRI signal and enhancement of image contrast. In order to improve the utility of MRI agents, the challenge in composition and structure needs to be addressed. One-dimensional (1D), superparamagnetic nanostructures have been reported to enhance magnetic and in vivo properties and therefore has a potential to improve contrast enhancement in MRI images. In this dissertation, the structure of 1D, multi-component NP chains, scaffolded on DNA, were pre-clinically examined as potential MRI agents. First, research was focused on characterizing and understanding the mechanism of proton relaxation for DNA-templated NP chains using nuclear magnetic resonance (NMR) spectrometry. Proton relaxation and transverse relaxivity were higher in multi-component NP chains compared to disperse NPs, indicating the arrangement of NPs on a 1D structure improved proton relaxation sensitivity. Second, in vitro evaluation for potential issues in toxicity and contrast efficiency in tissue environments using a 3 Tesla clinical MRI scanner was performed. Cell uptake of DNA-templated NP chains was enhanced after encapsulating the nanostructure with layers of polyelectrolytes and targeting ligands. Compared to dispersed NPs, DNA-templated NP chains improved MRI contrast in both the epithelial basement membrane and colon cancer tumors scaffolds. The last part of the project was focused on developing a novel MRI agent that detects changes in DNA methylation

Image-guided radiofrequency ablation of Bosniak category III or IV cystic renal tumors: initial clinical experience

Energy Technology Data Exchange (ETDEWEB)

Park, Byung Kwan; Kim, Chan Kyo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea); Lee, Hyun Moo [Sungkyunkwan University School of Medicine, Department of Urology, Samsung Medical Center, Seoul (Korea)

2008-07-15

The purpose of this study was to assess the efficacy of image-guided radiofrequency (RF) ablation of cystic renal tumors. Between November 2005 and August 2007, computed tomography (CT) or ultrasound-guided RF ablation was performed in nine patients with 14 Bosniak category III (n = 5) or IV (n = 9) cystic renal tumors using an internally cooled RF ablation system. We evaluated the number of sessions, cycles and duration of energy application, treatment results, lesion size change, and complications. Together the cystic renal tumors required 15 sessions and 23 cycles of energy application. The duration of energy application per one tumor ablation ranged from 1 to 12 min (mean 6 min). The last follow-up CT indicated complete coagulation of 14/14 (100%) lesions. None of these tumors had recurred within 1-19 months (mean 8 months). The maximum diameter of the cystic renal tumors was significantly reduced from 2.5 {+-} 0.6 cm before ablation to 1.7 {+-} 0.7 cm at the last follow-up CT (P < 0.01). Complications were pneumothorax (n = 2), inguinal paresthesia (n = 1), and arteriovenous fistula (n = 1). Image-guided RF ablation is an effective treatment for Bosniak category III or IV cystic renal tumors, which might need relatively shorter duration of energy application than purely solid renal tumors of the same size. (orig.)

Image-guided radiofrequency ablation of Bosniak category III or IV cystic renal tumors: initial clinical experience

International Nuclear Information System (INIS)

Park, Byung Kwan; Kim, Chan Kyo; Lee, Hyun Moo

2008-01-01

The purpose of this study was to assess the efficacy of image-guided radiofrequency (RF) ablation of cystic renal tumors. Between November 2005 and August 2007, computed tomography (CT) or ultrasound-guided RF ablation was performed in nine patients with 14 Bosniak category III (n = 5) or IV (n = 9) cystic renal tumors using an internally cooled RF ablation system. We evaluated the number of sessions, cycles and duration of energy application, treatment results, lesion size change, and complications. Together the cystic renal tumors required 15 sessions and 23 cycles of energy application. The duration of energy application per one tumor ablation ranged from 1 to 12 min (mean 6 min). The last follow-up CT indicated complete coagulation of 14/14 (100%) lesions. None of these tumors had recurred within 1-19 months (mean 8 months). The maximum diameter of the cystic renal tumors was significantly reduced from 2.5 ± 0.6 cm before ablation to 1.7 ± 0.7 cm at the last follow-up CT (P < 0.01). Complications were pneumothorax (n = 2), inguinal paresthesia (n = 1), and arteriovenous fistula (n = 1). Image-guided RF ablation is an effective treatment for Bosniak category III or IV cystic renal tumors, which might need relatively shorter duration of energy application than purely solid renal tumors of the same size. (orig.)

Three-dimensional renal CT angiography for guiding segmental renal artery clamping during laparoscopic partial nephrectomy

International Nuclear Information System (INIS)

Xu, Yi; Shao, Pengfei; Zhu, Xiaomei; Lv, Qiang; Liu, Wangyan; Xu, Hai; Zhu, Yinsu; Yang, Guangyu; Tang, Lijun; Yin, Changjun

2013-01-01

Aim: To evaluate the effectiveness of three-dimensional (3D) renal computed tomography angiography (CTA) in guiding segmental renal artery clamping during laparoscopic partial nephrectomy (LPN). Materials and methods: Forty-three patients with renal tumours undergoing renal CTA before LPN were retrospectively enrolled in this study. 3D arteriogram reconstructed images were created to identify the renal tumour-supplying arteries. The number and location of these targeted vessels were annotated on 3D images preoperatively and compared with the clamped vessels during LPN. The consistency between target vessels annotated at CTA and clamped arteries at LPN was compared both using a patient-based analysis and vessel-based analysis. The χ 2 test was applied to analyse the influence of tumour size, location, and growth pattern on the number of clamped segmental renal branches. Results: On patient-based analysis, the number of targeted vessels was consistent with the clamped vessels during LPN in 33 of 43 patients. On vessel-based analysis, 56 of 65 target vessels annotated at CTA were clamped during LPN. More segmental renal branches (p = 0.04) were clamped in patients with tumours of larger size. Tumour location and growth pattern had no association with the number of clamped segmental branches during LPN. Conclusion: High-quality CTA images and 3D reconstruction images can detect detailed information of tumour-supplying arteries to renal tumours. 3D renal CTA is an effective way to guide segmental renal artery clamping during LPN

Renal papillary necrosis

Science.gov (United States)

... asking your provider. Alternative Names Necrosis - renal papillae; Renal medullary necrosis Images Kidney anatomy Kidney - blood and urine flow References Bushinsky DA, Monk RD. Nephrolithiasis and nephrocalcinosis. ...

Induced renal artery stenosis in rabbits: magnetic resonance imaging, angiography, and radionuclide determination of blood volume and blood flow

International Nuclear Information System (INIS)

Mitchell, D.G.; Tobin, M.; LeVeen, R.; Tomaczewski, J.; Alavi, A.; Staum, M.; Kundel, H.

1988-01-01

To investigate the ability of MRI to detect alterations due to renal ischemia, a rabbit renal artery stenosis (RAS) model was developed. Seven rabbits had RAS induced by surgically encircling the artery with a polyethylene band which had a lumen of 1 mm, 1 to 2 weeks prior to imaging. The stenosis was confirmed by angiography, and the rabbits were then imaged in a 1.4 T research MRI unit. T1 was calculated using four inversion recovery sequences with different inversion times. Renal blood flow, using 113 Sn-microspheres, and regional water content by drying were then measured. The average T1 of the inner medulla was shorter for the ischemia (1574 msec) than for the contralateral kidney (1849 msec), while no change ws noted in the cortex. Ischemic kidneys had less distinct outer medullary zones on IR images with TI = 600 msec than did contralateral or control kidneys. Blood flow to both the cortex and medulla were markedly reduced in ischemic kidneys compared with contralateral kidneys (119.5 vs. 391 ml/min/100 gm for cortex and 19.8 vs. 50.8 ml/min/100 gm for medulla). Renal water and blood content were less affected. Our rabbit model of renal artery stenosis with MRI, radionuclide, and angiographic correlation has the potential to increase our understanding of MR imaging of the rabbit kidney

Integrated imaging (ultrasound, computed tomography, intravenous urography) in diagnosing renal tumors and tumor-like formations

International Nuclear Information System (INIS)

Drudi, F.M.; Capanna, G.; Poggi, R.; Occhiato, R.; Iannicelli, E.; Nardo, R.; di Passariello, R.

1994-01-01

This is an assessment of semiologic imaging criteria based on computerised tomography, ultrasound diagnosis and intravenous urography in renal tumors. The purpose is to obtain differential diagnostic data capable to modify the treatment approach. Over the last three years, a total of 570 cases of kidney tumors are observed. In 490 of them (86%) the imaging patterns obtained by either of the three techniques leads to correct diagnosis. In 62 of the remaining 80 patients, the integration of two techniques allows to unveil the neoplastic nature of the disease (27 cases), or the presence of a benign process (35 cases). In 15 of the remaining 18 cases only integration of the three techniques results in diagnosing renal tumors or tumor-like conditions (3 adeno-carcinomas, 5 abscesses, 3 cases of tuberculosis, 2 - pyeloxanthogranulomatosis, 2 dysmorphisms). In the last three cases definite diagnosis is made on the basis of needle biopsy. The radiological diagnosis is confirmed intraoperatively or during clinical follow-up study. The obtained data underscore the clinical relevance of imaging integration in evaluating renal lesions. This is particularly valid whenever the clinical data are nonspecific or misleading. 15 refs., 3 figs., 5 tabs. (orig.)

MR renography by semiautomated image analysis : Performance in renal transplant recipients

NARCIS (Netherlands)

de Priester, JA; Kessels, AGH; Giele, ELW; den Boer, J.A.; Christiaans, MHL; Hasman, A; van Engelshoven, JMA

We evaluated a method of semiautomated analysis of dynamic MR image series in renal transplants. Nine patients were studied twice, with an average time interval of 7 days. MR examination consisted of a run of 256 T1-weighted coronal scans (GE; TR/TE/flip: = 11/3.4/60 degrees; slice thickness = 6 mm;

Chemical Renal Denervation in the Rat

Energy Technology Data Exchange (ETDEWEB)

Consigny, Paul M., E-mail: paul.consigny@av.abbott.com; Davalian, Dariush, E-mail: dariush.davalian@av.abbott.com [Abbott Vascular, Innovation Incubator (United States); Donn, Rosy, E-mail: rosy.donn@av.abbott.com; Hu, Jie, E-mail: jie.hu@av.abbott.com [Abbott Vascular, Bioanalytical and Material Characterization (United States); Rieser, Matthew, E-mail: matthew.j.rieser@abbvie.com; Stolarik, DeAnne, E-mail: deanne.f.stolarik@abbvie.com [Abbvie, Analytical Pharmacology (United States)

2013-12-03

Introduction: The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Methods: Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose–response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography–mass spectrometry. Results: Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10{sup −5} M through 10{sup −2} M paclitaxel. Conclusion: We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

Chemical Renal Denervation in the Rat

International Nuclear Information System (INIS)

Consigny, Paul M.; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, DeAnne

2014-01-01

Introduction: The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Methods: Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose–response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography–mass spectrometry. Results: Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10 −5  M through 10 −2  M paclitaxel. Conclusion: We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel

[Complications due to contrast agent administration: what has been confirmed in prevention?].

Science.gov (United States)

Schönenberger, E; Mühler, M; Dewey, M

2010-12-01

Computed tomography (CT) and magnetic resonance imaging (MRI) have been evaluated by internists to be the most important medical innovations. Often, intravenous contrast agent administration is required for answering the clinical questions to CT and MRI. In this review we present an overview of the most common and most important aspects that need to be considered prior to intravenous contrast agent administration. We discuss aspects of renal impairment (contrast-induced nephropathy, nephrogenic systemic fibrosis), allergy-like reactions, hyperthyroidism, and pregnancy and breast-feeding.

[Hypertension and renal disease

DEFF Research Database (Denmark)

Kamper, A.L.; Pedersen, E.B.; Strandgaard, S.

2009-01-01

Renal mechanisms, in particular the renin-angiotensin system and renal salt handling, are of major importance in blood pressure regulation. Co-existence of hypertension and decreased renal function may be due to nephrosclerosis secondary to hypertension, or primary renal disease with secondary...... hypertension. Mild degrees of chronic kidney disease (CKD) can be detected in around 10% of the population, and detection is important as CKD is an important risk factor for atherosclerotic cardiovascular disease. Conversely, heart failure may cause an impairment of renal function. In chronic progressive...... nephropathy, effective blood pressure lowering is of paramount importance, and angiotensin converting enzyme inhibitors and angiotensin receptor blockers are agents of choice Udgivelsesdato: 2009/6/15...

Signaling pathways involved in renal oxidative injury: role of the vasoactive peptides and the renal dopaminergic system.

Science.gov (United States)

Rukavina Mikusic, N L; Kravetz, M C; Kouyoumdzian, N M; Della Penna, S L; Rosón, M I; Fernández, B E; Choi, M R

2014-01-01

The physiological hydroelectrolytic balance and the redox steady state in the kidney are accomplished by an intricate interaction between signals from extrarenal and intrarenal sources and between antinatriuretic and natriuretic factors. Angiotensin II, atrial natriuretic peptide and intrarenal dopamine play a pivotal role in this interactive network. The balance between endogenous antioxidant agents like the renal dopaminergic system and atrial natriuretic peptide, by one side, and the prooxidant effect of the renin angiotensin system, by the other side, contributes to ensuring the normal function of the kidney. Different pathological scenarios, as nephrotic syndrome and hypertension, where renal sodium excretion is altered, are associated with an impaired interaction between two natriuretic systems as the renal dopaminergic system and atrial natriuretic peptide that may be involved in the pathogenesis of renal diseases. The aim of this review is to update and comment the most recent evidences about the intracellular pathways involved in the relationship between endogenous antioxidant agents like the renal dopaminergic system and atrial natriuretic peptide and the prooxidant effect of the renin angiotensin system in the pathogenesis of renal inflammation.

Development of program for renal function study with quantification analysis of nuclear medicine image

International Nuclear Information System (INIS)

Song, Ju Young; Lee, Hyoung Koo; Suh, Tae Suk; Choe, Bo Young; Shinn, Kyung Sub; Chung, Yong An; Kim, Sung Joon; Chung, Soo Kyo

2001-01-01

In this study, we developed a new software tool for the analysis of renal scintigraphy which can be modified more easily by a user who needs to study new clinical applications, and the appropriateness of the results from our program was studied. The analysis tool was programmed with IDL5.2 and designed for use on a personal computer running Windows. For testing the developed tool and studying the appropriateness of the calculated glomerular filtration rate (GFR), 99m Tc-DTPA was adminstered to 10 adults in normal condition. In order to study the appropriateness of the calculated mean transit time (MTT). 99m Tc-DTPA and 99m Tc-MAG3 were administered to 11 adults in normal condition and 22 kidneys were analyzed. All the images were acquired with ORBITOR, the Siemens gamma camera. With the developed tool, we could show dynamic renal images and time activity curve (TAC) in each ROI and calculate clinical parameters of renal function. The results calculated by the developed tool were not different statistically from the results obtained by the Siemens application program (Tmax: p=0.68, Relative Renal Function: p=1.0 GFR: p=0.25) and the developed program proved reasonable. The MTT calculation tool proved to be reasonable by the evaluation of the influence of hydration status on MTT. We have obtained reasonable clinical parameters for the evaluation of renal function with the software tool developed in this study. The developed tool could prove more practical than conventional, commercial programs

Preoperative evaluation of renal anatomy and renal masses with helical CT, 3D-CT and 3D-CT angiography.

Science.gov (United States)

Toprak, Uğur; Erdoğan, Aysun; Gülbay, Mutlu; Karademir, Mehmet Alp; Paşaoğlu, Eşref; Akar, Okkeş Emrah

2005-03-01

The aim of this prospective study was to determine the efficacy of three-dimensional computed tomography (3D-CT) and three-dimensional computed tomographic angiography (3D-CTA) that were reconstructed by using the axial images of the multiphasic helical CT in the preoperative evaluation of renal masses and demonstration of renal anatomy. Twenty patients that were suspected of having renal masses upon initial physical examination and ultrasonographic evaluation were examined through multiphasic helical CT. Two authors executed CT evaluations. Axial images were first examined and then used to reconstruct 3D-CT and 3D- CTA images. Number, location and size of the renal masses and other findings were noted. Renal vascularization and relationships of the renal masses with the neighboring renal structures were further investigated with 3D-CT and 3D-CTA images. Out of 20 patients, 13 had histopathologically proven renal cell carcinoma. The diagnoses of the remaining seven patients were xanthogranulomatous pyelonephritis, abscess, simple cyst, infected cyst, angiomyolipoma, oncocytoma and arteriovenous fistula. In the renal cell carcinoma group, 3 patients had stage I, 7 patients had stage II, and 3 patients had stage III disease. Sizes of renal cell carcinoma masses were between 23 mm to 60 mm (mean, 36 mm). Vascular invasion was shown in 2 renal cell carcinoma patients. Collecting system invasion was identified in 11 of 13 renal cell patients. These radiologic findings were confirmed with surgical specimens. Three-dimensional CT and 3D-CTA are non-invasive, effective imaging techniques for the preoperative evaluation of renal masses.

Rotational digital subtraction angiography of the renal arteries: technique and evaluation in the study of native and transplant renal arteries.

Science.gov (United States)

Seymour, H R; Matson, M B; Belli, A M; Morgan, R; Kyriou, J; Patel, U

2001-02-01

Rotational digital subtraction angiography (RDSA) allows multidirectional angiographic acquisitions with a single injection of contrast medium. The role of RDSA was evaluated in 60 patients referred over a 7-month period for diagnostic renal angiography and 12 patients referred for renal transplant studies. All angiograms were assessed for their diagnostic value, the presence of anomalies and the quantity of contrast medium used. The effective dose for native renal RDSA was determined. 41 (68.3%) native renal RDSA images and 8 (66.7%) transplant renal RDSA images were of diagnostic quality. Multiple renal arteries were identified in 9/41 (22%) native renal RDSA diagnostic images. The mean volume of contrast medium in the RDSA runs was 51.2 ml and 50 ml for native and transplant renal studies, respectively. The mean effective dose for 120 degrees native renal RDSA was 2.36 mSv, equivalent to 1 year's mean background radiation. Those RDSA images that were non-diagnostic allowed accurate prediction of the optimal angle for further static angiographic series, which is of great value in transplant renal vessels.

Radionuclide evaluation of renal transplants

International Nuclear Information System (INIS)

Yang Hong; Zhao Deshan

2000-01-01

Radionuclide renal imaging and plasma clearance methods can quickly quantitate renal blood flow and function in renal transplants. They can diagnose acute tubular necrosis and rejection, renal scar, surgical complications such as urine leaks, obstruction and renal artery stenosis after renal transplants. At the same time they can assess the therapy effect of renal transplant complications and can also predict renal transplant survival from early post-operative function studies

Contrast agent based on nano-emulsion for targeted biomedical imaging

International Nuclear Information System (INIS)

Attia, Mohamed

2016-01-01

X-ray imaging agents are essential in combination with X-ray computed tomography to improve contrast enhancement aiming at providing complete visualization of blood vessels and giving structural and functional information on lesions allowing the detection of a tumor. As well as it is fundamental tool to discriminate between healthy cells and pathogens. We successfully limit the problems presented in commercial X-ray contrast agents like poor contrasting in Fenestra VC associated with short blood circulation time and to avoid rapid renal elimination from the body as found in Xenetix (Iobitriol). We developed nontoxic and blood pool iodine-containing nano-emulsion contrast agents serving in preclinical X-ray μ-CT imaging such as, a- Tocopherol (vitamin E), Cholecalciferol (vitamin D3), Castor oil, Capmul MCMC8 oil and oleic acid. Those formulated nano emulsions were prepared by low energy spontaneous emulsification technic with slight modification for each platform. They showed new specific features rendering them promising agents in in vivo experiments as improving the balance between the efficacy and the toxicity of targeted therapeutic interventions. We investigate the effect of size and the chemical composition of the nanoparticles on their biodistribution, pharmacokinetics and toxicity. They demonstrated that the chemical structures of the droplet's cores have significant role in targeting for example vitamin E was mainly accumulated in liver and castor oil formulation was passively accumulated in spleen explaining the proof-of-concept of EPR effect. On the other hand, two different platform sizes of Cholecalciferol molecule revealing that no real impact on the pharmacokinetics and biodistribution but presented remarkable effect on the toxicity. Of particular interest is studying the effect of the surface charge of nanoparticles on their biodistribution, this is why oleic acid nano-emulsion was selected to proceed this study by presence of amphiphilic polymer

Modified natural nanoparticles as contrast agents for medical imaging

NARCIS (Netherlands)

Cormode, David P.; Jarzyna, Peter A.; Mulder, Willem J. M.; Fayad, Zahi A.

2010-01-01

The development of novel and effective contrast agents is one of the drivers of the ongoing improvement in medical imaging. Many of the new agents reported are nanoparticle-based. There are a variety of natural nanoparticles known, e.g. lipoproteins, viruses or ferritin. Natural nanoparticles have

7 T renal MRI: challenges and promises.

Science.gov (United States)

de Boer, Anneloes; Hoogduin, Johannes M; Blankestijn, Peter J; Li, Xiufeng; Luijten, Peter R; Metzger, Gregory J; Raaijmakers, Alexander J E; Umutlu, Lale; Visser, Fredy; Leiner, Tim

2016-06-01

The progression to 7 Tesla (7 T) magnetic resonance imaging (MRI) yields promises of substantial increase in signal-to-noise (SNR) ratio. This increase can be traded off to increase image spatial resolution or to decrease acquisition time. However, renal 7 T MRI remains challenging due to inhomogeneity of the radiofrequency field and due to specific absorption rate (SAR) constraints. A number of studies has been published in the field of renal 7 T imaging. While the focus initially was on anatomic imaging and renal MR angiography, later studies have explored renal functional imaging. Although anatomic imaging remains somewhat limited by inhomogeneous excitation and SAR constraints, functional imaging results are promising. The increased SNR at 7 T has been particularly advantageous for blood oxygen level-dependent and arterial spin labelling MRI, as well as sodium MR imaging, thanks to changes in field-strength-dependent magnetic properties. Here, we provide an overview of the currently available literature on renal 7 T MRI. In addition, we provide a brief overview of challenges and opportunities in renal 7 T MR imaging.

The Role of Apparent Diffusion Coefficient Quantification in Differentiating Benign and Malignant Renal Masses by 3 Tesla Magnetic Resonance Imaging.

Science.gov (United States)

Göya, Cemil; Hamidi, Cihad; Bozkurt, Yaşar; Yavuz, Alpaslan; Kuday, Suzan; Gümüş, Hatice; Türkçü, Gül; Hattapoğlu, Salih; Bilici, Aslan

2015-07-01

Diffusion-weighted magnetic resonance imaging (DWI) is a widely-accepted diagnostic modality whose efficacy has been investigated by numerous past studies in the differentiation of malignant lesions from benign entities. The aim of this study was to evaluate the efficiency of diffusion-weighted magnetic resonance imaging in the characterization of renal lesions. Diagnostic accuracy study. A total of 137 patients with renal lesions were included in this study. The median apparent diffusion coefficient (ADC) values as well as the b 800 and b 1600 signal intensities of normal kidneys, solid components of mixed renal masses, and total cystic lesions were evaluated. There were significant differences between the ADC values of lesions and normal renal parenchyma, and between the ADC values of benign and malignant renal lesions on DWIs at b values of 800 and 1600 s/mm(2) (pbenign and malignant renal lesions. A cutoff value of 1.623 × 10(-3) mm(2)/s for the ADC with a b value of 1600 s/mm(2) provided 79% sensitivity and 96% specificity (pbenign and malignant renal lesions. Accurate assessment of renal masses is important for determining the necessity for surgical intervention. DWI provides additional value by differentiating benign from malignant renal tumors and can be added to routine kidney MRI protocols.

Re(CO)3([18F]FEDA), a novel 18F PET renal tracer: Radiosynthesis and preclinical evaluation.

Science.gov (United States)

Lipowska, Malgorzata; Jarkas, Nashwa; Voll, Ronald J; Nye, Jonathon A; Klenc, Jeffrey; Goodman, Mark M; Taylor, Andrew T

2018-03-01

Our previous work demonstrated that the 99m Tc renal tracer, 99m Tc(CO) 3 (FEDA) ( 99m Tc-1), has a rapid clearance comparable in rats to that of 131 I-OIH, the radioactive gold standard for the measurement of effective renal plasma flow. The uncharged fluoroethyl pendant group of 99m Tc-1 provides a route to the synthesis of a structurally analogous rhenium-tricarbonyl 18 F renal imaging agent, Re(CO) 3 ([ 18 F]FEDA) ( 18 F-1). Our goal was to develop an efficient one-step method for the preparation of 18 F-1 and to compare its pharmacokinetic properties with those of 131 I-OIH in rats. 18 F-1 was prepared by the nucleophilic 18 F-fluorination of its tosyl precursor. The labeled compound was isolated by HPLC and subsequently evaluated in Sprague-Dawley rats using 131 I-OIH as an internal control and by dynamic PET/CT imaging. Plasma protein binding (PPB) and erythrocyte uptake (RCB) were determined and the urine was analyzed for metabolites. 18 F-1 was efficiently prepared as a single species with high radiochemical purity (>99%) and it displayed high radiochemical stability in vitro and in vivo. PPB was 87% and RCB was 21%. Biodistribution studies confirmed rapid renal extraction and high specificity for renal excretion, comparable to that of 131 I-OIH, with minimal hepatic/gastrointestinal elimination. The activity in the urine, as a percentage of 131 I-OIH, was 92% and 95% at 10 and 60 min, respectively. All other organs (heart, spleen, lungs) showed a negligible tracer uptake (F-1 through the kidneys and into the bladder; there was no demonstrable activity in bone verifying the absence of free [ 18 F]fluoride. 18 F-1 exhibited a high specificity for the kidney, rapid renal excretion comparable to that of 131 I-OIH and high in vivo radiochemical stability. Not only is 18 F-1 a promising PET renal tracer, but it provides a route to the development of a pair of analogous 18 F/ 99m Tc renal imaging agents with almost identical structures and comparable

The 64-MSCT study of relationship between renal corticomedullary differentiation, contrast between renal cortex and medulla, renal cortex and medulla CT peak value with the single renal function in hydronephrotic kidney

International Nuclear Information System (INIS)

Wang Yunhua; Hou Weiwei; Liu Ruihong; He Jianjun; Zhi Ke

2009-01-01

Objective: To study 64-MSCT perfusion imaging features about renal corticomedullary differentiation, contrast between renal cortex and medulla (CMC), renal cortex and medulla CT peak value in normal and hydronephrotic kidneys, and to explore the relationship between them and the unilateral renal function. Methods: Thirty-six patients with obstructive nephrohydrosis underwent 64-MSCT perfusion scanning. The split renal glomerular filtration rates (GFR) of their kidneys were measured by SPECT renal dynamic imaging. The 72 kidneys were divided into groups of normal renal function group, mild and severe renal impairment groups according to GFR. Renal corticomedullary differentiation on CT images was graded as clear, obscure, part clear. The CT intensity of cortex and medulla was measured in order to calculate contrast between renal cortex and medulla (CMC). Using Pearson correlation test, the correlation between them and renal GFR were examined. Results: (1) In the 24 kidneys of normal group, all kidneys showed clear CMD. In the 21 kidneys of mild renal impairment group, 14 kidneys showed clear CMD, 2 showed obscure CMD and 5 showed part clear of CMD. In the 27 kidneys of severe renal impairment group, 7 kidneys showed clear CMD, 5 showed obscure CMD and 15 showed part clear of CMD. (2)The CMC of normal group was 0.62 ± 0.20, while it was 0.52 ± 0.14 and 0.37 ± 0.11 for mild renal impairment group and severe renal impairment group CMC respectively. The CMC had positive linear correlation with GFR (r=0.536,P<0.05). (3) The renal cortex and medulla CT peak value of normal group were (133 ± 22) and (104 ± 16) HU; The renal cortex and medulla CT peak value of mild renal impairment group were (91 ± 29) and (76 ± 25) HU; The renal cortex and medulla CT peak value of severe renal impairment group were (68 ± 24) and (57 ± 21) HU(F=42.76 and 32.68,P<0.05). The renal cortex and medulla CT peak value had positive linear correlation with GFR (r=0.672 and 0.623, P<0

The clinical significance of glomerular filtration rate measured by 99Tcm-diethylentriamine pentaacetic acid renal dynamic imaging in renal cercinoma patients before surgery

International Nuclear Information System (INIS)

Shao Xiaonan; Wang Yuetao; Wang Xiaosong; Chen Hailong

2011-01-01

Objective: To investigate the clinical significance of glomerular filtration rate (GFR) measured by 99 Tc m -diethylenetriamine pentaacetic acid ( 99 Tc m -DTPA) renal dynamic imaging in renal cell carcinoma (RCC) patients before surgery. Methods: There were 99 cases of RCC patients, 89 patients undergoing radical nephrectomy (RN) and 10 patients undergoing nephron-sparing surgery(NSS). 99 Tc m -DTPA renal dynamic imaging was performed for determining GFR before surgery. Make a comparison of GFR between RCC group and control group (normal kidney donors), RN group and NSS group. Make a comparison between GFR and serum creatinine in determining preoperative renal dysfunction of RCC patients. All of the data were analyzed by t-test and χ 2 -text. Results: Compared with control group, total GFR of RCC patients was lower, but there was no significant difference [(76.4±20.4)ml/min vs. (80.6±17.4)ml/min, t=0.650, P>0.05)]. Nineteen cases (19.2%) of RCC patients had preoperative renal dysfunction (total GFR 133μmol/L). There was no significant difference in GFR of neoplastic kidneys between RN group and NSS group [(34.1±11.7)ml/min vs.(37.9±11.9)ml/min, t=0.975, P>0.05]. GFR of contralateral kidneys was lower in NSS group than RN group [(32.7±10.3)ml/min vs. (39.6±10.1)ml/min, t=0.044, P 2 =6.808, P<0.01). Conclusion: GFR can provide the accurate information of both kidneys and single kidney before surgery, and this result possessed an important significance in choice of treatments. (authors)

99mTc-MAG3 vs 99mTc-DMSA early images: A practice options for the study of renal morphology

International Nuclear Information System (INIS)

Fraxedas, R.; Reyes, L.; Rodriguez, J.L.; Perera, A.; Solano, M.E.; Sanchez del Campo, M.

1997-01-01

99m Tc- DMSA renal scans are considered a gold standard for the evaluations of cortical defects Nevertheless 99m Tc -MAG3 early images (1-2 min after administration) present clearly defined images of the renal parenchyma. In this work 37 patients with clinical suspicion of upper tract infection were studied with both tracers. Renal ages were evaluated for the presence of cortical defects in a blind fashion by a group of three experts and split function was calculated. Results were highly coincident. It is concluded that early 99mT c -MAG3 can be used to study renal morphology and patient irradiated can be reduced

Primary Renal Carcinoid - A Case Report

LENUS (Irish Health Repository)

O’Sullivan, M

2018-01-01

Carcinoid tumours in the abdomen are uncommon, but typically occur in the gastrointestinal tract. Primary renal carcinoid is an extremely rare tumour, poorly described in the literature. We describe an unusual case where an atypical renal mass on imaging led to a preoperative diagnosis of renal carcinoid on imaging guiding biopsy.

SIMS imaging of gadolinium isotopes in tissue from Nephrogenic Systemic Fibrosis patients: Release of free Gd from magnetic resonance imaging (MRI) contrast agents

Energy Technology Data Exchange (ETDEWEB)

Abraham, Jerrold L. [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Chandra, Subhash [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)], E-mail: sc40@cornell.edu; Thakral, Charu [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Abraham, Joshua M. [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)

2008-12-15

Recently, Gd-based magnetic resonance imaging (MRI) contrast agents (GBMCA) have been linked to a new disease, Nephrogenic Systemic Fibrosis (NSF), with skin and systemic toxicity and death in certain patients with renal failure. Due to widespread use of GBMCA in diagnostic MRI, it is essential to study their excretion, metabolism, and target sites in cells and tissues. A CAMECA IMS-3f SIMS ion microscope and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) were used for imaging Gd isotopes in relation to calcium distributions in histologic sections of human tissues. SIMS imaging revealed two types of Gd localization in skin biopsies of patients who received GBMCA. The Gd was present in micrometer size deposits in association with calcium, and in detectable amounts in a more diffuse cellular distribution. Only the Gd-containing deposits associated with Ca and P were detectable using SEM/EDS. As only insoluble deposits remain in the biopsy tissues after aqueous and organic solvent processing of the tissue, our observations support release of free Gd from the GBMCA and selective localization of insoluble Gd in the target tissue from patients with NSF. This study opens new novel applications of SIMS for characterization of the safety of GBMCA.

Novel MR imaging contrast agents for cancer detection

Directory of Open Access Journals (Sweden)

Daryoush Shahbazi-Gahrouei

2009-05-01

Full Text Available

• BACKGROUND: Novel potential MR imaging contrast agents Gd-tetra-carboranylmethoxyphenyl-porphyrin (Gd-TCP, Gd-hematoporphyrin (Gd-H, Gd-DTPA-9.2.27 against melanoma, Gd-DTPA-WM53 against leukemia and Gd-DTPAC595 against breast cancer cells were synthesized and applied to mice with different human cancer cells (melanoma MM-138, leukemia HL-60, breast MCF-7. The relaxivity, the biodistribution, T1 relaxation times, and signal enhancement of the contrast agents are presented and the results are compared.
• METHODS: After preparation of contrast agents, the animal studies were performed. The cells (2×106 cells were injected subcutaneously in the both flanks of mice. Two to three weeks after tumor plantation, when the tumor diameter was 2-4 mm, mice were injected with the different contrast agents. The animals were sacrificed at 24 hr post IP injection followed by removal of critical organs. The T1 relaxation times and signal intensities of samples were measured using 11.4 T magnetic field and Gd concentration were measured using UV-spectrophotometer.
• RESULTS: For Gd-H, the percent of Gd localized to the tumors measured by UV-spect was 28, 23 and 21 in leukemia, melanoma and breast cells, respectively. For Gd-TCP this amount was 21%, 18% and 15%, respectively. For Gd-DTPA-9.2.27, Gd-DTPA-WM53 and Gd-DTPA-C595 approximately 35%, 32% and 27% of gadolinium localized to their specific tumor, respectively.
• CONCLUSION: The specific studied conjugates showed good tumor uptake in the relevant cell lines and low levels of Gd in the liver, kidney and spleen. The studied agents have considerable promise for further diagnosis applications of MR imaging.
• KEYWORDS: Magnetic Resonance, Imaging, Monoclonal Antibody, Contrast Agents, Gadolinium, Early Detection of Cancer.

Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model

DEFF Research Database (Denmark)

Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Graumann, Ole

2017-01-01

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention...... of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings...

Contrasts agents in magnetic resonance imaging

International Nuclear Information System (INIS)

Bonnet, P.A.; Fernandez, J.P.; Milhavet, J.C.; Chapat, J.P.; Almes, C.; Bruel, J.M.; Rouanet, J.P.; Lamarque, J.L.

1984-01-01

Changing different parameters involved in imaging procedures, paramagnetic substances provide contrast enhancement in MRI. Contrast agents presently studied in animals and clinical trials, are either salts or complexes of mineral ions either nitroxide stable free radicals. Their development should extend the possibilities of tissular characterization and fonctional or metabolic evaluation of the MRI [fr

Renal cell carcinoma associated with Xp11.2 translocation/TFE gene fusion: imaging findings in 21 patients

Energy Technology Data Exchange (ETDEWEB)

Chen, Xiao; Zhou, Hao; Duan, Na; Liu, Yongkang; Wang, Zhongqiu [Affiliated Hospital of Nanjing University of Chinese Medicine, Department of Radiology, Nanjing (China); Zhu, Qingqiang [Medical School of Yangzhou University, Department of Medical Imaging, Subei People' s Hospital, Yangzhou (China); Li, Baoxin [Gulou Hospital, Department of Radiology, Nanjing (China); Cui, Wenjing [Affiliated Hospital of Nanjing University of Chinese Medicine, Department of Radiology, Nanjing (China); Nanjing University Medical School, Department of Radiology, Jinling Hospital, Nanjing (China); Kundra, Vikas [The University of Texas, M.D. Anderson Cancer Center, Department of Radiology, Houston, TX (United States)

2017-02-15

To characterize imaging features of renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE gene fusion. Twenty-one patients with Xp11.2/TFE RCC were retrospectively evaluated. Tumour location, size, density, cystic or solid appearance, calcification, capsule sign, enhancement pattern and metastases were assessed. Fourteen women and seven men were identified with 12 being 25 years old or younger. Tumours were solitary and cystic-solid (76.2 %) masses with a capsule (76.2 %); 90.5 % were located in the medulla. Calcifications and lymph node metastases were each observed in 24 %. On unenhanced CT, tumour attenuation was greater than in normal renal parenchyma (85.7 %). Tumour enhancement was less than in normal renal cortex on all enhanced phases, greater than in normal renal medulla on cortical and medullary phases, but less than in normal renal medulla on delayed phase. On MR, the tumours were isointense on T1WI, heterogeneously hypointense on T2WI and slightly hyperintense on diffusion-weighted imaging. Xp11.2/TFE RCC usually occurs in young women. It is a cystic-solid, hyperdense mass with a capsule. It arises from the renal medulla with enhancement less than in the cortex but greater than in the medulla in all phases except the delayed phase, when it is lower than in the medulla. (orig.)

Dynamic renal scintigraphy in aortic disorders

International Nuclear Information System (INIS)

Terae, Satoshi; Itoh, Kazuo; Tsukamoto, Eriko; Nakada, Kunihiro; Fujimori, Kenji; Hashimoto, Masato; Tanabe, Tatsuzo; Furudate, Masayori; Irie, Goro

1986-01-01

Dynamic renal scintigraphy has been reviewed for evaluation of renal arterial involvement in aortic disorders such as arteriosclerosis obliterans, abdominal aortic aneurysm and dissecting aneurysm. As a diagnostic finding and parameters, we used blood perfusion images of both kidneys and relative split renal function index obtained with analysis of the time-activity curves which were generated using a renal region of interest. In the diagnosis of unilateral renal arterial involvement, sensitivity and specificity of blood perfusion images were 100 % (9/9) and 77 % (10/13) and those of relative split renal function index were 78 % (7/9) and 92 % (12/13), respectively. Dynamic renal scintigraphy was useful for evaluating unilateral renal arterial involvement in aortic diseases. However, scintigraphic diagnosis of bilateral renal arterial involvement were difficult. And in a severe case, we could not differentiate renal parenchymal damage due to renovascular involvement from senile renal dysfunction or hypertensive renal disease which is often a cause of aortic disorders. (author)

Energy-Specific Optimization of Attenuation Thresholds for Low-Energy Virtual Monoenergetic Images in Renal Lesion Evaluation.

Science.gov (United States)

Patel, Bhavik N; Farjat, Alfredo; Schabel, Christoph; Duvnjak, Petar; Mileto, Achille; Ramirez-Giraldo, Juan Carlos; Marin, Daniele

2018-05-01

The purpose of this study was to determine in vitro and in vivo the optimal threshold for renal lesion vascularity at low-energy (40-60 keV) virtual monoenergetic imaging. A rod simulating unenhanced renal parenchymal attenuation (35 HU) was fitted with a syringe containing water. Three iodinated solutions (0.38, 0.57, and 0.76 mg I/mL) were inserted into another rod that simulated enhanced renal parenchyma (180 HU). Rods were inserted into cylindric phantoms of three different body sizes and scanned with single- and dual-energy MDCT. In addition, 102 patients (32 men, 70 women; mean age, 66.8 ± 12.9 [SD] years) with 112 renal lesions (67 nonvascular, 45 vascular) measuring 1.1-8.9 cm underwent single-energy unenhanced and contrast-enhanced dual-energy CT. Optimal threshold attenuation values that differentiated vascular from nonvascular lesions at 40-60 keV were determined. Mean optimal threshold values were 30.2 ± 3.6 (standard error), 20.9 ± 1.3, and 16.1 ± 1.0 HU in the phantom, and 35.9 ± 3.6, 25.4 ± 1.8, and 17.8 ± 1.8 HU in the patients at 40, 50, and 60 keV. Sensitivity and specificity for the thresholds did not change significantly between low-energy and 70-keV virtual monoenergetic imaging (sensitivity, 87-98%; specificity, 90-91%). The AUC from 40 to 70 keV was 0.96 (95% CI, 0.93-0.99) to 0.98 (95% CI, 0.95-1.00). Low-energy virtual monoenergetic imaging at energy-specific optimized attenuation thresholds can be used for reliable characterization of renal lesions.

Microscopic validation of whole mouse micro-metastatic tumor imaging agents using cryo-imaging and sliding organ image registration

OpenAIRE

Liu, Yiqiao; Zhou, Bo; Qutaish, Mohammed; Wilson, David L.

2016-01-01

We created a metastasis imaging, analysis platform consisting of software and multi-spectral cryo-imaging system suitable for evaluating emerging imaging agents targeting micro-metastatic tumor. We analyzed CREKA-Gd in MRI, followed by cryo-imaging which repeatedly sectioned and tiled microscope images of the tissue block face, providing anatomical bright field and molecular fluorescence, enabling 3D microscopic imaging of the entire mouse with single metastatic cell sensitivity. To register ...

Imaging of renal medullary carcinoma in children and young adults: a report from the Children's Oncology Group

Energy Technology Data Exchange (ETDEWEB)

Sandberg, Jesse K.; Khanna, Geetika [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Mullen, Elizabeth A. [Children' s Hospital Boston/Dana-Farber Cancer Institute, Department of Pediatric Oncology, Boston, MA (United States); Cajaiba, Mariana M.; Perlman, Elizabeth J. [Northwestern University Feinberg School of Medicine, Department of Pathology and Laboratory Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Chicago, IL (United States); Smith, Ethan A. [University of Michigan Health System, Section of Pediatric Radiology, C. S. Mott Children' s Hospital, Department of Radiology, Ann Arbor, MI (United States); Servaes, Sabah [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Geller, James I. [University of Cincinnati, Division of Pediatric Oncology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Ehrlich, Peter F. [University of Michigan Health System, Section of Pediatric Surgery, C. S. Mott Children' s Hospital, Department of Surgery, Ann Arbor, MI (United States); Cost, Nicholas G. [University of Colorado School of Medicine, Division of Urology, Department of Surgery, Aurora, CO (United States); Dome, Jeffrey S. [Children' s National Medical Center, Division of Pediatric Oncology, Washington, DC (United States); Fernandez, Conrad V. [Dalhousie University and IWK Health Centre, Department of Pediatrics, Halifax, NS (Canada)

2017-11-15

Renal medullary carcinoma is a rare renal malignancy of childhood. There are no large series describing the imaging appearance of renal medullary carcinoma in children. To characterize the clinical and imaging features of pediatric renal medullary carcinoma at initial presentation. We retrospectively analyzed images of 25 pediatric patients with renal medullary carcinoma enrolled in the Children's Oncology Group renal tumors classification, biology and banking study (AREN03B2) from March 2006 to August 2016. Imaging findings of the primary mass, and patterns of locoregional and distant spread were evaluated in correlation with pathological and surgical findings. Median age at presentation was 13 years (range: 6-21 years), with a male predominance (3.2:1). The overall stage of disease at initial presentation was stage 1 in 1, stage 2 in 2 and stage 4 in 22. Maximum diameter of the primary renal mass ranged from 1.6 to 10.3 cm (mean: 6.6 cm) with a slight right side predilection (1.5:1). Enlarged (>1 cm short axis) retroperitoneal lymph nodes were identified at initial staging in 20/25 (80%) cases, 10 of which were histologically confirmed while the others did not undergo surgical sampling. Enlarged lymph nodes were also identified in the mediastinum (14/25; 56%) and supraclavicular regions (4/25; 16%). Metastatic disease was present in the lungs in 19/25 (76%) and liver in 6/25 (24%). The pattern of lung metastases was pulmonary lymphangitic carcinomatosis: 10 cases (9 bilateral, 1 unilateral), pulmonary nodules with indistinct margins: 6 cases, pulmonary nodules with distinct margins: 2 cases, while 1 case had pulmonary nodules with both indistinct and distinct margins. Pulmonary lymphangitic carcinomatosis was pathologically confirmed in 4/10 cases. All cases with pulmonary lymphangitic carcinomatosis had associated enlarged mediastinal lymph nodes. Renal medullary carcinoma in children and young adults presents at an advanced local and distant stage in the

Imaging of renal medullary carcinoma in children and young adults: a report from the Children's Oncology Group

International Nuclear Information System (INIS)

Sandberg, Jesse K.; Khanna, Geetika; Mullen, Elizabeth A.; Cajaiba, Mariana M.; Perlman, Elizabeth J.; Smith, Ethan A.; Servaes, Sabah; Geller, James I.; Ehrlich, Peter F.; Cost, Nicholas G.; Dome, Jeffrey S.; Fernandez, Conrad V.

2017-01-01

Renal medullary carcinoma is a rare renal malignancy of childhood. There are no large series describing the imaging appearance of renal medullary carcinoma in children. To characterize the clinical and imaging features of pediatric renal medullary carcinoma at initial presentation. We retrospectively analyzed images of 25 pediatric patients with renal medullary carcinoma enrolled in the Children's Oncology Group renal tumors classification, biology and banking study (AREN03B2) from March 2006 to August 2016. Imaging findings of the primary mass, and patterns of locoregional and distant spread were evaluated in correlation with pathological and surgical findings. Median age at presentation was 13 years (range: 6-21 years), with a male predominance (3.2:1). The overall stage of disease at initial presentation was stage 1 in 1, stage 2 in 2 and stage 4 in 22. Maximum diameter of the primary renal mass ranged from 1.6 to 10.3 cm (mean: 6.6 cm) with a slight right side predilection (1.5:1). Enlarged (>1 cm short axis) retroperitoneal lymph nodes were identified at initial staging in 20/25 (80%) cases, 10 of which were histologically confirmed while the others did not undergo surgical sampling. Enlarged lymph nodes were also identified in the mediastinum (14/25; 56%) and supraclavicular regions (4/25; 16%). Metastatic disease was present in the lungs in 19/25 (76%) and liver in 6/25 (24%). The pattern of lung metastases was pulmonary lymphangitic carcinomatosis: 10 cases (9 bilateral, 1 unilateral), pulmonary nodules with indistinct margins: 6 cases, pulmonary nodules with distinct margins: 2 cases, while 1 case had pulmonary nodules with both indistinct and distinct margins. Pulmonary lymphangitic carcinomatosis was pathologically confirmed in 4/10 cases. All cases with pulmonary lymphangitic carcinomatosis had associated enlarged mediastinal lymph nodes. Renal medullary carcinoma in children and young adults presents at an advanced local and distant stage in the

MR imaging of renal cell carcinoma: associations among signal intensity, tumor enhancement, and pathologic findings.

OpenAIRE

Yabuki, Takayuki; Togami, Izumi; Kitagawa, Takahiro; Sasai, Nobuya; Tsushima, Tomoyasu; Shirasaki, Yoshinori; Hiraki, Yoshio

2003-01-01

The purpose of this study was to compare the MR characteristics of renal cell carcinomas against histologic findings and to assess the correlations among signal intensity, tumor enhancement, and pathologic findings. Fifty-four patients (56 lesions) were examined by MR imaging and then underwent partial or radical nephrectomy. The pathologic diagnosis of all lesions was renal cell carcinoma. All MR examinations were performed as dynamic studies using the same 1.5-T scanner. MR characteristics ...

Renal artery origins: best angiographic projection angles.

Science.gov (United States)

Verschuyl, E J; Kaatee, R; Beek, F J; Patel, N H; Fontaine, A B; Daly, C P; Coldwell, D M; Bush, W H; Mali, W P

1997-10-01

To determine the best projection angles for imaging the renal artery origins in profile. A mathematical model of the anatomy at the renal artery origins in the transverse plane was used to analyze the amount of aortic lumen that projects over the renal artery origins at various projection angles. Computed tomographic (CT) angiographic data about the location of 400 renal artery origins in 200 patients were statistically analyzed. In patients with an abdominal aortic diameter no larger than 3.0 cm, approximately 0.5 mm of the proximal part of the renal artery and origin may be hidden from view if there is a projection error of +/-10 degrees from the ideal image. A combination of anteroposterior and 20 degrees and 40 degrees left anterior oblique projections resulted in a 92% yield of images that adequately profiled the renal artery origins. Right anterior oblique projections resulted in the least useful images. An error in projection angle of +/-10 degrees is acceptable for angiographic imaging of the renal artery origins. Patients sex, site of interest (left or right artery), and local diameter of the abdominal aorta are important factors to consider.

Dynamic CT of the renal parenchyma

International Nuclear Information System (INIS)

Ohyama, Yukio; Imanishi, Yoshimasa; Ishikawa, Tohru; Fujii, Masamichi; Uji, Teruyuki

1985-01-01

Normal renal dynamic CT findings of 57 cases were analysed in termes of sequential change of renal parenchymal CT image. Cortex, outer medulla and inner medulla were delineated and their sequential CT image was well correlated with the anatomicophysiological character of the kidney. Dynamic CT of 32 abnormal cases showed abnormal sequential CT findings explaining the mechanism of the abnormalities. Especially, delayed enhancement of renal cortex was noted in 17 of 19 kidneys with arterial obstruction and delayed enhancement of renal medulla in 22 of 25 cases with renal dysfunction. Compaired with excretory urography in 11 cases with renal dysfunction, advantage of dynamic CT were noted. (author)

Imaging the renal lesion with dual-energy multidetector CT and multi-energy applications in clinical practice: what can it truly do for you?

Energy Technology Data Exchange (ETDEWEB)

Mileto, Achille; Marin, Daniele [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Sofue, Keitaro [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Kobe University School of Medicine, Department of Radiology, Kobe (Japan)

2016-10-15

Many fortuitously detected renal lesions are incompletely characterised at traditional MDCT imaging, thus posing daily challenges to radiologists and referring physicians. There is burgeoning evidence that dual-energy MDCT and multi-energy applications provide an added value over traditional MDCT imaging in renal lesion characterisation and throughput. This special report gives a vendor-neutral outlook on technical essentials, recommended protocols, high-yield clinical opportunities and reviews radiation dose aspects of dual-energy MDCT imaging and multi-energy applications in renal lesions. In addition to a guide on interpretative traps and emerging problems, we provide an update on new, potential imaging horizons. Dual-energy MDCT and multi-energy applications can facilitate the imaging interpretation and throughput of renal lesions. Conjointly with capitalisation on the benefits, familiarity with dual- and multi-energy data sets as well as continuous scrutiny of interpretative traps can be the keys to the successful implementation and enhanced clinical acceptance of this powerful technique in the imaging community. Continuous advances in hardware and computer interfaces are expected to pave the way for the further expansion of the application spectrum. (orig.)

Bilateral papillary renal cell carcinoma

International Nuclear Information System (INIS)

Gossios, K.; Vazakas, P.; Argyropoulou, M.; Stefanaki, S.; Stavropoulos, N.E.

2001-01-01

Papillary renal cell carcinoma is a subgroup of malignant renal epithelial neoplasms. We report the clinical and imaging findings of a case with multifocal and bilateral renal cell carcinoma which are nonspecific. (orig.)

Assessment of renal impairment by non-contrast-enhanced conventional magnetic resonance imaging. Comparison with 99mTc-DTPA renography

International Nuclear Information System (INIS)

Hidaka, Fumitaka; Amano, Yasuo; Takahama, Katsuya; Takagi, Ryo; Murakami, Ryusuke; Onozawa, Shiro; Kumita, Shinichiro

2011-01-01

The aim of this study was to determine whether non-contrast-enhanced magnetic resonance imaging (MRI) can detect three levels of renal impairment by evaluating the differences and agreement with 99m Tc-diethylenetriamine pentaacetic acid (DTPA) renography. A total of 28 patients with kidney disease were enrolled in the study. MRI findings, including visual corticomedullary differentiation (CMD) on T1- and T2-weighted imaging (T1WI, T2WI), cortical irregularity, the number of renal cysts, and the volume of the kidney, were evaluated for individual kidneys and pairs of kidneys. The differences and agreement between MRI findings and the three levels of renal impairment based on the glomerular filtration rate (GFR) measured using 99m Tc-DTPA renography were analyzed. All MRI findings except the number of renal cysts in pairs of kidneys were consistent with the patient's classification. The agreement between the patient's classifications based on GFR and that based on the visual CMD on T1WI and T2WI was almost perfect or substantial in both individual kidneys and pairs of kidneys. Non-contrast-enhanced MRI was capable of distinguishing three levels of renal function, including serious renal impairment. (author)

Use of quantitative SPECT/CT reconstruction in 99mTc-sestamibi imaging of patients with renal masses.

Science.gov (United States)

Jones, Krystyna M; Solnes, Lilja B; Rowe, Steven P; Gorin, Michael A; Sheikhbahaei, Sara; Fung, George; Frey, Eric C; Allaf, Mohamad E; Du, Yong; Javadi, Mehrbod S

2018-02-01

Technetium-99m ( 99m Tc)-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) has previously been shown to allow for the accurate differentiation of benign renal oncocytomas and hybrid oncocytic/chromophobe tumors (HOCTs) apart from other malignant renal tumor histologies, with oncocytomas/HOCTs showing high uptake and renal cell carcinoma (RCC) showing low uptake based on uptake ratios from non-quantitative single-photon emission computed tomography (SPECT) reconstructions. However, in this study, several tumors fell close to the uptake ratio cutoff, likely due to limitations in conventional SPECT/CT reconstruction methods. We hypothesized that application of quantitative SPECT/CT (QSPECT) reconstruction methods developed by our group would provide more robust separation of hot and cold lesions, serving as an imaging framework on which quantitative biomarkers can be validated for evaluation of renal masses with 99m Tc-sestamibi. Single-photon emission computed tomography data were reconstructed using the clinical Flash 3D reconstruction and QSPECT methods. Two blinded readers then characterized each tumor as hot or cold. Semi-quantitative uptake ratios were calculated by dividing lesion activity by background renal activity for both Flash 3D and QSPECT reconstructions. The difference between median (mean) hot and cold tumor uptake ratios measured 0.655 (0.73) with the QSPECT method and 0.624 (0.67) with the conventional method, resulting in increased separation between hot and cold tumors. Sub-analysis of 7 lesions near the separation point showed a higher absolute difference (0.16) between QPSECT and Flash 3D mean uptake ratios compared to the remaining lesions. Our finding of improved separation between uptake ratios of hot and cold lesions using QSPECT reconstruction lays the foundation for additional quantitative SPECT techniques such as SPECT-UV in the setting of renal 99m Tc-sestamibi and other SPECT/CT exams. With robust

Correlation between differential renal uptake of 99mTc-MAG3 and 99mTc-DMSA

International Nuclear Information System (INIS)

Obaldo, J.M.; Gruenwald, F.; Menzel, C.; Biersack, H.J.

1994-01-01

We reviewed the quantitative indices obtained from sequential 99m Tc-MAG3 and 99m Tc-DMSA imaging studies performed in 134 patients with a variety of renal disorders in order to determine the correlation between the measured differential renal function using these two agents. Overall correlation was high with r=.86 and the derived regression equation was R.F. DMSA =8.2+0.84 (R.F. MAG3 ), where F.F. is the relative function. Highly divergent values for differential function were obtained however in some subjects. Patients with renal obstructive disorders had a correlation coefficient of.81 which was lower than those with nonobstructive pathologies (r=.95). Although relative kidney function measured using 99m Tc-MAG3 and 99m Tc-DMSA correlate significantly, certain patients such as those with renal obstruction may necessitate quantitation using different renal parameters. (orig.) [de

Computer-aided detection of renal calculi from noncontrast CT images using TV-flow and MSER features

Science.gov (United States)

Liu, Jianfei; Wang, Shijun; Turkbey, Evrim B.; Linguraru, Marius George; Yao, Jianhua; Summers, Ronald M.

2015-01-01

Purpose: Renal calculi are common extracolonic incidental findings on computed tomographic colonography (CTC). This work aims to develop a fully automated computer-aided diagnosis system to accurately detect renal calculi on CTC images. Methods: The authors developed a total variation (TV) flow method to reduce image noise within the kidneys while maintaining the characteristic appearance of renal calculi. Maximally stable extremal region (MSER) features were then calculated to robustly identify calculi candidates. Finally, the authors computed texture and shape features that were imported to support vector machines for calculus classification. The method was validated on a dataset of 192 patients and compared to a baseline approach that detects calculi by thresholding. The authors also compared their method with the detection approaches using anisotropic diffusion and nonsmoothing. Results: At a false positive rate of 8 per patient, the sensitivities of the new method and the baseline thresholding approach were 69% and 35% (p < 1e − 3) on all calculi from 1 to 433 mm3 in the testing dataset. The sensitivities of the detection methods using anisotropic diffusion and nonsmoothing were 36% and 0%, respectively. The sensitivity of the new method increased to 90% if only larger and more clinically relevant calculi were considered. Conclusions: Experimental results demonstrated that TV-flow and MSER features are efficient means to robustly and accurately detect renal calculi on low-dose, high noise CTC images. Thus, the proposed method can potentially improve diagnosis. PMID:25563255

Bone scan appearance of renal osteodystrophy in diabetic chronic renal failure patients

International Nuclear Information System (INIS)

So, Young; Hyun, In Young; Lee, Dong Soo; Ahn, Curie; Chung, June-Key; Kim, Suhnggwon; Lee, Myung Chul; Lee, Jung Sang; Koh, Chang-Soon

1998-01-01

To investigate Tc-99m methylenediphosphonate (MDP) bone scan appearance in diabetic chronic renal failure patients, we compared the bone scan images of chronic renal failure patients with and without diabetes. The number of patients studied was 134, of whom 43 had diabetes. Two nuclear medicine physicians read Tc-99m MDP bone scan images and for six areas - the axial skeleton, long bone, skull and mandible, periarticular areas, costochondral junction, and sternum - assigned a score of either 1 or 0. The sums of scores were compared. We also performed multivariate analysis including sex, age, and serum creatinine level using analysis of covariance. DM group patients scored significantly lower (2.01±0.95) than those of the non-DM group (3.26±1.16). Analysis of covariance revealed that the lower DM group score was independent of sex, age, and serum creatinine level. The bone scans of diabetic chronic renal failure patients showed less Tc-99m MDP uptake than those of non-diabetic patients. Thus, diagnosing renal osteodystrophy in diabetic chronic renal failure patients on bone scan images could be difficult. (author)

Renal artery stenosis.

Science.gov (United States)

Tafur-Soto, Jose David; White, Christopher J

2015-02-01

Atherosclerotic renal artery stenosis (RAS) is the single largest cause of secondary hypertension; it is associated with progressive renal insufficiency and causes cardiovascular complications such as refractory heart failure and flash pulmonary edema. Medical therapy, including risk factor modification, renin-angiotensin-aldosterone system antagonists, lipid-lowering agents, and antiplatelet therapy, is advised in all patients. Patients with uncontrolled renovascular hypertension despite optimal medical therapy, ischemic nephropathy, and cardiac destabilization syndromes who have severe RAS are likely to benefit from renal artery revascularization. Screening for RAS can be done with Doppler ultrasonography, CT angiography, and magnetic resonance angiography. Copyright © 2015 Elsevier Inc. All rights reserved.

Contrast agents in magnetic resonance imaging

International Nuclear Information System (INIS)

Karadjian, V.

1987-01-01

The origine of nuclear magnetic resonance signal is reminded and different ways for contrast enhancement in magnetic resonance imaging are presented, especially, modifications of tissus relaxation times. Investigations have focused on development of agents incorporating either paramagnetic ions or stable free radicals. Pharmacological and toxicological aspects are developed. The diagnostic potential of these substances is illustrated by the example of gadolinium complexes [fr

Metastatic renal cell carcinoma management

Directory of Open Access Journals (Sweden)

Flavio L. Heldwein

2009-06-01

Full Text Available PURPOSE: To assess the current treatment of metastatic renal cell carcinoma, focusing on medical treatment options. MATERIAL AND METHODS: The most important recent publications have been selected after a literature search employing PubMed using the search terms: advanced and metastatic renal cell carcinoma, anti-angiogenesis drugs and systemic therapy; also significant meeting abstracts were consulted. RESULTS: Progress in understanding the molecular basis of renal cell carcinoma, especially related to genetics and angiogenesis, has been achieved mainly through of the study of von Hippel-Lindau disease. A great variety of active agents have been developed and tested in metastatic renal cell carcinoma (mRCC patients. New specific molecular therapies in metastatic disease are discussed. Sunitinib, Sorafenib and Bevacizumab increase the progression-free survival when compared to therapy with cytokines. Temsirolimus increases overall survival in high-risk patients. Growth factors and regulatory enzymes, such as carbonic anhydrase IX may be targets for future therapies. CONCLUSIONS: A broader knowledge of clear cell carcinoma molecular biology has permitted the beginning of a new era in mRCC therapy. Benefits of these novel agents in terms of progression-free and overall survival have been observed in patients with mRCC, and, in many cases, have become the standard of care. Sunitinib is now considered the new reference first-line treatment for mRCC. Despite all the progress in recent years, complete responses are still very rare. Currently, many important issues regarding the use of these agents in the management of metastatic renal cancer still need to be properly addressed.

Progress of study on the dopamine D4 receptor imaging agent

International Nuclear Information System (INIS)

Tian Haibin; Zhang Lan; Zhang Chunfu; Li Junling; Yin Duanzhi

2001-01-01

Dopamine receptors were originally classified into five receptors subtypes, the dopamine D 4 receptor was included. Schizophrenic pathophysiology may be associated with expression and function of the dopamine D 4 receptor; it is of great importance to study the imaging agent of dopamine D 4 receptor. The study on radioactivity distribution and metabolize of radioligand remains hampered by the lack radioligand for the D 4 receptor which can be labeled using suitable nuclei. This paper reviews the progress of study on the dopamine D 4 receptor imaging agent, with particular emphasis vary nuclei, for example 11 C, 18 F, 123 I, labeled D 4 receptor ligands, antagonists and analogs as PET or SPECT imaging agents. Authors estimated affinity and selectivity of radioligands for the dopamine D 4 receptor in laboratory animal tests

Dynamic fluorescence imaging with molecular agents for cancer detection

Science.gov (United States)

Kwon, Sun Kuk

Non-invasive dynamic optical imaging of small animals requires the development of a novel fluorescence imaging modality. Herein, fluorescence imaging is demonstrated with sub-second camera integration times using agents specifically targeted to disease markers, enabling rapid detection of cancerous regions. The continuous-wave fluorescence imaging acquires data with an intensified or an electron-multiplying charge-coupled device. The work presented in this dissertation (i) assessed dose-dependent uptake using dynamic fluorescence imaging and pharmacokinetic (PK) models, (ii) evaluated disease marker availability in two different xenograft tumors, (iii) compared the impact of autofluorescence in fluorescence imaging of near-infrared (NIR) vs. red light excitable fluorescent contrast agents, (iv) demonstrated dual-wavelength fluorescence imaging of angiogenic vessels and lymphatics associated with a xenograft tumor model, and (v) examined dynamic multi-wavelength, whole-body fluorescence imaging with two different fluorescent contrast agents. PK analysis showed that the uptake of Cy5.5-c(KRGDf) in xenograft tumor regions linearly increased with doses of Cy5.5-c(KRGDf) up to 1.5 nmol/mouse. Above 1.5 nmol/mouse, the uptake did not increase with doses, suggesting receptor saturation. Target to background ratio (TBR) and PK analysis for two different tumor cell lines showed that while Kaposi's sarcoma (KS1767) exhibited early and rapid uptake of Cy5.5-c(KRGDf), human melanoma tumors (M21) had non-significant TBR differences and early uptake rates similar to the contralateral normal tissue regions. The differences may be due to different compartment location of the target. A comparison of fluorescence imaging with NIR vs. red light excitable fluorescent dyes demonstrates that NIR dyes are associated with less background signal, enabling rapid tumor detection. In contrast, animals injected with red light excitable fluorescent dyes showed high autofluorescence. Dual

Magnetisation transfer MR imaging of the kidney: evaluation at 3.0 T in association with renal function

Energy Technology Data Exchange (ETDEWEB)

Ito, Katsuyoshi [Kawasaki Medical School, Department of Diagnostic Radiology, Kurashiki, Okayama (Japan); Kurashiki Daiichi Hospital, Department of Radiology, Kurashiki, Okayama (Japan); Hayashida, Minoru; Izumitani, Shogo; Fujimine, Tomoko; Onishi, Takeo; Genba, Katsuhiro [Kurashiki Daiichi Hospital, Department of Radiology, Kurashiki, Okayama (Japan)

2013-08-15

To evaluate the feasibility of using magnetisation transfer (MT) MRI of the kidney at 3.0 T to assess renal function. Forty-four patients who underwent abdominal MRI on a 3.0-T system including gradient-echo (GRE) sequences with and without MT pulse were included. In each patient, MT ratio (MTR) of the renal cortex and medulla was measured by using regions of interest (ROIs) placed on the MTR map image. Regression analysis showed good correlation between estimated glomerular filtration rate (eGFR) and MTR of the renal cortex (r = -0.645, P < 0.0001). Among 44 patients, 22 were categorised as the normal renal function group and 22 were classified as the decreased eGFR group. The mean MTR of the renal cortex in patients with decreased eGFR (mean MTR, 30.7 {+-} 3.2 %) was significantly higher (P < 0.0001) than that in patients with normal renal function (mean MTR, 25.3 {+-} 2.2 %), although the mean MTRs of the renal medulla in the two groups were not significantly different. There was good correlation between eGFR and MTR of the renal cortex derived from MT MRI at 3.0 T. This technique may have the potential to evaluate the degree of renal function non-invasively in patients with renal impairment. (orig.)

Vascular fluorscene casting and imaging cryomicrotomy for computerized three-dimensional renal arterial reconstruction

NARCIS (Netherlands)

Lagerveld, B.W.; Wee, ter R.; Rosette, de la J.J.M.C.H.; Spaan, J.A.; Wijkstra, H.

2010-01-01

OBJECTIVE To assess the combined use of a casting technique, cryomicrotomy imaging, and three-dimensional (3D) computer analysis as a method for visualizing and reconstructing the arterial vascular tree in a porcine renal model. MATERIAL AND METHODS The arterial branches of two porcine kidneys were

Vascular fluorescence casting and imaging cryomicrotomy for computerized three-dimensional renal arterial reconstruction

NARCIS (Netherlands)

Lagerveld, Brunolf W.; ter Wee, Rene D.; de La Rosette, Jean J. M. C. H.; Spaan, Jos A. E.; Wijkstra, Hessel

2007-01-01

OBJECTIVES To assess the combined use of a casting technique, cryomicrotomy imaging, and three-dimensional (3D) computer analysis as a method for visualizing and reconstructing the arterial vascular tree in a porcine renal model. MATERIAL AND METHODS The arterial branches of two porcine kidneys were

Influences of renal stone surgeries on renal function; Evaluation of renal function with sup 99m Tc-DMSA renal scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Katayama, Yasushi (Niigata Univ. (Japan). School of Medicine)

1991-10-01

From 1984 to 1990, {sup 99m}Tc-DMSA renal scintigraphy was performed before and after nephrolithotomy (15 cases), pyelolithotomy (15 cases), percutaneous nephrolithotripsy (PNL: 15 cases) and extracorporeal shock wave lithotripsy (ESWL: 16 cases, 17 kidneys) in order to evaluate of influences of renal stone surgeries on split renal function. DMSA renal uptake change ratio of treated kidneys of nephrolithotomy (-24.94{+-}5.60%) was significantly lower than that of PNL (-0.06{+-}3.92%), pyelolithotomy (-4.08{+-}4.79%) (p<0.01) and ESWL (-7.72{+-}3.87%) (p<0.05). The average change ratios of contralateral kidneys were as follows: PNL 4.80{+-}4.21% nephrolithotomy 4.67{+-}4.73%, pyelolithotomy -1.46{+-}5.39% and ESWL -2.02{+-}4.44%. One to 3 weeks after PNL, the cold area on the renal image was found in 10 (66.7%) of 15 cases. In cases of ESWL, DMSA renal uptake decreased even 4-10 weeks (mean 7 weeks) after treatment. In conclusion, possibility of deterioration of renal function after ESWL was suggested. (author).

Mid-Term Vascular Safety of Renal Denervation Assessed by Follow-up MR Imaging

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Schmid, Axel, E-mail: axel.schmid@uk-erlangen.de; Schmieder, Raphael; Lell, Michael; Janka, Rolf [Friedrich-Alexander University Erlangen-Nuremberg, Department of Radiology (Germany); Veelken, Roland; Schmieder, Roland E. [Friedrich-Alexander University Erlangen-Nuremberg, Department of Nephrology and Hypertension (Germany); Uder, Michael [Friedrich-Alexander University Erlangen-Nuremberg, Department of Radiology (Germany); Ott, Christian [Friedrich-Alexander University Erlangen-Nuremberg, Department of Nephrology and Hypertension (Germany)

2016-03-15

Background/AimsRenal denervation (RDN) emerged as a treatment option for reducing blood pressure (BP) in patients with treatment-resistant hypertension (TRH). However, concerns have been raised regarding the incidence of late renal artery stenosis or thromboembolism after RDN. The goal of the current study was, therefore, to conduct a prospective clinical trial on the mid-term vascular integrity of the renal arteries and the perfusion of the renal parenchyma assessed by magnetic resonance imaging (MRI) in the follow-up after catheter-based RDN.MethodsIn our single-centre investigator initiated study, 51 patients with true TRH underwent catheter-based RDN using the Symplicity Flex{sup TM} catheter (Medtronic Inc., Palo Alto, CA). Follow-up MRI was performed at a median of 11 months (interquartile range 6–18 months) after RDN on a 1.5T MR unit. High-resolution MR angiography (MRA) and MRI results were compared to the baseline digital angiography of renal arteries obtained at time of RDN. In case of uncertainties (N = 2) catheter angiography was repeated.ResultsBoth office and 24-h ambulatory BP were significantly reduced 6 and 12 months after RDN. Renal function remained unchanged 6 and 12 months after RDN. In all patients, MRA excluded new or progression of pre-existing low grade renal artery stenosis as well as focal aneurysms at the sites of radiofrequency ablation. In none of the patients new segmental perfusion deficits in either kidney were detected on MRI.ConclusionsNo vascular or parenchymal complications after radiofrequency-based RDN were detected in 51 patients followed up by MRI.

Renal streaky artifact during contrast-enhanced abdominal and pelvic CT: Comparison of high versus low osmolality contrast media

International Nuclear Information System (INIS)

Kim, Dae Hong; Kim, Jong Chul; Lee, Chung Keun; Shin, Kyoung Suk

1994-01-01

Introduction of low osmolality contrast agent(LOCA) has allowed safer, more comfortable contrast-enhanced CT examination, but there has been significant increase in image degradation when evaluating the kidneys due to streaky artifact. The authors reviewed findings of contrast- enhanced abdominal and pelvic computed tomography(CT) to know the difference of renal streaky artifact between a high osmolality contrast agent (HOCA) and LOCA. This study included two hundred contrast-enhanced CT in 200 patients, 100 performed with HOCA(meglumine ioglicate, 150 ml) and 100 performed with LOCA (iopromide,150 ml). The severity of renal streaky artifact was compared between HOCA and LOCA groups. Of the scans performed with HOCA, 40 had no artifact, 52 had grade I artifact, 6 had grade II artifact, and 2 had grade III artifact. Of the scans preformed with LOCA, 23 had no artifact, 44 had grade I artifact, 29 had grade II artifact, and 4 had grade III artifact. There was significant difference in the degree of the streaky artifact depending upon the osmolality of the contrast media used(by χ 2 -test, P=.0001). The results of this study revealed a statistically significant increased incidence of artifacts and distortions of renal image with LOCA when compared with HOCA

Non-invasive imaging of acute renal allograft rejection in rats using small animal F-FDG-PET.

Directory of Open Access Journals (Sweden)

Stefan Reuter

Full Text Available BACKGROUND: At present, renal grafts are the most common solid organ transplants world-wide. Given the importance of renal transplantation and the limitation of available donor kidneys, detailed analysis of factors that affect transplant survival are important. Despite the introduction of new and effective immunosuppressive drugs, acute cellular graft rejection (AR is still a major risk for graft survival. Nowadays, AR can only be definitively by renal biopsy. However, biopsies carry a risk of renal transplant injury and loss. Most important, they can not be performed in patients taking anticoagulant drugs. METHODOLOGY/PRINCIPAL FINDINGS: We present a non-invasive, entirely image-based method to assess AR in an allogeneic rat renal transplantation model using small animal positron emission tomography (PET and (18F-fluorodeoxyglucose (FDG. 3 h after i.v. injection of 30 MBq FDG into adult uni-nephrectomized, allogeneically transplanted rats, tissue radioactivity of renal parenchyma was assessed in vivo by a small animal PET-scanner (post operative day (POD 1,2,4, and 7 and post mortem dissection. The mean radioactivity (cps/mm(3 tissue as well as the percent injected dose (%ID was compared between graft and native reference kidney. Results were confirmed by histological and autoradiographic analysis. Healthy rats, rats with acute CSA nephrotoxicity, with acute tubular necrosis, and syngeneically transplanted rats served as controls. FDG-uptake was significantly elevated only in allogeneic grafts from POD 1 on when compared to the native kidney (%ID graft POD 1: 0.54+/-0.06; POD 2: 0.58+/-0.12; POD 4: 0.81+/-0.06; POD 7: 0.77+/-0.1; CTR: 0.22+/-0.01, n = 3-28. Renal FDG-uptake in vivo correlated with the results obtained by micro-autoradiography and the degree of inflammatory infiltrates observed in histology. CONCLUSIONS/SIGNIFICANCE: We propose that graft FDG-PET imaging is a new option to non-invasively, specifically, early detect, and follow

Bimodal MR-PET agent for quantitative pH imaging

Science.gov (United States)

Frullano, Luca; Catana, Ciprian; Benner, Thomas; Sherry, A. Dean; Caravan, Peter

2010-01-01

Activatable or “smart” magnetic resonance contrast agents have relaxivities that depend on environmental factors such as pH or enzymatic activity, but the MR signal depends on relaxivity and agent concentration – two unknowns. A bimodal approach, incorporating a positron emitter, solves this problem. Simultaneous positron emission tomography (PET) and MR imaging with the biomodal, pH-responsive MR-PET agent GdDOTA-4AMP-F allows direct determination of both concentration (PET) and T1 (MRI), and hence pH. PMID:20191650

Three-dimensional contrast-enhanced magnetic-resonance angiography of the renal arteries: Interindividual comparison of 0.2 mmol/kg gadobutrol at 1.5 T and 0.1 mmol/kg gadobenate dimeglumine at 3.0 T

International Nuclear Information System (INIS)

Attenberger, Ulrike I.; Wintersperger, Bernd J.; Sourbron, Steven P.; Reiser, Maximilian F.; Michaely, Henrik J.; Schoenberg, Stefan O.; Lodemann, Klaus-Peter

2008-01-01

The purpose was to evaluate the image quality of high-spatial resolution MRA of the renal arteries at 1.5 T after contrast-agent injection of 0.2 mmol/kg body weight (BW) in an interindividual comparison to 3.0 T after contrast-agent injection of 0.1 mmol/kg BW contrast agent (CA). After IRB approval and informed consent, 40 consecutive patients (25 men, 15 women; mean age 53.9 years) underwent MRA of the renal arteries either at a 1.5-T MR system with 0.2 mmol/kg BW gadobutrol or at a 3.0-T MR scanner with 0.1 mmol/kg BW gadobenate dimeglumine used as CA in a randomized order. A constant volume of 15 ml of these contrast agents was applied. The spatial resolution of the MRA sequences was 1.0 x 0.8 x 1.0 mm 3 at 1.5 T and 0.9 x 0.8 x 0.9 mm 3 at 3.0 T, which was achieved by using parallel imaging acceleration factors of 2 at 1.5 T and 3 at 3.0 T, respectively. Two radiologists blinded to the administered CA and the field strength assessed the image quality and the venous overlay for the aorta, the proximal and distal renal arteries independently on a four-point Likert-type scale. Phantom measurements were performed for a standardized comparison of SNR at 1.5 T and 3.0 T. There was no significant difference (p > 0.05) between the image quality at 3.0 T with 0.1 mmol/kg BW gadobenate dimeglumine compared to the exams at 1.5 T with 0.2 mmol/kg BW gadobutrol. The median scores were between 3 and 4 (good to excellent vessel visualization) for the aorta (3 at 1.5 T/4 at 3.0 T for reader 1 and 2). For the proximal renal arteries, median scores were 3 for the left and right renal artery at 1.5 T for both readers. At 3.0 T, median scores were 3 (left proximal renal artery) and 4 (right proximal renal artery) for reader 1 and 3 (left/right) for reader 2 at 3.0 T. For the distal renal arteries, median scores were between 2 and 3 at both field strengths (moderate and good) for both readers. The κ values for both field strengths were comparable and ranged between 0

Three-dimensional contrast-enhanced magnetic-resonance angiography of the renal arteries: Interindividual comparison of 0.2 mmol/kg gadobutrol at 1.5 T and 0.1 mmol/kg gadobenate dimeglumine at 3.0 T

Energy Technology Data Exchange (ETDEWEB)

Attenberger, Ulrike I.; Wintersperger, Bernd J.; Sourbron, Steven P.; Reiser, Maximilian F. [University Hospitals-Grosshadern, Ludwig-Maximilians-University Munich, Institute of Clinical Radiology, Munich (Germany); Michaely, Henrik J.; Schoenberg, Stefan O. [University Hospital Mannheim, University of Heidelberg, Institute of Clinical Radiology, Mannheim (Germany); Lodemann, Klaus-Peter [Bracco-Altana Pharma, Konstanz (Germany)

2008-06-15

The purpose was to evaluate the image quality of high-spatial resolution MRA of the renal arteries at 1.5 T after contrast-agent injection of 0.2 mmol/kg body weight (BW) in an interindividual comparison to 3.0 T after contrast-agent injection of 0.1 mmol/kg BW contrast agent (CA). After IRB approval and informed consent, 40 consecutive patients (25 men, 15 women; mean age 53.9 years) underwent MRA of the renal arteries either at a 1.5-T MR system with 0.2 mmol/kg BW gadobutrol or at a 3.0-T MR scanner with 0.1 mmol/kg BW gadobenate dimeglumine used as CA in a randomized order. A constant volume of 15 ml of these contrast agents was applied. The spatial resolution of the MRA sequences was 1.0 x 0.8 x 1.0 mm{sup 3} at 1.5 T and 0.9 x 0.8 x 0.9 mm{sup 3} at 3.0 T, which was achieved by using parallel imaging acceleration factors of 2 at 1.5 T and 3 at 3.0 T, respectively. Two radiologists blinded to the administered CA and the field strength assessed the image quality and the venous overlay for the aorta, the proximal and distal renal arteries independently on a four-point Likert-type scale. Phantom measurements were performed for a standardized comparison of SNR at 1.5 T and 3.0 T. There was no significant difference (p > 0.05) between the image quality at 3.0 T with 0.1 mmol/kg BW gadobenate dimeglumine compared to the exams at 1.5 T with 0.2 mmol/kg BW gadobutrol. The median scores were between 3 and 4 (good to excellent vessel visualization) for the aorta (3 at 1.5 T/4 at 3.0 T for reader 1 and 2). For the proximal renal arteries, median scores were 3 for the left and right renal artery at 1.5 T for both readers. At 3.0 T, median scores were 3 (left proximal renal artery) and 4 (right proximal renal artery) for reader 1 and 3 (left/right) for reader 2 at 3.0 T. For the distal renal arteries, median scores were between 2 and 3 at both field strengths (moderate and good) for both readers. The {kappa} values for both field strengths were comparable and ranged

Spectral Imaging Technology-Based Evaluation of Radiation Treatment Planning to Remove Contrast Agent Artifacts.

Science.gov (United States)

Yi-Qun, Xu; Wei, Liu; Xin-Ye, Ni

2016-10-01

This study employs dual-source computed tomography single-spectrum imaging to evaluate the effects of contrast agent artifact removal and the computational accuracy of radiotherapy treatment planning improvement. The phantom, including the contrast agent, was used in all experiments. The amounts of iodine in the contrast agent were 30, 15, 7.5, and 0.75 g/100 mL. Two images with different energy values were scanned and captured using dual-source computed tomography (80 and 140 kV). To obtain a fused image, 2 groups of images were processed using single-energy spectrum imaging technology. The Pinnacle planning system was used to measure the computed tomography values of the contrast agent and the surrounding phantom tissue. The difference between radiotherapy treatment planning based on 80 kV, 140 kV, and energy spectrum image was analyzed. For the image with high iodine concentration, the quality of the energy spectrum-fused image was the highest, followed by that of the 140-kV image. That of the 80-kV image was the worst. The difference in the radiotherapy treatment results among the 3 models was significant. When the concentration of iodine was 30 g/100 mL and the distance from the contrast agent at the dose measurement point was 1 cm, the deviation values (P) were 5.95% and 2.20% when image treatment planning was based on 80 and 140 kV, respectively. When the concentration of iodine was 15 g/100 mL, deviation values (P) were -2.64% and -1.69%. Dual-source computed tomography single-energy spectral imaging technology can remove contrast agent artifacts to improve the calculated dose accuracy in radiotherapy treatment planning. © The Author(s) 2015.

Computed tomography on renal masses in dogs and cats

International Nuclear Information System (INIS)

Yamazoe, Kazuaki; Ohashi, Fumihito; Kadosawa, Tsuyoshi; Nishimura, Ryohei; Sasaki, Nobuo; Takeuchi, Akira.

1994-01-01

Computed tomography (CT) was performed on renal tumors (Wilms' tumor and renal cell carcinoma) and renal cysts in dogs and cats. CT images in renal tumors were well correlated with macroscopic findings, and contrast CT images were quite useful in differentiating tumoral regions from non-tumoral ones. On renal cysts, intravenous pyelography and ultrasonography were as effective as CT images in morphological diagnosis, but CT was considered to be superior for evaluating three-dimensional (3-D) relationships in complicated lesions. (author)

Computed tomography on renal masses in dogs and cats

Energy Technology Data Exchange (ETDEWEB)

Yamazoe, Kazuaki (Gifu Univ. (Japan). Faculty of Agriculture); Ohashi, Fumihito; Kadosawa, Tsuyoshi; Nishimura, Ryohei; Sasaki, Nobuo; Takeuchi, Akira

1994-08-01

Computed tomography (CT) was performed on renal tumors (Wilms' tumor and renal cell carcinoma) and renal cysts in dogs and cats. CT images in renal tumors were well correlated with macroscopic findings, and contrast CT images were quite useful in differentiating tumoral regions from non-tumoral ones. On renal cysts, intravenous pyelography and ultrasonography were as effective as CT images in morphological diagnosis, but CT was considered to be superior for evaluating three-dimensional (3-D) relationships in complicated lesions. (author).

Tc-99m-DMSA renal uptake rate and renal volume of elderly persons

International Nuclear Information System (INIS)

Ohishi, Yukihiko; Machida, Toyohei; Kido, Akira

1987-01-01

Renal function of erderly persons was evaluated by the radionuclide renal function test based on the renal uptake rate and the renal volume determined by Tc-99m-DMSA transectional tomographic images using single photon emission computed tomography (SPECT). Forty-three erderly cases (13 healthy persons and 30 patients with various types of renal disorders) aged between 60 and 87 on an average of 70 were studied and compared with results obtained from 20 healthy adults (18 - 45 years old). Renal volume was calculated from the summation of voxels in the region districted by equi-count threshold level (percentage to maximum count) on each section of the SPECT image. Attenuation correction was made by GE-STAR protocol utilizing Sorrenson's precorrection method. The renal uptake rate was expressed as a percentage of the total radioactivity detected within the renal volume, against an amount of dose injected. In the 26 kidneys of 13 healthy elderly persons, Tc-99m-DMSA renal uptake was 23 ± 5 %, which was significantly lower (p < 0.01) than that of healthy adults being 27 ± 2 %. A correlation coefficient between renal volume and uptake of 79 kidneys of 43 elderly persons was 0.5081 (p < 0.01). Creatinine clearance (Ccr) was better correlated with the total renal uptake (r = 0.6471, p < 0.01) than with the total renal volume (r = 0.3592, p < 0.01). This method is considered to be useful for clinical purpose as a test of renal function for elderly persons since it requires neither blood nor urine samples. (author)

Contrast-enhanced peripheral MRA. Technique and contrast agents

International Nuclear Information System (INIS)

Nielsen, Yousef W.; Thomsen, Henrik S.

2012-01-01

In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X

Acute renal failure secondary to rhabdomyolysis

International Nuclear Information System (INIS)

Kim, S.H.; Han, M.C.; Kim, S.; Lee, J.S.

1992-01-01

MR imaging of the kidney was performed in 6 patients with acute renal failure (ARF) secondary to rhabdomyolysis caused by snake bite (n = 4), crush injury (n = 1), and carbon monoxide poisoning (n = 1). A test for urine myoglobin was positive in all 6 patients and MR imaging was done 6 to 18 days after the causative event of the rhabdomyolysis. MR images in all 6 patients showed globular swelling of the kidneys, preserved corticomedullary contrast on T1-weighted images, and obliteration of corticomedullary contrast on T2-weighted images. Unlike other medical renal diseases in which corticomedullary contrast is lost on T1-weighted images, preservation of the corticomedullary contrast on T1-weighted MR images with globular renal swelling was a constant finding in patients with ARF secondary to rhabdomyolysis. (orig.)

Detailing the relation between renal T2* and renal tissue pO2 using an integrated approach of parametric magnetic resonance imaging and invasive physiological measurements.

Science.gov (United States)

Pohlmann, Andreas; Arakelyan, Karen; Hentschel, Jan; Cantow, Kathleen; Flemming, Bert; Ladwig, Mechthild; Waiczies, Sonia; Seeliger, Erdmann; Niendorf, Thoralf

2014-08-01

This study was designed to detail the relation between renal T2* and renal tissue pO2 using an integrated approach that combines parametric magnetic resonance imaging (MRI) and quantitative physiological measurements (MR-PHYSIOL). Experiments were performed in 21 male Wistar rats. In vivo modulation of renal hemodynamics and oxygenation was achieved by brief periods of aortic occlusion, hypoxia, and hyperoxia. Renal perfusion pressure (RPP), renal blood flow (RBF), local cortical and medullary tissue pO2, and blood flux were simultaneously recorded together with T2*, T2 mapping, and magnetic resonance-based kidney size measurements (MR-PHYSIOL). Magnetic resonance imaging was carried out on a 9.4-T small-animal magnetic resonance system. Relative changes in the invasive quantitative parameters were correlated with relative changes in the parameters derived from MRI using Spearman analysis and Pearson analysis. Changes in T2* qualitatively reflected tissue pO2 changes induced by the interventions. T2* versus pO2 Spearman rank correlations were significant for all interventions, yet quantitative translation of T2*/pO2 correlations obtained for one intervention to another intervention proved not appropriate. The closest T2*/pO2 correlation was found for hypoxia and recovery. The interlayer comparison revealed closest T2*/pO2 correlations for the outer medulla and showed that extrapolation of results obtained for one renal layer to other renal layers must be made with due caution. For T2* to RBF relation, significant Spearman correlations were deduced for all renal layers and for all interventions. T2*/RBF correlations for the cortex and outer medulla were even superior to those between T2* and tissue pO2. The closest T2*/RBF correlation occurred during hypoxia and recovery. Close correlations were observed between T2* and kidney size during hypoxia and recovery and for occlusion and recovery. In both cases, kidney size correlated well with renal vascular conductance

Complex cystic renal masses: characterization with contrast-enhanced US.

Science.gov (United States)

Ascenti, Giorgio; Mazziotti, Silvio; Zimbaro, Giovanni; Settineri, Nicola; Magno, Carlo; Melloni, Darwin; Caruso, Rosario; Scribano, Emanuele

2007-04-01

To prospectively compare contrast material-enhanced ultrasonography (US) with computed tomography (CT) in the classification of complex cystic renal masses with the Bosniak system. Ethics committee approval and written informed consent were obtained. Forty patients (17 women, 23 men; age range, 31-77 years) with 44 complex cystic renal masses detected with conventional US were prospectively examined by using second-harmonic US with a second-generation contrast agent and multiphasic helical CT. Thirty-six patients had one lesion, and four patients had two lesions. Surgical resection in nine patients and imaging follow-up in 31 patients were used to determine the outcome. On contrast-enhanced US images, masses were classified as Bosniak category II (n = 18), IIF (ie, lesions were classified as category II and follow-up was needed) (n = 16), III (n = 7), or IV (n = 3) lesions. On CT images, masses were classified as Bosniak category II (n = 24), IIF (n = 10), III (n = 7), or IV (n = 3) lesions. Interobserver agreement was high (kappa = 0.86, P < .001) for classification with US. Complete concordance between the readers was found for classification with CT. Complete concordance between contrast-enhanced US and CT was observed in the differentiation of surgical and nonsurgical complex cysts. Complete concordance among the three readers in the assessment of vascularity with contrast-enhanced US was found. Interobserver agreement in the evaluation of enhancement on CT images was high (kappa = 0.88, P < .001). Concordance between contrast-enhanced US and CT in the evaluation of vascularization was high (kappa = 0.77, P < .001). The study data suggest that contrast-enhanced second-harmonic US is appropriate for renal cyst classification with the Bosniak system.

Ultrasonography in chronic renal failure

International Nuclear Information System (INIS)

Buturovic-Ponikvar, Jadranka; Visnar-Perovic, Alenka

2003-01-01

Many chronic renal diseases lead to the final common state of decrease in renal size, parenchymal atrophy, sclerosis and fibrosis. The ultrasound image show a smaller kidney, thinning of the parenchyma and its hyperechogenicity (reflecting sclerosis and fibrosis). The frequency of renal cysts increases with the progression of the disease. Ultrasound generally does not allow for the exact diagnosis of an underlying chronic disease (renal biopsy is usually required), but it can help to determine an irreversible disease, assess prognosis and avoid unnecessary diagnostic or therapeutic procedures. The main exception in which the ultrasound image does not show a smaller kidney with parenchymal atrophy is diabetic nephropathy, the leading cause of chronic and end-stage renal failure in developed countries in recent years. In this case, both renal size and parenchymal thickness are preserved until end-stage renal failure. Doppler study of intrarenal vessels can provide additional information about microvascular and parenchymal lesions, which is helpful in deciding for or against therapeutic intervention and timely planning for optimal renal replacement therapy option

Microbubbles as contrast agent for in-line x-ray phase-contrast imaging

International Nuclear Information System (INIS)

Xi Yan; Zhao Jun; Tang Rongbiao; Wang Yujie

2011-01-01

In the present study, we investigated the potential of gas-filled microbubbles as contrast agents for in-line x-ray phase-contrast imaging (PCI) in biomedical applications. When imaging parameters are optimized, the microbubbles function as microlenses that focus the incoming x-rays to form bright spots, which can significantly enhance the image contrast. Since microbubbles have been shown to be safe contrast agents in clinical ultrasonography, this contrast-enhancement procedure for PCI may have promising utility in biomedical applications, especially when the dose of radiation is a serious concern. In this study, we performed both numerical simulations and ex vivo experiments to investigate the formation of the contrast and the effectiveness of microbubbles as contrast agents in PCI.

Design and Optimization of Gadolinium Based Contrast Agents for Magnetic Resonance Imaging

International Nuclear Information System (INIS)

Pereira, G.A.; Geraldes, C.F.G.C.; University of Coimbra

2007-01-01

The role of Gd 3+ chelates as contrast agents in Magnetic Resonance Imaging is discussed. The theory describing the different contributions to paramagnetic relaxation relevant to the understanding of the molecular parameters determining the relativity of those Gd 3+ chelates, is presented. The experimental techniques used to obtain those parameters are also described. Then, the various approaches taken to optimize those parameters, leading to maximum relativity (efficiency) of the contrast agents, are also illustrated with relevant examples taken from the literature. The various types of Gd 3+ -based agents, besides non-specific and hepatobiliary agents, are also discussed, namely blood pool, targeting, responsive and paramagnetic chemical shift saturation transfer (PARACEST) agents. Finally, a perspective is presented of some of the challenges lying ahead in the optimization of MRI contrast agents to be useful in Molecular Imaging. (author)

Mechanistic and quantitative insight into cell surface targeted molecular imaging agent design.

Science.gov (United States)

Zhang, Liang; Bhatnagar, Sumit; Deschenes, Emily; Thurber, Greg M

2016-05-05

Molecular imaging agent design involves simultaneously optimizing multiple probe properties. While several desired characteristics are straightforward, including high affinity and low non-specific background signal, in practice there are quantitative trade-offs between these properties. These include plasma clearance, where fast clearance lowers background signal but can reduce target uptake, and binding, where high affinity compounds sometimes suffer from lower stability or increased non-specific interactions. Further complicating probe development, many of the optimal parameters vary depending on both target tissue and imaging agent properties, making empirical approaches or previous experience difficult to translate. Here, we focus on low molecular weight compounds targeting extracellular receptors, which have some of the highest contrast values for imaging agents. We use a mechanistic approach to provide a quantitative framework for weighing trade-offs between molecules. Our results show that specific target uptake is well-described by quantitative simulations for a variety of targeting agents, whereas non-specific background signal is more difficult to predict. Two in vitro experimental methods for estimating background signal in vivo are compared - non-specific cellular uptake and plasma protein binding. Together, these data provide a quantitative method to guide probe design and focus animal work for more cost-effective and time-efficient development of molecular imaging agents.

Editor’s Pick: Targeted Agents in Patients with Metastatic Renal Cell Carcinoma on Dialysis: Myths and Reality

Directory of Open Access Journals (Sweden)

Annalisa Guida

2016-07-01

Full Text Available Agents targeting the vascular endothelial growth factor (VEGF/VEGF receptor (VEGFR pathway, as well as mammalian target of rapamycin (mTOR inhibitors have revolutionised the therapeutic landscape of metastatic renal cell carcinoma (mRCC in the past decade, greatly improving the survival rates of these patients. However, translating results of registrative Phase III trials into everyday clinical practice is often troublesome, since real-world patients are completely different from those enrolled in randomised controlled Phase III trials. Prospective data on active oncological treatments in mRCC patients on dialysis are dramatically lacking. This literature review summarises and critically comments on available data relative to mRCC patients on dialysis receiving either VEGF/VEGFR-targeting agents, or mTOR inhibitors. Although prospective studies would definitely be warranted in these specific patient populations, all the available data suggest that mRCC patients on dialysis have the same outcome, both in terms of efficacy and safety, as mRCC patients with normal or marginally impaired kidney function, when treated with VEGF/VEGFR-targeting agents and/or mTOR inhibitors.

The clinical use of contrast agents in magnetic resonance imaging

International Nuclear Information System (INIS)

Bydder, G.M.

1987-01-01

Interest in the use of external agents to increase tissue contrasts has come from many sources dating back to the earliest work in NMR, to animal studies and to the widespread use of contrast agents in conventional radiological practice. The first clinical magnetic resonance images were published in 1980 and in the following year a brief account of the use of the paramagnetic agents in human volunteers was established. It was apparent relatively early in the development of magnetic resonance imaging (MRI) that a high level of soft tissue contrast was available de novo and the need for externally administered agents might therefore be small. This observation was tempered by the fact that separation of tumour from oedema was frequently better with contrast enhanced CT X-ray than with unenhanced MRI and that of a contrast agent might therefore be needed for MRI. At the end of 1983 the first parenteral agent gadoliminum diethylene triamine pentaacetic acid (Gd-DTPA) was used in volunteers and clinical studies began in 1984. At the present time only molecular O/sub 2/, oral iron compounds and Gd-DTPA are in clinical use although there are a number of other agents which have been used in animals and some of these may become available for clinical use in the foreseeable future

Quantitative analysis of MR perfusion/diffusion images in a dog model of renal artery stenosis with microsphere correlation

International Nuclear Information System (INIS)

Lorens, C.H.; Powers, T.A.; Holburn, G.E.; Price, R.R.

1990-01-01

This paper compares MR perfusion/diffusion-derived parameters with microsphere determination of asymmetry of renal perfusion in a dog model of renal artery stenosis. A left renal artery stenosis was created by placement of a silk ligature. Nb-95-labeled microspheres were injected into the left ventricle, and a reference blood sample was drawn. The dog was imaged in a 1.5-T MR imager with both spin-echo and turbo-FLASH perfusion/diffusion-sensitive pulse sequences. The kidneys were excised, weighted, divided into sections, and counted. Two dogs have been studied to date. In dog 1, left renal blood flow (RBF) was 42 mL/min/100g and right RBF was 337 mL/min/100g. In dog 2 left RBF was 444 mL/min/100g and right RBF was 608 mL/min/100g. The apparent diffusion coefficients (ADC) reflected the asymmetry of flow in dog 1 for both spin-echo and turbo-FLASH sequences (RADC/LADC = 1.7) and showed essentially equal flow in dog 2(RADC/LADC = 0.7)

The application of Gadopentate-Dimeneglumin has no impact on progression free and overall survival as well as renal function in patients with monoclonal plasma cell disorders if general precautions are taken

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Hillengass, J. [University of Heidelberg, Department of Hematology, Oncology and Rheumatology, Heidelberg (Germany); German Cancer Research Center Heidelberg, Department of Radiology, Heidelberg (Germany); Stoll, J.; Wagner, B.; Goldschmidt, H. [University of Heidelberg, Department of Hematology, Oncology and Rheumatology, Heidelberg (Germany); Zechmann, C.M. [Rinecker Proton Therapy Center, Munich (Germany); Kunz, C.; Heiss, C. [German Cancer Research Center Heidelberg, Department of Biostatistics, Heidelberg (Germany); Sumkauskaite, M. [University of Heidelberg, Department of Radiology, Heidelberg (Germany); Moehler, T.M. [InVentiv Health Clinical, Wiesbaden (Germany); Schlemmer, H.P.; Delorme, S. [German Cancer Research Center Heidelberg, Department of Radiology, Heidelberg (Germany)

2014-10-31

The current analysis investigated the prognostic significance of gadopentetate dimeglumine on survival and renal function in patients with monoclonal plasma cell disorders. In this study 263 patients who had received gadopentetate dimeglumine within a prospective trial investigating dynamic contrast-enhanced magnetic resonance imaging (MRI) were compared with 335 patients who had undergone routine, unenhanced MRI. We found no significant prognostic impact of the application of contrast agent on progression-free survival in patients with either monoclonal gammopathy of undetermined significance, smouldering or symptomatic myeloma and no significant prognostic impact on overall survival in patients with symptomatic myeloma. Since renal impairment is a frequent complication of myeloma, and decreased renal function is associated with a higher risk of complications in patients receiving contrast agents, we evaluated the impact of contrast agent on renal function after 1 year. In the present analysis the only significant adverse impact on kidney function occurred in symptomatic myeloma patients who already had impaired renal parameters at baseline. Here, the renal function did not recover during therapy, whereas it did so in patients with normal or only slightly impaired renal function. If general recommendations are adhered to, gadopentetate dimeglumine can be safely applied in patients with monoclonal plasma cell disease. (orig.)

Adverse Renal Effects of Novel Molecular Oncologic Targeted Therapies: A Narrative Review

Directory of Open Access Journals (Sweden)

Kenar D. Jhaveri

2017-01-01

Full Text Available Novel targeted anti-cancer therapies have resulted in improvement in patient survival compared to standard chemotherapy. Renal toxicities of targeted agents are increasingly being recognized. The incidence, severity, and pattern of renal toxicities may vary according to the respective target of the drug. Here we review the adverse renal effects associated with a selection of currently approved targeted cancer therapies, directed to EGFR, HER2, BRAF, MEK, ALK, PD1/PDL1, CTLA-4, and novel agents targeted to VEGF/R and TKIs. In summary, electrolyte disorders, renal impairment and hypertension are the most commonly reported events. Of the novel targeted agents, ipilumumab and cetuximab have the most nephrotoxic events reported. The early diagnosis and prompt recognition of these renal adverse events are essential for the general nephrologist taking care of these patients.

Recent developments in 99mTc and 123I-radiopharmaceuticals for SPECT imaging

International Nuclear Information System (INIS)

Kulkarni, P.V.

1991-01-01

Availability of 123 I of high radionuclidic purity has encouraged the development of 123 I-based radiopharmaceuticals for the assessment of myocardial fatty acid metabolism, myocardial neuronal activity, and for receptor and antibody imaging. Advances in the chemistry of technetium have resulted in the development of novel agents for myocardial and cerebral perfusion and renal function studies. Monoclonal antibodies labeled with 99m Tc show promise for imaging neoplastic lesions, myocardial infarcts, and thrombus localization. Recent developments in 123 I and 99m Tc agents for myocardial and brain imaging studies are discussed. (author)

Perioperative acute renal failure.

LENUS (Irish Health Repository)

Mahon, Padraig

2012-02-03

PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

Cyclosporine A induces senescence in renal tubular epithelial cells

NARCIS (Netherlands)

Jennings, Paul; Koppelstaetter, Christian; Aydin, Sonia; Abberger, Thomas; Wolf, Anna Maria; Mayer, Gert; Pfaller, Walter

The nephrotoxic potential of the widely used immunosuppressive agent cyclosporine A (CsA) is well recognized. However, the mechanism of renal tubular toxicity is not yet fully elucidated. Chronic CsA nephropathy and renal organ aging share some clinical features, such as renal fibrosis and tubular

Magnetisation transfer MR imaging of the kidney: evaluation at 3.0 T in association with renal function

International Nuclear Information System (INIS)

Ito, Katsuyoshi; Hayashida, Minoru; Izumitani, Shogo; Fujimine, Tomoko; Onishi, Takeo; Genba, Katsuhiro

2013-01-01

To evaluate the feasibility of using magnetisation transfer (MT) MRI of the kidney at 3.0 T to assess renal function. Forty-four patients who underwent abdominal MRI on a 3.0-T system including gradient-echo (GRE) sequences with and without MT pulse were included. In each patient, MT ratio (MTR) of the renal cortex and medulla was measured by using regions of interest (ROIs) placed on the MTR map image. Regression analysis showed good correlation between estimated glomerular filtration rate (eGFR) and MTR of the renal cortex (r = -0.645, P < 0.0001). Among 44 patients, 22 were categorised as the normal renal function group and 22 were classified as the decreased eGFR group. The mean MTR of the renal cortex in patients with decreased eGFR (mean MTR, 30.7 ± 3.2 %) was significantly higher (P < 0.0001) than that in patients with normal renal function (mean MTR, 25.3 ± 2.2 %), although the mean MTRs of the renal medulla in the two groups were not significantly different. There was good correlation between eGFR and MTR of the renal cortex derived from MT MRI at 3.0 T. This technique may have the potential to evaluate the degree of renal function non-invasively in patients with renal impairment. (orig.)

Fetal and Postnatal Magnetic Resonance Imaging of Unilateral Cystic Renal Dysplasia in a Neonate with Tuberous Sclerosis

Directory of Open Access Journals (Sweden)

Vineet Tyagi

2016-10-01

Full Text Available Tuberous sclerosis (TS is an autosomal dominant condition associated with mutations in the TSC1 and/or TSC2 genes. Clinical manifestations are multisystemic, and they often include lesions in the brain, skin, heart, kidneys, and bones. TSC2 gene mutations can be seen concomitantly with autosomal dominant polycystic kidney disease gene mutations. We present a case of a fetus with prenatal diagnosis of TS that had unique asymmetrical distribution of renal cystic disease. We describe the extensive work up with both fetal and neonatal magnetic resonance imaging with correlating images of the unilateral polycystic renal disease in addition to typical TS brain findings.

In vivo imaging agents: an international market report

International Nuclear Information System (INIS)

1990-01-01

The purpose of this study is to provide a global perspective of the in vivo imaging agents business to market planning executives who are working for companies that develop, produce and distribute various types of in vivo imaging agents. Others that could find this study useful include investment bankers, regulatory and governmental authorities and purchasers of these products. The study attempts to diligently provide market data by type for important geographic markets - Western Europe, the U.S.A., and Japan. A competitive intelligence section which discusses companies involved in these markets constitutes the last part of this study. These profiles are not intended to extensively evaluate each company's marketing strengths or strategies but to provide a general idea of the market presence and prospects. A combination of primary and secondary research is used for all findings. (author)

Gadolinium chloride as a contrast agent for imaging wood composite components by magnetic resonance

Science.gov (United States)

Thomas L. Eberhardt; Chi-Leung So; Andrea Protti; Po-Wah So

2009-01-01

Although paramagnetic contrast agents have an established track record in medical uses of magnetic resonance imaging (MRI), only recently has a contrast agent been used for enhancing MRI images of solid wood specimens. Expanding on this concept, wood veneers were treated with a gadolinium-based contrast agent and used in a model system comprising three-ply plywood...

Imaging efficiency of an X-ray contrast agent-incorporated polymeric microparticle.

Science.gov (United States)

Ahn, Sungsook; Jung, Sung Yong; Lee, Jin Pyung; Lee, Sang Joon

2011-01-01

Biocompatible polymeric encapsulants have been widely used as a delivery vehicle for a variety of drugs and imaging agents. In this study, X-ray contrast agent (iopamidol) is encapsulated into a polymeric microparticle (polyvinyl alcohol) as a particulate flow tracer in synchrotron X-ray imaging system. The physical properties of the designed microparticles are investigated and correlated with enhancement in the imaging efficiency by experimental observation and theoretical interpretation. The X-ray absorption ability of the designed microparticle is assessed by Beer-Lambert-Bouguer law. Particle size, either in dried state or in solvent, primarily dominates the X-ray absorption ability under the given condition, thus affecting imaging efficiency of the designed X-ray contrast flow tracers. Copyright © 2011 John Wiley & Sons, Ltd.

Dual-energy CT with tin filter technology for the discrimination of renal lesion proxies containing blood, protein, and contrast-agent. An experimental phantom study

International Nuclear Information System (INIS)

Karlo, Christoph; Lauber, Arno; Goetti, Robert Paul; Baumueller, Stephan; Stolzmann, Paul; Scheffel, Hans; Desbiolles, Lotus; Marincek, Borut; Leschka, Sebastian; Schmidt, Bernhard; Alkadhi, Hatem

2011-01-01

To differentiate proxy renal cystic lesions containing protein, blood, iodine contrast or saline solutions using dual-energy CT (DECT) equipped with a new tin filter technology (TFT). 70 proxies (saline, protein, blood and contrast agent) were placed in unenhanced and contrast-enhanced kidney phantoms. DECT was performed at 80/140 kV with and without tin filtering. Two readers measured the CT attenuation values in all proxies twice. An 80/140 kV ratio was calculated. All intra- and interobserver agreements were excellent (r = 0.93-0.97; p 0.05). The CT attenuation of protein, blood and contrast agent solution differed significantly with tin filtering (p < 0.01-0.05). Significant differences were found between the ratios of protein and blood compared to contrast medium solution (each, p < 0.05) and between the ratios of protein and blood in both phantoms with tin filtering (each, p < 0.05). DECT allows discrimination between a proxy renal lesion containing contrast agent and lesions containing protein and blood through their different attenuation at 80 kV and 140 kV. Further discrimination between protein and blood containing proxies is possible when using a tin filter. (orig.)

Distal renal tubular acidosis

Science.gov (United States)

... this disorder. Alternative Names Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA Images Kidney anatomy Kidney - blood and urine flow References Bose A, Monk RD, Bushinsky DA. Kidney ...

Advances in the staging of renal cell carcinoma with high-resolution imaging; Fortschritte im Staging des Nierenzellkarzinoms mittels hochaufloesender Bildgebung

Energy Technology Data Exchange (ETDEWEB)

Hallscheidt, P.; Noeldge, G.; Schawo, S.; Kauffmann, G.; Palmowski, M. [Abt. Radiodiagnostik, Radiologische Klinik, Univ. Heidelberg (Germany); Bartling, S. [Medizinische Physik, DKFZ Heidelberg (Germany); Pfitzenmaier, J. [Urologische Klinik, Univ. Heidelberg (Germany)

2007-12-15

Modern imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) allow high-resolution imaging of the abdomen. Modern scanners made high temporal as well as high spatial resolution available. Therapeutic approaches to the treatment of renal cell carcinoma have been improved over the recent years. Besides conventional and open laparoscopic tumor nephrectomy and nephron sparing, surgical approaches such as local tumor cryotherapy and radiofrequency ablation (RF) are ablative modalities and are used increasingly. Improved anesthesiological methods and new surgical approaches also allow curative treatment in extended tumors. Prerequisites for preoperative imaging modalities include visualization of the kidney tumor as well as its staging. Tumor-related infiltration of the renal pelvis or invasion of the perinephric fat and the renal hilus has to be excluded prior to nephron sparing surgery. In cases with extended tumors with infiltration of the inferior vena cava, it is necessary to visualize the exact extension of the tumor growth towards the right atrium in the vena cava. The radiologist should be informed about the diagnostic possibilities and limitations of the imaging modalities of CT and MRI in order to support the urologist in the planning and performance of surgical therapeutical approaches. (orig.)

Individual renal function study using dynamic computed tomography

International Nuclear Information System (INIS)

Fukuda, Yutaka; Kiya, Keiichi; Suzuki, Yoshiharu

1990-01-01

Dynamic CT scans of individual kindneys were obtained after an intravenous bolus injection of contrast agent. Time-density curves measured from the renal cortex, medulla and pelvis revealed the changes in density produced by the contrast agent reflecting the differential phase of renal function. Renal cortical density increased rapidly after bolus administration and then renal medullary and pelvic density increased continuously. In analyzing time-density curve, the cortico-medullary junction time, which is the time when the cortical and medullary curves cross was 57±8 seconds in patients with normal renal function. The cortico-medullary junction time was delayed in patient with decreased glomerular filtration rate. The cortico-pelvic junction time, which is the time when the cortical and pelvic curves cross was 104±33 seconds in patients with normal renal function. The cortico-pelvic junction time was delayed in patients with declined urinary concentrating capacity. In patients with unilateral renal agenesis and patients who were treated surgically by ureteral sprits, the relationship between individual renal functions and these junction times was examined. As a result of study there were inversely significant correlations between C-M junction time and unilateral GFR and between C-P junction time and urinary concentrating capacity. These studies indicate that dynamic CT scanning is an effective way that individual renal function can be monitored and evaluated. (author)

Novel Gd nanoparticles enhance vascular contrast for high-resolution magnetic resonance imaging.

Directory of Open Access Journals (Sweden)

Tot Bui

2010-09-01

Full Text Available Gadolinium (Gd, with its 7 unpaired electrons in 4f orbitals that provide a very large magnetic moment, is proven to be among the best agents for contrast enhanced MRI. Unfortunately, the most potent MR contrast agent based on Gd requires relatively high doses of Gd. The Gd-chelated to diethylene-triamine-penta-acetic acid (DTPA, or other derivatives (at 0.1 mmole/kg recommended dose, distribute broadly into tissues and clear through the kidney. These contrast agents carry the risk of Nephrogenic Systemic Fibrosis (NSF, particularly in kidney impaired subjects. Thus, Gd contrast agents that produce higher resolution images using a much lower Gd dose could address both imaging sensitivity and Gd safety.To determine whether a biocompatible lipid nanoparticle with surface bound Gd can improve MRI contrast sensitivity, we constructed Gd-lipid nanoparticles (Gd-LNP containing lipid bound DTPA and Gd. The Gd-LNP were intravenously administered to rats and MR images collected. We found that Gd in Gd-LNP produced a greater than 33-fold higher longitudinal (T(1 relaxivity, r(1, constant than the current FDA approved Gd-chelated contrast agents. Intravenous administration of these Gd-LNP at only 3% of the recommended clinical Gd dose produced MRI signal-to-noise ratios of greater than 300 in all vasculatures. Unlike current Gd contrast agents, these Gd-LNP stably retained Gd in normal vasculature, and are eliminated predominately through the biliary, instead of the renal system. Gd-LNP did not appear to accumulate in the liver or kidney, and was eliminated completely within 24 hrs.The novel Gd-nanoparticles provide high quality contrast enhanced vascular MRI at 97% reduced dose of Gd and do not rely on renal clearance. This new agent is likely to be suitable for patients exhibiting varying degrees of renal impairment. The simple and adaptive nanoparticle design could accommodate ligand or receptor coating for drug delivery optimization and in vivo drug

Comparison of FDG-PET/CT images between chronic renal failure patients on hemodialysis and controls.

Science.gov (United States)

Toriihara, Akira; Kitazume, Yoshio; Nishida, Hidenori; Kubota, Kazunori; Nakadate, Masashi; Tateishi, Ukihide

2015-01-01

The whole-body 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) distribution in chronic renal failure (CRF) patients on hemodialysis would be different from that in subjects with normal renal function, because they lack urinary FDG excretion and remain in a constant volume overload. We evaluated the difference in the physiological uptake pattern of FDG between chronic renal failure patients on hemodialysis and control subjects. The subjects for this retrospective study consisted of 24 chronic renal failure patients on hemodialysis (HD group) and 24 age- and sex-matched control subjects (NC group). Standardized uptake values normalized by the body weight (SUVbw), ideal body weight (SUVibw), lean body mass (SUVlbm), and body surface area (SUVbsa) in the cerebellum, lungs, liver, gluteal muscles and subcutaneous fat, spleen, thoracolumbar spine, thoracic and abdominal aorta, and right atrium were calculated in positron emission tomography/computed tomography (PET/CT) images. SUVbw in the gluteal muscles, subcutaneous fat, spleen and right atrium was significantly higher in the HD group as compared to that in the NC group (p chronic renal failure patients on hemodialysis show significantly higher physiological FDG uptake in the soft tissues, spleen and blood pool.

Comparison of FDG-PET/CT images between chronic renal failure patients on hemodialysis and controls

Science.gov (United States)

Toriihara, Akira; Kitazume, Yoshio; Nishida, Hidenori; Kubota, Kazunori; Nakadate, Masashi; Tateishi, Ukihide

2015-01-01

The whole-body 2-deoxy-2-[18F]fluoro-D-glucose (FDG) distribution in chronic renal failure (CRF) patients on hemodialysis would be different from that in subjects with normal renal function, because they lack urinary FDG excretion and remain in a constant volume overload. We evaluated the difference in the physiological uptake pattern of FDG between chronic renal failure patients on hemodialysis and control subjects. The subjects for this retrospective study consisted of 24 chronic renal failure patients on hemodialysis (HD group) and 24 age- and sex-matched control subjects (NC group). Standardized uptake values normalized by the body weight (SUVbw), ideal body weight (SUVibw), lean body mass (SUVlbm), and body surface area (SUVbsa) in the cerebellum, lungs, liver, gluteal muscles and subcutaneous fat, spleen, thoracolumbar spine, thoracic and abdominal aorta, and right atrium were calculated in positron emission tomography/computed tomography (PET/CT) images. SUVbw in the gluteal muscles, subcutaneous fat, spleen and right atrium was significantly higher in the HD group as compared to that in the NC group (p chronic renal failure patients on hemodialysis show significantly higher physiological FDG uptake in the soft tissues, spleen and blood pool. PMID:25973341

Gadolinium-based contrast agents in pediatric magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Gale, Eric M.; Caravan, Peter [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, The Martinos Center for Biomedical Imaging, Boston, MA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); McDonald, Robert J. [College of Medicine, Mayo Clinic, Department of Radiology, Rochester, MN (United States); Winfeld, Matthew [University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Pediatric Radiology, Cincinnati, OH (United States); Gee, Michael S. [MassGeneral Hospital for Children, Harvard Medical School, Division of Pediatric Imaging, Department of Radiology, Boston, MA (United States)

2017-05-15

Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

Comparison of positive and negative enteral contrast agents for MR imaging of the abdomen

International Nuclear Information System (INIS)

Kaminsky, S.; Langer, M.

1994-01-01

Following oral administration of a buffered gadopentetate-dimeglumine solution (Magnevist enteral R , 1 mmol/l, 6-17 ml/kg) T 1 -, proton-density- and T 2 -weighted spin-echo images of abdominal and retroperitoneal lesions were acquired (0.5 T). Gadopentetate is a signal-enhancing, positive MR contrast agent, intraluminar air served as a model of a signal-free, negative agent. In 21 patients contrast/noise ratios of gadopentetate and air versus lesions and fat were compared quantitatively (t-test). In T 1 - and T 2 -weighted images contrast/noise ratios of gadopentetate versus lesions were significantly higher than those of air. In proton-density images there was no significant difference. In T 1 - and proton-density images contrast/noise ratios of air versus abdominal fat were significantly higher than those of gadopentetate, in T 2 -weighted images gadopentetate had a significantly higher contrast/noise ratio than air. Signal-enhancing positive contrast agents seem advantageous over signal-free negative enteral MR contrast agents. (orig.) [de

Evaluation of renal allograft function early after transplantation with diffusion-weighted MR imaging

Energy Technology Data Exchange (ETDEWEB)

Eisenberger, Ute; Frey, Felix J. [University Hospital of Bern, Department of Nephrology and Hypertension, Bern (Switzerland); Thoeny, Harriet C. [University Hospital of Bern, Department of Radiology, Neuroradiology and Nuclear Medicine, Bern (Switzerland); Binser, Tobias; Boesch, Chris [University Hospital of Bern, Department of Clinical Research, Bern (Switzerland); Gugger, Mathias [University Hospital of Bern, Department of Pathology, Bern (Switzerland); Vermathen, Peter [University Hospital of Bern, Department of Clinical Research, Bern (Switzerland); University Bern, Department of Clinical Research/AMSM, Pavillon 52, Inselspital, P.O. Box 35, Bern (Switzerland)

2010-06-15

To determine the inter-patient variability of apparent diffusion coefficients (ADC) and concurrent micro-circulation contributions from diffusion-weighted MR imaging (DW-MRI) in renal allografts early after transplantation, and to obtain initial information on whether these measures are altered in histologically proven acute allograft rejection (AR). DW-MRI was performed in 15 renal allograft recipients 5-19 days after transplantation. Four patients presented with AR and one with acute tubular necrosis (ATN). Total ADC (ADC{sub T}) was determined, which includes diffusion and micro-circulation contributions. Furthermore, diffusion and micro-circulation contributions were separated, yielding the ''perfusion fraction'' (F{sub P}), and ''perfusion-free'' diffusion (ADC{sub D}). Diffusion parameters in the ten allografts with stable function early after transplantation demonstrated low variabilities. Values for ADC{sub T} and ADC{sub D} were (x 10{sup -5} mm{sup 2}/s) 228 {+-} 14 and 203 {+-} 9, respectively, in cortex and 226 {+-} 16 and 199 {+-} 9, respectively, in medulla. F{sub P} values were 18 {+-} 5% in cortex and 19 {+-} 5% in medulla. F{sub P} values were strongly reduced to less than 12% in cortex and medulla of renal transplants with AR and ATN. F{sub P} values correlated with creatinine clearance. DW-MRI allows reliable determination of diffusion and micro-circulation contributions in renal allografts shortly after transplantation; deviations in AR indicate potential clinical utility of this method to non-invasively monitor derangements in renal allografts. (orig.)

Evaluation of renal allograft function early after transplantation with diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Eisenberger, Ute; Frey, Felix J.; Thoeny, Harriet C.; Binser, Tobias; Boesch, Chris; Gugger, Mathias; Vermathen, Peter

2010-01-01

To determine the inter-patient variability of apparent diffusion coefficients (ADC) and concurrent micro-circulation contributions from diffusion-weighted MR imaging (DW-MRI) in renal allografts early after transplantation, and to obtain initial information on whether these measures are altered in histologically proven acute allograft rejection (AR). DW-MRI was performed in 15 renal allograft recipients 5-19 days after transplantation. Four patients presented with AR and one with acute tubular necrosis (ATN). Total ADC (ADC T ) was determined, which includes diffusion and micro-circulation contributions. Furthermore, diffusion and micro-circulation contributions were separated, yielding the ''perfusion fraction'' (F P ), and ''perfusion-free'' diffusion (ADC D ). Diffusion parameters in the ten allografts with stable function early after transplantation demonstrated low variabilities. Values for ADC T and ADC D were (x 10 -5 mm 2 /s) 228 ± 14 and 203 ± 9, respectively, in cortex and 226 ± 16 and 199 ± 9, respectively, in medulla. F P values were 18 ± 5% in cortex and 19 ± 5% in medulla. F P values were strongly reduced to less than 12% in cortex and medulla of renal transplants with AR and ATN. F P values correlated with creatinine clearance. DW-MRI allows reliable determination of diffusion and micro-circulation contributions in renal allografts shortly after transplantation; deviations in AR indicate potential clinical utility of this method to non-invasively monitor derangements in renal allografts. (orig.)

Extraperitoneal urine leak after renal transplantation: the role of radionuclide imaging and the value of accompanying SPECT/CT - a case report

International Nuclear Information System (INIS)

Son, Hongju; Heiba, Sherif; Kostakoglu, Lale; Machac, Josef

2010-01-01

The differentiation of the nature of a fluid collection as a complication of kidney transplantation is important for management and treatment planning. Early and delayed radionuclide renography can play an important role in the evaluation of a urine leak. However, it is sometimes limited in the evaluation of the exact location and extent of a urine leak. A 71-year-old male who had sudden anuria, scrotal swelling and elevated creatinine level after cadaveric renal transplantation performed Tc-99 m MAG3 renography to evaluate the renal function, followed by an ultrasound which was unremarkable. An extensive urine leak was evident on the planar images. However, an exact location of the urine leak was unknown. Accompanying SPECT/CT images confirmed a urine leak extending from the lower aspect of the transplant kidney to the floor of the pelvic cavity, presacral region and the scrotum via right inguinal canal as well as to the right abdominal wall. Renal scintigraphy is very useful to detect a urine leak after renal transplantation. However, planar imaging is sometimes limited in evaluating the anatomical location and extent of a urine leak accurately. In that case accompanying SPECT/CT images are very helpful and valuable to evaluate the anatomical relationships exactly

Evaluation of renal function using 99mTc-MAG3

International Nuclear Information System (INIS)

Takayama, Teruhiko; Aburano, Tamio; Shuke, Noriyuki

1993-01-01

The utility of 99m Tc-mercaptoacetyltriglycine (MAG3) was studied clinically. In the renography obtained with 99m Tc-MAG3, the abdominal aorta and the common iliac arteries were clearly visualized in the vascular phase. Due to less background activity and high target to background ratio, the quality of 99m Tc-MAG3 image was superior to that of 123 I-OIH or 99m Tc-DTPA image. The parameters on the renogram including T max , T 2/3 , and T 1/2 were compared. The correlation of T max and T 2/3 or T 1/2 were not significant between 99m Tc-MAG3 and 123 I-OIH. Another parameter of C 20 /C max , where C 20 and C max are renal activities at 20 min after injection and at T max respectively, showed an excellent correlation between 99m Tc-MAG3 and 123 I-OIH. Using C 20 /C max , pattern of renogram can be characterized numerically. Concerning the relation between C 20 /C max and renogram pattern, standard renogram pattern showed the C 20 /C max value of less than 0.4, while hypofunctioning pattern showed more than 0.5. The correlation coefficient between the renal uptake of 99m Tc-MAG3 and 123 I-OIH was 0.880 with a correlation plot: 'Y=1.16X-0.043', where X and Y represent renal uptake of 99m Tc-MAG3 and 123 I-OIH, respectively. It can be concluded that 99m Tc-MAG3 is a useful renal imaging agent as an alternative to 123 I-OIH, in order to evaluate the proximal tubular function and calculate ERPF. (author)

Visualization of the renal venous system by renal arteriography with digital subtraction angiography

International Nuclear Information System (INIS)

Nagai, Jun

1989-01-01

The purpose of this study was to obtain vivid and precise images of intrarenal venous branching using DSA for renal arteriography. The type of system used was an ADAC DPS-4100C with 70-80 kVp, and 320 mA, 25-50 msec at 6 frames/sec. The duration was 10 sec and the matrix size was 512x512. In order to retain clear subtracted images of intrarenal venous branching with minimal noise the three frames were selected on the time-density curve of DSA: (Fig.3). 1) a frame on which renal arteries disappear (frame X), 2) the frame with highest renal venous density value as (frame Y), 3) the difference of the nephrogram density between X and Y frames in which only the density of the nephrogram decreases (frame Z). The mask image is the image subtracted by the equation of the weighted averaging method on X and Z frame and is subtracted from the image of Y frame in the final step. By this method, 40 kidneys in 36 patients were studied, and the intrarenal venous branches up to the interlobar vein was clearly demonstrated in 28 of these cases (70%). This method is useful to estimate the extent of intrarenal lesions and detect abnormal renal blood flow compared with conventional temporal subtraction method. (author)

[Utilization of polymeric micelle magnetic resonance imaging (MRI) contrast agent for theranostic system].

Science.gov (United States)

Shiraishi, Kouichi

2013-01-01

We applied a polymeric micelle carrier system for the targeting of a magnetic resonance imaging (MRI) contrast agent. Prepared polymeric micelle MRI contrast agent exhibited a long circulation characteristic in blood, and considerable amount of the contrast agent was found to accumulate in colon 26 solid tumor by the EPR effect. The signal intensities of tumor area showed 2-folds increase in T1-weighted images at 24 h after i.v. injection. To observe enhancement of the EPR effect by Cderiv pretreatment on tumor targeting, we used the contrast agent for the evaluation by means of MRI. Cderiv pretreatment significantly enhanced tumor accumulation of the contrast agent. Interestingly, very high signal intensity in tumor region was found at 24 h after the contrast agent injection in Cderiv pretreated mice. The contrast agent visualized a microenvironmental change in tumor. These results indicate that the contrast agent exhibits potential use for tumor diagnostic agent. To combine with a polymeric micelle carrier system for therapeutic agent, the usage of the combination makes a new concept of "theranostic" for a better cancer treatment.

Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

Energy Technology Data Exchange (ETDEWEB)

King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E. [Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland); Centre for Advanced Medical Imaging (CAMI), St James' s Hospital, Dublin 8 (Ireland); Department of Medical Physics, University of Edinburgh, Edinburgh EH16 4TJ (United Kingdom); Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland)

2011-02-15

Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T{sub 1},T{sub 2}) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast

Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

International Nuclear Information System (INIS)

King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E.

2011-01-01

Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T 1 ,T 2 ) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast to allow