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Sample records for renal imaging agents

  1. Renal perfusion image using harmonic ultrasound with microbble contrast agent: preliminary study

    International Nuclear Information System (INIS)

    Kim, Jung Hoon; Choi, Jae Ho; Han, Dong Chul; Lee, Hi Bahl; Choi, Deuk Lin; Eun, Hyo Won; Lee, Hun Jae

    2003-01-01

    To compare, in terms of their feasibility and normal range, 99m Tc-DTPA renal perfusion imaging and renal perfusion imaging using harmonic ultrasound (US) with a microbubble contrast agent for the evaluation of renal perfusion after renal transplantation. During a six-month period, thirty patients who had received a renal transplant underwent both 99m Tc-DTPA renal perfusion imaging and renal perfusion imaging using harmonic US with a microbubble contrast agent. Sonographic renal perfusion images were obtained before and after a bolus injection of the microbubble contrast agent Levovist TM (SH U 5084; Schering AG, Berlin, Germany) every 3 seconds for 3 minutes. Sonographic renal perfusion images were converted into a renal perfusion curve by a computer program and T peak of the curve thus obtained was compared with that of the 99m Tc-DTPA curve. Average T peak of the 99m Tc-DTPA renal perfusion curve was 16.2 seconds in the normal group and 39.6 seconds in the delayed perfusion group, while average T peak of the sonographic renal perfusion curve was 23.7 seconds and 46.2 seconds, respectively. T peak of the sonographic renal perfusion curve showed a good correlation with that of the 99m Tc-DTPA curve (correlation coefficient=0.8209; p=0.0001). The cut-off value of T peak of the sonographic renal perfusion curve was 35 seconds (sensitivity=90%, specificity=95%). In patients who have received a renal transplant, the findings of renal perfusion imaging using harmonic US with a microbubble contrast agent show close correlation with those of 99m Tc-DTPA renal perfusion imaging. The optimal cut-off value of T peak of the sonographic renal perfusion curve was 35 seconds

  2. Technetium-99m-dimethylglyoxime ([sup 99m]Tc-DMG) as renal imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Adonaylo, V.N. (Buenos Aires Univ. (Argentina). Facultad de Ciencias Exactas y Naturales Buenos Aires Univ. (Argentina). Dept. de Ciencias Biologicas); Stahl, Adriana; Pomilio, A.B.; Vitale, A.A. (Buenos Aires Univ. (Argentina). Facultad de Ciencias Exactas y Naturales); Canellas, C.O. (Buenos Aires Univ. (Argentina). Facultad de Ciencias Exactas y Naturales Comision Nacional de Energia Atomica, Buenos Aires (Argentina))

    1993-06-01

    Dimethylglyoxime (DMG) labelled with [sup 99m]Tc is presented as a renal imaging agent. The behaviour of this complex was analysed at different pH by means of UV spectral data and using DMG-calcium chloride as a reference complex. Biokinetic data were evaluated in two biological models, Sprague-Dawley rats and Didelphis albiventris argentine opossum. Biodistribution in rats demonstrated fast and specific renal excretion. Time-activity values over both kidneys could be quantified for this complex. Renographic studies led to mean time-to maximum values on twelve assays of 2.0 [+-] 0.1 min and a mean relative function of 53.0 [+-] 2.3 and 47.0 [+-] 3.2 for right and left kidneys, respectively. [sup 99m]Tc-DMG showed specificity for the renal excretion pathway and therefore seems to be a very useful radiopharmaceutical for renal function studies. (Author).

  3. Preparation and evaluation of 68Ga-ECC as a PET renal imaging agent

    International Nuclear Information System (INIS)

    Mizaei, Alireza; Jaililan, Amir Reza; Mazidi, Mohammad; Aghanejad, Ayuob; Yousefnia, Hassan; Shabani, Gholamli; Ardaneh, Khosro; Geramifar, Patham; Beiki, Davood

    2015-01-01

    Development of a gallium-68-labeled renal tracer can be a good substitute for Tc-99m, a known SPECT tracer. In this study, effort was made to develop 68 Ga-ethylenecysteamine cysteine ( 68 Ga-ECC). Ga-ECC was prepared using generator-based 68 GaCl3 and ethylenecysteamine cysteine (ECC) at optimized conditions. Stability of the complex was checked in human serum followed by partition coefficient determination of the tracer. The biodistribution of the tracer in rats was studied using tissue counting and PET/CT imaging up to 120 min. Ga-ECC was prepared at optimized conditions in 15 min at 90 °C (radiochemical purity ≈97 ± 0.88 % ITLC, >99 % HPLC, specific activity: 210 ± 5 GBq/mM). 68 Ga-ECC was a water-soluble complex based on partition coefficient data (log P; −1.378) and was stable in the presence of human serum for 2 h at 37 °C. The biodistribution of the tracer demonstrated high kidney excretion of the tracer in 10–20 min. The SUV max ratios of the liver to left kidney were 0.38 and 0.39 for 30 and 90 min, respectively, indicating high kidney uptake. Initial biodistribution results showed significant kidney and urinary excretion of the tracer comparable to that of the homologous 99m Tc compound. The complex could be a possible PET kidney imaging agent with a fast imaging time

  4. Preparation and evaluation of {sup 68}Ga-ECC as a PET renal imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Mizaei, Alireza; Jaililan, Amir Reza; Mazidi, Mohammad; Aghanejad, Ayuob; Yousefnia, Hassan; Shabani, Gholamli; Ardaneh, Khosro [Radiation Application Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Geramifar, Patham; Beiki, Davood [Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2015-09-15

    Development of a gallium-68-labeled renal tracer can be a good substitute for Tc-99m, a known SPECT tracer. In this study, effort was made to develop {sup 68}Ga-ethylenecysteamine cysteine ({sup 68}Ga-ECC). Ga-ECC was prepared using generator-based {sup 68}GaCl3 and ethylenecysteamine cysteine (ECC) at optimized conditions. Stability of the complex was checked in human serum followed by partition coefficient determination of the tracer. The biodistribution of the tracer in rats was studied using tissue counting and PET/CT imaging up to 120 min. Ga-ECC was prepared at optimized conditions in 15 min at 90 °C (radiochemical purity ≈97 ± 0.88 % ITLC, >99 % HPLC, specific activity: 210 ± 5 GBq/mM). {sup 68}Ga-ECC was a water-soluble complex based on partition coefficient data (log P; −1.378) and was stable in the presence of human serum for 2 h at 37 °C. The biodistribution of the tracer demonstrated high kidney excretion of the tracer in 10–20 min. The SUV{sub max} ratios of the liver to left kidney were 0.38 and 0.39 for 30 and 90 min, respectively, indicating high kidney uptake. Initial biodistribution results showed significant kidney and urinary excretion of the tracer comparable to that of the homologous {sup 99m}Tc compound. The complex could be a possible PET kidney imaging agent with a fast imaging time.

  5. A phase 2 clinical study of 99mTc-MAG3 injectable, a dynamic renal imaging agent

    International Nuclear Information System (INIS)

    Torizuka, Kanji; Yamamoto, Kazutaka; Nishibuchi, Shigeo; Ishibashi, Akira; Ikekubo, Katsuji.

    1993-01-01

    A phase 2 clinical study of 99m Tc-mercapto acetyl glycylglycylglycine ( 99m Tc-MAG3) injectable, a new dynamic renal imaging agent, was performed in 110 patients with renal and/or urinary disorders to evaluate the safety, efficacy and optimal dose of this agent. Neither adverse reactions nor abnormal laboratory findings due to intravenous administration of 99m Tc-MAG3 were observed. The investigators evaluated the clinical efficacy of 99m Tc-MAG3 was to be effective in 96 of 97 cases. Among the doses of 92.5 MBq, 370 MBq and 555 MBq, the dose of 92.5 MBq was not large enough to provide adequate-quality blood flow images or reliable information for evaluation of the renal blood flow. It was concluded that the optimal dose range of 99m Tc-MAG3 was 185-555 MBq with 370 MBq as the standard dose. Also, we summarize that 555 MBq is especially recommendable when detailed blood flow information is required. These results indicate that 99m Tc-MAG3 injectable is useful for the diagnosis of renal and urinary disorders. (author)

  6. 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)

  7. Imaging of renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Jevtic, V. E-mail: vladimir.jevtic@mf.uni-lj.si

    2003-05-01

    Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination.

  8. Imaging of renal osteodystrophy

    International Nuclear Information System (INIS)

    Jevtic, V.

    2003-01-01

    Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination

  9. 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

  10. Imaging of Renal Leiomyomas

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    Derchi, L. E.; Grenier, N.; Heinz-Peer, G.; Dogra, V.; Franco, F.; Rollandi, G. A.; Deminiere, C. (Radiologia - DICMI, Univ. di Genova, Genova (Italy))

    2008-09-15

    Background: Renal leiomyomas are rare benign tumors of the kidney which can be found at autopsy as small capsular nodules in about 5% of cases. The clinical incidence of such lesions is much smaller, and only case reports or small series have been reported in the imaging literature. Purpose: To describe the imaging characteristics observed in a series of eight patients with pathology-proven asymptomatic leiomyomas of the kidney. Material and Methods: We reviewed the imaging findings observed in eight patients with pathologically proven asymptomatic renal leiomyomas discovered during studies performed for reasons unrelated to the kidney. All patients had undergone computed tomography (CT), two ultrasonography, and one magnetic resonance imaging (MRI). Results: Lesions ranged in size from 1.2 to 13 cm. Six were at the periphery of the kidney, compressed its outer surface, but did not cause disruption of the cortex; two involved the renal cortex. All had regular outer margins. A cleavage plane between the tumor and the kidney was revealed at CT and/or ultrasonography in three of the cases located at the periphery. At ultrasonography, leiomyomas appeared hypoechogenic. At CT, they were slightly hyperdense before contrast medium injection; all were hypodense to the renal cortex after contrast medium. Four were homogeneous, two were slightly heterogeneous, and the remaining two were frankly heterogeneous. The lesion studied by MRI, which was homogeneous at the postcontrast CT study, had a heterogeneous structure on both T1- and T2-weighted images, with internal areas of hypointensity on T1. Conclusion: There are some imaging findings that can help to suggest the diagnosis of renal leiomyomas. First, their density: all tumors examined before contrast were hyperdense to the kidney, with density similar to that of muscles, and all had lower enhancement than the adjacent renal parenchyma. Second, the location and margins of the tumors: most were peripheral, without

  11. Extensive extraosseous localization of bone imaging agent in a patient with renal failure and rhabdomyolysis accompanied by combined hypercalcemia and hyperphosphatemia

    International Nuclear Information System (INIS)

    Shih, W.J.; Flueck, J.; O'Connor, W.; Domstad, P.A.

    1989-01-01

    Four sequential Tc-99m pyrophosphate (PYP) imaging studies were performed in a 28-year-old man with high fever and exudate pharyngitis associated with renal failure. Radiotracer localization in the left ventricle (LV), lungs, kidneys, and skeletal muscles were seen in two, initial imaging studies. In the second and third imaging studies, area of increase in activity was seen in the left-sided bowel. In studies done two months later (in the third study), the radioactivity in the skeletal muscles was no longer seen. Studies obtained nine months (in the fourth study) after the first imaging showed less radiotracer localization in the LV, lungs, and kidneys as compared to that seen in the initial study. Myocardial necrosis and microcalcification were proved by LV biopsy. The exact mechanism of extraosseous bone-imaging agent localization is unknown. However, this phenomenon may be related to renal failure, rhabdomyolysis, hypercalcemia, hyperphosphatemia, or elevated parathyroid hormone. The Tc-99m PYP imaging study is useful and sensitive in the detection of extraosseous tissue calcification and monitoring of the disease process

  12. Graphene Oxide/Ag Nanoparticles Cooperated with Simvastatin as a High Sensitive X-Ray Computed Tomography Imaging Agent for Diagnosis of Renal Dysfunctions.

    Science.gov (United States)

    Li, Zhan; Tian, Longlong; Liu, Jianli; Qi, Wei; Wu, Qiang; Wang, Haijing; Ali, Mohammad Chand; Wu, Wangsuo; Qiu, Hongdeng

    2017-09-01

    Graphene oxides (GO) are attracting much attention in the diagnosis and therapy of the subcutaneous tumor as a novel biomaterial, but its diagnosis to tissue dysfunction is yet to be found. Here, a novel application of GO for diagnosis of renal dysfunction via contrast-enhanced computed tomography (CT) is proposed. In order to serve as contrast-enhanced agent, Ag nanoparticles (AgNPs) are composited on the surface of GO to promote its X-ray absorption, and then simvastatin is coinjected for eliminating in vivo toxicity induced by AgNPs. It is found that GO/AgNPs can enhance the imaging of CT into the lung, liver, and kidney of mice for a long circulation time (≈24 h) and a safety profile in vivo in the presence of simvastatin. Interestingly, the lower dose of GO/AgNPs (≈0.5 mg per kg bw) shows an excellent performance for CT imaging of renal perfusion, and visually exhibits the right renal dysfunction in model mice. Hence, this work suggests that graphene nanoparticles will play a vital role for the future medical translational development including drug carrier, biosensing, and disease therapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 99mTc renal tubular function agents: Current status

    International Nuclear Information System (INIS)

    Eshima, D.; Fritzberg, A.R.; Taylor, A. Jr.

    1990-01-01

    Orthoiodohippuric (OIH) acid labeled with 131I is a widely used renal radiopharmaceutical agent and has been the standard radiopharmaceutical agent for the measurement of effective renal plasma flow (EPRF). Limitations to the routine clinical use of 131I OIH are related to the suboptimal imaging properties of the 131I radionuclide and its relatively high radiation dose. 123I has been substituted for 131I; however, its high cost and short shelf-life have limited its widespread use. Recent work has centered on the development of a new 99mTc renal tubular function agent, which would use the optimal radionuclidic properties and availability of 99mTc and combine the clinical information provided by OIH. The search for a suitable 99mTc renal tubular function agent has focused on the diamide dithiolate (N2S2), the paraaminohippuric iminodiacetic acid (PAHIDA), and the triamide mercaptide (N3S) donor ligand systems. To date, the most promising 99mTc tubular function agent is the N3S complex: 99mTc mercaptoacetyltriglycine (99mTc MAG3). Studies in animal models in diuresis, dehydration, acid or base imbalance, ischemia, and renal artery stenosis demonstrate that 99mTc MAG3 behaves similarly to 131I OIH. A simple kit formulation is available that yields the 99mTc MAG3 complex in high radiochemical purity. Studies in normal subjects and patients indicate that 99mTc MAG3 is an excellent 99mTc renal tubular agent, but its plasma clearance is only 50% to 60% that of OIH. In an effort to develop an improved 99mTc renal tubular function agent, changes have been made in the core N3S donor ligand system, but to date no agent has been synthesized that is clinically superior to 99mTc MAG3. 61 references

  14. Absolute quantification of regional renal blood flow in swine by dynamic contrast-enhanced magnetic resonance imaging using a blood pool contrast agent.

    Science.gov (United States)

    Lüdemann, Lutz; Nafz, Benno; Elsner, Franz; Grosse-Siestrup, Christian; Meissler, Michael; Kaufels, Nicola; Rehbein, Hagen; Persson, Pontus B; Michaely, Henrik J; Lengsfeld, Philipp; Voth, Matthias; Gutberlet, Matthias

    2009-03-01

    To evaluate for the first time in an animal model the possibility of absolute regional quantification of renal medullary and cortical perfusion by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a blood pool contrast agent. A total of 18 adult female pigs (age, 16-22 weeks; body weight, 45-65 kg; no dietary restrictions) were investigated by DCE-MRI. Absolute renal blood flow (RBF) measured by an ultrasound transit time flow probe around the renal vein was used as the standard of reference. An inflatable stainless cuff placed around the renal artery near its origin from the abdominal aorta was used to reduce RBF to 60%, 40%, and 20% of the baseline flow. The last measurement was performed with the cuff fully reopened. Absolute RBF values during these 4 perfusion states were compared with the results of DCE-MRI performed on a 1.5-T scanner with an 8-channel phased-array surface coil. All scans were acquired in breath-hold technique in the coronal plane using a field of view of 460 mm.Each dynamic scan commenced with a set of five 3D T1-weighted gradient echo sequences with different flip angles (alpha = 2 degrees, 5 degrees, 10 degrees, 20 degrees, 30 degrees): TE, 0.88 milliseconds; TR, 2.65 milliseconds; slice thickness, 8.8 mm for 4 slices; acquisition matrix, 128 x 128; and acquisitions, 4. These data served to calculate 3D intrinsic longitudinal relaxation rate maps (R10) and magnetization (M0). Immediately after these images, the dynamic 3D T1-weighted gradient echo images were acquired with the same parameters and a constant alpha = 30 degrees, half Fourier, 1 acquisition, 64 frames, a time interval of 1.65 seconds between each frame, and a total duration of 105.6. Three milliliters of an albumin-binding blood pool contrast agent (0.25 mmol/mL gadofosveset trisodium, Vasovist, Bayer Schering Pharma AG, Berlin, Germany) was injected at a rate of 3 mL/s. Perfusion was calculated using the arterial input function from the aorta, which was

  15. 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

  16. 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

  17. 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

  18. Blood oxygenation level dependent (BOLD). Renal imaging. Concepts and applications

    International Nuclear Information System (INIS)

    Nissen, Johanna C.; Haneder, Stefan; Schoenberg, Stefan O.; Michaely, Henrik J.

    2010-01-01

    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 * -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.)

  19. 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.)

  20. Magnetic resonance imaging in the staging of renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kishi, Hiroichi; Umeda, Takashi; Niijima, Tadao; Yashiro, Naobumi; Kawabe, Kazuki

    1987-07-01

    Eighteen patients with renal neoplasm underwent magnetic resonance imaging (MRI) using a 1.5 Tesla superconducting magnetic system and spin echo images were obtained by quick scan technique under holding breath. MR images were interpreted independently of the computerized tomography (CT) findings. The preoperative stagings of the 18 renal carcinomas, as judged by MRI, were compared with those obtained at laparotomy. The anatomic staging was correctly performed by MRI in 13 patients (72 %). In the patients who had intrarenal small tumor with normal renal contour, MRI demonstrated a solid mass clearly distinguishable from surrounding renal parenchyma using the paramagnetic contrast agent (gadolinium-DTPA). When compared with results of evaluation by CT in staging, MRI appeared to have several advantages in determination of whole mass; the detection of tumor thrombus into renal vein and inferior vena cava; and the evaluation of direct tumor invasion of adjacent organs. MRI should play an important role in the staging of renal cell carcinoma.

  1. Magnetic resonance imaging in the staging of renal cell carcinoma

    International Nuclear Information System (INIS)

    Kishi, Hiroichi; Umeda, Takashi; Niijima, Tadao; Yashiro, Naobumi; Kawabe, Kazuki

    1987-01-01

    Eighteen patients with renal neoplasm underwent magnetic resonance imaging (MRI) using a 1.5 Tesla superconducting magnetic system and spin echo images were obtained by quick scan technique under holding breath. MR images were interpreted independently of the computerized tomography (CT) findings. The preoperative stagings of the 18 renal carcinomas, as judged by MRI, were compared with those obtained at laparotomy. The anatomic staging was correctly performed by MRI in 13 patients (72 %). In the patients who had intrarenal small tumor with normal renal contour, MRI demonstrated a solid mass clearly distinguishable from surrounding renal parenchyma using the paramagnetic contrast agent (gadolinium-DTPA). When compared with results of evaluation by CT in staging, MRI appeared to have several advantages in determination of whole mass; the detection of tumor thrombus into renal vein and inferior vena cava; and the evaluation of direct tumor invasion of adjacent organs. MRI should play an important role in the staging of renal cell carcinoma. (author)

  2. /sup 99m/Tc penicillamine: a renal cortical scanning agent

    International Nuclear Information System (INIS)

    Taylor, A.; Davis, G.; Halpern, S.; Ashburn, W.

    1977-01-01

    /sup 99m/Technetium penicillamine, a renal cortical imaging agent, can be used to provide a rapid, safe and non-invasive assessment of renal morphology and the renal vascular supply. Since this agent is not excreted significantly during the imaging procedure cortical scans of high quality can be obtained without image deterioration owing to a superimposed collecting system. These scans, which are clearly superior in anatomical detail to earlier scans using 131 I hippuran, can be obtained along with the 131 I hippuran renogram when the patient comes to the nuclear medicine department. Herein we demonstrate the anatomical detail it is now possible to achieve by presenting the cortical renal scans and accompanying radiograms from 5 patients with different renal pathology

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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.)

  9. 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

  10. 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.

  11. 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

  12. Renal enhancement and excretion of the hepatobiliary contrast agent Gd-EOB-DTPA

    International Nuclear Information System (INIS)

    Zangos, S.; Hammerstingl, R.; Mack, M.G.; Straub, R.; Engelmann, K.; Eichler, K.; Vogl, T.J.

    2001-01-01

    Purpose: To evaluate the clinical value of the renal clearance using MR imaging with different doses of gadolinium ethoxybenzyl-DTPA (Gd-EOB-DTPA) in comparison to gadolinium DTPA (Gd-DTPA). Material and Methods: In a double-blind and randomized clinical phase II study. MR imaging at 1.5 T was performed in 61 patients with five different doses of Gd-EOB-DTPA (3, 6, 12.5, 25 and 50 μmol/kg b.w. as a bolus injection). The study protocol comprised T 1 - and T 2 -weighted spin-echo magnetic resonance and two-dimensional fast low-angle shot imaging before and at increasing intervals for up to 45 min after injection of Gd-EOB-DTPA. These images were compared with Gd-DTPA-enhanced imaging (0.1 mmol/kg b. w. as a bolus injection). Results: After bolus injection of the hepatobiliary MR contrast agent Gd-EOB-DTPA a renal elimination was observed. Immediately after the injection of Gd-EOB-DTPA until the eighth minute a corticomedullary enhancement of the kidney was conspicuous. After the fourth minute a contrast enhancement could be seen in the renal pelvis. The best enhancement was noted after 20 minutes in the FLASH GRE and T 1 -weighted images with good pelvicaliceal contrast. After 45 minutes an outflow of Gd-EOB-DTPA into the ureter could be observed. Conclusion: In addition to the hepatobiliary secretion Gd-EOB-DTPA appears useful for the evaluation of renal structures and renal function on account of the renal excretion without diuretic preparation of the patients. (orig.) [de

  13. 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.)

  14. 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

  15. 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

  16. 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

  17. 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...

  18. Immediate renal imaging and renography with /sup 99m/Tc methylene diphosphonate to assess renal blood flow, excretory function, and anatomy

    International Nuclear Information System (INIS)

    Glass, E.C.; DeNardo, G.L.; Hines, H.H.

    1980-01-01

    /sup 99m/Tc methylene diphosphonate (/sup 99m/Tc MDP) was evaluated as a clinical renal imaging agent in 20 patients referred for bone scintigraphy. Sequential scintigraphy, which was started immediately after injection, yielded blood flow studies of high quality, and subsequent images accurately delineated renal anatomy and excretion in nonazotemic patients. In comparison with delayed images, early images were vastly superior in quality and demonstrated improved target-to-nontarget activity ratios (p < 0.001) and improved lesion detectability (p < 0.01). Renal imaging performed incidental to bone scintigraphy with MDP can be greatly enhanced by initiating sequential scintigraphy immediately after injection

  19. Rhenium(V) oxo complexes relevant to technetium renal imaging agents derived from mercaptoacetylglycylglycylaminobenzoic acid isomers. Structural and molecular mechanics studies

    International Nuclear Information System (INIS)

    Hansen, L.; Taylor, A. Jr; Marzilli, L.G.; Cini, R.

    1992-01-01

    The synthesis and characterization of three rhenium(V) oxo complexes derived from isomers of mercaptoacetylglycylglycylaminobenzoic acid (MAG 2 -ABAH 5 ) are reported. The isomers were synthesized from o-, m- and p-aminobenzoic acid and differed in the position of the terminal carboxyl group. The anions of 8-10, [ReO(MAG 2 -*ABAH)] - (* = para (8), meta (9), ortho (10)), contained the tetraanionic form of the ligands with the carboxyl group protonated. Compounds 8,9, and 10 were synthesized by exchange reactions of ReOCl 3 (Me 2 SO)(Ph 3 P) under moderate conditions and were isolated as [Ph 4 P] + , [Bu 4 N] + , and [Ph 4 P] + salts, respectively. The structures of 8 and 10 were determined by X-ray diffraction methods; except for the location of the carboxyl group, the structures are similar. The coordination geometry is pseudo square pyramidal, with nitrogen and sulfur donor atoms forming a square base and the oxo ligand at the apex. The orientation of the carboxyl group in 10 is anti to the Re double-bond O group. Since the carboxyl groups are protonated in 8 and 10 and in other relevant structures from this class of radiopharmaceuticals including [Ph 4 As][TcO(MAG 3 H)] (MAG 3 H = tetraanionic form of mercaptoacetyltriglycine), the authors developed molecular mechanics parameters that allowed them to calculate the structures of 8, 10, and [TcO(MAG 3 H)] - . They then extended the calculations to all three isomeric complexes in their deprotonated forms and to [TcO(MAG 3 )] 2- in order to approximate their solution phase structures. They conclude that the [TcO(MAG 3 )] 2- species is conformationally flexible, and they have made an initial assessment of structures vs renal clearance

  20. Radiologic imaging of the renal parenchyma structure and function.

    Science.gov (United States)

    Grenier, Nicolas; Merville, Pierre; Combe, Christian

    2016-06-01

    Radiologic imaging has the potential to identify several functional and/or structural biomarkers of acute and chronic kidney diseases that are useful diagnostics to guide patient management. A renal ultrasound examination can provide information regarding the gross anatomy and macrostructure of the renal parenchyma, and ultrasound imaging modalities based on Doppler or elastography techniques can provide haemodynamic and structural information, respectively. CT is also able to combine morphological and functional information, but the use of CT is limited due to the required exposure to X-ray irradiation and a risk of contrast-induced nephropathy following intravenous injection of a radio-contrast agent. MRI can be used to identify a wide range of anatomical and physiological parameters at the tissue and even cellular level, such as tissue perfusion, oxygenation, water diffusion, cellular phagocytic activity, tissue stiffness, and level of renal filtration. The ability of MRI to provide valuable information for most of these parameters within a renal context is still in development and requires more clinical experience, harmonization of technical procedures, and an evaluation of reliability and validity on a large scale.

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. 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....

  6. 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)

  7. 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

  8. 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

  9. 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.

  10. Stable agents for imaging investigations

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    This invention concerns highly stable compounds useful in preparing technetium 99m based scintiscanning exploration agents. The compounds of this invention include a pertechnetate reducing agent or a solution of oxidized pertechnetate and an efficient proportion, sufficient to stabilize the compounds in the presence of oxygen and of radiolysis products, of ascorbic acid or a pharmaceutically acceptable salt or ester of this acid. The invention also concerns a perfected process for preparing a technetium based exploration agent, consisting in codissolving the ascorbic acid or a pharmaceutically acceptable salt or ester of such an acid and a pertechnetate reducing agent in a solution of oxidized pertechnetate [fr

  11. 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

  12. 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

  13. 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...

  14. 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.)

  15. 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.)

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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'.

  1. 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

  2. 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

  3. 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...

  4. 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)

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.)

  10. 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

  11. 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

  12. 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.)

  13. 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.

  14. 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.

  15. 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.)

  16. Nanoparticles as image enhancing agents for ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. 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)

  18. 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

  19. 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

  20. Synchrotron-based DEI for bio-imaging and DEI-CT to image phantoms with contrast agents

    International Nuclear Information System (INIS)

    Rao, Donepudi V.; Swapna, Medasani; Cesareo, Roberto; Brunetti, Antonio; Akatsuka, Tako; Yuasa, Tetsuya; Zhong, Zhong; Takeda, Tohoru; Gigante, Giovanni E.

    2012-01-01

    The introduction of water, physiological, or iodine as contrast agents is shown to enhance minute image features in synchrotron-based X-ray diffraction radiographic and tomographic imaging. Anatomical features of rat kidney, such as papillary ducts, ureter, renal artery and renal vein are clearly distinguishable. Olfactory bulb, olfactory tact, and descending bundles of the rat brain are visible with improved contrast. - Highlights: ► Distinguishable anatomical structures features of rat kidney and rat brain are acquired with Sy-DEI in planar mode. ► Images of a small brain phantom and cylindrical phantom are acquired in tomography mode (Sy-DEI-CT) with contrast agents. ► Sy-DEI and Sy-DEI-CT techniques provide new source of information related to biological microanatomy.

  1. 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

  2. Quantitation of renal function with glomerular and tubular agents

    International Nuclear Information System (INIS)

    Dubovsky, E.V.; Russell, C.D.

    1982-01-01

    Quantitative methods to measure the glomerular and tubular function of the kidneys with radionuclides have been available for many years. They have not been widely used because the techniques and the calculations exceeded the scope of routine nuclear medicine practice. Validation of simplified methods and the introduction of computer technology have made measurement of the effective renal plasma flow (ERPF) and the glomerular filtration rate (GFR) simple enough so that they can be performed reproducibly in most nuclear medicine departments. The estimation of ERPF with radioiodinated OIH and GFR with /sup 99m/TcDTPA can be achieved in many ways, all of which yield clinically useful results. How to get the best results using the simplest methods is still unclear. The required accuracy depends on the intended clinical use. Our preference at the present time is to use a single or double plasma sample to calculate global ERPF or GFR, and to use the 1-2 min OIH or 1-3 min Tc-DTPA uptake to calculate relative function of the two kidneys (split function ERPF or GFR). The choice of method will be influenced by local factors, such as the nature of the patient population, the case volume, and the resources available. A desirable goal for future studies is to document carefully the capabilities and limitations of each alternative method, so that the choice can be rational

  3. 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.)

  4. 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.)

  5. 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.)

  6. 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)

  7. 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

  8. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. 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

  11. 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

  12. 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)

  13. 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.)

  14. 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

  15. Renal fine structures detected by NMR imaging

    International Nuclear Information System (INIS)

    Zilch, H.G.

    1986-01-01

    A significantly improved image quality is achieved by the technique described, as compared to the magnetic resonance data obtained so far. The detailed analysis of the kidney goes as deep as into anatomic fine structures, and there is reason to hope for far better diagnostic details. (orig.) [de

  16. 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

  17. 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.

  18. 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

  19. 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)

  20. Comparison of several potential myocardial imaging agents

    International Nuclear Information System (INIS)

    Watson, E.E.; Stabin, M.G.; Goodman, M.M.; Knapp, F.F. Jr.; Srivastava, P.C.

    1985-01-01

    Although myocardial imaging is currently dominated by Tl-201, several alternative agents with improved physiologic or radionuclidic properties have been proposed. Based on human and animal studies in the literature, the metabolism of several of these compounds was studied for the purpose of generating radiation dose estimates. Dose estimates are listed for several I-123 labeled free fatty acids, an I-123 labeled phosphonium compound, Rb-82, Cu-64, F-18 FDG (all compounds which are taken up by the normal myocardium), and for Tc-99m pyrophosphate (PYP) (which localizes in myocardial infarcts). Dose estimates could not be generated for C-11 palmitate, but this compound was included in a comparison of myocardial retention times. For the I-123 labeled compounds, I-124 was included as a contaminant in generating the dose estimates. Radiation doses were lowest for Rb-82 (gonads 0.3 to 0.5 μGy/MBq, heart wall 15 μGy/MBq). Doses for the I-123 labeled fatty acids were similar to one another, with IPPA being the lowest (gonads 20 μGy/MBq, heart wall 15 μGy/MBq). Doses for Tc-99m PYP were also low (gonads 4 to 7 μGy/MBq, heart wall 4 μGy/MBq, skeleton 15 μGy/MBq). The desirability of these compounds is discussed briefly, considering half life, imaging mode and energy, and dosimetry, including a comparison of the effective whole body dose equivalents. 34 refs., 11 tabs

  1. 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

  2. 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.)

  3. 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.

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  6. 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 ...

  7. 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.

  8. Radiolabelled spiroperidol: Possible pituitary adenoma imaging agent

    International Nuclear Information System (INIS)

    Otto, C.A.; Marshall, J.C.; Lloyd, R.V.; Sherman, P.S.; Wieland, D.M.

    1984-01-01

    Prolactin-secreting pituitary adenomas are the most common type of pituitary tumors. Detection currently depends on physical symptoms, elevated serum prolactin levels and CT scans. An imaging agent which specifically localized in prolactinomas based on some functional characteristic of the tumor would be of considerable clinical value not only for early detection but also for monitoring of therapy. Tritiated spiroperidol ( 3 H-Sp) was selected for evaluation based on 1) the presence of D-2 receptors in normal anterior pituitary and adenoma tissue and 2) the high affinity of spiroperidol for D-2 receptors. Recent data have established that implantation of diethylstilbestrol (DES) in Fischer F344 rats induced prolactin-secreting tumors in the pituitary. 3 HSp was evaluated in pituitary tissue of both control and DES-treated rats. 3 HSp concentration in normal female anterior pituitary tissue was found to be about 0.27% kg dose/g from 5 min to 4hrs. This value was about 10 times levels in cortex, cerebellum and striatum. In DES-treated rats the % kg dose/g values remained approximately the same. A 5-fold increase in serum prolactin was associated with a 6-fold increase in both pituitary weight and % dose/organ. The data suggests that although total pituitary weight has increased due to tumor growth (reflected in increased values for % dose/organ), the relative number of receptors per g of tissue has remained constant. This result is in agreement with observations of others on D-2 receptor concentration in prolactinomas

  9. 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.

  10. 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.)

  11. 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)

  12. 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.)

  13. Renal imaging in paediatrics; Nuklearmedizinische Nierendiagnostik in der Paediatrie

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. 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)

  15. 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.)

  16. 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

  17. 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

  18. 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.

  19. 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

  20. Development of a Multifaceted Ovarian Cancer Therapeutic and Imaging Agent

    National Research Council Canada - National Science Library

    Markland, Francis S

    2008-01-01

    ...%. This project outlines the development of a recombinant version of a member of a class of proteins known as disintegrins as an innovative imaging and diagnostic agent for ovarian cancer (OC). Vicrostatin (VN...

  1. Quinone-fused porphyrins as contrast agents for photoacoustic imaging

    KAUST Repository

    Banala, Srinivas; Fokong, Stanley; Brand, Christian; Andreou, Chrysafis; Krä utler, Bernhard; Rueping, Magnus; Kiessling, Fabian

    2017-01-01

    Photoacoustic (PA) imaging is an emerging non-invasive diagnostic modality with many potential clinical applications in oncology, rheumatology and the cardiovascular field. For this purpose, there is a high demand for exogenous contrast agents

  2. 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

  3. 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.)

  4. 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)

  5. 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...

  6. 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.

  7. Cardiac image segmentation for contrast agent videodensitometry

    NARCIS (Netherlands)

    Mischi, M.; Kalker, A.A.C.M.; Korsten, H.H.M.

    2005-01-01

    Indicator dilution techniques are widely used in the intensive care unit and operating room for cardiac parameter measurements. However, the invasiveness of current techniques represents a limitation for their clinical use. The development of stable ultrasound contrast agents allows new applications

  8. 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.

  9. 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

  10. 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.)

  11. 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.

  12. 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

  13. 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)

  14. 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

  15. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. 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

  18. 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.

  19. 64Cu loaded liposomes as positron emission tomography imaging agents

    DEFF Research Database (Denmark)

    Petersen, Anncatrine Luisa; Binderup, Tina; Rasmussen, Palle

    2011-01-01

    applicable as PET imaging agents. We show the utility of the 64Cu-liposomes for quantitative in vivo imaging of healthy and tumor-bearing mice using PET. This remote loading method is a powerful tool for characterizing the in vivo performance of liposome based nanomedicine, and has great potential...

  20. 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.

  1. 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.

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  4. Evaluation of renal transplant perfusion by functional imaging

    International Nuclear Information System (INIS)

    Nicoletti, R.

    1990-01-01

    Radionuclide angiography (RNA) is used as a noninvasive method for the evaluation of renal transplant perfusion. The computer processing method generally used, based on regions of interest, is unsatisfactory because it does not permit the regional differentiation of perfusion defects. Furthermore, the subjective delineation of the regions of interest introduces considerable inter-observer variation of results. We developed a processing method which is less operator-dependent and permits the evaluation of local defects; it is based on the concept of functional imaging. The method was evaluated in 62 patient examinations, which were subdivided into four groups: Normal transplant perfusion (23 examinations), acute tubular necrose (ATN) (16), cellular rejection (13), and vascular rejection (10). Quantitative results derived from profile curves were combined with visual estimation of the functional images and yielded a synoptic graph which allowed differentiation into three groups: Normal transplant perfusion (sensitivity 0.78, specificity 0.97), ATN or cellular rejection (sens. 0.83, spec. 0.82), and vascular rejection (sens. 0.90, spec. 0.92). (orig.)

  5. 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.

  6. 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.

  7. 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

  8. The role of erythropoiesis stimulating agents and intravenous (IV) iron in the cardio renal anemia syndrome.

    Science.gov (United States)

    Silverberg, Donald S

    2011-11-01

    Anemia is common in Congestive Heart Failure (CHF) and is associated with an increased mortality, morbidity and progressive renal failure. The most common causes of the anemia in CHF are (1) the associated Chronic Kidney Disease (CKD), which causes depression of erythropoietin (EPO) production in the kidney, and (2) excessive cytokine production in CHF, which can cause both depression of erythropoietin production in the kidney and depression of erythropoietin response in the bone marrow. The cytokines can also induce iron deficiency by increasing hepcidin production from the liver, which both reduces gastrointestinal iron absorption and reduces iron release from iron stores located in the macrophages and hepatocytes. It appears that iron deficiency is very common in CHF and is rarely recognized or treated. The iron deficiency can cause a thrombocytosis that might contribute to cardiovascular complications in both CHF and CKD and is reversible with iron treatment. Thus, attempts to control this anemia in CHF will have to take into consideration both the use of both Erythropoiesis Stimulating Agents (ESA) such as EPO and oral and, probably more importantly, intravenous (IV) iron. Many studies of anemia in CHF with ESA and oral or IV iron and even with IV iron without ESA have shown a positive effect on hospitalization, New York Heart Association functional class, cardiac and renal function, quality of life, exercise capacity and reduced Beta Natriuretic Peptide and have not demonstrated an increase in cardiovascular damage related to the therapy. However, adequately powered long-term placebo-controlled studies of ESA and of IV iron in CHF are still needed and are currently being carried out.

  9. 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.

  10. 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.)

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Fluorescence Imaging/Agents in Tumor Resection.

    Science.gov (United States)

    Stummer, Walter; Suero Molina, Eric

    2017-10-01

    Intraoperative fluorescence imaging allows real-time identification of diseased tissue during surgery without being influenced by brain shift and surgery interruption. 5-Aminolevulinic acid, useful for malignant gliomas and other tumors, is the most broadly explored compound approved for fluorescence-guided resection. Intravenous fluorescein sodium has recently received attention, highlighting tumor tissue based on extravasation at the blood-brain barrier (defective in many brain tumors). Fluorescein in perfused brain, unselective extravasation in brain perturbed by surgery, and propagation with edema are concerns. Fluorescein is not approved but targeted fluorochromes with affinity to brain tumor cells, in development, may offer future advantages. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. Viscous optical clearing agent for in vivo optical imaging

    Science.gov (United States)

    Deng, Zijian; Jing, Lijia; Wu, Ning; lv, Pengyu; Jiang, Xiaoyun; Ren, Qiushi; Li, Changhui

    2014-07-01

    By allowing more photons to reach deeper tissue, the optical clearing agent (OCA) has gained increasing attention in various optical imaging modalities. However, commonly used OCAs have high fluidity, limiting their applications in in vivo studies with oblique, uneven, or moving surfaces. In this work, we reported an OCA with high viscosity. We measured the properties of this viscous OCA, and tested its successful performances in the imaging of a living animal's skin with two optical imaging modalities: photoacoustic microscopy and optical coherence tomography. Our results demonstrated that the viscous OCA has a great potential in the study of different turbid tissues using various optical imaging modalities.

  19. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.).

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  2. 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

  3. Multimodality Imaging of Calcinosis of Chronic Renal Failure

    OpenAIRE

    Loya, Raul; Beavers, Kimberly; Scherer, Kurt

    2017-01-01

    Secondary tumoral calcinosis (STC) refers to periarticular calcified masses associated with an identifiable condition. The most common of these identifiable conditions is a chronic renal failure. We present a unique case in which massive periarticular masses in a patient with calcinosis of chronic renal failure (CCRF) are demonstrated in the shoulder and hip on sonography, radiography and computed tomography (CT).

  4. 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.

  5. 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.

  6. 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

  7. 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)

  8. 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)

  9. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  11. 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)

  12. 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.

  13. 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)

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. Paramagnetic metal complexes as potential relaxation agents for NMR imaging

    International Nuclear Information System (INIS)

    Coroiu, Ilioara; Demco, D. E.; Darabont, Al.; Bogdan, M.

    1997-01-01

    The development of nuclear magnetic resonance (NMR) imaging technique as a clinical diagnostic modality has prompted the need for a new class of pharmaceuticals. These drugs must be administered to a patient in order to enhance the image contrast between the normal and diseased tissue and/or indicate the status of organ function or blood flow. Paramagnetic compounds are presently undergoing extensive evaluation as contrast agents in magnetic resonance imaging (MRI). These agents increase contrast in MRI by differentially localizing in tissue where they increase the relaxation rates of nearby water protons. The longitudinal R 1 and transverse R 2 relaxivities were measured as a function of molar concentrations for some new paramagnetic complexes like the following: dysprosium, erbium and gadolinium citrates, gadolinium methylene diphosphonate, dysprosium and gadolinium iminodiacetate, manganese para-aminobenzoate and copper nicotinate. The available theoretical approaches for quantitative understanding are presented. (authors)

  19. 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)

  20. Cellular image segmentation using n-agent cooperative game theory

    Science.gov (United States)

    Dimock, Ian B.; Wan, Justin W. L.

    2016-03-01

    Image segmentation is an important problem in computer vision and has significant applications in the segmentation of cellular images. Many different imaging techniques exist and produce a variety of image properties which pose difficulties to image segmentation routines. Bright-field images are particularly challenging because of the non-uniform shape of the cells, the low contrast between cells and background, and imaging artifacts such as halos and broken edges. Classical segmentation techniques often produce poor results on these challenging images. Previous attempts at bright-field imaging are often limited in scope to the images that they segment. In this paper, we introduce a new algorithm for automatically segmenting cellular images. The algorithm incorporates two game theoretic models which allow each pixel to act as an independent agent with the goal of selecting their best labelling strategy. In the non-cooperative model, the pixels choose strategies greedily based only on local information. In the cooperative model, the pixels can form coalitions, which select labelling strategies that benefit the entire group. Combining these two models produces a method which allows the pixels to balance both local and global information when selecting their label. With the addition of k-means and active contour techniques for initialization and post-processing purposes, we achieve a robust segmentation routine. The algorithm is applied to several cell image datasets including bright-field images, fluorescent images and simulated images. Experiments show that the algorithm produces good segmentation results across the variety of datasets which differ in cell density, cell shape, contrast, and noise levels.

  1. Magnetic nanoparticles as contrast agents for molecular imaging in medicine

    Science.gov (United States)

    O'Donnell, Matthew

    2018-05-01

    For over twenty years, superparamagnetic nanoparticles have been developed for a number of medical applications ranging from bioseparations, magnetic drug targeting, hyperthermia and imaging. Recent studies have shown that they can be functionalized for in vivo biological targeting, potentially enabling nanoagents for molecular imaging and site-localized drug delivery. Here we review several imaging technologies developed using functionalized superparamagnetic iron oxide nanoparticles (SPIONs) as targeted molecular agents. Several imaging modalities have exploited the large induced magnetic moment of SPIONs to create local mechanical force. Magnetic force microscopy can probe nanoparticle uptake in single cells. For in vivo applications, magnetomotive modulation of primary images in ultrasound (US), photoacoustics (PA), and optical coherence tomography (OCT) can help identify very small concentrations of nanoagents while simultaneously suppressing intrinsic background signals from tissue.

  2. 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

  3. 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.

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. 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

  7. 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 ...

  8. Development of (F-18)-Labeled Amyloid Imaging Agents for PET

    International Nuclear Information System (INIS)

    Mathis, C.A.

    2007-01-01

    The applicant proposes to design and synthesize a series of fluorine-18-labeled radiopharmaceuticals to be used as amyloid imaging agents for positron emission tomography (PET). The investigators will conduct comprehensive iterative in vitro and in vivo studies based upon well defined acceptance criteria in order to identify lead agents suitable for human studies. The long term goals are to apply the selected radiotracers as potential diagnostic agents of Alzheimer's disease (AD), as surrogate markers of amyloid in the brain to determine the efficacy of anti-amyloid therapeutic drugs, and as tools to help address basic scientific questions regarding the progression of the neuropathology of AD, such as testing the 'amyloid cascade hypothesis' which holds that amyloid accumulation is the primary cause of AD.

  9. 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

  10. 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.

  11. 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

  12. 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)

  13. 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 ...

  14. 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.

  15. 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.).

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. Quinone-fused porphyrins as contrast agents for photoacoustic imaging

    KAUST Repository

    Banala, Srinivas

    2017-06-27

    Photoacoustic (PA) imaging is an emerging non-invasive diagnostic modality with many potential clinical applications in oncology, rheumatology and the cardiovascular field. For this purpose, there is a high demand for exogenous contrast agents with high absorption coefficients in the optical window for tissue imaging, i.e. the near infrared (NIR) range between 680 and 950 nm. We herein report the photoacoustic properties of quinone-fused porphyrins inserted with different transition metals as new highly promising candidates. These dyes exhibit intense NIR absorption, a lack of fluorescence emission, and PA sensitivity in concentrations below 3 nmol mL. In this context, the highest PA signal was obtained with a Zn(ii) inserted dye. Furthermore, this dye was stable in blood serum and free thiol solution and exhibited negligible cell toxicity. Additionally, the Zn(ii) probe could be detected with an up to 3.2 fold higher PA intensity compared to the clinically most commonly used PA agent, ICG. Thus, further exploration of the \\'quinone-fusing\\' approach to other chromophores may be an efficient way to generate highly potent PA agents that do not fluoresce and shift their absorption into the NIR range.

  1. Application of I-123 HIPDM as a lung imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Shih, W J; Coupal, J J; Dillon, M L; Kung, H F

    1988-04-01

    N,N,N'-Trimethyl-N'-(2-Hydroxyl-3-Methyl-5-/sup 123/I Iodobenzyl)-1,3-Propanediamine.Hcl (/sup 123/I-HIPDM) has been used for diagnosis of patients with strokes and demantias. Since this radiopharmaceutical is also accumulated in the lung, we routinely performed a lung image or images immediately prior to cerebral planar and SPECT images after a 3-5 mCi /sup 123/I-HIPDM injection. During the past 14 months, we obtained 78 (age from 41 to 92 years, average 66.7+-8.9 years; 64 males, 14 females) suspected stroke or dementia patients' lung images. All lung images were correlated to chest X-ray (CXR) or CT and other clinical data. Sixty five of 78 patients had normal lungs showing homogeneous distribution of activity throughout the lungs which correlated well to normal CXR and/or CT studies. Abnormal scintigraphic patterns of the 13 patients included lung defect (5 bronchogenic carcinoma with or without atelectasis) and decreased uptake in apices (8 chronic obstructive pulmonary disease). The findings of pulmonary intrathoracic pathologies on lung images with /sup 123/I-HIPDM suggests further evaluation of the agent for detection of localized pulmonary diseases and pulmonary physiological studies relating to amine metabolism.

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. 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

  5. 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.

  6. Renal imaging with radionuclides, ultrasound, and computed tomography

    International Nuclear Information System (INIS)

    Kahn, P.C.

    1979-01-01

    Nuclear medicine, ultrasound, and computed tomography have all contributed greatly to the diagnosis and understanding of renal disease. The /sup 99m/Tc-glucoheptonate scan is a multipurpose test for evaluating blood flow, cortical function and excretion, and the location of renal tissue. It is especially useful in renal trauma and vascular disease, congenital anomalies, and pseudomasses. Technetium-99m diethylene triamine pentaacetic acid (DTPA) is most helpful in evaluating obstruction and reflux, and 67 Ga citrate has a major role in inflammatory disease. The gray-scale ultrasound examination helps to characterize masses as cysts, abscesses, or tumors, and is particularly helpful in localization for aspiration, biopsy, or drainage procedures. Its total innocuousness makes echography useful for sequential follow-up in hydronephrosis and masses. Computed tomography with a fast scanner allows the identification of small lesions, and gives the most anatomic information. It permits the differentiation of fat from pelvic tumors and small cysts from neoplasms, and clearly identifies perirenal structures. With contrast enhancement, additional information about the vascularity of lesions is obtained. Although these tests use different physical principles and instruments, the data they provide are often similar, and for practical purposes the use of one modality may preclude the use of others. Difficult judgments are required to make certain that the proper examination or sequence of examinations is done in each case

  7. AAZTA: an ideal chelating agent for the development of {sup 44}Sc PET imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Gabor; Szikra, Dezso; Trencsenyi, Gyoergy [Scanomed Ltd., Debrecen (Hungary); University of Debrecen, Medical Imaging Clinic (Hungary); Fekete, Aniko [University of Debrecen, Medical Imaging Clinic (Hungary); Garai, Ildiko [Scanomed Ltd., Debrecen (Hungary); Giani, Arianna M.; Negri, Roberto [Dipartimento di Scienze del Farmaco, Universita del Piemonte Orientale, Novara (Italy); Masciocchi, Norberto [Dipartimento di Scienza e Alta Tecnologia e To.Sca.Lab, Universita degli Studi dell' Insubria, Como (Italy); Maiocchi, Alessandro; Uggeri, Fulvio [Bracco Imaging spa, Bracco Research Centre, Colleretto Giacosa (Italy); Toth, Imre [Department of Inorganic and Analytical Chemistry, University of Debrecen (Hungary); Aime, Silvio [Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Centro di Imaging Molecolare e Preclinico, Universita degli Studi di Torino (Italy); Giovenzana, Giovanni B. [Dipartimento di Scienze del Farmaco, Universita del Piemonte Orientale, Novara (Italy); CAGE Chemicals srl, Novara (Italy); Baranyai, Zsolt [Bracco Imaging spa, Bracco Research Centre, Colleretto Giacosa (Italy); Department of Inorganic and Analytical Chemistry, University of Debrecen (Hungary)

    2017-02-13

    Unprecedented fast and efficient complexation of Sc{sup III} was demonstrated with the chelating agent AAZTA (AAZTA=1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)] amino-6-methylperhydro-1,4-d iazepine) under mild experimental conditions. The robustness of the {sup 44}Sc(AAZTA){sup -} chelate and conjugated biomolecules thereof is further shown by in vivo PET imaging in healthy and tumor mice models. The new results pave the way towards development of efficient Sc-based radiopharmaceuticals using the AAZTA chelator. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. 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.)

  9. 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.)

  10. 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

  11. The use of contrast agent for imaging biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Dammer, J; Sopko, V; Jakubek, J [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Weyda, F, E-mail: jiri.dammer@utef.cvut.cz [Biological center of the Academy of Sciences of the Czech Republic, Institute of Entomology, Branisovska 31, CZ-37005 Ceske Budejovice (Czech Republic)

    2011-01-15

    The technique of X-ray transmission imaging has been available for over a century and is still among the fastest and easiest approaches to the studies of internal structure of biological samples. Recent advances in semiconductor technology have led to the development of new types of X-ray detectors with direct conversion of interacting X-ray photon to an electric signal. Semiconductor pixel detectors seem to be specially promising; compared to the film technique, they provide single-quantum and real-time digital information about the objects being studied. We describe the recently developed radiographic apparatus, equipped with Medipix2 semiconductor pixel detector. The detector is used as an imager that counts individual photons of ionizing radiation, emitted by an X-ray tube (micro- or nano-focus FeinFocus). Thanks to the wide dynamic range of the Medipix2 detector and its high spatial resolution better than 1{mu}m, the setup is particularly suitable for radiographic imaging of small biological samples, including in-vivo observations with contrast agent (Optiray). Along with the description of the apparatus we provide examples of the use iodine contrast agent as a tracer in various insects as model organisms. The motivation of our work is to develop our imaging techniques as non-destructive and non-invasive. Microradiographic imaging helps detect organisms living in a not visible environment, visualize the internal biological processes and also to resolve the details of their body (morphology). Tiny live insects are an ideal object for our studies.

  12. 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 ...

  13. Liver nodules. MR imaging using extracellular gadolinium agent

    International Nuclear Information System (INIS)

    Yoshimitsu, Kengo; Honda, Hiroshi

    2009-01-01

    Extracellular gadolinium (Gd)-containing contrast medium, including gadopentetate dimeglumine (Gd-DTPA), has been playing a main role in the diagnostic MR imaging of the liver. Its significance is two-fold: assessment of the degree of neovascularity or angiogenesis in its early dynamic phase, and that of bulk of interstitium in its equilibrium phase. With the advent of gadolinium ethoxybenzyl diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA), which can be used as a dynamic study agent by bolus injection in addition to its original use as a tissue-specific agent, some possibility has been suggested that extracellular Gd agent would be no longer available in the near future in the field of liver MR imaging. Neovascularity or arterial supply of a lesion may well be assessed by Gd-EOB-DTPA, when carefully selected pulse sequence and well designed injection protocol are used, as well as by Gd-DTPA. However, the pertinent assessment of interstitium or stroma can never be achieved by Gd-EOB-DTPA or any other contrast medium present. The interstitium of neoplasm, typically called as stromal fibrosis, is generated through the interaction between the neoplasm per se and its host, and its clinicopathological significance related to disease prognosis has well been established in some disease entities. Extracellular Gd agent is the only contrast medium that can provide information regarding the tumor stroma in a simple, easy, safe and non-invasive fashion, when properly used. This review article discusses, dynamic MR imaging features of representative liver diseases, including several recent topics. From technical point of view, 3D gradient-echo sequence with fat suppression should be used for dynamic studies along with tailored injection protocol using autoinjector and saline flush. Vascularity of hepatocellular carcinoma (HCC) can now be properly assessed by dynamic MR with approximately 90% concordance with CT during hepatic arteriography. Portal phase images can be used to

  14. 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)

  15. Magnetic susceptibility imaging with a nonionic contrast agent

    International Nuclear Information System (INIS)

    Cacheris, W.; Rocklage, S.M.; Quay, S.; Dow, W.; Love, D.; Worah, D.; Lim, K.

    1988-01-01

    The magnetic susceptibility mechanism for MR imaging contrast enhancement has the advantage of providing useful information, such as cerebral blood flow, without crossing the blood-brain barrier. In this paper the authors report the use of a highly effective, relatively nontoxic chelate as a magnetic susceptibility agent. Dy-DTPA-bis(methylamide) (Dy-DTPA-BMA) has an extremely low acute toxicity (LD-50, intravenous, mice ∼ 40 mmol/kg). Doses of 1 mmol/kg and 2 mmol/kg Dy-DTPA-BMA lowered the initial signal intensity 63% to 57%, respectively. The utility of this technique in detecting areas of reduced blood flow within the brain was demonstrated by imaging a rabbit with a cerebral perfusion deficit

  16. The preparation and characterization of peptide's lung cancer imaging agent

    International Nuclear Information System (INIS)

    Liu Jianfeng; Chu Liping; Wang Yan; Wang Yueying; Liu Jinjian; Wu Hongying

    2010-01-01

    Objective: To screen in vivo lung cancer specific binding seven peptides by T7 phage display peptide library, so as to prepare peptide's lung cancer early diagnostic agent. Methods: Use phage display in vivo technology, the 7-peptide phage that binding the lung cancer specifically was obtained, then the DNA sequence was measured and the seven peptide was synthesized. After labeled by 125 I, the seven peptide was injected into mice via vein and the distribution was observed. Results: One peptide was obtained by four rounds screening, and the peptide can bind lung cancer tissue specifically. Two hours after injection get the best imaging of lung cancer, metabolism of peptide in mice is fast, the distribution in vivo is decrease six hours and almost disappear 20 hours after injection. Conclusion: The peptide can image and diagnose lung cancer better. (authors)

  17. 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.

  18. 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.

  19. 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.)

  20. 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.)

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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;

  6. 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.

  7. 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

  8. 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.

  9. 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.)

  10. Nicotinic α4β2 receptor imaging agents

    International Nuclear Information System (INIS)

    Pichika, Rama; Easwaramoorthy, Balasubramaniam; Collins, Daphne; Christian, Bradley T.; Shi, Bingzhi; Narayanan, Tanjore K.; Potkin, Steven G.; Mukherjee, Jogeshwar

    2006-01-01

    The α4β2 nicotinic acetylcholine receptor (nAChR) has been implicated in various neurodegenerative diseases. Optimal positron emission tomography (PET) imaging agents are therefore highly desired for this receptor. We report here the development and initial evaluation of 2-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine (nifene). In vitro binding affinity of nifene in rat brain homogenate using 3 H-cytisine exhibited a K i =0.50 nM for the α4β2 sites. The radiosynthesis of 2- 18 F-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine ( 18 F-nifene) was accomplished in 2.5 h with an overall radiochemical yield of 40-50%, decay corrected. The specific activity was estimated to be approx. 37-185 GBq/μmol. In vitro autoradiography in rat brain slices indicated selective binding of 18 F-nifene to anteroventral thalamic (AVT) nucleus, thalamus, subiculum, striata, cortex and other regions consistent with α4β2 receptor distribution. Rat cerebellum showed some binding, whereas regions in the hippocampus had the lowest binding. The highest ratio of >13 between AVT and cerebellum was measured for 18 F-nifene in rat brain slices. The specific binding was reduced (>95%) by 300 μM nicotine in these brain regions. Positron emission tomography imaging study of 18 F-nifene (130 MBq) in anesthetized rhesus monkey was carried out using an ECAT EXACT HR+ scanner. PET study showed selective maximal uptake in the regions of the anterior medial thalamus, ventro-lateral thalamus, lateral geniculate, cingulate gyrus, temporal cortex including the subiculum. The cerebellum in the monkeys showed lower binding than the other regions. Thalamus-to-cerebellum ratio peaked at 30-35 min postinjection to a value of 2.2 and subsequently reduced. The faster binding profile of 18 F-nifene indicates promise as a PET imaging agent and thus needs further evaluation

  11. 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.)

  12. Shape Effects in Nanoparticle-Based Imaging Agents

    Science.gov (United States)

    Culver, Kayla Shani Brook

    At the nanoscale, material properties become highly size and shape dependent. These properties can be manipulated and exploited for a variety of biomedical applications, including sensing, drug delivery, diagnostics, and imaging. In particular, nanoparticles of different materials, sizes and shapes have been developed as high-performance contrast agents for optical, electron, and medical imaging. In this thesis, I focus on gold nanoparticles because they are widely used as contrast agents in multiple types of imaging modalities. Additionally, the surface of gold can be readily functionalized with ligands and the structure of the particles can be manipulated to modulate their performance as imaging agents. The properties of nanoparticles can generate contrast directly. For example, the light scattering properties of gold particles can be visualized in optical microscopy, the high electron density of gold produces contrast in electron microscopy, and the x-ray absorption properties of gold can be detected in medical x-ray and computed tomography imaging. Alternatively, the properties of the nanomaterial can be exploited to modulate the signal produced by other molecules that are bound to the particle surface. The light emission of molecular fluorophores can be quenched or dramatically increased by coupling to the optical field enhancements of gold nanoparticles, and the performance of gadolinium (Gd(III))-based magnetic resonance imaging (MRI) contrast agents can be increased by coupling to the rotational motion of nanoparticles. In this dissertation, I focus specifically on how the structure of star-shaped gold particles (nanostars) can be exploited as single-particle optical probes and to dramatically enhance the relaxivity of Gd(III) bound to the surface. Differential interference contrast (DIC) is a type of wide-field diffraction-limited optical microscopy that is commonly used by biologists to image cells without labels. Here, I demonstrate the DIC can be used

  13. 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...

  14. 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

  15. Chemistry and biology of Tc-99m renal function agents. Final report

    International Nuclear Information System (INIS)

    Fritzberg, A.M.

    1986-01-01

    A major aim of the project was to develop a Tc-99m renal tubular function radiopharmaceutical. Progress was made in synthesizing and evaluating Tc-99m 2,3-dimercaptoaceta-midoprepanoate (CO 2 DADS). In animals and clinical studies the A epimer (early component on reversed phase HPLC) demonstrated high efficiency and specificity for renal tubular secretion. We were unable to obtain only the desired stereoisomer. Synthesis of about twenty diamide dimercaptide N 2 S 2 ligand analogs suggested two others that were of comparable efficiency in humans, but with less difference between stereoisomers; Tc-99m 1,3-dimercaptoacetamide-2-hydroxypropane (HoDADS) and 1,8-dithiol- 2,7-dioxo-3,6-diazanonanoate (α -S-CO 2 DADS). 15 refs

  16. 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

  17. Amla as an antihyperglycemic and hepato-renal protective agent in fluoride induced toxicity

    Directory of Open Access Journals (Sweden)

    Rupal A Vasant

    2012-01-01

    Full Text Available Purpose of the study was to examine the antihyperglycemic and hepato-renal protective effects of Emblica officinalis (Eo fruit as a food supplement in fluoride induced toxicity. Eo fruit powder was incorporated into the diet (2.5, 5 and 10 gm % of fluoride exposed animals for a duration of 30 days. Fluoride exposure caused significant elevation in plasma glucose, serum glutamate oxaloacetate transaminase (SGOT, serum glutamate pyruvate transaminase (SGPT, acid phosphatase (ACP, alkaline phosphatase (ALP activities, hepatic glucose-6-phosphatase (G-6-Pase and decreased hepatic glycogen content, hexokinase activity and antioxidant profiles (hepatic and renal. An inclusion of Eo fruit powder significantly reduced plasma glucose levels, SGOT, SGPT, ACP and ALP activities, hepatic G-6-Pase activity and increased hepatic glycogen content and hexokinase activity. Hepatic and renal antioxidant status of fluoride exposed animals improved upon feeding Eo fruit powder. We, therefore, conclude that E. officinalis fruit could be useful in regulating hyperglycemia and enhances antioxidant status of fluoride exposed animals.

  18. Positrons as imaging agents and probes in nanotechnology

    International Nuclear Information System (INIS)

    Smith, Suzanne V

    2009-01-01

    Positron emission tomography (PET) tracks a positron emitting radiopharmaceutical injected into the body and generates a 3-dimensional image of its location. Introduced in the early 70s, it has now developed into a powerful medical diagnostic tool for routine clinical use as well as in drug development. Unrivalled as a highly sensitive, specific and non-invasive imaging tool, PET unfortunately lacks the resolution of Computer Tomography (CT) and Magnetic Resonance Imaging (MRI). As the resolution of PET depends significantly on the energy of the positron incorporated in the radiopharmaceutical and its interaction with its surrounding tissue, there is growing interest in expanding our understanding of how positrons interact at the atomic and molecular level. A better understanding of these interactions will contribute to improving the resolution of PET and assist in the design of better imaging agents. Positrons are also used in Positron Annihilation Lifetime Spectroscopy (PALS) to determine electron density and or presence and incidence of micro- and mesopores (0.1 to 10 nm) in materials. The control of porosity in engineered materials is crucial for applications such as controlled release or air and water resistant films. Equally important to the design of nano and microtechnologies, is our understanding of the microenvironments within these pores and on surfaces. Hence as radiopharmaceuticals are designed to track disease, nuclear probes (radioactive molecules) are synthesized to investigate the chemical properties within these pores. This article will give a brief overview of the present role of positrons in imaging as well as explore its potential to contribute in the engineering of new materials to the marketplace.

  19. 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

  20. 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)

  1. Formulation of MIBI Kit as a heart imaging agent

    International Nuclear Information System (INIS)

    Widyastuti; A, Hanafiah; Yunilda; A, Laksmi; Setyowati, Sri; Y Veronika

    1999-01-01

    9 9 m Tc labelled 2-methoxy-isobutyl-isonitrile(MIBI) has been known as an imaging agent for myocardial perfusion. This radiopharmaceutical preparation gives the same satisfactory result as Thallium- 2 10TI, and presumably could replace 2 01TI because of same advantages. MIBI kit was formulated from MIBI ligand produced by RPC-BATAN which has been characterized and tested for quality. The formula used in this research referred to the formula of imported product(Cardiolite, MIBI kit produced by Dupont), and the quality control testing was performed by comparing some parameters to the imported product. The parameters used for QC testing were radiochemical purity, biodistribution in nice and heart imaging in human volunteer using gamma camera. The result of the experiment showed that the radiochemical purity was 95 % in average, biodistribution in heart to liver gave the ratio of 0.67, 1.5, and 2.53 respectively at 10, 30 and 60 minutes after injection. The result of clinical testing in some volunteers gave contrast images as good as given by Cardiolite. The optimum condition of freeze drying has been found, and the kit can be used for more than 6 months

  2. 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.

  3. Diffusion-weighted imaging in assessing renal pathology of chronic kidney disease: A preliminary clinical study

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qinghai; Li, Jinning; Zhang, Lan; Chen, Ying; Zhang, Minming [Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Yan, Fuhua, E-mail: zemylife@163.com [Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China)

    2014-05-15

    Objective: To investigate the clinical potential of diffusion-weighted imaging (DWI) in assessing renal pathology of chronic kidney disease (CKD). Methods: Seventy-one CKD patients and twelve healthy volunteers were examined using DWI with prospective acquisition correction. Renal biopsy specimens from the CKD patients were scored based on the severity of renal pathology and to confirm pathology type. CKD patients were divided into three groups according to pathology scores: mild, moderate, or severe. The association between renal apparent diffusion coefficient (ADC) values and pathology scores was investigated using Pearson's correlation and single factor analysis of variance. Multiple linear regression analysis was performed to explore associations between renal ADC values and pathology score, glomerular filtration rate, serum creatinine, and age. The Kruskal–Wallis H test was conducted to compare ADC values and pathology type. Results: Renal ADC values correlated negatively with pathology scores (r = −0.633, P < 0.001). The ADC values among the four groups (mild, moderate, severe impairment, and controls) were significantly different (F = 19.512, P < 0.001). However, when patients were stratified by pathology type, no significant differences were found in ADC values among these groups (χ{sup 2} = 9.929, P = 0.270). Further multiple linear regression analysis showed that only the pathology score and ADC values were related (t = −4.586, P = 0.000). Conclusions: DWI has clinical potential in assessing the severity of renal pathology in CKD and shows promise as a non-invasive and effective technique to guide therapy and follow-up.

  4. Diffusion-weighted imaging in assessing renal pathology of chronic kidney disease: A preliminary clinical study

    International Nuclear Information System (INIS)

    Li, Qinghai; Li, Jinning; Zhang, Lan; Chen, Ying; Zhang, Minming; Yan, Fuhua

    2014-01-01

    Objective: To investigate the clinical potential of diffusion-weighted imaging (DWI) in assessing renal pathology of chronic kidney disease (CKD). Methods: Seventy-one CKD patients and twelve healthy volunteers were examined using DWI with prospective acquisition correction. Renal biopsy specimens from the CKD patients were scored based on the severity of renal pathology and to confirm pathology type. CKD patients were divided into three groups according to pathology scores: mild, moderate, or severe. The association between renal apparent diffusion coefficient (ADC) values and pathology scores was investigated using Pearson's correlation and single factor analysis of variance. Multiple linear regression analysis was performed to explore associations between renal ADC values and pathology score, glomerular filtration rate, serum creatinine, and age. The Kruskal–Wallis H test was conducted to compare ADC values and pathology type. Results: Renal ADC values correlated negatively with pathology scores (r = −0.633, P < 0.001). The ADC values among the four groups (mild, moderate, severe impairment, and controls) were significantly different (F = 19.512, P < 0.001). However, when patients were stratified by pathology type, no significant differences were found in ADC values among these groups (χ 2 = 9.929, P = 0.270). Further multiple linear regression analysis showed that only the pathology score and ADC values were related (t = −4.586, P = 0.000). Conclusions: DWI has clinical potential in assessing the severity of renal pathology in CKD and shows promise as a non-invasive and effective technique to guide therapy and follow-up

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. 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.)

  7. Uptake of myocardial imaging agents by rejected hearts

    International Nuclear Information System (INIS)

    Bergsland, J.; Carr, E.A.; Carroll, M.; Wright, J.W.; Feldman, M.J.; Massucci, J.; Bhayana, J.N.; Gona, J.M.

    1985-01-01

    Technetium 99 m pyrophosphate, Gallium 67 and Thallium 201 uptakes were measured in heterotopically transplanted rat hearts. Five days after transplantation, Technetium 99 m pyrophosphate, and Gallium 67 uptakes were significantly higher in allogeneic grafts than in syngeneic grafts. At an early stage of rejection (three days after transplantation), only Technetium 99 m pyrophosphate uptake in the left ventricle of allogeneic grafts showed a significant difference (p less than 0.04). At five days, Thallium 201 uptake was significantly lower in allo- than syngeneic grafts. There was a positive correlation between radionuclide uptake and histologic degree of rejection for Technetium 99 m pyrophosphate and Gallium 67 while Thallium 201 uptake correlated negatively. Analysis of variance revealed that hearts with no or minimal rejection had statistically different uptakes than hearts with mild to moderate rejection. These results suggest that uptake of imaging agents might be useful in the diagnosis of rejection of the transplanted heart

  8. Tracers and contrast agents in cardiovascular imaging: present and future

    International Nuclear Information System (INIS)

    Marmion, M.; Deutsch, E.

    1996-01-01

    This brief article addresses the current status and future potential of nuclear medicine, X-ray computed tomography (CT), ultrasound (US), and magnetic resonance (MR) imaging in the diagnosis of cardiovascular diseases. The currently perceived advantages and disadvantages, as well as the possible future roles, of each of the modalities with regard to the evaluation of coronary artery disease are delineated. The certain advent of Mr and US myocardial contrast agents, combined with the inexorable pressures of health care reform, will alter the future usage patterns of all four modalities. Future debates about which modality should be used in which clinical situation will be based not on 'anatomy vs function', nor on the issues of cost effectiveness and patient outcomes

  9. Kit for preparing a technetium-99m myocardial imaging agent

    International Nuclear Information System (INIS)

    Woulfe, S.R.; Deutsch, E.A.; Dyszlewski, M.; Neumann, W.L.

    1992-01-01

    This patent describes a kit for preparing a technetium 99m myocardial imaging agent. It comprises a first vial containing a lyophilized pyrogen free, sterile mixture of an effective reducing agent and a first ligand having the following general formula: wherein the R 1 groups may be the same or different and are selected from the group consisting of hydrogen, hydroxy, C 1 - C 5 alkyl, C 1 - C 5 alkyl substituted by hydroxyl, ether, ester, amide, ketone, aldehyde and nitrile; the R 2 groups may be the same or different and are selected from the group consisting of hydrogen, hydroxy, C 1 - C 5 alkyl, C 1 - C 5 alkyl substituted by hydroxyl, ether, ester, amide, ketone, aldehyde, and nitrile; the X and Y groups may be the same or different and are selected from the group consisting of oxygen and sulfur; and n is equal to 1 or 2; and a second vial containing a lyophilized pyrogen free, sterile protected salt of a phosphine ligand

  10. 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.

  11. Contrast agents for tumor diagnosis in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Rensuke; Doi, Hisayoshi; Okada, Shoji [University of Shizuoka (Japan). School of Pharmaceutical Science; Yano, Masayuki; Katano, Susumu; Nakajima, Nobuaki

    1992-01-01

    In order to develop contrast agents for tumor diagnosis in magnetic resonance imaging (MRI), we investigated the effects of several gadolinium complexes on T{sub 1} relaxation time of proton in some tissues of Ehrlich solid tumor-bearing mice. L-Aspartic acid, L-glutamic acid, DL-homocysteine, L-glutamyl-glutamic acid, glutathione, sperimidine and ethylenediaminetetrakis (methylenephosphate) (EDTMP) were used as ligands for Gd{sup 3+}. Since each Gd-complex could not be purified except Gd-EDTMP, the mixture of GdCl{sub 3} and a ligand was administered intravenously. Among the compounds tested, the mixture of aspartic acid, glutathione or spermidine with GdCl{sub 3} showed almost the same or above reduction of T{sub 1} relaxation times in the tumor tissue compared with Gd-diethylenetriamine pentaacetic acid (Gd-DTPA) which is used clinically. Furthermore, the contrast-enhancing effect of the three mixtures in the tumor was observed by in vivo T{sub 1}-weighted magnetic resonance imaging. The in vivo tissue distribution using radioactive {sup 153}Gd{sup 3+} showed that these mixtures mentioned above were also taken up more highly in the tumor than {sup 153}GdCl{sub 3} itself and {sup 153}Gd-DTPA, suggesting the formation of Gd-complexes. However, the overall tissue distribution of the mixtures was similar to that of {sup 153}GdCl{sub 3} because the Gd-complexes were not purified. Gd-EDTMP exhibited the almost same effects with Gd-DTPA as a contrast agent. (author).

  12. 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.)

  13. 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.

  14. 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

  15. Occupational risk factors for renal cell carcinoma: agent-specific results from a case-control study in Germany. MURC Study Group. Multicenter urothelial and renal cancer study.

    Science.gov (United States)

    Pesch, B; Haerting, J; Ranft, U; Klimpel, A; Oelschlägel, B; Schill, W

    2000-12-01

    This case-control study was conducted to estimate the renal cell cancer (RCC) risk for exposure to occupation-related agents, besides other suspected risk factors. In a population-based multicentre study, 935 incident RCC cases and 4298 controls matched for region, sex, and age were interviewed between 1991 and 1995 for their occupational history and lifestyle habits. Agent-specific exposure was expert-rated with two job-exposure matrices and a job task-exposure matrix. Conditional logistic regression was used to calculate smoking adjusted odds ratios (OR). Very long exposures in the chemical, rubber, and printing industries were associated with risk for RCC. Males considered as 'substantially exposed to organic solvents' showed a significant excess risk (OR = 1.6, 95% CI : 1.1-2.3). In females substantial exposure to solvents was also a significant risk factor (OR = 2.1, 95% CI : 1.0-4.4). Excess risks were shown for high exposure to cadmium (OR = 1.4, 95% CI : 1.1-1.8, in men, OR = 2.5, 95% CI : 1.2-5.3 in women), for substantial exposure to lead (OR = 1.5, 95% CI : 1.0-2.3, in men, OR = 2.6, 95% CI : 1.2-5.5, in women) and to solder fumes (OR = 1.5, 95% CI : 1.0-2.4, in men). In females, an excess risk for the task 'soldering, welding, milling' was found (OR = 3.0, 95% CI : 1.1-7.8). Exposure to paints, mineral oils, cutting fluids, benzene, polycyclic aromatic hydrocarbons, and asbestos showed an association with RCC development. Our results indicate that substantial exposure to metals and solvents may be nephrocarcinogenic. There is evidence for a gender-specific susceptibility of the kidneys.

  16. Renal Function and Ultrasound Imaging in Elderly Subjects

    Directory of Open Access Journals (Sweden)

    Luca Zanoli

    2014-01-01

    Full Text Available We evaluated in elderly subjects (a the ability of GFR formulas to discriminate chronic kidney disease (CKD, (b the correlation between renal morphology and function, and (c the usefulness of combined r-US and GFR formulas to detect CKD. A total of 72 patients were enrolled (mean age 80 ± 7 years, male sex 44%, serum creatinine 0.98 ± 0.42 mg/dL, and CKD 57%. Cockcroft-Gault showed the highest sensitivity (78% and specificity (94% for CKD and was correlated with kidney volume (R=0.68, P<0.001. All formulas failed to provide a reliable estimate of GFR. In multivariate analysis, Cockcroft-Gault < 52 mL/min and kidney sinus section area < 28 cm2 showed the highest accuracy for the identification of CKD subjects (AUC 0.90, P<0.001. MDRD and CKD-EPI differed significantly for GFR ≥90 mL/min. Conclusions. Cockcroft-Gault < 52 mL/min was able to discriminate subjects with CKD but all formulas failed to provide a reliable estimate of GFR. The combined use of r-US and Cockcroft-Gault formula improved the ability to discriminate CKD in elderly subjects.

  17. Medical image of the week: calvairial renal cell mestastases

    Directory of Open Access Journals (Sweden)

    Witten A

    2016-01-01

    Full Text Available No abstract available. Article truncated at 150 words. A 57-year-old woman with past medical history significant for clear cell renal carcinoma and radical nephrectomy 9 years prior was admitted to our hospital for headache and left hemiparesis with associated numbness. Symptoms were progressive and had begun about 5 days prior to her presenting to our emergency department. Neurologic exam was significant for reduced strength in her left upper and lower extremities as well as well as sensory deficit to fine touch and vibratory sensation in her left arm. Her gait was unsteady and she was unable to ambulate without assistance. Her right calvarium was grossly enlarged and asymmetrical with softening of the underlying boney structures. MRI of the brain showed a 10 cm x 5 cm mass that was obliterating the calvarium and invading the dura mater (Figure 1. There was mass effect with shift of the midline structures from right to left by approximately 6.5 mm (Figures ...

  18. 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.)

  19. 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.)

  20. 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

  1. 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

  2. Comparison of radiation dosimetry for several potential myocardial imaging agents

    International Nuclear Information System (INIS)

    Watson, E.E.; Stabin, M.G; Goodman, M.M.; Knapp, F.F. Jr.; Srivastava, P.C.

    1986-01-01

    Although myocardial imaging is currently dominated by Tl-201, several alternative agents with improved physiologic or radionuclidic properties have been proposed. Based on human and animal studies in the literature, the metabolism of several of these compounds was studied for the purpose of generating radiation dose estimates. Dose estimates are listed for several I-123-labeled free fatty acids, an I-123-labeled phosphonium compound, Rb-82, Cu-64, F-18 FDG (all compounds which are taken up by the normal myocardium), and for Tc-99m pyrophosphate (PYP) (which localizes in myocardial infarcts). Dose estimates could not be generated for C-11 palmitate, but his compound was included in a comparison of myocardial retention times. For the I-123-labeled compounds, I-124 was included as a contaminant in generating the dose estimates. Radiation doses were lowest for Rb-82 (gonads 0.3-0.4 Gy/MBq, kidneys 8.6 Gy/MBq). Doses for the I-123-labeled fatty acids were similar to one another, with IPPA being the lowest (gonads 15 Gy/MBq, heart wall 18 Gy/MBq). Doses for Tc-99m PYP were also low (gonads 4-7 Gy/MBq, heart wall 4 Gy/MBq, skeleton 15 Gy/MBq). The desirability of these compounds is discussed briefly, considering half-life, imaging mode and energy, and dosimetry, including a comparison of the effective whole body dose equivalents. 37 references, 11 tables

  3. 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)

  4. Nicotinic {alpha}4{beta}2 receptor imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Pichika, Rama [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Easwaramoorthy, Balasubramaniam [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Collins, Daphne [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Christian, Bradley T. [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Shi, Bingzhi [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Narayanan, Tanjore K. [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Potkin, Steven G. [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Mukherjee, Jogeshwar [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States)]. E-mail: j.mukherjee@uci.edu

    2006-04-15

    The {alpha}4{beta}2 nicotinic acetylcholine receptor (nAChR) has been implicated in various neurodegenerative diseases. Optimal positron emission tomography (PET) imaging agents are therefore highly desired for this receptor. We report here the development and initial evaluation of 2-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine (nifene). In vitro binding affinity of nifene in rat brain homogenate using {sup 3}H-cytisine exhibited a K {sub i}=0.50 nM for the {alpha}4{beta}2 sites. The radiosynthesis of 2-{sup 18}F-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine ({sup 18}F-nifene) was accomplished in 2.5 h with an overall radiochemical yield of 40-50%, decay corrected. The specific activity was estimated to be approx. 37-185 GBq/{mu}mol. In vitro autoradiography in rat brain slices indicated selective binding of {sup 18}F-nifene to anteroventral thalamic (AVT) nucleus, thalamus, subiculum, striata, cortex and other regions consistent with {alpha}4{beta}2 receptor distribution. Rat cerebellum showed some binding, whereas regions in the hippocampus had the lowest binding. The highest ratio of >13 between AVT and cerebellum was measured for {sup 18}F-nifene in rat brain slices. The specific binding was reduced (>95%) by 300 {mu}M nicotine in these brain regions. Positron emission tomography imaging study of {sup 18}F-nifene (130 MBq) in anesthetized rhesus monkey was carried out using an ECAT EXACT HR+ scanner. PET study showed selective maximal uptake in the regions of the anterior medial thalamus, ventro-lateral thalamus, lateral geniculate, cingulate gyrus, temporal cortex including the subiculum. The cerebellum in the monkeys showed lower binding than the other regions. Thalamus-to-cerebellum ratio peaked at 30-35 min postinjection to a value of 2.2 and subsequently reduced. The faster binding profile of {sup 18}F-nifene indicates promise as a PET imaging agent and thus needs further evaluation.

  5. 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

  6. Tc-99m labeled Sparfloxacin: A specific infection imaging agent

    International Nuclear Information System (INIS)

    Singh, A.K.; Verma, J.; Bhatnagar, A.; Ali, A.

    2003-01-01

    lesions as well as lesions with infection because of hypervascularity. However, rapid wash out of tracer was noted from sterile inflammatory lesions, while progressive concentration of radiotracer was seen in the lesions with infection. Delayed scans done at two hours post-injection revealed a four fold increase radio tracer concentration at the sites of infection as compared to the sites of sterile inflammation. Based on the results of this preliminary study it was concluded that Tc- 99m Sparfloxacin specifically concentrates in infection in animal models and could potentially be a specific bacterial infection-imaging agent. (author)

  7. 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.

  8. 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...

  9. 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.)

  10. 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.)

  11. 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

  12. 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. ...

  13. 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.

  14. 18F-Labelled metomidate analogues as adrenocortical imaging agents

    International Nuclear Information System (INIS)

    Erlandsson, Maria; Karimi, Farhad; Lindhe, Orjan; Langstroem, Bengt

    2009-01-01

    Introduction: Two- and one-step syntheses of 18 F-labelled analogues of metomidate, such as 2-[ 18 F]fluoroethyl 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylate (1), 2-[ 18 F]fluoroethyl 1-[(1R)-1-(4-chlorophenyl)ethyl]-1H-imidazole-5-carboxylate (2), 2-[ 18 F]fluoroethyl 1-[(1R)-1-(4-bromophenyl)ethyl]-1H-imidazole-5-carboxylate (3), 3-[ 18 F]fluoropropyl 1-[(1R)-1-(4-bromophenyl)ethyl]-1H-imidazole-5-carboxylate (4) and 3-[ 18 F]fluoropropyl 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylate (5) are presented. Methods: Analogues 1-5 were prepared by a two-step reaction sequence that started with the synthesis of either 2-[ 18 F]fluoroethyl 4-methylbenzenesulfonate or 3-[ 18 F]fluoropropyl 4-methylbenzenesulfonate. These were used as 18 F-alkylating agents in the second step, in which they reacted with the ammonium salt of a 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylic acid. One-step-labelling syntheses of 1, 2 and 5 were also explored. Analogues 1-4 were biologically validated by frozen-section autoradiography and organ distribution. Metabolite analysis was performed for 2 and 3. Results: The radiochemical yield of the two-step synthesis was in the range of 10-29% and that of the one-step synthesis was 25-37%. Using microwave irradiation in the one-step synthesis of 1 and 2 increased the radiochemical yield to 46±3% and 79±30%, respectively. Conclusion: Both the frozen-section autoradiography and organ distribution results indicated that analogue 2 has a potential as an adrenocortical imaging agent, having the highest degree of specific adrenal binding and best ratio of adrenal to organ uptake among the compounds studied.

  15. Intratumoral Administration of Holmium-166 Acetylacetonate Microspheres : Antitumor Efficacy and Feasibility of Multimodality Imaging in Renal Cancer

    NARCIS (Netherlands)

    Bult, Wouter; Kroeze, Stephanie G. C.; Elschot, Mattijs; Seevinck, Peter R.; Beekman, Freek J.; de Jong, Hugo W. A. M.; Uges, Donald R. A.; Kosterink, Jos G. W.; Luijten, Peter R.; Hennink, Wim E.; Schip, Alfred D. van Het; Bosch, J. L. H. Ruud; Nijsen, J. Frank W.; Jans, Judith J. M.

    2013-01-01

    Purpose: The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of

  16. 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

  17. Grape Seed oil as Anti hepatic and Anti renal Dysfunction agent in Paracetamol Administrated Rats

    International Nuclear Information System (INIS)

    Farag, M.F.; Osman, N.N.; Darwish, M.M.

    2010-01-01

    The protection conferred by dietary grape seed oil (GSO) against paracetamol (PCL)-induced liver and kidney dysfunction have been evaluated in adult male albino Wistar rats. The animals (180-200 g) were randomly divided into four groups of seven rats each. Group l: normal control, group II: animals received GSO (3.7 g Kg-1 body wt/day orally), group III: animals received PCL (4 g Kg-1 body wt/day orally) and group IV: animals received PCL plus GSO. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP), gamma glutamyl transferase (GGT), urea (U), creatinine (Cr) and albumin (A) levels in serum and blood urea nitrogen (BUN) were measured. In addition, the levels of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and the activity of superoxide dismutase (SOD) and catalase (CAT) in the liver and kidney homogenates were chosen for assessing. The PCL induced a significant elevation in the serum AST, ALT, AP and GGT. Moreover, a significant increase in serum U, Cr, A and BUN were evident. Furthermore, a significant rise in TBARS, while a significant declined activity of SOD and CAT and GSH content in liver and kidney homogenates were also observed. Oral administration of GSO resulted in a significant reduction in liver and kidney markers in serum, BUN as well hepatic and renal TBARS accompanied by a significant improvement in the tissue antioxidants and A, when compared with PCL damaged rats. It was suggested that GSO has potent hepatic and renal protective effects against the oxidative damage induced in rats due to PCL treatment, perhaps by its antioxidative effects hence eliminating the deleterious effects of PCL.

  18. 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

  19. A review of 99mTc labeled myocardial imaging agents for tumor-positive imaging

    International Nuclear Information System (INIS)

    Xing Shian; Zhang Yongxue; An Rui

    2002-01-01

    The tumor-positive imaging with high sensitivity and specificity was useful in primary tumor and recurrences and metastases. The 99m Tc labeled myocardial imaging agents are easily available and stable and the radiochemical purity is high. 99m Tc is the preferred choice in routine works because its physical properties. The preparation, quality control, mechanism of accumulation and the clinical use of 99m Tc-sestamibi, 99m Tc-tetrofosmin, 99m Tc-furifosmin, and 99m Tc-N-NOET were reviewed

  20. 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.

  1. 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.)

  2. 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...

  3. Gadolinium based contrast agents in current practice: Risks of accumulation and toxicity in patients with normal renal function

    Directory of Open Access Journals (Sweden)

    Anju Ranga

    2017-01-01

    Full Text Available Despite being decked as the most prized compounds in the nugget box of contrast agents for clinical radiologists, and carrying an indisputable tag of safety of the US Food and Drug Administration for close to three decades, all may not be seemingly well with the family of gadolinium compounds. If the first signs of violations of primum non nocere in relation to gadolinium-based contrast agents (GBCAs appeared in the millennium year with the first published report of skin fibrosis in patients with compromised renal function, the causal relationship between the development of nephrogenic systemic fibrosis (NSF and GBCAs, first proposed by two European groups in 2006, further precluded their use in renocompromised patients. The toxicity, pharmacokinetics, and pharmacodynamics of GBCAs, however, has come under hawk-eyed scrutiny with recent reports that gadolinium tends to deposit cumulatively in the brain of patients with normal hepatobiliary function and intact blood–brain barrier. While the jury on the long-term hazard significance of this critical scientific finding is still out, the use of GBCAs must be guided by due clinical diligence, avoidance of repeated doses, and preferring GBCAs with the best safety profiles.

  4. 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

  5. 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

  6. Computer-assisted imaging algorithms facilitate histomorphometric quantification of kidney damage in rodent renal failure models

    Directory of Open Access Journals (Sweden)

    Marcin Klapczynski

    2012-01-01

    Full Text Available Introduction: Surgical 5/6 nephrectomy and adenine-induced kidney failure in rats are frequently used models of progressive renal failure. In both models, rats develop significant morphological changes in the kidneys and quantification of these changes can be used to measure the efficacy of prophylactic or therapeutic approaches. In this study, the Aperio Genie Pattern Recognition technology, along with the Positive Pixel Count, Nuclear and Rare Event algorithms were used to quantify histological changes in both rat renal failure models. Methods: Analysis was performed on digitized slides of whole kidney sagittal sections stained with either hematoxylin and eosin or immunohistochemistry with an anti-nestin antibody to identify glomeruli, regenerating tubular epithelium, and tubulointerstitial myofibroblasts. An anti-polymorphonuclear neutrophil (PMN antibody was also used to investigate neutrophil tissue infiltration. Results: Image analysis allowed for rapid and accurate quantification of relevant histopathologic changes such as increased cellularity and expansion of glomeruli, renal tubular dilatation, and degeneration, tissue inflammation, and mineral aggregation. The algorithms provided reliable and consistent results in both control and experimental groups and presented a quantifiable degree of damage associated with each model. Conclusion: These algorithms represent useful tools for the uniform and reproducible characterization of common histomorphologic features of renal injury in rats.

  7. Physicochemical and biological study of a renal scintigraphy agent: the DMSA - 99mTc complex

    International Nuclear Information System (INIS)

    Laroche, Dominique

    1979-01-01

    This research thesis deals with the study of the dimercaptosuccinic acid (DMSA) marked with 99m Tc, a recently developed scintigraphy agent used for the kidney isotopic exploration. The author notably studied the relationships between the physicochemical properties of solutions of dimercaptosuccinic acid marked with 99m Tc and the biological distribution of 99m Tc in order to reach a better understanding of the biological mechanism which results in technetium fixation to the kidney

  8. Radioiodinated carnitine and acylcarnitine analogs as potential myocardial imaging agents

    International Nuclear Information System (INIS)

    McConnell, D.S.

    1991-01-01

    R-carnitine is extremely important in mammalian energy metabolism. Gamma-butyrobetaine, the immediate biosynthetic precursor to R-carnitine, is synthesized in many organs. However, only liver can hydroxylate gamma-butyrobetaine to carnitine. Thus the transport of carnitine from its site of synthesis to the site of utilization is of utmost importance. Carnitine is found in highest concentration in cardiac and skeletal muscle, where it is required for the transport of fatty acids into the mitochondria. Before fatty acids are utilized as fuel for the myocyte by beta-oxidation, they are bound to carnitine as an acylcarnitine ester at the 3-hydroxyl, and transported across the micochondrial membranes. R,S-Carnitine has been shown to be taken up by myocytes. The author has begun a study on the use of carnitine derivatives as potential carriers for the site-specific delivery of radioiodine to bidning sites in the myocardium. Such agents labeled with a gamma-emitting nuclide such as iodine-123 would be useful for the noninvasive imaging of these tissues. The aim was to synthesize a variety of radiolabeled analogs of carnitine and acylcarnitine to address questions of transport, binding and availability for myocardial metabolism. These analogs consist of N-alkylated derivatives of carnitine, acylcarnitine esters as well as carnitine amides and ethers. One C-alkylated derivative showed interesting biodistribution, elevated myocardial uptake and competition with carnitine for binding in the myocardium

  9. Development of Iron Doped Silicon Nanoparticles as Bimodal Imaging Agents

    Science.gov (United States)

    Singh, Mani P.; Atkins, Tonya M.; Muthuswamy, Elayaraja; Kamali, Saeed; Tu, Chuqiao; Louie, Angelique Y.; Kauzlarich, Susan M.

    2012-01-01

    We demonstrate the synthesis of water-soluble allylamine terminated Fe doped Si (SixFe) nanoparticles as bimodal agents for optical and magnetic imaging. The preparation involves the synthesis of a single source iron containing precursor, Na4Si4 with x% Fe (x = 1, 5, 10), and its subsequent reaction with NH4Br to produce hydrogen terminated SixFe nanoparticles. The hydrogen-capped nanoparticles are further terminated with allylamine via thermal hydrosilylation. Transmission electron microscopy (TEM) indicates that the average particle diameter is ~3.0±1.0 nm. The Si5Fe nanoparticles show strong photoluminescence quantum yield in water (~ 10 %) with significant T2 contrast (r2/r1value of 4.31). Electron paramagnetic resonance (EPR) and Mössbauer spectroscopies indicate that iron in the nanoparticles is in the +3 oxidation state. Analysis of cytotoxicity using the resazurin assay on HepG2 liver cells indicates that the particles have minimal toxicity. PMID:22616623

  10. DTPA: Bis benzimidazole as multi model imaging agent

    International Nuclear Information System (INIS)

    Srivastava, Vikas; Tiwari, A.K.; Sharma, H.; Sharma, R.; Mishra, A.K.

    2010-01-01

    Full text: The DTPA bis benzimidazole analogue has been tested for radiopharmaceutical efficacy. The radiolabelling was found more then 98% after 8 hrs and blood kinetics was fast. The compound was also tested for optical imaging agent. The Eu 3+ ion has an absorption band in the visible spectrum (578-582 nm) whose wavelength is very sensitive to even small changes in the coordination environment. Although the intensity of this 7F0 → 5D0 transition is low, the bands are relatively narrow, which allows distinguishing different coordination states of the metal. For Eu 3+ complexes which have two differently hydrated forms in aqueous solution, one observes two absorption bands belonging to the two species. High-resolution UV-visible spectra were recorded in aqueous solutions which show a temperature invariant absorption with two distinct, temperature-dependent absorption bands. The intensity ratio of these two bands changes with temperature: the band at shorter wavelengths is decreasing very slightly, while that at longer wavelengths is increasing with the temperature. The ratio of the integrals of the two bands is related to the equilibrium constant, and its temperature dependence yields the reaction enthalpy and entropy

  11. 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

  12. Chemical composition and biological evaluation of Physalis peruviana root as hepato-renal protective agent.

    Science.gov (United States)

    El-Gengaihi, Souad E; Hassan, Emad E; Hamed, Manal A; Zahran, Hanan G; Mohammed, Mona A

    2013-03-01

    This study was designed to investigate the potential of Physalis peruviana root as a functional food with hepato-renal protective effects against fibrosis. The chemical composition of the plant root suggested the presence of alkaloids, withanolides and flavonoids. Five compounds were isolated and their structures elucidated by different spectral analysis techniques. One compound was isolated from the roots: cuscohygrine. The biological evaluation was conducted on different animal groups; control rats, control treated with ethanolic root extract, CCl(4) group, CCl(4) treated with root extract, and CCl(4) treated with silymarin as a standard herbal drug. The evaluation used the oxidative stress markers malondialdehyde (MDA), superoxide dismutase (SOD), and nitric oxide (NO). The liver function indices; aspartate and alanine aminotransferases (AST & ALT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), bilirubin, and total hepatic protein were also estimated. Kidney disorder biomarkers; creatinine, urea, and serum protein were also evaluated. The results suggested safe administration, and improvement of all the investigated parameters. The liver and kidney histopathological analysis confirmed the results. In conclusion, P. peruviana succeeded in protecting the liver and kidney against fibrosis. Further studies are needed to discern their pharmacological applications and clinical uses.

  13. 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.

  14. 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)....

  15. 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.

  16. Benign renal complex cysts: MR imaging. Kystes atypiques benins du rein: aspects IRM

    Energy Technology Data Exchange (ETDEWEB)

    Levy, P.; Helenon, O.; Melki, P.; Paraf, F.; Chauveau, D.; Chretien, Y.; Moreau, J.F. (Hopital Necker-Enfants-Malades, 75 - Paris (France))

    1994-10-01

    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.

  17. 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

  18. Dynamic magnetic resonance imaging in the assessment of chronic medical nephropathies with impaired renal function

    International Nuclear Information System (INIS)

    Dalla-Palma, L.; Pozzi-Mucelli, R.S.; Cova, M.; Meduri, S.; Panzetta, G.; Galli, G.

    2000-01-01

    We examined the value of dynamic magnetic resonance imaging (MRI) in chronic renal disease with renal insufficiency. In 33 consecutive patients (21 vascular nephropathy, 12 glomerular nephropathy) MRI was performed using a 1.5-T unit and a body coil, with SE T1-weighted (TR/TE = 600/19 ms) and dynamic TFFE T1-weighted sequences (TR/TE = 12/5 ms, flip angle = 25 ) after manual bolus injection (via a cubital vein) of 0.1 mmol/kg Gd-DTPA-BMA. Morphological evaluation was performed in unblinded fashion by three radiologists, evaluating renal size, cortical thickness, and corticomedullary differentiation. Functional analysis was performed by one reviewer. Time-signal intensity curves, peak intensity value (P), time to peak intensity (T), and the P/T ratio were obtained at the cortex, medulla, and pyelocaliceal system of each kidney. The relationship of these parameters to serum creatinine and with creatinine clearance was investigated. A good correlation between morphological features of the kidneys and serum creatinine values was found. Morphological findings could not distinguish between vascular and glomerular nephropathies. A statistically significant correlation (P <0.01) between cortical P, cortical P/T, medullary P, and serum creatinine and creatinine clearance was found. A significant correlation (P <0.01) was also found between cortical T, medullary P/T, T of the excretory system, and creatinine clearance. The cortical T value was significantly higher (P <0.01) in vascular nephropathy than in glomerular nephropathy. Thus in patients with chronic renal failure dynamic MRI shows both morphological and functional changes. Morphological changes are correlated with the degree of renal insufficiency and not with the type of nephropathy; the functional changes seem to differ in vascular from glomerular nephropathies. (orig.)

  19. In vivo imaging of cellular proliferation in renal cell carcinoma using 18F-fluorothymidine PET

    International Nuclear Information System (INIS)

    Wong, Peter K.; Lee, Sze Ting; Murone, Carmel; Eng, John; Lawrentschuk, Nathan; Berlangieri, Salvatore University; Pathmaraj, Kunthi; O’Keefe, Graeme J.; Sachinidis, John; Byrne, Amanda J.; Bolton, Damien M.; Davis, Ian D.; Scott, Andrew M.

    2014-01-01

    The ability to measure cellular proliferation non-invasively in renal cell carcinoma may allow prediction of tumour aggressiveness and response to therapy. The aim of this study was to evaluate the uptake of 18F-fluorothymidine (FLT) PET in renal cell carcinoma (RCC), and to compare this to 18F-fluorodeoxyglucose (FDG), and to an immunohistochemical measure of cellular proliferation (Ki-67). Twenty seven patients (16 male, 11 females; age 42-77) with newly diagnosed renal cell carcinoma suitable for resection were prospectively enrolled. All patients had preoperative FLT and FDG PET scans. Visual identification of tumour using FLT PET compared to normal kidney was facilitated by the use of a pre-operative contrast enhanced CT scan. After surgery tumour was taken for histologic analysis and immunohistochemical staining by Ki-67. The SUVmax (maximum standardized uptake value) mean±SD for FLT in tumour was 2.59±1.27, compared to normal kidney (2.47±0.34). The mean SUVmax for FDG in tumour was similar to FLT (2.60±1.08). There was a significant correlation between FLT uptake and the immunohistochemical marker Ki-67 (r=0.72, P<0.0001) in RCC. Ki-67 proliferative index was mean ± SD of 13.3%±9.2 (range 2.2% - 36.3%). There is detectable uptake of FLT in primary renal cell carcinoma, which correlates with cellular proliferation as assessed by Ki-67 labelling index. This finding has relevance to the use of FLT PET in molecular imaging studies of renal cell carcinoma biology

  20. 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.)

  1. Detection and Evaluation of Renal Injury in Burst Wave Lithotripsy Using Ultrasound and Magnetic Resonance Imaging.

    Science.gov (United States)

    May, Philip C; Kreider, Wayne; Maxwell, Adam D; Wang, Yak-Nam; Cunitz, Bryan W; Blomgren, Philip M; Johnson, Cynthia D; Park, Joshua S H; Bailey, Michael R; Lee, Donghoon; Harper, Jonathan D; Sorensen, Mathew D

    2017-08-01

    Burst wave lithotripsy (BWL) is a transcutaneous technique with potential to safely and effectively fragment renal stones. Preclinical investigations of BWL require the assessment of potential renal injury. This study evaluates the capabilities of real-time ultrasound and MRI to detect and evaluate BWL injury that was induced in porcine kidneys. Ten kidneys from five female farm pigs were treated with either a 170 or 335 kHz BWL transducer using variable treatment parameters and monitored in real-time with ultrasound. Eight kidneys were perfusion fixed and scanned with a 3-Tesla MRI scanner (T1-weighted, T2-weighted, and susceptibility-weighted imaging), followed by processing via an established histomorphometric technique for injury quantification. In addition, two kidneys were separately evaluated for histologic characterization of injury quality. Observed B-mode hyperechoes on ultrasound consistent with cavitation predicted the presence of BWL-induced renal injury with a sensitivity and specificity of 100% in comparison to the histomorphometric technique. Similarly, MRI detected renal injury with a sensitivity of 90% and specificity of 100% and was able to identify the scale of lesion volumes. The injuries purposefully generated with BWL were histologically similar to those formed by shock wave lithotripsy. BWL-induced renal injury can be detected with a high degree of sensitivity and specificity by real-time ultrasound and post-treatment ex vivo MRI. No injury occurred in this study without cavitation detected on ultrasound. Such capabilities for injury detection and lesion volume quantification on MRI can be used for preclinical testing of BWL.

  2. 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

  3. Imaging tumor hypoxia: Blood-borne delivery of imaging agents is fundamentally different in hypoxia subtypes

    Directory of Open Access Journals (Sweden)

    Peter Vaupel

    2014-03-01

    Full Text Available Hypoxic tissue subvolumes are a hallmark feature of solid malignant tumors, relevant for cancer therapy and patient outcome because they increase both the intrinsic aggressiveness of tumor cells and their resistance to several commonly used anticancer strategies. Pathogenetic mechanisms leading to hypoxia are diverse, may coexist within the same tumor and are commonly grouped according to the duration of their effects. Chronic hypoxia is mainly caused by diffusion limitations resulting from enlarged intercapillary distances and adverse diffusion geometries and — to a lesser extent — by hypoxemia, compromised perfusion or long-lasting microregional flow stops. Conversely, acute hypoxia preferentially results from transient disruptions in perfusion. While each of these features of the tumor microenvironment can contribute to a critical reduction of oxygen availability, the delivery of imaging agents (as well as nutrients and anticancer agents may be compromised or remain unaffected. Thus, a critical appraisal of the effects of the various mechanisms leading to hypoxia with regard to the blood-borne delivery of imaging agents is necessary to judge their ability to correctly represent the hypoxic phenotype of solid malignancies.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Transcatheter Arterial Embolization With Spherical Embolic Agent for Pulmonary Metastases From Renal Cell Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Akihiko, E-mail: sekia@igtc.jp; Hori, Shinichi, E-mail: horishin@igtc.jp; Sueyoshi, Satoru, E-mail: sueyoshis@igtc.jp; Hori, Atsushi, E-mail: horiat@igtc.jp; Kono, Michihiko, E-mail: konom@igtc.jp; Murata, Shinichi, E-mail: muratas@igtc.jp; Maeda, Masahiko, E-mail: maedam@igtc.jp [Gate Tower Institute for Image Guided Therapy, Department of Radiology (Japan)

    2013-12-15

    Purpose: This retrospective study aimed to evaluate the safety and local efficacy of transcatheter arterial embolization (TAE) with superabsorbent polymer microspheres (SAP-MS) in patients with pulmonary metastases from renal cell carcinoma (RCC). Methods: Sixteen patients with unresectable pulmonary metastases from RCC refractory to standard therapy were enrolled to undergo TAE with the purpose of mass reduction and/or palliation. The prepared SAP-MS swell to approximately two times larger than their dry-state size (100-150 {mu}m [n = 14], 50-100 {mu}m [n = 2]). Forty-nine pulmonary nodules (lung n = 22, mediastinal lymph node n = 17, and hilar lymph node n = 10) were selected as target lesions for evaluation. Local tumor response was evaluated 3 months after TAE according to Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1). The relationship between tumor enhancement ratio by CT during selective angiography and local tumor response was evaluated. Results: The number of TAE sessions per patient ranged from 1 to 5 (median 2.9). Embolized arteries at initial TAE were bronchial arteries in 14 patients (87.5 %) and nonbronchial systemic arteries in 11 patients (68.8 %). Nodule-based evaluation showed that 5 (10.2 %) nodules had complete response, 17 (34.7 %) had partial response, 15 (30.6 %) had stable disease, and 12 (24.5 %) had progressive disease. The response rate was significantly greater in 22 lesions that had a high tumor enhancement ratio than in 27 lesions that had a slight or moderate ratio (90.9 vs. 7.4 %, p = 0.01). Severe TAE-related adverse events did not occur. Conclusion: TAE with SAP-MS might be a well-tolerated and locally efficacious palliative option for patients with pulmonary metastases from RCC.

  10. Relation between chemical shift artifact and infiltration on MR imaging of renal cell carcinoma

    International Nuclear Information System (INIS)

    Yoshigoe, Fukuo; Makino, Hideki; Yanada, Syuichi; Ohishi, Yukihiko; Mashima, Yasuoki; Yamada, Hideo.

    1994-01-01

    Retrospective study on the relation between existence of the interruption and disturbance of chemical shift artifact and tumor infiltration at the periphery of the kidney on MR imaging was evaluated in 28 cases with renal cell carcinoma. Judgement was possible in 9 out of the 11 cases with pathological stage below pT2 and 14 cases out of 17 pT3 cases. Judgement was impracticable in 5 cases because the peripheral fat tissue of the kidney was too less to observe chemical shift artifact and the tumor was spreading at the side opposite to the chemical shift artifact. Chemical shift artifact on MRI in this study correlated well with renal tumor infiltration. (author)

  11. Radioiodinated fenetylline (captagon): A new potential brain imaging agent

    International Nuclear Information System (INIS)

    Biersack, H.J.; Klunenberg, H.; Breuel, H.P.; Reske, S.N.; Reichmann, K.; Winkler, C.

    1984-01-01

    Since about 2 years /sup 123/I-labeled iodamphetamines (IMP) and diamines (HIPDM) have been used for scintigraphic brain investigations. As another possibly useful brain imaging agent we studied radioiodine labeled Fenetylline which is metabolized into amphetamine. Thirty wistar rats were injected 5 μCi /sup 125/I-IMP and 2 μCi /sup 131/I-Fenetylline each simultaneously. The animals were sacrificed 5,10,15,30,60, and 120 min. p.i. The radioactivity content of tissue specimens (brain, cerebellum, liver, kidney, lung, myocardium, muscle) was measured in a well-counter (% dose/g tissue). In 2 dogs sequential cerebral scintigraphy was performed following the injection of 0.5 mCi /sup 131/I-Fenetylline. Three patients underwent brain SPECT after injection of 6.5 mCi /sup 123/I-Fenetylline. The results can be summarized as follows: after 5/10 min. p.i. Fenetylline-uptake in the brain of rats was 1.0/1.3% compared to 1.3/1.9% (IMP). A fast decrease of cerebral Fenetylline concentration was established after 30 (0.2%) and 60 (0.5%) min. The canine and human sequential scintigraphy revealed a rapid cerebral uptake (maximum after 2-10 min.) suggesting that Fenetylline is concentrated in the brain as a function of cerebral blood flow. From the first clinical findings it appears to be likely that the combined use of /sup 123/I labelled IMP and Fenetylline for SPECT may lead to a more differentiated evaluation of cerebral blood flow and metabolism

  12. [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

  13. Prospective of 68Ga Radionuclide Contribution to the Development of Imaging Agents for Infection and Inflammation

    Science.gov (United States)

    2018-01-01

    During the last decade, the utilization of 68Ga for the development of imaging agents has increased considerably with the leading position in the oncology. The imaging of infection and inflammation is lagging despite strong unmet medical needs. This review presents the potential routes for the development of 68Ga-based agents for the imaging and quantification of infection and inflammation in various diseases and connection of the diagnosis to the treatment for the individualized patient management. PMID:29531507

  14. 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

  15. 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

  16. Measurement of renal blood flow by 131I-labelled sodium iodohippurate imaging in a rat model of herpes encephalitis

    International Nuclear Information System (INIS)

    Cleator, G.M.; Klapper, P.E.; Lewis, A.G.; Sharma, H.L.; Smith, A.M.; Manchester Univ.

    1990-01-01

    Renal blood flow was assessed qualitatively over a 30 min period in a rat model of herpes encephalitis by extra-renal scintigraphic imaging following the injection of 131 I-labelled sodium iodohippurate. No significant differences were observed for renal blood flow in either kidney between (or within) infected and control groups. Our data suggest that kidney function is not compromised in this animal model of encephalitis. The results are discussed in the context of the development of a non-invasive protocol for the in vivo diagnosis of herpes encephalitis. (orig.)

  17. 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)

  18. Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

    International Nuclear Information System (INIS)

    Rimondini, A.; Mucelli, R.P.; Dalla Palma, L.; De Denaro, M.; Bregant, P.

    2001-01-01

    The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6±0.8 mGy; protocol B 14.4±0.6 mGy; protocol C 12.5±1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality. (orig.)

  19. Management of Renal Tumors by Image-Guided Radiofrequency Ablation: Experience in 105 Tumors

    International Nuclear Information System (INIS)

    Breen, David J.; Rutherford, Elizabeth E.; Stedman, Brian; Roy-Choudhury, Shuvro H.; Cast, James E. I.; Hayes, Matthew C.; Smart, Christopher J.

    2007-01-01

    Aims. In this article we present our experience with radiofrequency ablation (RFA) in the treatment of 105 renal tumors. Materials and Methods. RFA was performed on 105 renal tumors in 97 patients, with a mean tumor size of 32 mm (11-68 mm). The mean patient age was 71.7 years (range, 36-89 years). The ablations were carried out under ultrasound (n = 43) or CT (n = 62) guidance. Imaging follow-up was by contrast-enhanced CT within 10 days and then at 6-monthly intervals. Multivariate analysis was performed to determine variables associated with procedural outcome. Results. Eighty-three tumors were completely treated at a single sitting (79%). Twelve of the remaining tumors were successfully re-treated and a clinical decision was made not to re-treat seven patients. A patient with a small residual crescent of tumor is under follow-up and may require further treatment. In another patient, re-treatment was abandoned due to complicating pneumothorax and difficult access. One patient is awaiting further re-treatment. The overall technical success rate was 90.5%. Multivariate analysis revealed tumor size to be the only significant variable affecting procedural outcome. (p = 0.007, Pearson χ 2 ) Five patients had complications. There have been no local recurrences. Conclusion. Our experience to date suggests that RFA is a safe and effective, minimally invasive treatment for small renal tumors

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

    Energy Technology Data Exchange (ETDEWEB)

    Yabuki, Takayuki; Togami, Izumi; Kitagawa, Takahiro; Sasai, Nobuya; Tsushima, Tomoyasu; Shirasaki, Yoshinori; Hiraki, Yoshio [Okayama Univ. (Japan). Graduate School of Medicine and Dentistry

    2003-08-01

    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 were compared against pathologic findings after resection, and the correlations among signal intensity, tumor enhancement, and pathologic findings were then assessed. A significant correlation was observed between tumor grade and tumor enhancement, with G3 lesions tending to show little enhancement. Regardless of the histologic classification, G3 tumors were found to contain highly heterotypic cancer cells and very few vessels by histopathologic examination. No significant correlations were noted between the other MR characteristics and pathologic findings. Renal cell carcinomas showing little enhancement tend to be highly malignant lesions based on the pathologic findings. Special consideration is required for these tumors with regard to the selection of surgical intervention and follow-up observation. (author)

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

    International Nuclear Information System (INIS)

    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 were compared against pathologic findings after resection, and the correlations among signal intensity, tumor enhancement, and pathologic findings were then assessed. A significant correlation was observed between tumor grade and tumor enhancement, with G3 lesions tending to show little enhancement. Regardless of the histologic classification, G3 tumors were found to contain highly heterotypic cancer cells and very few vessels by histopathologic examination. No significant correlations were noted between the other MR characteristics and pathologic findings. Renal cell carcinomas showing little enhancement tend to be highly malignant lesions based on the pathologic findings. Special consideration is required for these tumors with regard to the selection of surgical intervention and follow-up observation. (author)

  2. 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

  3. 3D Texture Analysis in Renal Cell Carcinoma Tissue Image Grading

    Directory of Open Access Journals (Sweden)

    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.

  4. Cardiac risk stratification with myocardial perfusion imaging in potential renal-pancreas transplant recipients

    International Nuclear Information System (INIS)

    McCarthy, M.C.; Larcos, G.; Chapman, J.

    1998-01-01

    Full text: Combined renal/pancreas transplantation is used in patients with severe type-1 diabetes and renal failure. Many patients have asymptomatic coronary artery disease (CAD). Thus, myocardial perfusion imaging (MPI) is widely used for preoperative risk assessment, however, its value has recently been challenged. The purpose of this study was to determine the predictive value of MPI compared to coronary angiography and/or thirty day perioperative cardiac events (cardiac death, myocardial infarction and unstable angina). We reviewed the MPI in 132 patients that were referred for possible renal pancreas transplantation during the period between 1987 - June 1997. Fifty five patients were excluded because of: still awaiting transplantation (n=19) ongoing medical assessment (n=21), received kidney only transplant (n=6) or other factors (n=9). Thus, 77 patients form the basis of this report. Seventy one patients were transplanted, 5 had coronary angiography and one died before transplantation but with coronary anatomy defined at autopsy. All patients (39 male, 38 female; mean age 37 years) had Tl-201 or Tc-99m MIBI SPECT at Westmead (n=54) or elsewhere (n=23). Patients underwent MPI, a mean of 12.1 months before transplantation and a mean of 6 months before coronary angiography or autopsy. MPI was normal in 64 (83%) and abnormal in 13 (17%) patients. Of the abnormal MPI, 7 patients had CAD and one had unstable angina post-operatively (PPV = 8/13; 61%). One patient had a fixed defect post CABG but proceeded to transplant with-out event; the other 4 patients had normal coronary anatomy. Of the normal MPIs there were no transplant related cardiac events, but one patient required CABG >12 months post MPI and a further patient died >12 months post transplant and was shown to have CAD at autopsy (NPV=62/64;97%). In conclusion we have found an excellent NPV and an acceptable PPV for MPI in potential renal pancreas graft recipients

  5. Cardiac risk stratification with myocardial perfusion imaging in potential renal-pancreas transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, M.C.; Larcos, G.; Chapman, J. [Westmead Hospital, Westmead, Sydney, NSW (Australia). Departments of Nuclear Medicine and Ultrasound

    1998-06-01

    Full text: Combined renal/pancreas transplantation is used in patients with severe type-1 diabetes and renal failure. Many patients have asymptomatic coronary artery disease (CAD). Thus, myocardial perfusion imaging (MPI) is widely used for preoperative risk assessment, however, its value has recently been challenged. The purpose of this study was to determine the predictive value of MPI compared to coronary angiography and/or thirty day perioperative cardiac events (cardiac death, myocardial infarction and unstable angina). We reviewed the MPI in 132 patients that were referred for possible renal pancreas transplantation during the period between 1987 - June 1997. Fifty five patients were excluded because of: still awaiting transplantation (n=19) ongoing medical assessment (n=21), received kidney only transplant (n=6) or other factors (n=9). Thus, 77 patients form the basis of this report. Seventy one patients were transplanted, 5 had coronary angiography and one died before transplantation but with coronary anatomy defined at autopsy. All patients (39 male, 38 female; mean age 37 years) had Tl-201 or Tc-99m MIBI SPECT at Westmead (n=54) or elsewhere (n=23). Patients underwent MPI, a mean of 12.1 months before transplantation and a mean of 6 months before coronary angiography or autopsy. MPI was normal in 64 (83%) and abnormal in 13 (17%) patients. Of the abnormal MPI, 7 patients had CAD and one had unstable angina post-operatively (PPV = 8/13; 61%). One patient had a fixed defect post CABG but proceeded to transplant with-out event; the other 4 patients had normal coronary anatomy. Of the normal MPIs there were no transplant related cardiac events, but one patient required CABG >12 months post MPI and a further patient died >12 months post transplant and was shown to have CAD at autopsy (NPV=62/64;97%). In conclusion we have found an excellent NPV and an acceptable PPV for MPI in potential renal pancreas graft recipients

  6. 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.

  7. Ultrasound contrast agent imaging: Real-time imaging of the superharmonics

    Energy Technology Data Exchange (ETDEWEB)

    Peruzzini, D.; Viti, J. [MSD lab, Department of Information Engineering, Univ of Florence, Via S.Marta, 3, 50139 Firenze (Italy); Erasmus MC, ’s-Gravendijkwal 230, Faculty Building, Ee 2302, 3015 CE Rotterdam (Netherlands); Tortoli, P. [MSD lab, Department of Information Engineering, Univ of Florence, Via S.Marta, 3, 50139 Firenze (Italy); Verweij, M. D. [Acoustical Wavefield Imaging, ImPhys, Delft Univ Technology, van der Waalsweg 8, 2628 CH Delft (Netherlands); Jong, N. de; Vos, H. J., E-mail: h.vos@erasmusmc.nl [Erasmus MC, ’s-Gravendijkwal 230, Faculty Building, Ee 2302, 3015 CE Rotterdam (Netherlands); Acoustical Wavefield Imaging, ImPhys, Delft Univ Technology, van der Waalsweg 8, 2628 CH Delft (Netherlands)

    2015-10-28

    Currently, in medical ultrasound contrast agent (UCA) imaging the second harmonic scattering of the microbubbles is regularly used. This scattering is in competition with the signal that is caused by nonlinear wave propagation in tissue. It was reported that UCA imaging based on the third or higher harmonics, i.e. “superharmonic” imaging, shows better contrast. However, the superharmonic scattering has a lower signal level compared to e.g. second harmonic signals. This study investigates the contrast-to-tissue ratio (CTR) and signal to noise ratio (SNR) of superharmonic UCA scattering in a tissue/vessel mimicking phantom using a real-time clinical scanner. Numerical simulations were performed to estimate the level of harmonics generated by the microbubbles. Data were acquired with a custom built dual-frequency cardiac phased array probe. Fundamental real-time images were produced while beam formed radiofrequency (RF) data was stored for further offline processing. The phantom consisted of a cavity filled with UCA surrounded by tissue mimicking material. The acoustic pressure in the cavity of the phantom was 110 kPa (MI = 0.11) ensuring non-destructivity of UCA. After processing of the acquired data from the phantom, the UCA-filled cavity could be clearly observed in the images, while tissue signals were suppressed at or below the noise floor. The measured CTR values were 36 dB, >38 dB, and >32 dB, for the second, third, and fourth harmonic respectively, which were in agreement with those reported earlier for preliminary contrast superharmonic imaging. The single frame SNR values (in which ‘signal’ denotes the signal level from the UCA area) were 23 dB, 18 dB, and 11 dB, respectively. This indicates that noise, and not the tissue signal, is the limiting factor for the UCA detection when using the superharmonics in nondestructive mode.

  8. Anatomic characteristics and natural history of renal artery aneurysms during longitudinal imaging surveillance.

    Science.gov (United States)

    Wayne, Erik J; Edwards, Matthew S; Stafford, Jeanette M; Hansen, Kimberley J; Corriere, Matthew A

    2014-08-01

    Renal artery aneurysms (RAAs) are uncommon, and rates of growth and rupture are unknown. Limited evidence therefore exists to guide clinical management of RAAs, particularly small aneurysms that are asymptomatic. To further characterize the natural history of RAAs, we studied anatomic characteristics and changes in diameter during imaging surveillance. Patients evaluated for native RAAs at a single institution during a 5-year period (July 2008 to July 2013) were identified and analyzed retrospectively. Patients with two or more cross-sectional imaging studies (computed tomography or magnetic resonance imaging) more than 1 month apart were included. Demographic and clinical data were collected from medical records, and anatomic data (including aneurysm diameter, calcification, and location) were obtained from electronic images. Changes in RAA diameters over time were evaluated by plots and Wilcoxon signed rank tests. Sixty-eight RAAs in 55 patients were analyzed. Median follow-up was 19.4 months (interquartile range, 11.2-49.0 months). Mean age at presentation was 61.8 ± 9.8 years, and 73% of patients were women. Hypertension was prevalent among 73% of patients. Multiple RAAs were present in 18% of patients, and 24% also had arterial aneurysms of other splanchnic or iliac vessels. The majority of RAAs were calcified and located at the main renal artery bifurcation. Mean initial aneurysm diameter was 16.0 ± 6.4 mm. Median annualized growth rate was 0.06 mm (interquartile range, -0.07 to 0.33 mm; P = .11). No RAA ruptures or acute symptoms occurred during surveillance, and 10.3% of RAAs were repaired electively. Risk of short-term RAA growth or rupture was low. These findings suggest that annual (or less frequent) imaging surveillance is safe in the majority of patients and do not support pre-emptive repair of asymptomatic, small-diameter RAAs. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  9. 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)

  10. 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)

  11. Microbubble embedded with upconversion nanoparticles as a bimodal contrast agent for fluorescence and ultrasound imaging

    International Nuclear Information System (INIS)

    Jin, Birui; Lin, Min; You, Minli; Xu, Feng; Lu, Tianjian; Zong, Yujin; Wan, Mingxi; Duan, Zhenfeng

    2015-01-01

    Bimodal imaging offers additional imaging signal thus finds wide spread application in clinical diagnostic imaging. Fluorescence/ultrasound bimodal imaging contrast agent using fluorescent dyes or quantum dots for fluorescence signal has emerged as a promising method, which however requires visible light or UV irradiation resulting in photobleaching, photoblinking, auto-fluorescence and limited tissue penetration depth. To surmount these problems, we developed a novel bimodal contrast agent using layer-by-layer assembly of upconversion nanoparticles onto the surface of microbubbles. The resulting microbubbles with average size of 2 μm provide enhanced ultrasound echo for ultrasound imaging and upconversion emission upon near infrared irradiation for fluorescence imaging. The developed bimodal contrast agent holds great potential to be applied in ultrasound target technique for targeted diseases diagnostics and therapy. (paper)

  12. 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

  13. 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)

  14. 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.

  15. Diffusion tensor imaging and tractography for assessment of renal allograft dysfunction - initial results

    Energy Technology Data Exchange (ETDEWEB)

    Hueper, Katja; Gutberlet, M.; Rodt, T.; Wacker, F.; Galanski, M.; Hartung, D. [Institute for Diagnostic and Interventional Radiology, Hannover Medical School - Germany, Hannover (Germany); Gwinner, W. [Clinic for Nephrology, Hannover Medical School - Germany, Hannover (Germany); Lehner, F. [Clinic for General, Abdominal and Transplant Surgery, Hannover Medical School - Germany, Hannover (Germany)

    2011-11-15

    To evaluate MR diffusion tensor imaging (DTI) as non-invasive diagnostic tool for detection of acute and chronic allograft dysfunction and changes of organ microstructure. 15 kidney transplanted patients with allograft dysfunction and 14 healthy volunteers were examined using a fat-saturated echo-planar DTI-sequence at 1.5 T (6 diffusion directions, b = 0, 600 s/mm{sup 2}). Mean apparent diffusion coefficient (ADC) and mean fractional anisotropy (FA) were calculated separately for the cortex and for the medulla and compared between healthy and transplanted kidneys. Furthermore, the correlation between diffusion parameters and estimated GFR was determined. The ADC in the cortex and in the medulla were lower in transplanted than in healthy kidneys (p < 0.01). Differences were more distinct for FA, especially in the renal medulla, with a significant reduction in allografts (p < 0.001). Furthermore, in transplanted patients a correlation between mean FA in the medulla and estimated GFR was observed (r = 0.72, p < 0.01). Tractography visualized changes in renal microstructure in patients with impaired allograft function. Changes in allograft function and microstructure can be detected and quantified using DTI. However, to prove the value of DTI for standard clinical application especially correlation of imaging findings and biopsy results is necessary. (orig.)

  16. Extrinsic ureteropelvic junction obstruction from a crossing renal vessel: demography and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rooks, V.J.; Lebowitz, R.L. [Children' s Hospital and Harvard Medical School, Dept. of Radiology, Boston, MA (United States)

    2001-02-01

    Background. The increase in the use of prenatal ultrasound has revolutionized the detection of hydronephrosis and has had an unanticipated consequence. Objective. To describe the new demographics of symptomatic ureteropelvic junction (UPJ) obstruction and the characteristic imaging findings, when the obstruction is extrinsic, from a crossing renal vessel. Materials and methods. From a uroradiology database (1994 through 1999) we identified children with surgically corrected UPJ obstruction from intrinsic and extrinsic causes. Results. One hundred children had symptomatic UPJ obstruction treated by surgery. In 51 (49 %), obstruction was due to a crossing vessel. One hundred and one had UPJ obstruction detected by prenatal sonography. Only 11 (11 %) were due to a vessel. Two clinical and imaging findings were strongly suggestive of obstruction from a vessel: (1) in 5 of the 100 children the symptoms (pain, nausea, and vomiting) were intermittent. Only when symptoms were present were there hydronephrosis and obstruction; (2) in 51 of the 100 children a short segment of ureter, just below the UPJ, was filled with contrast or urine (on renal sonography, intravenous urography, or retrograde/antegrade ureterography). Conclusions. Extrinsic UPJ obstruction caused by a vessel is an uncommon cause of obstruction when all patients are considered. However, in symptomatic older patients whose hydronephrosis was not first identified on prenatal sonography, a vessel was the cause of obstruction in one-half. (orig.)

  17. 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

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

    Science.gov (United States)

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

    2016-03-01

    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 MRI volumes to the cryo bright field reference, we used our standard mutual information, non-rigid registration which proceeded: preprocess --> affine --> B-spline non-rigid 3D registration. In this report, we created two modified approaches: mask where we registered locally over a smaller rectangular solid, and sliding organ. Briefly, in sliding organ, we segmented the organ, registered the organ and body volumes separately and combined results. Though sliding organ required manual annotation, it provided the best result as a standard to measure other registration methods. Regularization parameters for standard and mask methods were optimized in a grid search. Evaluations consisted of DICE, and visual scoring of a checkerboard display. Standard had accuracy of 2 voxels in all regions except near the kidney, where there were 5 voxels sliding. After mask and sliding organ correction, kidneys sliding were within 2 voxels, and Dice overlap increased 4%-10% in mask compared to standard. Mask generated comparable results with sliding organ and allowed a semi-automatic process.

  19. 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.)

  20. 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.)

  1. 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.)

  2. [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.

  3. 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.

  4. 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

  5. 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

  6. Renal scan

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003790.htm Renal scan To use the sharing features on this ... anaphylaxis . Alternative Names Renogram; Kidney scan Images Kidney anatomy Kidney - blood and urine flow References Chernecky CC, ...

  7. 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.

  8. Development of a Multifaceted Ovarian Cancer Therapeutic and Imaging Agent

    Science.gov (United States)

    2011-04-01

    by 1-ethyl-3- [3-(dimethylamino) propyl ]carbodiimide (EDC) and N-hydroxysulfonosuccinimide (SNHS) at pH 5.5 for 30 min with a molar ratio of...particle-coated migratory substrate that can act as a permanent record of cellular movement. The gold chloride solution was prepared using 0.342 g... Synthesis and clinical Evaluation. Anticancer Agents Med. Chem. McLane, M.A., Joerger, T., Mahmoud, A., 2008. Disintegrins in health and disease. Front

  9. High-Relaxivity MRI Contrast Agents: Where Coordination Chemistry Meets Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Eric J.; Datta, Ankona; Jocher, Christoph J.; Raymond, Kenneth N.

    2008-01-15

    The desire to improve and expand the scope of clinical magnetic resonance imaging (MRI) has prompted the search for contrast agents of higher efficiency. The development of better agents requires consideration of the fundamental coordination chemistry of the gadolinium(III) ion and the parameters that affect its efficacy as a proton relaxation agent. In optimizing each parameter, other practical issues such as solubility and in vivo toxicity must also be addressed, making the attainment of safe, high-relaxivity agents a challenging goal. Here we present recent advances in the field, with an emphasis on the hydroxypyridinone family of Gd{sup III} chelates.

  10. 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.

  11. Renal cell carcinoma metastases to the pancreas - Value of arterial phase imaging at MDCT

    International Nuclear Information System (INIS)

    Corwin, Michael T.; Lamba, Ramit; McGahan, John P.; Wilson, Machelle

    2013-01-01

    Background: The pancreas is an increasingly recognized site of renal cell carcinoma metastases. It is important to determine the optimal MDCT protocol to best detect RCC metastases to the pancreas. Purpose: To compare the rate of detection of renal cell carcinoma metastases to the pancreas between arterial and portal venous phase MDCT. Material and Methods: A retrospective review of CTs of the abdomen yielded six patients with metastatic RCC to the pancreas. Five of six patients had pathologically proven clear cell RCC. Two blinded reviewers independently reported the number of pancreatic lesions seen in arterial and venous phases. Each lesion was graded as definite or possible. The number of lesions was determined by consensus review of both phases. Attenuation values were obtained for metastatic lesions and adjacent normal pancreas in both phases. Results: There were a total of 24 metastatic lesions to the pancreas. Reviewer 1 identified 20/24 (83.3%) lesions on the arterial phase images and 13/24 (54.2%) lesions on the venous phase. Seventeen of 20 (85.0%) arterial lesions were deemed definite and 9/13 (69.2%) venous lesions were definite. Reviewer 2 identified 19/24 (79.2%) lesions on the arterial phase and 14/24 (58.3%) on the venous phase. Seventeen of 19 (89.5%) arterial lesions were definite and 7/14 (50%) venous lesions were definite. Mean attenuation differential between lesion and pancreas was 114 HU and 39 HU for arterial and venous phases, respectively (P<0.0001). Conclusion: Detection of RCC metastases to the pancreas at MDCT is improved using arterial phase imaging compared to portal venous phase imaging

  12. 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)

  13. Noninvasive measurement of renal blood flow by magnetic resonance imaging in rats.

    Science.gov (United States)

    Romero, Cesar A; Cabral, Glauber; Knight, Robert A; Ding, Guangliang; Peterson, Edward L; Carretero, Oscar A

    2018-01-01

    Renal blood flow (RBF) provides important information regarding renal physiology and nephropathies. Arterial spin labeling-magnetic resonance imaging (ASL-MRI) is a noninvasive method of measuring blood flow without exogenous contrast media. However, low signal-to-noise ratio and respiratory motion artifacts are challenges for RBF measurements in small animals. Our objective was to evaluate the feasibility and reproducibility of RBF measurements by ASL-MRI using respiratory-gating and navigator correction methods to reduce motion artifacts. ASL-MRI images were obtained from the kidneys of Sprague-Dawley (SD) rats on a 7-Tesla Varian MRI system with a spin-echo imaging sequence. After 4 days, the study was repeated to evaluate its reproducibility. RBF was also measured in animals under unilateral nephrectomy and in renal artery stenosis (RST) to evaluate the sensitivity in high and low RBF models, respectively. RBF was also evaluated in Dahl salt-sensitive (SS) rats and spontaneous hypertensive rats (SHR). In SD rats, the cortical RBFs (cRBF) were 305 ± 59 and 271.8 ± 39 ml·min -1 ·100 g tissue -1 in the right and left kidneys, respectively. Retest analysis revealed no differences ( P = 0.2). The test-retest reliability coefficient was 92 ± 5%. The cRBFs before and after the nephrectomy were 296.8 ± 30 and 428.2 ± 45 ml·min -1 ·100 g tissue -1 ( P = 0.02), respectively. The kidneys with RST exhibited a cRBF decrease compared with sham animals (86 ± 17.6 vs. 198 ± 33.7 ml·min -1 ·100 g tissue -1 ; P < 0.01). The cRBFs in SD, Dahl-SS, and SHR rats were not different ( P = 0.35). We conclude that ASL-MRI performed with navigator correction and respiratory gating is a feasible and reliable noninvasive method for measuring RBF in rats.

  14. Metal complex-based templates and nanostructures for magnetic resonance/optical multimodal imaging agents

    NARCIS (Netherlands)

    Galindo Millan, Jealemy

    2012-01-01

    In this thesis, new approaches directed towards simple and functional imaging agents (IAs) for magnetic resonance (MR) and fluorescence multimodal imaging are proposed. In Chapter 3, hybrid silver nanostructures (hAgNSs), grown using a polyamino carboxylic acid scaffold, namely

  15. EPR and DNP Properties of Certain Novel Single Electron Contrast Agents Intended for Oximetric Imaging

    DEFF Research Database (Denmark)

    Ardenkjær-Larsen, J. H.; Laursen, I; Leunbach, I.

    1998-01-01

    Parameters of relevance to oximetry with Overhauser magnetic resonance imaging (OMRI) have been measured for three single electron contrast agents of the triphenylmethyl type. The single electron contrast agents are stable and water soluble. Magnetic resonance properties of the agents have been...... examined with electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and dynamic nuclear polarization (DNP) at 9.5 mT in water, isotonic saline, plasma, and blood at 23 and 37°C. The relaxivities of the agents are about 0.2–0.4 mM−1s−1and the DNP enhancements extrapolate close...... to the dipolar limit. The agents have a single, narrow EPR line, which is analyzed as a Voigt function. The linewidth is measured as a function of the agent concentration and the oxygen concentration. The concentration broadenings are about 1–3 μT/mM and the Lorentzian linewidths at infinite dilution are less...

  16. Suture Granuloma Mimicking Renal Cell Carcinoma: Magnetic Resonance Imaging (MRI and Pathologic Correlation

    Directory of Open Access Journals (Sweden)

    İbrahim İlker Öz

    2014-11-01

    Full Text Available Solid renal masses are generally distinguished with contrast enhancement and intratumoral fatty foci by radiological examinations. The present of enhancement is most important criteria for diagnosis of malignant lesions. Generally, a contrast enhanced solid mass in kidney is accepted as a neoplasm. Foreign body granuloma is an extraordinary cause of enhanced solid renal mass. This case of a renal suture granuloma demonstrated peripheral enhanced exophytic renal mass mimic renal cell carcinoma, and underwent surgery. At the solid renal mass with different radiological features, biopsy is an option to determining the necessity of surgery as well as the surgical approach.

  17. Biochemical Stability Analysis of Nano Scaled Contrast Agents Used in Biomolecular Imaging Detection of Tumor Cells

    Science.gov (United States)

    Kim, Jennifer; Kyung, Richard

    Imaging contrast agents are materials used to improve the visibility of internal body structures in the imaging process. Many agents that are used for contrast enhancement are now studied empirically and computationally by researchers. Among various imaging techniques, magnetic resonance imaging (MRI) has become a major diagnostic tool in many clinical specialties due to its non-invasive characteristic and its safeness in regards to ionizing radiation exposure. Recently, researchers have prepared aqueous fullerene nanoparticles using electrochemical methods. In this paper, computational simulations of thermodynamic stabilities of nano scaled contrast agents that can be used in biomolecular imaging detection of tumor cells are presented using nanomaterials such as fluorescent functionalized fullerenes. In addition, the stability and safety of different types of contrast agents composed of metal oxide a, b, and c are tested in the imaging process. Through analysis of the computational simulations, the stabilities of the contrast agents, determined by optimized energies of the conformations, are presented. The resulting numerical data are compared. In addition, Density Functional Theory (DFT) is used in order to model the electron properties of the compound.

  18. Use of radiolabeled antibodies as diagnostic imaging agents

    International Nuclear Information System (INIS)

    Wang, T.S.T.; Seldin, D.; Fawwaz, R.A.; Srivastava, S.; Olvwole, S.

    1989-01-01

    Recent advances in hybridoma technology have led to the development of monoclonal antibodies to a variety of antigens. The high degree of specificity of such reagents coupled with refinements in instrumentation and production of new radionuclides has rekindled interest in the application of radioimmunoscintigraphy in the diagnosis of various diseases. Although much of the work with monoclonal antibodies has been devoted to the diagnosis and treatment of tumors, increasing use is being made of these agents for the study of nontumor related disorders. This chapter focuses on the application of radioimmunoscintigraphy in the diagnosis of malignancies with a discussion on the other uses, notably those related to the vascular system

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

    OpenAIRE

    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 ...

  20. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  2. 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...

  3. Molecular imaging agents for SPECT (and SPECT/CT)

    International Nuclear Information System (INIS)

    Gnanasegaran, Gopinath; Ballinger, James R.

    2014-01-01

    The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers. (orig.)

  4. Molecular imaging agents for SPECT (and SPECT/CT)

    Energy Technology Data Exchange (ETDEWEB)

    Gnanasegaran, Gopinath [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); Ballinger, James R. [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom)

    2014-05-15

    The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers. (orig.)

  5. Fluorescence lifetime imaging microscopy using near-infrared contrast agents.

    Science.gov (United States)

    Nothdurft, R; Sarder, P; Bloch, S; Culver, J; Achilefu, S

    2012-08-01

    Although single-photon fluorescence lifetime imaging microscopy (FLIM) is widely used to image molecular processes using a wide range of excitation wavelengths, the captured emission of this technique is confined to the visible spectrum. Here, we explore the feasibility of utilizing near-infrared (NIR) fluorescent molecular probes with emission >700 nm for FLIM of live cells. The confocal microscope is equipped with a 785 nm laser diode, a red-enhanced photomultiplier tube, and a time-correlated single photon counting card. We demonstrate that our system reports the lifetime distributions of NIR fluorescent dyes, cypate and DTTCI, in cells. In cells labelled separately or jointly with these dyes, NIR FLIM successfully distinguishes their lifetimes, providing a method to sort different cell populations. In addition, lifetime distributions of cells co-incubated with these dyes allow estimate of the dyes' relative concentrations in complex cellular microenvironments. With the heightened interest in fluorescence lifetime-based small animal imaging using NIR fluorophores, this technique further serves as a bridge between in vitro spectroscopic characterization of new fluorophore lifetimes and in vivo tissue imaging. © 2012 The Author Journal of Microscopy © 2012 Royal Microscopical Society.

  6. 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.)

  7. 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

  8. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Joyce T. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Robinson, Joshua D. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Deng, Jie [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Rigsby, Cynthia K. [Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

    2016-12-15

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  9. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

    International Nuclear Information System (INIS)

    Johnson, Joyce T.; Robinson, Joshua D.; Deng, Jie; Rigsby, Cynthia K.

    2016-01-01

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  10. Amphetamines and pH-shift agents for brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Biersack, H.J.; Winkler, C.

    1986-01-01

    This book gives a review of the results of experimental and clinical research on both I-amphetamine derivatives and pH-shift agents. Virtually all relevant working groups from the USA and Europe have contributed to this volume. The pharmacology of amphetamine and the corresponding receptor theories are described in detail, whereas other chapters deal with the labeling as well as the metabolic process of this drug. In addition to this, new amphetamine derivatives are presented together with other essential products which play a significant role in scintigraphy of the brain function. Finally, there are two chapters on instrumentation problems followed by eight contributions on the clinical results of amphetamine scintigraphy in cerebral vascular diseases, epilepsy, migraine and brain tumors.

  11. Parametric renal blood flow imaging using [{sup 15}O]H{sub 2}O and PET

    Energy Technology Data Exchange (ETDEWEB)

    Kudomi, Nobuyuki; Liukko, Kaisa E.; Oikonen, Vesa J.; Tolvanen, Tuula [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); Koivuviita, Niina; Tertti, Risto; Metsaerinne, Kaj [University of Turku, Department of Medicine, Turku (Finland); Iida, Hidehiro [National Cardiovascular Center-Research Institute, Department of Investigative Radiology, Advanced Medical-Engineering Center, Suita, Osaka (Japan); Iozzo, Patricia [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); National Research Council, Institute of Clinical Physiology, Pisa (Italy); Nuutila, Pirjo [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); University of Turku, Department of Medicine, Turku (Finland)

    2009-04-15

    The quantitative assessment of renal blood flow (RBF) may help to understand the physiological basis of kidney function and allow an evaluation of pathophysiological events leading to vascular damage, such as renal arterial stenosis and chronic allograft nephropathy. The RBF may be quantified using PET with H{sub 2} {sup 15}O, although RBF studies that have been performed without theoretical evaluation have assumed the partition coefficient of water (p, ml/g) to be uniform over the whole region of renal tissue, and/or radioactivity from the vascular space (V{sub A}. ml/ml) to be negligible. The aim of this study was to develop a method for calculating parametric images of RBF (K{sub 1}, k{sub 2}) as well as V{sub A} without fixing the partition coefficient by the basis function method (BFM). The feasibility was tested in healthy subjects. A simulation study was performed to evaluate error sensitivities for possible error sources. The experimental study showed that the quantitative accuracy of the present method was consistent with nonlinear least-squares fitting, i.e. K{sub 1,BFM}=0.93K{sub 1,NLF}-0.11 ml/min/g (r=0.80, p<0.001), k{sub 2,BFM}=0.96k{sub 2,NLF}-0.13 ml/min/g (r=0.77, p<0.001), and V{sub A,BFM}=0.92V{sub A,NLF}-0.00 ml/ml (r=0.97, p<0.001). Values of the Akaike information criterion from this fitting were the smallest for all subjects except two. The quality of parametric images obtained was acceptable. The simulation study suggested that delay and dispersion time constants should be estimated within an accuracy of 2 s. V{sub A} and p cannot be neglected or fixed, and reliable measurement of even relative RBF values requires that V{sub A} is fitted. This study showed the feasibility of measurement of RBF using PET with H{sub 2} {sup 15}O. (orig.)

  12. Body-mounted robotic instrument guide for image-guided cryotherapy of renal cancer

    Science.gov (United States)

    Hata, Nobuhiko; Song, Sang-Eun; Olubiyi, Olutayo; Arimitsu, Yasumichi; Fujimoto, Kosuke; Kato, Takahisa; Tuncali, Kemal; Tani, Soichiro; Tokuda, Junichi

    2016-01-01

    Purpose: Image-guided cryotherapy of renal cancer is an emerging alternative to surgical nephrectomy, particularly for those who cannot sustain the physical burden of surgery. It is well known that the outcome of this therapy depends on the accurate placement of the cryotherapy probe. Therefore, a robotic instrument guide may help physicians aim the cryotherapy probe precisely to maximize the efficacy of the treatment and avoid damage to critical surrounding structures. The objective of this paper was to propose a robotic instrument guide for orienting cryotherapy probes in image-guided cryotherapy of renal cancers. The authors propose a body-mounted robotic guide that is expected to be less susceptible to guidance errors caused by the patient’s whole body motion. Methods: Keeping the device’s minimal footprint in mind, the authors developed and validated a body-mounted, robotic instrument guide that can maintain the geometrical relationship between the device and the patient’s body, even in the presence of the patient’s frequent body motions. The guide can orient the cryotherapy probe with the skin incision point as the remote-center-of-motion. The authors’ validation studies included an evaluation of the mechanical accuracy and position repeatability of the robotic instrument guide. The authors also performed a mock MRI-guided cryotherapy procedure with a phantom to compare the advantage of robotically assisted probe replacements over a free-hand approach, by introducing organ motions to investigate their effects on the accurate placement of the cryotherapy probe. Measurements collected for performance analysis included accuracy and time taken for probe placements. Multivariate analysis was performed to assess if either or both organ motion and the robotic guide impacted these measurements. Results: The mechanical accuracy and position repeatability of the probe placement using the robotic instrument guide were 0.3 and 0.1 mm, respectively, at a depth

  13. Towards a framework for agent-based image analysis of remote-sensing data.

    Science.gov (United States)

    Hofmann, Peter; Lettmayer, Paul; Blaschke, Thomas; Belgiu, Mariana; Wegenkittl, Stefan; Graf, Roland; Lampoltshammer, Thomas Josef; Andrejchenko, Vera

    2015-04-03

    Object-based image analysis (OBIA) as a paradigm for analysing remotely sensed image data has in many cases led to spatially and thematically improved classification results in comparison to pixel-based approaches. Nevertheless, robust and transferable object-based solutions for automated image analysis capable of analysing sets of images or even large image archives without any human interaction are still rare. A major reason for this lack of robustness and transferability is the high complexity of image contents: Especially in very high resolution (VHR) remote-sensing data with varying imaging conditions or sensor characteristics, the variability of the objects' properties in these varying images is hardly predictable. The work described in this article builds on so-called rule sets. While earlier work has demonstrated that OBIA rule sets bear a high potential of transferability, they need to be adapted manually, or classification results need to be adjusted manually in a post-processing step. In order to automate these adaptation and adjustment procedures, we investigate the coupling, extension and integration of OBIA with the agent-based paradigm, which is exhaustively investigated in software engineering. The aims of such integration are (a) autonomously adapting rule sets and (b) image objects that can adopt and adjust themselves according to different imaging conditions and sensor characteristics. This article focuses on self-adapting image objects and therefore introduces a framework for agent-based image analysis (ABIA).

  14. Diagnosis of secondary hyperparathyroidism with 99mTc-MIBI/131I parathyroid imaging in chronic renal failure

    International Nuclear Information System (INIS)

    Tang Anwu; Luo Yaowu; Wu Yongkang; Pan Jianzhong; Ji Liangyuan

    1995-01-01

    20 chronic renal failure (CRF) patients and 15 normals were investigated with radionuclide parathyroid imaging and parathyroid hormone (PTH) RIA measurement for the detection of hyperparathyroidism. The serum PTH concentrations were 800.47 +- 665.25 pmol/L and 82.81 +- 13.79 pmol/L in two groups respectively. The radionuclide parathyroid images revealed that 1∼4 enlarged parathyroid glands were visualized in the CRF patients, none in the normals

  15. Fluorine-18 nuclide and its PET imaging agent

    International Nuclear Information System (INIS)

    Wang Mingfang

    2003-01-01

    Fluorine-18 has predominant physical features with long half-life and the enough time for preparation of radiopharmaceuticals and PET imaging. Also, the chemical nature of fluorine-18 is similar to that of hydrogen, and the fluorine-18 labelled organic molecules can not change the non-labelled molecular character. Therefore, fluorine-18 is widely applied in the labelled glucose, amino acids, fatty acids, nucleotide, receptor-ligand and neurotransmitter molecular etc., with the propose of detecting the blood flow, metabolism, synthesis of the protein and the neurotransmitter function in brain by PET imaging. It is very important in the basic science and clinical research to understand and master the preparation of the fluorine-18 and its labelled compounds

  16. Elemental imaging of MRI contrast agents: benchmarking of LA-ICP-MS to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, J.A.T. [University of Sheffield, Centre for Analytical Sciences, Sheffield (United Kingdom); University of Sheffield, Department of Chemical and Biological Engineering, Sheffield (United Kingdom); Cox, A.G.; McLeod, C.W. [University of Sheffield, Centre for Analytical Sciences, Sheffield (United Kingdom); Bunch, J. [University of Birmingham, School of Chemistry, Birmingham (United Kingdom); Writer, M.J.; Hart, S.L. [UCL Institute of Child Health, Wolfson Centre for Gene Therapy of Childhood Disease, London (United Kingdom); Bienemann, A.; White, E. [University of Bristol, School of Clinical Sciences, Southmead Hospital, Bristol (United Kingdom); Bell, J. [Hammersmith Hospital, Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Imperial College London, London (United Kingdom)

    2012-06-15

    Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been used to map the spatial distribution of magnetic resonance imaging (MRI) contrast agents (Gd-based) in histological sections in order to explore synergies with in vivo MRI. Images from respective techniques are presented for two separate studies namely (1) convection enhanced delivery of a Gd nanocomplex (developmental therapeutic) into rat brain and (2) convection enhanced delivery, with co-infusion of Magnevist (commercial Gd contrast agent) and Carboplatin (chemotherapy drug), into pig brain. The LA technique was shown to be a powerful compliment to MRI not only in offering improved sensitivity, spatial resolution and signal quantitation but also in giving added value regarding the fate of administered agents (Gd and Pt agents). Furthermore simultaneous measurement of Fe enabled assignment of an anomalous contrast enhancement region in rat brain to haemorrhage at the infusion site. (orig.)

  17. 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.)

  18. Mesenchymal stem cells in renal function recovery after acute kidney injury: use of a differentiating agent in a rat model.

    Science.gov (United States)

    La Manna, Gaetano; Bianchi, Francesca; Cappuccilli, Maria; Cenacchi, Giovanna; Tarantino, Lucia; Pasquinelli, Gianandrea; Valente, Sabrina; Della Bella, Elena; Cantoni, Silvia; Claudia, Cavallini; Neri, Flavia; Tsivian, Matvey; Nardo, Bruno; Ventura, Carlo; Stefoni, Sergio

    2011-01-01

    Acute kidney injury (AKI) is a major health care condition with limited current treatment options. Within this context, stem cells may provide a clinical approach for AKI. Moreover, a synthetic compound previously developed, hyaluronan monoesters with butyric acid (HB), able to induce metanephric differentiation, formation of capillary-like structures, and secretion of angiogenic cytokines, was tested in vitro. Thereafter, we investigated the effects of human mesenchymal stem cells from fetal membranes (FMhMSCs), both treated and untreated with HB, after induction of ischemic AKI in a rat model. At reperfusion following 45-min clamping of renal pedicles, each rat was randomly assigned to one of four groups: CTR, PBS, MSC, and MSC-HB. Renal function at 1, 3, 5, and 7 days was assessed. Histological samples were analyzed by light and electron microscopy and renal injury was graded. Cytokine analysis on serum samples was performed. FMhMSCs induced an accelerated renal functional recovery, demonstrated by biochemical parameters and confirmed by histology showing that histopathological alterations associated with ischemic injury were less severe in cell-treated kidneys. HB-treated rats showed a minor degree of inflammation, both at cytokine and TEM analyses. Better functional and morphological recovery were not associated to stem cells' regenerative processes, but possibly suggest paracrine effects on microenvironment that induce retrieval of renal damaged tissues. These results suggest that FMhMSCs could be useful in the treatment of AKI and the utilization of synthetic compounds could enhance the recovery induction ability of cells.

  19. 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

  20. Diagnosis of Popliteal Venous Entrapment Syndrome by Magnetic Resonance Imaging Using Blood-Pool Contrast Agents

    International Nuclear Information System (INIS)

    Beitzke, Dietrich; Wolf, Florian; Juelg, Gregor; Lammer, Johannes; Loewe, Christian

    2011-01-01

    Popliteal vascular entrapment syndrome is caused by aberrations or hypertrophy of the gastrocnemius muscles, which compress the neurovascular structures of the popliteal fossa, leading to symptoms of vascular and degeneration as well as aneurysm formation. Imaging of popliteal vascular entrapment may be performed with ultrasound, magnetic resonance imaging (MRI), computed tomography angiography, and conventional angiography. The use of blood-pool contrast agents in MRI when popliteal vascular entrapment is suspected offers the possibility to perform vascular imaging with first-pass magnetic resonance angiographic, high-resolution, steady-state imaging and allows functional tests all within one examination with a single dose of contrast agent. We present imaging findings in a case of symptomatic popliteal vein entrapment diagnosed by the use of blood pool contrast-enhanced MRI.

  1. 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.

  2. 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

  3. 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)

  4. Enhanced renal image contrast by ethanol fixation in phase-contrast X-ray computed tomography.

    Science.gov (United States)

    Shirai, Ryota; Kunii, Takuya; Yoneyama, Akio; Ooizumi, Takahito; Maruyama, Hiroko; Lwin, Thet Thet; Hyodo, Kazuyuki; Takeda, Tohoru

    2014-07-01

    Phase-contrast X-ray imaging using a crystal X-ray interferometer can depict the fine structures of biological objects without the use of a contrast agent. To obtain higher image contrast, fixation techniques have been examined with 100% ethanol and the commonly used 10% formalin, since ethanol causes increased density differences against background due to its physical properties and greater dehydration of soft tissue. Histological comparison was also performed. A phase-contrast X-ray system was used, fitted with a two-crystal X-ray interferometer at 35 keV X-ray energy. Fine structures, including cortex, tubules in the medulla, and the vessels of ethanol-fixed kidney could be visualized more clearly than that of formalin-fixed tissues. In the optical microscopic images, shrinkage of soft tissue and decreased luminal space were observed in ethanol-fixed kidney; and this change was significantly shown in the cortex and outer stripe of the outer medulla. The ethanol fixation technique enhances image contrast by approximately 2.7-3.2 times in the cortex and the outer stripe of the outer medulla; the effect of shrinkage and the physical effect of ethanol cause an increment of approximately 78% and 22%, respectively. Thus, the ethanol-fixation technique enables the image contrast to be enhanced in phase-contrast X-ray imaging.

  5. 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

  6. Gd-DTPA as a paramagnetic contrast agent in MR imaging of focal liver lesions

    International Nuclear Information System (INIS)

    Hamm, B.; Roemer, T.; Wolf, K.J.; Felix, R.; Weinmann, H.J.

    1986-01-01

    Gd-DTPA enhances signal intensity in healthy liver and in intrahepatic tumors. However, after contrast agent administration, tumor enhances significantly more than liver parenchyma (2α≤ 0.05). Doubling the dose of Gd-DTPA from 0.1 to 0.2 mmol/kg of body weight increases the enhancement of intrahepatic tumors (2α≤ 0.05) and optimizes the contrast between tumor and liver in T1-weighted spin-echo sequences. However, the contrast between tumor and liver on inversion-recovery and T2-weighted images obtained before contrast agent administration is much greater than the difference on T1-weighted images obtained after contrast agent administration (2α≤ 0.05). In fast images the contrast between liver and tumor can be markedly improved by administering Gd-DTPA

  7. 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.

  8. Diethylenetriaminepentaacetic acid-gadolinium (DTPA-Gd)-conjugated polysuccinimide derivatives as magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Lee, Ha Young; Jee, Hye Won; Seo, Sung Mi; Kwak, Byung Kook; Khang, Gilson; Cho, Sun Hang

    2006-01-01

    Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylamine as hydrophobic ligand, and DTPA-Gd as contrast agent. PSI was synthesized by the polycondensation polymerization of aspartic acid. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Critical micellization concentrations were determined using fluorescent probes (pyrene). Micelle size and shape were measured by electro-photometer light scattering (ELS) and atomic force microscopy (AFM). The formed micelle size ranged from 100 to 300 nm. The T1-weighted MR images of the phantom prepared with PSI-mPEG-C16-(DTPA-Gd) were obtained in a 3.0 T clinical MR imager, and the conjugates showed a great potential as MRI contrast agents.

  9. 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

  10. Submicron polycaprolactone particles as a carrier for imaging contrast agent for in vitro applications.

    Science.gov (United States)

    Iqbal, Muhammad; Robin, Sophie; Humbert, Philippe; Viennet, Céline; Agusti, Geraldine; Fessi, Hatem; Elaissari, Abdelhamid

    2015-12-01

    Fluorescent materials have recently attracted considerable attention due to their unique properties and high performance as imaging agent in biomedical fields. Different imaging agents have been encapsulated in order to restrict its delivery to a specific area. In this study, a fluorescent contrast agent was encapsulated for in vitro application by polycaprolactone (PCL) polymer. The encapsulation was performed using modified double emulsion solvent evaporation technique with sonication. Fluorescent nanoparticles (20 nm) were incorporated in the inner aqueous phase of double emulsion. A number of samples were fabricated using different concentrations of fluorescent contrast agent. The contrast agent-containing submicron particle was characterized by a zetasizer for average particle size, SEM and TEM for morphology observations and fluorescence spectrophotometer for encapsulation efficiency. Moreover, contrast agent distribution in the PCL matrix was determined by confocal microscopy. The incorporation of contrast agent in different concentrations did not affect the physicochemical properties of PCL particles and the average size of encapsulated particles was found to be in the submicron range. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. 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.

  12. Phytate (IP6) is a powerful agent for preventing calcifications in biological fluids: usefulness in renal lithiasis treatment.

    Science.gov (United States)

    Grases, F; Costa-Bauzá, A

    1999-01-01

    The extraordinary capacity of phytate (myo-inositol hexaphosphate), a substance present in blood, urine, interstitial and intracellular fluids, to inhibit crystallization of calcium salts (oxalate and phosphate) is discussed. Its role in preventing calcium renal stone formation is specifically presented and discussed. "In vitro" and "in vivo" experiments, as well as clinical studies clearly demonstrated that phytate plays an important role as a crystallization inhibitor of calcium salts in biological fluids and becomes a clear alternative in the treatment of calcium oxalate renal lithiasis.

  13. 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.

  14. 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)

  15. The use contrast agent for imaging biological samples

    Czech Academy of Sciences Publication Activity Database

    Dammer, J.; Weyda, František; Sopko, V.; Jakůbek, J.

    2011-01-01

    Roč. 6, C01096 (2011), s. 1-7 ISSN 1748-0221. [International Workshop on Radiation Imaging Detectors /12./. Cambridge, 11.07.2010-15.7.2010] R&D Projects: GA MŠk 2B06005 Grant - others:Research Program(CZ) 6840770029; Research Program(CZ) 6840770040; GA AV ČR(CZ) IAA600550614; GA MŠk(CZ) 2B06007; GA MŠk(CZ) 1PO4LA211; GA MŠk(CZ) LC06041 Program:IA; 2B; LC Institutional research plan: CEZ:AV0Z50070508 Keywords : x-ray radiography and digital radiography (DR) * x-ray detectors * inspections with x-rays Subject RIV: EA - Cell Biology Impact factor: 1.869, year: 2011

  16. Analyse of influence elements in the process of dynamic renal imaging to measure glomerular filtration rate and effective renal plasma flow in patients with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Yao Lixin; Li Zuofei; Liu Bo; Guo Leiming

    2010-01-01

    Objective: To detect the changes and clinical influence elements of radionuclide renal dynamic imaging to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) in patients with type 2 diabetes mellitus (T2DM). Methods: One hundred and eight patients with T 2 DM were divided into 4 groups according to the values of urinary albumin excretion rate (UAER): Group I: UAER -1 , 31 cases. Group II: UAER 20∼200μg·min -1 , 28 cases. Group III: UAER >200μg·min -1 , serum creatinine(SCr) 200μg·min -1 , SCr≥ 105μmol/L, 23 cases. 99 Tc m -diethylenetriamine pentaacetic acid and 99 Tc m -ethylenedicysteine renal dynamic imaging were performed in all patients. GFR, ERPF and renogram were derived simultaneously. The levels of blood creatinine, blood urea nitrogen, urine albumin, blood press, fasting blood insulin, glycosylated hemoglobin, fasting blood glucousewere measured in the four groups. Results: With the evolvement of diabetes nephropathy (DN), UAERs were gradually ascended and the values of GFR and ERPF was gradually descended, the former offered remarkable inverse correlation with the two latters (r 1 = -0.497, P 2 =-0.215, P 1 =1.8, t 2 =2.1, t 3 =1.9, P 4 =3.2, P<0.01). Multielement stepwise regression analyses assumed that age, systolic pressure, glycosylated hemoglobin and insulin resistance index offered inverse correlation with GFR and ERPF (coefficient of regression factor: -0.507, -0.874, -0.528, -0.587, -0.336, -0.697, -0.348, -0.371, P<0.01). Conclusion: GFR and ERPF were sensitive index reflecting the changes of DN.Hypertension and insulin resistance were independence risk factors to make the value of GFR and ERPF decreased in patients with DN. (authors)

  17. Study of new 113mIn-BAT complexes for myocardial imaging agents

    International Nuclear Information System (INIS)

    Zhu Lin; Liu Boli; Kojima, M.

    1991-01-01

    Some new BAT derivatives are designed and synthesized in order to find some ideal myocardial imaging agents. These ligands form pentacoordinated complexes with indium cation. The structures of ligand BAT-TE and complexes In-BAT-TE and In-BAT-ETE are determined by X-ray crystallography at first. Biodistribution shows that the higher lipophilicity of complex induces apparently higher myocardial accumulation. Up to date, complex B is the best 113m In-labeled myocardial imaging agent. It is also suited to 111 In

  18. Iron-EHPG as an hepatobiliary MR contrast agent: initial imaging and biodistribution studies

    International Nuclear Information System (INIS)

    Lauffer, R.B.; Greif, W.L.; Stark, D.D.; Vincent, A.C.; Saini, S.; Wedeen, V.J.; Brady, T.J.

    1988-01-01

    A paramagnetic relaxation agent targeted to functioning hepatocytes of the liver and excreted into the bile would be useful in the enhancement of normal liver and biliary anatomy in MR imaging. We sought to demonstrate the feasibility of this approach using the prototype hepatobiliary MR contrast agent, iron(III) ethylenebis-(2-hydroxyphenylglycine) (Fe(EHPG) - ). The biodistribution, relaxation enhancement, and imaging characteristics of Fe(EHPG) - were compared to those of the non-specific iron chelate iron(III) diethylenetriaminepentaacetic acid (Fe(DTPA) 2- ), which has a comparable effect on water proton relaxation times. (author)

  19. Recommendations on procedures for renal function imaging; Anleitung zur Durchfuehrung der Nierenfunktionsszintigraphie

    Energy Technology Data Exchange (ETDEWEB)

    Klaeser, B.; Eberl, A.; Bubeck, B. [Klinik fuer Nuklearmedizin, Kantonsspital St. Gallen (Switzerland)

    2003-09-01

    Renal function diagnostics in nuclear medicine is nowadays performed primarily as scintigraphic study using {sup 99m}Tc-MAG3, in many cases accompanied by quantitative clearance measurement. The present recommendations are based on the technical protocols of the Clinic of Nuclear Medicine at the Kantonsspital St. Gallen and do not claim to be complete or the Gold Standard. The procedures described are not subject to discussion, but the authors attempt to give practical guidelines as orientation for users in their daily routine. Focal points are preparation and performance of the diuretic renography with furosemide to evaluate urinary outflow obstructions and scintigraphic studies under captopril for detection of renovascular hypertension. Further subjects are the quantitative clearance measurement according to the single-sample method and, of course, the calculation of the split clearance. All of these subjects are described mainly under practical aspects, looking in particular at frequent pitfalls or wrong interpretations, but also taking into account quality assurance and data analysis. Selected cases are presented to document the importance of renal function imaging in practice. (orig.) [German] Die nuklearmedizinische Nierenfunktionsdiagnostik wird heute vorrangig als Szintigraphie mit {sup 99m}Tc-MAG3 betrieben, haeufig mit begleitender quantitativer Clearancemessung. Die vorliegende Anleitung basiert auf den Untersuchungsprotokollen der Klinik fuer Nuklearmedizin des Kantonsspitals St. Gallen und erhebt weder Anspruch auf Vollstaendigkeit noch darauf, als Goldstandard zu gelten. Die beschriebenen Vorgehensweisen werden nicht diskutiert, sondern die Autoren versuchen, pragmatische Leitlinien zu vermitteln, an denen sich der Anwender in der taeglichen Routine orientieren kann. Schwerpunkte bilden die Vorbereitung und Durchfuehrung der so genannten Lasix-Szintigraphie zur Beurteilung der renalen Abflussverhaeltnisse und die Captopril-Szintigraphie bei der Frage

  20. Longitudinal assessment of mouse renal injury using high-resolution anatomic and magnetization transfer MR imaging.

    Science.gov (United States)

    Wang, Feng; Jiang, Rosie; Takahashi, Keiko; Gore, John; Harris, Raymond C; Takahashi, Takamune; Quarles, C Chad

    2014-11-01

    The purpose of this study is to evaluate the utility of high-resolution non-invasive endogenous high-field MRI methods for the longitudinal structural and quantitative assessments of mouse kidney disease using the model of unilateral ureter obstruction (UUO). T1-weighted, T2-weighted and magnetization transfer (MT) imaging protocols were optimized to improve the regional contrast in mouse kidney. Conventional T1 and T2 weighted images were collected in UUO mice on day 0 (~3h), day 1, day 3 and day 6 after injury, on a 7 T small animal MRI system. Cortical and medullary thickness, corticomedullary contrast and Magnetization Transfer Ratio (MTR) were assessed longitudinally. Masson trichrome staining was used to histologically assess changes in tissue microstructure. Over the course of UUO progression there were significant (prenal cortical and medullary atrophy, cortical-medullary differentiation and MTR changes provide an endogenous, non-invasive and quantitative evaluation of renal morphology and tissue composition during UUO progression. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Renal water molecular diffusion characteristics in healthy native kidneys: assessment with diffusion tensor MR imaging.

    Directory of Open Access Journals (Sweden)

    Zhenfeng Zheng

    Full Text Available BACKGROUND: To explore the characteristics of diffusion tensor imaging (DTI and magnetic resonance (MR imaging in healthy native kidneys. METHODS: Seventy-three patients without chronic kidney disease underwent DTI-MRI with spin echo-echo planar (SE-EPI sequences accompanied by an array spatial sensitivity encoding technique (ASSET. Cortical and medullary mean, axial and radial diffusivity (MD, AD and RD, fractional anisotropy (FA and primary, secondary and tertiary eigenvalues (λ1, λ2, λ3 were analysed in both kidneys and in different genders. RESULTS: Cortical MD, λ2, λ3, and RD values were higher than corresponding medullary values. The cortical FA value was lower than the medullary FA value. Medullary λ1 and RD values in the left kidney were lower than in the right kidney. Medullary λ2, and λ3 values in women were higher than those in men. Medullary FA values in women were lower than those in men. Medullary FA (r = 0.351, P = 0.002 and λ1 (r = 0.277, P = 0.018 positively correlated with eGFR. Medullary FA (r = -0.25, P = 0.033 negatively correlated with age. CONCLUSIONS: Renal water molecular diffusion differences exist in human kidneys and genders. Age and eGFR correlate with medullary FA and primary eigenvalue.

  2. Advancing Cardiovascular, Neurovascular and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology

    Directory of Open Access Journals (Sweden)

    Thoralf eNiendorf

    2015-11-01

    Full Text Available Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF coils in small animal MR as a means of boosting image quality (e.g. by supporting MR microscopy and making data acquisition more efficient (e.g. by reducing measuring time; both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (biomedical imaging, molecular medicine and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (pathophysiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular and renal disease will be discussed.

  3. Machine learning-based quantitative texture analysis of CT images of small renal masses. Differentiation of angiomyolipoma without visible fat from renal cell carcinoma

    International Nuclear Information System (INIS)

    Feng, Zhichao; Rong, Pengfei; Zhou, Qingyu; Zhu, Wenwei; Yan, Zhimin; Liu, Qianyun; Wang, Wei; Cao, Peng

    2018-01-01

    To evaluate the diagnostic performance of machine-learning based quantitative texture analysis of CT images to differentiate small (≤ 4 cm) angiomyolipoma without visible fat (AMLwvf) from renal cell carcinoma (RCC). This single-institutional retrospective study included 58 patients with pathologically proven small renal mass (17 in AMLwvf and 41 in RCC groups). Texture features were extracted from the largest possible tumorous regions of interest (ROIs) by manual segmentation in preoperative three-phase CT images. Interobserver reliability and the Mann-Whitney U test were applied to select features preliminarily. Then support vector machine with recursive feature elimination (SVM-RFE) and synthetic minority oversampling technique (SMOTE) were adopted to establish discriminative classifiers, and the performance of classifiers was assessed. Of the 42 extracted features, 16 candidate features showed significant intergroup differences (P < 0.05) and had good interobserver agreement. An optimal feature subset including 11 features was further selected by the SVM-RFE method. The SVM-RFE+SMOTE classifier achieved the best performance in discriminating between small AMLwvf and RCC, with the highest accuracy, sensitivity, specificity and AUC of 93.9 %, 87.8 %, 100 % and 0.955, respectively. Machine learning analysis of CT texture features can facilitate the accurate differentiation of small AMLwvf from RCC. (orig.)

  4. Machine learning-based quantitative texture analysis of CT images of small renal masses: Differentiation of angiomyolipoma without visible fat from renal cell carcinoma.

    Science.gov (United States)

    Feng, Zhichao; Rong, Pengfei; Cao, Peng; Zhou, Qingyu; Zhu, Wenwei; Yan, Zhimin; Liu, Qianyun; Wang, Wei

    2018-04-01

    To evaluate the diagnostic performance of machine-learning based quantitative texture analysis of CT images to differentiate small (≤ 4 cm) angiomyolipoma without visible fat (AMLwvf) from renal cell carcinoma (RCC). This single-institutional retrospective study included 58 patients with pathologically proven small renal mass (17 in AMLwvf and 41 in RCC groups). Texture features were extracted from the largest possible tumorous regions of interest (ROIs) by manual segmentation in preoperative three-phase CT images. Interobserver reliability and the Mann-Whitney U test were applied to select features preliminarily. Then support vector machine with recursive feature elimination (SVM-RFE) and synthetic minority oversampling technique (SMOTE) were adopted to establish discriminative classifiers, and the performance of classifiers was assessed. Of the 42 extracted features, 16 candidate features showed significant intergroup differences (P Machine learning analysis of CT texture features can facilitate the accurate differentiation of small AMLwvf from RCC. • Although conventional CT is useful for diagnosis of SRMs, it has limitations. • Machine-learning based CT texture analysis facilitate differentiation of small AMLwvf from RCC. • The highest accuracy of SVM-RFE+SMOTE classifier reached 93.9 %. • Texture analysis combined with machine-learning methods might spare unnecessary surgery for AMLwvf.

  5. Development of Tc-99m labeled myocardial imaging agent

    International Nuclear Information System (INIS)

    Jeong, J. M.; Jang, Y. S.; Kim, Y. J.; Lee, Y. S.; Kim, H. W.; Ray, G.; Lee, M. S.

    2006-02-01

    Lipophilic cations have been widely used for myocardial SPECT. We synthesized novel +1 charged lipophilic Tc-99m-labeled N,N'-disubstituted N2S2 derivatives and investigated their biodistribution. The N,N'-dimethyl-, N,N'-diethyl-, N,N'-bis(methoxyethyl)-, and N,N'-bis(ethoxyethyl)N2S2 derivatives were synthesized by alkylating disulfide form of N2S2 with corresponding alkyl halides and subsequently reduced with LAH in THF. To label with Tc-99m, 50% gluconic acid (0.1 ml), SnCl2·2H2O (10 μg), Tc-99m-pertechnetate (370 MBq/2.5 ml) and 0.5 M Na2CO3 (0.3 ml) were added to the compounds. These mixtures were reacted in boiling water bath for 30∼60 min. Radiochemical purities were checked by Whatman No.1 chromatography (normal saline, Rf 0.3∼0.4). Biodistribution of each compound was investigated after injecting 74 kBq (0.1 ml) of each Tc-99m-labeled compound to ICR-mice through the tail vein. Chemical structures of synthesized compounds were confirmed by GC-MSD and 1H-NMR spectroscopy. All of the Tc-99m-labeled compound showed labeling efficiencies of higher than 93%. In biodistribution study, the myocardial uptake of Tc-99m-N,N'-dimethylN2S2, Tc-99m-N,N'-diethylN2S2, Tc-99m-N,N'-bis(methoxyethyl)N2S2 and Tc-99m-N,N'-bis(ethoxyethyl)N2S2 were 5.38 ±0.96, 2.98 ±0.16, 4.27 ±0.47, 7.24 ±1.01% ID/g at 10 min and 5.34 ±1.57, 2.05 ±0.40, 1.02 ±0.16, 1.69 ±0.04% ID/g at 2 hr, respectively. We successfully synthesized Tc-99m-labeled N,N-disubstituted N2S2 derivatives that are novel lipophilic +1 charged compounds. We thought our results prove the feasibility of these compounds to use for myocardial SPECT agent

  6. 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

  7. 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 ...

  8. 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

  9. Gadolinium-porphyrins: new potential magnetic resonance imaging contrast agents for melanoma detection

    Directory of Open Access Journals (Sweden)

    Daryoush Shahbazi-Gahrouei

    2006-11-01

    Full Text Available BACKGROUND: Two new porphyrin-based magnetic resonance imaging (MRI contrast agents, Gd-hematoporphyrin (Gd-H and Gd-tetra-carboranylmethoxyphenyl-porphyrin (Gd-TCP were synthesized and tested in nude mice with human melanoma (MM-138 xenografts as new melanoma contrast agents. METHODS: Subcutaneous xenografts of human melanoma cells (MM-138 were studied in 30 (five groups of six nude mice. The effect of different contrast agents (Gd-TCP, Gd-H, GdCl3 and Gd-DTPA on proton relaxation times was measured in tumors and other organs. T1 values, signal enhancement and the Gd concentration for different contrast agent solutions were also investigated. RESULTS: The porphyrin agents showed higher relaxivity compared to the clincal agent, Gd-DTPA. A significant 16% and 21% modification in T1 relaxation time of the water in human melanoma tumors grafted in the nude mice was revealed 24 hours after injection of Gd-TCP and Gd-H, respectively. The percentage of injected Gd localized to the tumor measured by inductively coupled plasma atomic emission spectrometry (ICP-AES was approximately 21% for Gd-TCP and 28% for Gd-H which were higher than that of Gd-DTPA (10%. CONCLUSIONS: The high concentration of Gd in the tumor is indicative of a selective retention of the compounds and indicates that Gd-TCP and Gd-H are promising MR imaging contrast agents for melanoma detection. Gd-porphyrins have considerable promise for further diagnostic applications in magnetic resonance imaging. KEY WORDS: MRI, porphyrin-based contrast agent, hematoporphyrin, melanoma.

  10. Analogues of estradiol as potential breast tumor imaging agents

    International Nuclear Information System (INIS)

    Gibson, R.E.; Rzeszotarski, W.J.; Ferriera, N.L.; Jagoda, E.M.; Reba, R.C.; Eckelman, W.C.

    1984-01-01

    The radioiodinated analogue of estradiol, 11β-methoxy-17α-[/sup 125/I]iodovinylestradiol (MIVE/sub 2/), has been shown to be a good candidate for the imaging of estrogen dependent breast tumors. Although there has been no extensive study on the sensitivity of radiotracers of this type, the authors have not observed localization of the radiotracer in metastatic lesions containing less than 20 fmole estrogen receptor/mg protein or in bone metasteses. In order to improve the sensitivity, they have examined several structural analogues of moxestrol (the parent structure for MIVE/sub 2/) for affinity to the ER isolated from immature rat uterus. The 11β-ethyl analogue (EEE/sub 2/) of ethynyl estradiol (EE/sub 2/) exhibits the highest affinity with the 11β-methyl analogue second best. Although the lipophilicity is also very high this compound should not be much more lipophilic than 16-iodoestradiol or MIVE/sub 2/ since the introduction of iodine increases the log P by greater than 1. The distribution of the tritiated derivative of EEE/sub 2/ is under study

  11. Tissue gadolinium deposition in renally impaired rats exposed to different gadolinium-based MRI contrast agents: evaluation with inductively coupled plasma mass spectrometry (ICP-MS).

    Science.gov (United States)

    Sato, Tomohiro; Ito, Katsuyoshi; Tamada, Tsutomu; Kanki, Akihiko; Watanabe, Shigeru; Nishimura, Hirotake; Tanimoto, Daigo; Higashi, Hiroki; Yamamoto, Akira

    2013-10-01

    To quantify tissue gadolinium (Gd) deposition in renally impaired rats exposed to Gd-EOB-DTPA and other Gd-based MRI contrast agents by means of inductively coupled plasma mass spectrometry (ICP-MS), and to compare the differences in distribution among major organs as possible triggers for nephrogenic systemic fibrosis (NSF). A total of 15 renally impaired rats were injected with Gd-EOB-DTPA, Gd-DTPA-BMA and Gd-HP-DO3A. Gd contents of skin, liver, kidney, lung, heart, spleen, diaphragm and femoral muscle were measured by inductively coupled plasma mass spectrometry (ICP-MS). Histological assessment was also conducted. Tissue Gd deposition in all organs was significantly higher (P=0.005~0.009) in the Gd-DTPA-BMA group than in the Gd-HP-DO3A and Gd-EOB-DTPA groups. In the Gd-DTPA-BMA group, Gd was predominantly deposited in kidney (1306±605.7μg/g), followed by skin, liver, lung, spleen, femoral muscle, diaphragm and heart. Comparing Gd-HP-DO3A and Gd-EOB-DTPA groups, Gd depositions in the kidney, liver and lung were significantly lower (P=0.009~0.011) in the Gd-EOB-DTPA group than in the Gd-HP-DO3A group although no significant differences were seen for any other organs. Gd-EOB-DTPA is a stable and safe Gd-based contrast agent (GBCA) showing lower Gd deposition in major organs in renally impaired rats, compared with other GBCAs. This fact suggests that the risk of NSF onset would be low in the use of Gd-EOB-DTPA. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Arterial spin labelling in imaging of renal diseases and renal allograft pathology; MRT-Perfusionsmessung mit Arterial Spin Labelling. Anwendung fuer die Niere und Transplantatniere

    Energy Technology Data Exchange (ETDEWEB)

    Hueper, Katja; Gutberlet, Marcel [Medizinische Hochschule Hannover (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Kuehn, Bernd [Siemens AG/Siemens Healthcare GmbH, Erlangen (Germany)

    2016-06-15

    Arterial Spin Labelling (ASL) is a technique for non-invasive and contrast-free assessment of perfusion with MRI. Renal ASL allows examination of renal pathophysiology, evaluation of the course of renal disease and therapy effects by longitudinal measurements as well as characterization of renal tumors. In this article, techniques of ASL will be explained and challenges of renal ASL will be emphasized. In addition, examples for clinical application of ASL for diagnosis of renal disease and renal allograft pathology will be given.

  13. Studies on polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents

    International Nuclear Information System (INIS)

    Yan Guoping; Liu Maili; Li Liyun

    2005-01-01

    Purpose: A series of polyaspartamide gadolinium complexes containing pyridoxamine groups were studied as the potential magnetic resonance imaging (MRI) contrast agents for liver enhancement. Methods: These polyaspartamide gadolinium complexes were prepared and evaluated by relaxivity, acute toxicity studies and magnetic resonance imaging of the liver in rats. Results: These polyaspartamide gadolinium complexes have higher relaxation effectiveness than that of the clinically used gadolinium diethylenetriaminepentaacetic acid and possess the low intravenous acute toxicities to Institute for Cancer Research (ICR) mice. Magnetic resonance imaging of the liver in rats indicated that they greatly enhance the contrast of magnetic resonance images and provide prolonged intravascular duration in the liver. Conclusion: These results indicated that the polyaspartamide gadolinium complexes containing pyridoxamine groups could be considered as the appropriate MRI contrast agents for liver enhancement

  14. 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.

  15. Contrast agents and cardiac MR imaging of myocardial ischemia: from bench to bedside

    International Nuclear Information System (INIS)

    Croisille, Pierre; Revel, Didier; Saeed, Maythem

    2006-01-01

    This review paper presents, in the first part, the different classes of contrast media that are already used or are in development for cardiac magnetic resonance imaging. A classification of the different types of contrast media is proposed based on the distribution of the compounds in the body, their type of relaxivity and their potential affinity to particular molecules. In the second part, the different uses of the extracellular type of T1-enhancing contrast agent for myocardial imaging is covered from the detection of stable coronary artery disease to the detection and characterization of chronic infarction. A particular emphasis is placed on the clinical use of gadolinium-chelates, which are the universally used type of MRI contrast agent in the clinical routine. Both approaches, first-pass magnetic resonance imaging (FP-MRI) as well as delayed-enhanced magnetic resonance imaging (DE-MRI), are covered in the different situations of acute and chronic myocardial infarction. (orig.)

  16. 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

  17. 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)

  18. 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.

  19. Assessment of myocardial infarction by magnetic resonance imaging with the aid of contrast agents

    International Nuclear Information System (INIS)

    Roos, A. de; Doornbos, J.

    1991-01-01

    The potential of MR imaging in myocardial ischemia with low-temporal-resolution spin-echo techniques both with and without MR contrast agents has been explored. There are indications that early MR imaging after administration of Gd-DTPA is capable to differentiate reperfused from non-reperfused infarcts. Furthermore, MR infarct sizing using Gd-DTPA is feasible to demonstrate infarct size reduction in patients with successful reperfusion. (H.W.). 50 refs.; 9 figs

  20. 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

  1. Development of CD3 cell quantitation algorithms for renal allograft biopsy rejection assessment utilizing open source image analysis software.

    Science.gov (United States)

    Moon, Andres; Smith, Geoffrey H; Kong, Jun; Rogers, Thomas E; Ellis, Carla L; Farris, Alton B Brad

    2018-02-01

    Renal allograft rejection diagnosis depends on assessment of parameters such as interstitial inflammation; however, studies have shown interobserver variability regarding interstitial inflammation assessment. Since automated image analysis quantitation can be reproducible, we devised customized analysis methods for CD3+ T-cell staining density as a measure of rejection severity and compared them with established commercial methods along with visual assessment. Renal biopsy CD3 immunohistochemistry slides (n = 45), including renal allografts with various degrees of acute cellular rejection (ACR) were scanned for whole slide images (WSIs). Inflammation was quantitated in the WSIs using pathologist visual assessment, commercial algorithms (Aperio nuclear algorithm for CD3+ cells/mm 2 and Aperio positive pixel count algorithm), and customized open source algorithms developed in ImageJ with thresholding/positive pixel counting (custom CD3+%) and identification of pixels fulfilling "maxima" criteria for CD3 expression (custom CD3+ cells/mm 2 ). Based on visual inspections of "markup" images, CD3 quantitation algorithms produced adequate accuracy. Additionally, CD3 quantitation algorithms correlated between each other and also with visual assessment in a statistically significant manner (r = 0.44 to 0.94, p = 0.003 to algorithms presents salient correlations with established methods of CD3 quantitation. These analysis techniques are promising and highly customizable, providing a form of on-slide "flow cytometry" that can facilitate additional diagnostic accuracy in tissue-based assessments.

  2. 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

  3. Biodistribution and dosimetry of 195mPt-cisplatin in normal volunteers. Imaging agent for single photon emission computed tomography.

    Science.gov (United States)

    Sathekge, M; Wagener, J; Smith, S V; Soni, N; Marjanovic-Painter, B; Zinn, C; Van de Wiele, C; D'Asseler, Y; Perkins, G; Zeevaart, J R

    2013-12-13

    195mPt-cisplatin is regarded as a promising imaging agent for optimizing dosage in patients receiving cisplatin chemotherapy. We investigated the whole-body distribution and radiation dosimetry of 195mPt-cisplatin in humans. Whole-body scans were obtained up to 144 h after intravenous injection of 112.4 MBq 195mPt-cisplatin in each of five subjects. Blood samples were taken at various times up to 144 h after injection. Urine was collected up to 114 h after injection for calculation of renal clearance and whole-body clearance. Time/activity curves were generated by fitting the organ-specific geometric mean counts, obtained from regions of interest, on the respective images as a function of the time after injection. OLINDA software package was applied to calculate the absorbed radiation dose for various organs. Most of the activity (32 ± 4%) was excreted in the urine during the first 5 h. The effective clearance half-life derived from extrapolation of the whole-body curve was 40 hours (1.7 days). On average, the highest dose was received by the kidneys (mean dose received 2.68 ± 1.5 mGy/MBq), followed by the spleen (mean dose received 1.6 ± 0.8 mGy/MBq) followed by the liver (mean dose received 1.45 ± 0.38 mGy/MBq). The estimated mean effective dose for the adult subject was 0.185 ± 0.034 mSv/MBq. 195mPt-cisplatin proved a safe radiopharmaceutical with a favourable biodistribution for early and delayed imaging of pathology above the diaphragm. The ED obtained was 0.185 ± 0.034 mSv/MBq. The highest organ dose was received by the kidneys (2.68 ± 1.5 mGy/MBq).

  4. The analytical of radiochemical purity of tumor receptor imaging agent 99Tcm-octreotide

    International Nuclear Information System (INIS)

    Wang Xufu; Zuo Shuyao; Shao Wenbo; Wang Guoming; Sun Jianwen; Zhang Qin

    2003-01-01

    The radiochemical purity of tumor receptor imaging agent 99 Tc m -octreotide is measured by High Pressure Liquid Chromatography (HPLC) and two systems of chromatography combining method of silver stain. The results show that the radiochemical purity of 98 Tc m -octreotide measured by both methods are effective and correct. It can separate 99 Tc m -octreotide from other radioactive compositions correctly and effectively

  5. Identification of a Common Binding Mode for Imaging Agents to Amyloid Fibrils from Molecular Dynamics Simulations

    DEFF Research Database (Denmark)

    Skeby, Katrine Kirkeby; Sørensen, Jesper; Schiøtt, Birgit

    2013-01-01

    experimentally due to the insoluble nature of amyloid fibrils. This study uses molecular dynamics simulations to investigate the interactions between 13 aromatic amyloid imaging agents, entailing 4 different organic scaffolds, and a model of an amyloid fibril. Clustering analysis combined with free energy...

  6. Zirconia-doped nanoparticles: organic coating, polymeric entrapment and application as dual-imaging agents

    OpenAIRE

    Rebuttini, Valentina; Pucci, Andrea; Arosio, Paolo; Bai, Xue; Locatelli, Erica; Pinna, Nicola; Lascialfari, Alessandro; Franchini, Mauro Comes

    2013-01-01

    Zirconia nanoparticles doped with Eu3+, Tb3+ and Gd3+ ions have been synthesized following the benzyl alcohol route. The nanoparticles were coated with N-hydroxydodecanamide and encapsulated in PLGA-b-PEG-COOH nanomicelles. The magnetic and fluorescent properties of these hybrid nanocarriers were investigated, proving them to be potential dual-imaging contrast agents.

  7. A theranostic agent to enhance osteogenic and magnetic resonance imaging properties of calcium phosphate cements

    NARCIS (Netherlands)

    Ventura, M.; Sun, Y.; Cremers, S.; Borm, P.; Tahmasebi Birgani, Zeinab; Habibovic, Pamela; Heerschap, A.; van der Kraan, P.M.; Jansen, J.A.; Walboomers, X.F.

    2014-01-01

    With biomimetic biomaterials, like calcium phosphate cements (CPCs), non-invasive assessment of tissue regeneration is challenging. This study describes a theranostic agent (TA) to simultaneously enhance both imaging and osteogenic properties of such a bone substitute material. For this purpose,

  8. Synthesis and evaluation of three iodinated haloperidol derivatives as potential dopamine receptor imaging agents

    International Nuclear Information System (INIS)

    Hunter, D.H.; Strickland, L.A.; Zabel, P.L.

    1990-01-01

    Haloperidol, a neuroleptic which shows D-2 receptor affinity and selectivity, has been labelled primarily with positron emitting isotopes. The authors have synthesized three iodinated analogues of Haloperidol to investigate the possibility of an iodine-123 labelled agent for SPECT imaging. These compounds were obtained from the substitution of halogenated butyrophenones by halogenated arylpiperidols. In vitro and in vivo experiments will be discussed

  9. Amphetamines and pH-shift agents for brain imaging: Basic research and clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Biersack, H.J.; Winkler, C.

    1986-01-01

    This book contains 18 selections. Some of the titles are: Labelling of amphetamines with /sup 123/I: Receptors for amphetamines; New amphetamine derivatives; Potential new approaches for the development of brain imaging agents for single-photon applications; and IM SPECT with the pinhole collimator.

  10. RGD-based strategies for selective delivery of therapeutics and imaging agents to the tumour vasculature

    NARCIS (Netherlands)

    Temming, K; Molema, G; Kok, RJ

    2005-01-01

    During the past decade, RGD-peptides have become a popular tool for the targeting of drugs and imaging agents to a(v)beta(3)-integrin expressing tumour vasculature. RGD-peptides have been introduced by recombinant means into therapeutic proteins and viruses. Chemical means have been applied to

  11. NaGdF4:Nd3+/Yb3+ Nanoparticles as Multimodal Imaging Agents

    Science.gov (United States)

    Pedraza, Francisco; Rightsell, Chris; Kumar, Ga; Giuliani, Jason; Monton, Car; Sardar, Dhiraj

    Medical imaging is a fundamental tool used for the diagnosis of numerous ailments. Each imaging modality has unique advantages; however, they possess intrinsic limitations. Some of which include low spatial resolution, sensitivity, penetration depth, and radiation damage. To circumvent this problem, the combination of imaging modalities, or multimodal imaging, has been proposed, such as Near Infrared Fluorescence imaging (NIRF) and Magnetic Resonance Imaging (MRI). Combining individual advantages, specificity and selectivity of NIRF with the deep penetration and high spatial resolution of MRI, it is possible to circumvent their shortcomings for a more robust imaging technique. In addition, both imaging modalities are very safe and minimally invasive. Fluorescent nanoparticles, such as NaGdF4:Nd3 +/Yb3 +, are excellent candidates for NIRF/MRI multimodal imaging. The dopants, Nd and Yb, absorb and emit within the biological window; where near infrared light is less attenuated by soft tissue. This results in less tissue damage and deeper tissue penetration making it a viable candidate in biological imaging. In addition, the inclusion of Gd results in paramagnetic properties, allowing their use as contrast agents in multimodal imaging. The work presented will include crystallographic results, as well as full optical and magnetic characterization to determine the nanoparticle's viability in multimodal imaging.

  12. Element-specific spectral imaging of multiple contrast agents: a phantom study

    Science.gov (United States)

    Panta, R. K.; Bell, S. T.; Healy, J. L.; Aamir, R.; Bateman, C. J.; Moghiseh, M.; Butler, A. P. H.; Anderson, N. G.

    2018-02-01

    This work demonstrates the feasibility of simultaneous discrimination of multiple contrast agents based on their element-specific and energy-dependent X-ray attenuation properties using a pre-clinical photon-counting spectral CT. We used a photon-counting based pre-clinical spectral CT scanner with four energy thresholds to measure the X-ray attenuation properties of various concentrations of iodine (9, 18 and 36 mg/ml), gadolinium (2, 4 and 8 mg/ml) and gold (2, 4 and 8 mg/ml) based contrast agents, calcium chloride (140 and 280 mg/ml) and water. We evaluated the spectral imaging performances of different energy threshold schemes between 25 to 82 keV at 118 kVp, based on K-factor and signal-to-noise ratio and ranked them. K-factor was defined as the X-ray attenuation in the K-edge containing energy range divided by the X-ray attenuation in the preceding energy range, expressed as a percentage. We evaluated the effectiveness of the optimised energy selection to discriminate all three contrast agents in a phantom of 33 mm diameter. A photon-counting spectral CT using four energy thresholds of 27, 33, 49 and 81 keV at 118 kVp simultaneously discriminated three contrast agents based on iodine, gadolinium and gold at various concentrations using their K-edge and energy-dependent X-ray attenuation features in a single scan. A ranking method to evaluate spectral imaging performance enabled energy thresholds to be optimised to discriminate iodine, gadolinium and gold contrast agents in a single spectral CT scan. Simultaneous discrimination of multiple contrast agents in a single scan is likely to open up new possibilities of improving the accuracy of disease diagnosis by simultaneously imaging multiple bio-markers each labelled with a nano-contrast agent.

  13. 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

  14. 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)

  15. 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.

  16. Patients with advanced and metastatic renal cell carcinoma treated with targeted therapy in the Czech Republic: twenty cancer centres, six agents, one database.

    Science.gov (United States)

    Poprach, Alexandr; Bortlíček, Zbyněk; Büchler, Tomáš; Melichar, Bohuslav; Lakomý, Radek; Vyzula, Rostislav; Brabec, Petr; Svoboda, Marek; Dušek, Ladislav; Gregor, Jakub

    2012-12-01

    The incidence and mortality of renal cell carcinoma (RCC) in the Czech Republic are among the highest in the world. Several targeted agents have been recently approved for the treatment of advanced/metastatic RCC. Presentation of a national clinical database for monitoring and assessment of patients with advanced/metastatic RCC treated with targeted therapy. The RenIS (RENal Information System, http://renis.registry.cz ) registry is a non-interventional post-registration database of epidemiological and clinical data of patients with RCC treated with targeted therapies in the Czech Republic. Twenty cancer centres eligible for targeted therapy administration participate in the project. As of November 2011, six agents were approved and reimbursed from public health insurance, including bevacizumab, everolimus, pazopanib, sorafenib, sunitinib, and temsirolimus. As of 10 October 2011, 1,541 patients with valid records were entered into the database. Comparison with population-based data from the Czech National Cancer Registry revealed that RCC patients treated with targeted therapy are significantly younger (median age at diagnosis 59 vs. 66 years). Most RenIS registry patients were treated with sorafenib and sunitinib, many patients sequentially with both agents. Over 10 % of patients were also treated with everolimus in the second or third line. Progression-free survival times achieved were comparable to phase III clinical trials. The RenIS registry has become an important tool and source of information for the management of cancer care and clinical practice, providing comprehensive data on monitoring and assessment of RCC targeted therapy on a national level.

  17. 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

  18. 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

  19. 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

  20. Economic impact of an ultrasonographic contrast agent on the diagnosis and initial management of patients with suspected renal artery stenosis

    International Nuclear Information System (INIS)

    Levesque, J.; Lacourciere, Y.; Onrot, J.M.

    2002-01-01

    To determine resource use in the diagnosis and management of Canadian hypertensive patients with suspected renal artery stenosis and to estimate the impact of diagnosis with contrast-enhanced duplex Doppler ultrasonography (US) on resource use. Seventy-eight patients with suspected renal artery stenosis underwent usual diagnostic tests (captopril-enhanced renal scintigraphy or duplex Doppler US) and contrast-enhanced US. A management pathway ('planned') describing the medical resources required for further patient care was outlined on the basis of results from each test (separately), and a modified management pathway ('recommended'), which considered data from both diagnostic methods, was also outlined. Medical resources and productivity losses were assessed prospectively for a 3-month period after patients underwent both tests ('actual' management pathway). With usual diagnostic methods, 14 (18%) of the tests were inconclusive, whereas only 1 (1%) of the enhanced US examinations was inconclusive; the cost-efficacy ratio was $422 and $343 per successful diagnosis, respectively. Further management costs for patients with an inconclusive diagnosis were estimated at $6370 after the usual diagnostic tests, but only $1278 with enhanced US. Although the costs of the planned and recommended management pathways were similar ($227 and $294 per patient respectively), the proportion of patients requiring further resources was lower with enhanced US (56% v. 46%). Three-month actual management costs ranged from $121 to $1605 per patient (mean $360). Diagnostic tests and surgical procedures were the major cost drivers in all pathways, and costs wore highest for patients in whom stenosis was diagnosed. For patients with suspected renal artery stenosis, contrast-enhanced US had a higher diagnostic success rate than usual diagnostic methods and afforded savings through lower administrative costs and lower medical resource consumption for patients whose diagnosis was unclear after

  1. Direct-acting antiviral agent efficacy and safety in renal transplant recipients with chronic hepatitis C virus infection

    OpenAIRE

    Chen, Keliang; Lu, Pei; Song, Rijin; Zhang, Jiexiu; Tao, Rongzhen; Wang, Zijie; Zhang, Wei; Gu, Min

    2017-01-01

    Abstract Background: The efficacy and safety of direct-acting antivirals (DAAs) for treating hepatitis C virus (HCV)-infected renal transplant recipients (RTRs) has not been determined. Methods: We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials and assessed the quality of eligible studies using the Joanna Briggs Institute scale. DAA efficacy and safety were assessed using standard mean difference (SMD) with 95% confidence intervals (95%CIs). Results: Six studi...

  2. 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

  3. Assessment of early renal allograft dysfunction with blood oxygenation level-dependent MRI and diffusion-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Yoon [Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Chan Kyo, E-mail: chankyokim@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, Byung Kwan [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Sung Ju; Lee, Sanghoon [Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Huh, Wooseong [Department of Nephrology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2014-12-15

    Highlights: • R2* and ADC in renal allografts are moderately correlated with eGFR. • R2* and ADC are lower in early allograft dysfunction than normal allograft function. • No significant difference between AR and ATN was found in both R2* and ADC. - Abstract: Purpose: To investigate blood oxygenation level-dependent (BOLD) MRI and diffusion-weighted imaging (DWI) at 3 T for assessment of early renal allograft dysfunction. Materials and methods: 34 patients with a renal allograft (early dysfunction, 24; normal, 10) were prospectively enrolled. BOLD MRI and DWI were performed at 3 T. R2* and apparent diffusion coefficient (ADC) values were measured in cortex and medulla of the allografts. Correlation between R2* or ADC values and estimated glomerular filtration rate (eGFR) was investigated. R2* or ADC values were compared among acute rejection (AR), acute tubular necrosis (ATN) and normal function. Results: In all renal allografts, cortical or medullary R2* and ADC values were moderately correlated with eGFR (P < 0.05). Early dysfunction group showed lower R2* and ADC values than normal function group (P < 0.05). AR or ATN had lower R2* values than normal allografts (P < 0.05), and ARs had lower cortical ADC values than normal allografts (P < 0.05). No significant difference of R2* or ADC values was found between AR and ATN (P > 0.05). Conclusion: BOLD MRI and DWI at 3 T may demonstrate early functional state of renal allografts, but may be limited in characterizing a cause of early renal allograft dysfunction. Further studies are needed.

  4. Clinical significance of nuclide renal dynamic imaging and urine microalbumin inspection of type II diabetic patients

    International Nuclear Information System (INIS)

    Wang Ying; Jin Yaoge; Shi Xueying; Gao Yong

    2011-01-01

    To investigate clinical value of glomerular filtration rate (GFR) and urine microalbumin in early diagnosis of diabetic nephropathy, GFR in 60 patients with type II diabetes mellitus and a control group of 20 were determined using 99 Tc m DTPA renal dynamic imaging and urine microalbumin. The following results were obtained.Among the 60 patients with diabetes, 5 patients had increased GFRs of, 142.0±13.6 mg/min, which was 35% higher than that of controls and differed significantly from the control (P<0.01); 20 patients had GFRs of 102.2±10.2 mg/min, which differed little from the control; and 35 patients had declined GFRs of 57.2±18.0 mg/min, which was 54.3% lowered than the control and differed significantly from the control (P<0.01). The urine microalbumin in diabetes patients was significantly higher than the control. In conclusion, the GFR is a good index of the early kidney injury in diabetic patients. The combined detection of GFR and urine microalbumin can improve the early diagnosis of diabetic nephropathy, and may help to monitor the treatment response and assess prognosis. (authors)

  5. Biodistribution and micro PET imaging of 18F-FECNT as a dopamine transporter imaging agent

    International Nuclear Information System (INIS)

    Chen Zhengping; Wang Songpei; Li Xiaomin; Liu Chunyi; Tang Jie; Lu Chunxiong; Pan Donghui; Xu Yuping; Yang Ming; Jiang Quanfu; Huang Hongbo; Zhou Xingqing

    2009-01-01

    Objective: 2β-carbomethoxy-3β-(4-corophenyl)-8-(2- 18 F-fluoroethyl) nortropane ( 18 F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biodistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods: Six groups of mice (5 mice each group) received 18 F-FECNT were sacrificed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorphenyl)tropane (β-CFT) at before 18 F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results: The brain uptake of 18 F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 1 '8F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00 ± 0.05) and the highest uptake of radioactivity (striatum/cerebellum =2.18 ± 0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions: The results suggest that 18 F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential

  6. Unenhanced multidetector CT (CT KUB) in the initial imaging of suspected acute renal colic: evaluating a new service

    International Nuclear Information System (INIS)

    Chowdhury, F.U.; Kotwal, S.; Raghunathan, G.; Wah, T.M.; Joyce, A.; Irving, H.C.

    2007-01-01

    Aim: To evaluate a new imaging pathway for the investigation of patients presenting with suspected acute renal colic. Materials and methods: A retrospective review of 500 consecutive cases of suspected acute renal colic was undertaken to evaluate the initial results of a new imaging pathway introduced at our institution, which completely replaced the intravenous urogram (IVU) with unenhanced multidetector CT (CT KUB). Results: The positive rate for urolithiasis was 44% (221/500), the negative rate 46% (229/500) and the rate of other significant findings was 12% (59/500). Female patients had a low positive rate compared with male patients (27.5 versus 57.5%; p < 0.001). Urological intervention was required in 28% (61/221) and these patients had a larger average stone size (6.6 versus 3.7 mm; p < 0.001) and the stone was located more proximally. Out-of-hours imaging was performed in 37% (186/500), and these patients had a higher positive rate (52 versus 40%; p < 0.001). Other findings included a wide range of acute non-urological conditions. Conclusion: The feasibility of replacing the acute IVU with CT KUB in the initial assessment of suspected acute renal colic was demonstrated in the present study. The technique enables rapid diagnosis of urolithiasis, stratification of patients likely to proceed to urological intervention, and prompt diagnosis of a variety of other acute pathological conditions

  7. RNA aptamer probes as optical imaging agents for the detection of amyloid plaques.

    Directory of Open Access Journals (Sweden)

    Christian T Farrar

    Full Text Available Optical imaging using multiphoton microscopy and whole body near infrared imaging has become a routine part of biomedical research. However, optical imaging methods rely on the availability of either small molecule reporters or genetically encoded fluorescent proteins, which are challenging and time consuming to develop. While directly labeled antibodies can also be used as imaging agents, antibodies are species specific, can typically not be tagged with multiple fluorescent reporters without interfering with target binding, and are bioactive, almost always eliciting a biological response and thereby influencing the process that is being studied. We examined the possibility of developing highly specific and sensitive optical imaging agents using aptamer technology. We developed a fluorescently tagged anti-Aβ RNA aptamer, β55, which binds amyloid plaques in both ex vivo human Alzheimer's disease brain tissue and in vivo APP/PS1 transgenic mice. Diffuse β55 positive halos, attributed to oligomeric Aβ, were observed surrounding the methoxy-XO4 positive plaque cores. Dot blots of synthetic Aβ aggregates provide further evidence that β55 binds both fibrillar and non-fibrillar Aβ. The high binding affinity, the ease of probe development, and the ability to incorporate multiple and multimodal imaging reporters suggest that RNA aptamers may have complementary and perhaps advantageous properties compared to conventional optical imaging probes and reporters.

  8. Molecular Imaging Agents Specific for the Annulus Fibrosus of the Intervertebral Disk

    Directory of Open Access Journals (Sweden)

    Summer L. Gibbs-Strauss

    2010-05-01

    Full Text Available Low back pain is a prevalent medical condition that is difficult to diagnose and treat. Current imaging methods are unable to correlate pain reliably with spinal structures, and surgical removal of painful damaged or degenerating disks is technically challenging. A contrast agent specific for the intervertebral disk could assist in the detection, diagnosis, and surgical treatment of low back pain. The styryl pyridinium (FM fluorophores were characterized and structure-activity relationships between chemical structure and in vivo uptake were established. Two novel FM fluorophores with improved optical properties for imaging the intervertebral disks were synthesized and evaluated in mice, rats, and pigs. After a single systemic injection, eight of eight FM fluorophores provided high-contrast imaging of the trigeminal ganglia, whereas six of eight provided high-contrast imaging of the dorsal root ganglia. Unexpectedly, three of eight FM fluorophores provided high-contrast imaging of annulus fibrosus tissue of the intervertebral disks, confirmed histologically. We present the first known contrast agent specific for the intervertebral disks and identify the chemical structural motif that mediates uptake. FM fluorophores could be used for image-guided surgery to assist in the removal of intervertebral disk and lay the foundation for derivatives for magnetic resonance imaging and positron emission tomography.

  9. Experimental studies of the physiologic properties of technetium-99m agents: Myocardial transport of perfusion imaging agents

    International Nuclear Information System (INIS)

    Meerdink, D.J.; Leppo, J.A.

    1990-01-01

    The physiologic properties of new technetium-99m-labeled myocardial imaging agents (Tc-99m sestamibi, an isonitrile; and Tc-99m teboroxime, a boronic acid adduct of technetium dioxime) are discussed and compared to thallium-201 (Tl-201). Studies with isolated hearts, subcellular fractions and cell cultures indicate that Tc-99m sestamibi, Tc-99m teboroxime and Tl-201 do not share common transport or sequestration mechanisms. Although peak Tc-99m sestamibi myocardial extraction over time is about half that of Tl-201 at equivalent coronary blood flows, the amount of Tc-99m sestamibi that remains in the heart is similar to that of Tl-201 because of its higher retention efficiency. The high retention efficiency for Tc-99m sestamibi also results in minimal redistribution. In contrast, Tc-99m teboroxime myocardial extraction is higher than that of Tl-201, but its retention is less efficient, resulting in relatively rapid washout characteristics which may quickly result in tracer redistribution. During reperfusion after a no-flow period, Tc-99m sestamibi extraction and retention increase, but for Tc-99m teboroxime and Tl-201 these values tend to decrease. All tracers show adequate transport characteristics for perfusion imaging, and differences in transport and retention should lead to the development of new clinical protocols.27 references

  10. 19F labelled dextrans and antibodies as NMR imaging and spectroscopy agents

    International Nuclear Information System (INIS)

    Antich, P.P.; Kulkarni, P.V.

    1993-01-01

    A method is described of NMR imaging or spectroscopy, comprising the steps of administering to a living subject a 19 F labelled NMR agent, the NMR agent comprising (a) a transport polymer selected from the group consisting of dextran polymers and amino dextrans, having a molecular weight between approximately 100 d and 500 kd, and antibodies and fragments thereof, and (b) a 19F-containing sensor moiety selected from the group consisting of fluorinated alkyls, fluorinated acetates, fluoroaniline, and fluoroalkyl phosphonates, in an amount effective to provide a detectable NMR signal; and then detecting the 19 F NMR signal produced

  11. Functional magnetic resonance imaging for evaluation of radiation-induced renal damage; Funktionelle MRT der Niere zur Erfassung strahleninduzierter Nierenschaedigungen

    Energy Technology Data Exchange (ETDEWEB)

    Haneder, S.; Schoenberg, S.O.; Michaely, H.J. [Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Mannheim (Germany); Boda-Heggemann, J. [Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Klinik fuer Strahlentherapie und Radioonkologie, Mannheim (Germany)

    2012-03-15

    The diagnosis of radiation-induced (especially chronic) renal alterations/damage is difficult and currently relies primarily on clinical evaluation. The importance of renal diagnostic evaluation will increase continuously due to the increasing number of long-term survivors after radiotherapy. This article evaluates the potentia diagnostic contribution of magnetic resonance (MR) imaging with a focus on functional MRI. The following functional MRI approaches are briefly presented and evaluated: blood oxygenation level-dependent imaging (BOLD), diffusion-weighted imaging (DWI) or diffusion tensor imaging (DTI), MR perfusion measurements and {sup 23}Na imaging. In summary, only DWI and contrast-enhanced MR perfusion currently seem to be suitable approaches for a broader, clinical implementation. However, up to now valid data from larger patient studies are lacking for both techniques in regard to radiation-induced renal alterations. The BOLD and {sup 23}Na imaging procedures have a huge potential but are currently neither sufficiently evaluated with regard to radiation-induced renal alterations nor technically simple and reliable for implementation into the clinical routine. (orig.) [German] Die Diagnostik strahleninduzierter, insbesondere chronischer Schaedigungen der Niere ist nach wie vor schwierig und beruht primaer auf der klinischen Beurteilung. Durch die zunehmende Anzahl von Langzeitueberlebenden nach einer Strahlentherapie wird die Bedeutung dieser Diagnostik jedoch weiter zunehmen. In diesem Beitrag wird der Frage nachgegangen, in wieweit hierzu die MRT-Bildgebung und hier besonders die funktionellen Bildgebungsmodalitaeten ihren Beitrag leisten koennen. Die folgenden Verfahren werden kurz vorgestellt und bewertet: die Blood-oxygenation-level-dependent-Bildgebung (BOLD), die diffusionsgewichtete Bildgebung (''diffusion-weighted imaging'', DWI) bzw. das ''diffusion tensor imaging'' (DTI), die MR-Perfusionsmessungen, und

  12. Triamide mercaptide (N/sub 3/S) ligands for Tc-99m as potential Tc-99m renal function agents

    International Nuclear Information System (INIS)

    Fritzberg, A.R.; Kasina, S.; Johnson, D.L.; Eshima, D.

    1985-01-01

    A number of diamide dimercaptide (N/sub 2/S/sub 2/) complexes of Tc-99m have shown potential as renal tubular function radiopharmaceuticals that could replace radioiodinated hippurate (OIH). Evaluation of such ligands suggested that maximum efficiency for tubular secretion and specificity resulted from addition of a carboxylate group. However, such derivatives resulted in chelate ring stereoisomers that were differently transported by the renal tubular system. The problem of stereoisomers was obviated by replacing one sulfur with an effectively planar amido nitrogen. Groups on the nitrogen then result in diastereomers only when an additional asymetric center is present. A series of triamide mercaptide compounds have been synthesized to evaluate this class as ligands for Tc-99m. One of the simplest of the series, mercaptoacetylglycylglycylglycine (MAG/sub 3/), formed a single Tc-99m product in high yield as determined by HPLC. Preliminary results with pmr and ms of the Tc-99 complex indicate a structure consistent with a 1:1 metal to ligand ratio and monooxo technetium group. Biological evaluation of Tc-99m MAG/sub 3/ showed high renal specificity and rate of excretion exceeding OIH in several species including humans. Members of the N/sub 3/S series studied include mercaptoacetylglycylglycyl-amino acids. In some cases with second asymmetric centers, two components were seen on HPLC. In mice several dianionic Tc-99m complexes were excreted faster than OIH, Tc-99m MAG/sub 2/-ala, -asn, and -gln. Trianionic Tc-99m MAG/sub 2/-asp and -glu were excreted more slowly, and Tc-99m MAG/sub 2/-phe showed hepatobiliary excretion. Triamide mercaptides represent a new ligand class for Tc-99m

  13. Uptake of perfusion imaging agents by transplanted hearts: an experimental study in rats

    International Nuclear Information System (INIS)

    Bergsland, J.; Carr, E.A. Jr.; Carroll, M.; Feldman, M.J.; Kung, H.; Wright, J.R.

    1989-01-01

    There is a need for a reliable noninvasive marker of rejection in transplanted hearts. Endomyocardial biopsy is now the universally accepted diagnostic method of choice, but the invasiveness of the procedure and the limited size of the sample obtained makes this method far from ideal. As coronary blood flow may be expected to decrease during acute rejection, there has been interest in thallium-201 chloride (T1), a perfusion marker, as an imaging agent for diagnosing cardiac rejection. Hexakis(t-butylisonitrile)-technetium (Tc-TBI) is a representative of a new class of radiopharmaceuticals proposed as perfusion markers. We have compared the uptake of these imaging agents in a rat model of cardiac transplantation. Uptake of Tc-TBI as well as of T1 was significantly lower in rejecting than in nonrejecting hearts. This change was found in both left (LV) and right (RV) ventricles. Allografts in animals treated with cyclosporine (CyA) showed less severe rejection and higher uptakes of both imaging agents as compared to unmodified rejection. Our results suggest that perfusion imaging with these radionuclides is a potentially useful approach to the problem of detecting allograft rejection

  14. The synthesis of radioiodinated carbohydrates and butyrothenones as potential imaging agents for computed tomography

    International Nuclear Information System (INIS)

    Waterhouse, R.N.

    1993-01-01

    Positron Emission tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are two relatively new imaging techniques which allow for the non-invasive evaluation of biochemical processes in living subjects. Currently, SPECT is more widely accessible than PET, however, only a limited number of radiotracers have been successfully developed for imaging by SPECT. Two classes of radioiodinated compounds were developed as potential imaging agents for SPECT: (1) Radioiodinated carbohydrates for the assessment of glucose metabolism and (2) Radioiodinated butyrothienones for the evaluation of dopamine D 2 receptors in the brain. In both classes of compounds, the radioiodine was attached to an sp 2 hybridized carbon atom to provide radiotracers that were chemically and metabolically stable. Radioiodine incorporation was easily accomplished by radioiododestannylation of vinyl- and aryl-trialkylstannanes in the presence of an oxidizing agent. The incorporation of radioiodine into small molecules can have a significant effect on the biological activity of the resulting radiotracer because of the relatively large size and lipophilicity of the iodine atom. Preliminary evaluations of the effectiveness of the radioiodinated carbohydrates and butyrothienones as imaging agents are presented

  15. A naturally occurring contrast agent for OCT imaging of smokers' lung

    International Nuclear Information System (INIS)

    Yang Ying; Bagnaninchi, Pierre O; Whiteman, Suzanne C; Pittius, Daniel Gey van; Haj, Alicia J El; Spiteri, Monica A; Wang, Ruikang K

    2005-01-01

    Optical coherence tomography (OCT) offers great potential for clinical applications in terms of its cost, safety and real-time imaging capability. Improvement of its resolution for revealing sub-layers or sub-cellular components within a tissue will further widen its application. In this study we report that carbon pigment, which is frequently present in the lungs of smokers, could be used as a contrast agent to improve the OCT imaging of lung tissue. Carbon produced an intense bright OCT image at a relatively deep location. The parallel histopathological section analysis confirmed the presence of carbon pigment in such tissues. The underlying mechanism of the OCT image formation has been discussed based on a model system in which carbon particles were dispersed in agar gel. Calculations and in-depth intensity profiles of OCT revealed that higher refractive index particles with a size close to or smaller than the wavelength would greatly increase backscattering and generate a sharp contrast, while a particle size several times larger than the wavelength would absorb or obstruct the light path. The naturally occurring contrast agent could provide a diagnostic biomarker of lung tissue in smokers. Furthermore, carbon under such circumstances, can be used as an effective exogenous contrast agent, with which specific components or tissues exhibiting early tumour formation can be optically labelled to delineate the location and boundary, providing potential for early cancer detection and its treatment

  16. Agentes calciomiméticos en el tratamiento del hiperparatiroidismo secundario a la insuficiencia renal crónica Calcimimetic agents in the treatment of hyperparathyroidism secondary to chronic renal failure

    Directory of Open Access Journals (Sweden)

    A. L. Negri

    2003-04-01

    Full Text Available La reciente identificación y clonación del receptor sensor de calcio (RSCa ha permitido tener una mejor comprensión de la regulación normal del metabolismo del calcio y entender un número de trastornos relativamente poco frecuentes del metabolismo mineral. En la glándula paratiroides el RSCa es el mecanismo responsable de modular la liberación de la hormona paratiroidea en función del nivel de calcio extracelular. Este descubrimiento también ha permitido desarrollar drogas que imitan o potencian las acciones del calcio extracelular sobre el RSCa (llamadas calciomiméticos que disminuyen la secreción de paratohormona sin incrementar el calcio sérico. Los calciomiméticos de última generación son pequeñas moléculas orgánicas que actúan como moduladores alostéricos del RSCa y se encuentran en su fase inicial de desarrollo clínico. A pesar de que la experiencia obtenida con estas drogas hasta ahora es limitada, ellas han mostrado ser efectivas para reducir los niveles de paratohormona en pacientes con hiperparatiroidismo secundario a fallo renal terminal sin inducir efectos secundarios de importancia. Es por ello que los compuestos calciomiméticos tienen un considerable potencial como nuevas drogas para el tratamiento del hiperparatiroidismo secundario y de la enfermedad ósea secundaria a la insuficiencia renal.The recent discovery and cloning of the extra cellular calcium sensing receptor (CaSR has allowed a better understanding of the regulation of normal calcium metabolism and of rare disturbances in mineral metabolism. In the parathyroid glands the CaSR is responsable for modulating parathyroid hormone release as a function of the extra cellular calcium level. This discovery has allowed the development of drugs that mimics or potentiates the actions of extra cellular calcium on the CaSR, called calcimimetics that decrease parathyroid hormone secretion without increasing serum calcium. The new calcimimetics are small organic

  17. A novel nitroreductase-enhanced MRI contrast agent and its potential application in bacterial imaging

    Directory of Open Access Journals (Sweden)

    Yun Liu

    2018-05-01

    Full Text Available Nitroreductases (NTRs are known to be able to metabolize nitro-substitute