Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “IOTHALAMIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
PubMed1982

Iopamidol in urography. A comparison between ionic and nonionic contrast media in patients with normal and impaired renal function.

The radiographic results obtained in urography with iopamidol, a new low osmolality contrast medium, given to 50 patients with normal renal function and 42 patients with impaired renal function, have been evaluated and compared with those obtained with ionic media of current use (meglumine sodium diatrizoate and sodium iothalamate). Based on this comparison, the authors believe there are no significant radiographic advantages to iopamidol.

Contrast Media↗
PubMed1983

Iohexol in urography.

Thirty patients injected intravenously with a nonionic contrast medium, iohexol, for urography were compared with 30 patients similarly injected with sodium iothalamate. Comparable radiographic results were obtained in these patients with normal renal function. Few minor responses were observed with the iohexol, suggesting that it may prove to be an attractive contrast medium for this purpose.

Clinical Trials as Topic↗
PubMed1985

Persistent wedge-shaped contrast enhancement of the kidney.

A case with a single wedge-shaped high-density area of the kidney that persists after urography was observed by CT scan. This might be an aberrant form of acute renal failure with multiple wedge-shaped contrast enhancement.

Acute Kidney Injury↗
PubMed2002

Short-term moderate sodium restriction induces relative hyperfiltration in normotensive normoalbuminuric Type I diabetes mellitus.

AIMS/HYPOTHESIS: Type I (insulin-dependent) diabetes mellitus is associated with an increased extracellular volume. Sodium restriction might seem a logical form of treatment but data on its renal effects is conflicting. We therefore studied the effects of sodium restriction on renal haemodynamics in uncomplicated Type I diabetes mellitus. METHODS: Uncomplicated Type I diabetic patients ( n = 24) and matched control subjects ( n = 24) were studied twice in random order: after a week of 50 mmol or after 200 mmol sodium intake, respectively. The diabetic patients were studied under normoglycaemic clamp conditions. Glomerular filtration rate and effective renal plasma flow were measured as the clearances of iothalamate and hippuran, respectively. RESULTS: During liberal sodium intake, glomerular filtration, effective renal plasma flow and filtration fraction were similar between the diabetic patients and the control subjects. Sodium restriction decreased the effective renal plasma flow in both groups, whereas glomerular filtration rate only decreased in the control subjects. Consequently, in the diabetic patients, the filtration fraction was increased on low sodium (4.1 +/- 8.4 %, p < 0.05 vs liberal sodium). As a consequence, filtration fraction (24.0 +/- 2.6 vs 22.1 +/- 2.0 %, p < 0.05) and glomerular filtration (119 +/- 14 vs 110 +/- 13 ml/min, p < 0.05) were higher in the diabetic patients than in the control subjects during sodium restriction. CONCLUSION/INTERPRETATION: Short-term moderate sodium restriction induces relative hyperfiltration in uncomplicated Type I diabetes. This could indicate an increased intraglomerular pressure. Sodium restriction could be an unfavourable preventive approach in diabetes mellitus but its long-term effects are not known.

Adult↗
PubMed1999

Long-term maintenance of therapeutic cyclosporine levels leads to optimal graft survival without evidence of chronic nephrotoxicity.

Since the introduction of cyclosporine into clinical use, a major area of concern within the transplant community has been the fear of chronic nephrotoxicity. Although progressive renal damage does appear to occur in native kidneys of heart and liver transplant patients receiving cyclosporine, it has been our contention that its use is not a major cause of deterioration in renal allografts. We therefore undertook a study of 91 consecutive renal transplants performed over a three-year period with a minimum graft survival of 1 year and a follow-up of 7-9 years. Serial serum creatinine values, iothalamate clearances and cyclosporine levels were obtained at 3 months after transplantation and yearly thereafter. Biopsies were performed on all grafts that had failed as well as on the majority of patients with deteriorating renal function, and were interpreted by two nephropathologists. As measured by iothalamate clearances, 65% of the patients in this series exhibited absolutely stable renal function despite the maintenance of cyclosporine levels of more than 200 ng/ml for 7-9 years. Since these stable patients did not reveal any decline in renal function, it therefore follows that they did not experience chronic cyclosporine nephrotoxicity. Furthermore, none of the patients with declining renal function or with failed grafts showed any evidence of nephrotoxicity on biopsy. Chronic cyclosporine nephrotoxicity may be a cause of declining function or graft loss with renal transplant recipients, but if so, it is exceedingly rare.

Creatine↗
PubMed1997

A study of the factors affecting the metabolic clearance of quinine in malaria.

OBJECTIVE: To assess the factors that contribute to impaired quinine clearance in acute falciparum malaria. PATIENTS: Sixteen adult Thai patients with severe or moderately severe falciparum malaria were studied, and 12 were re-studied during convalescence. METHODS: The clearance of quinine, dihydroquinine (an impurity comprising up to 10% of commercial quinine formulations), antipyrine (a measure of hepatic mixed-function oxidase activity), indocyanine green (ICG) (a measure of liver blood flow), and iothalamate (a measure of glomerular filtration rate) were measured simultaneously, and the relationship of these values to the biotransformation of quinine to the active metabolite 3-hydroxyquinine was assessed. RESULTS: During acute malaria infection, the systemic clearance of quinine, antipyrine and ICG and the biotransformation of quinine to 3-hydroxyquinine were all reduced significantly when compared with values during convalescence. Iothalamate clearance was not affected significantly and did not correlate with the clearance of any of the other compounds. The clearance of total and free quinine correlated significantly with antipyrine clearance (rs = 0.70, P = 0.005 and rs = 0.67, P = 0.013, respectively), but not with ICG clearance (rs = 0.39 and 0.43 respectively, P > 0.15). In a multiple regression model, antipyrine clearance and plasma protein binding accounted for 71% of the variance in total quinine clearance in acute malaria. The pharmacokinetic properties of dihydroquinine were generally similar to those of quinine, although dihydroquinine clearance was less affected by acute malaria. The mean ratio of quinine to 3-hydroxyquinine area under the plasma concentration-time curve (AUC) values in acute malaria was 12.03 compared with 6.92 during convalescence P = 0.01. The mean plasma protein binding of 3-hydroxyquinine was 46%, which was significantly lower than that of quinine (90.5%) or dihydroquinine (90.5%). CONCLUSION: The reduction in quinine clearance in acute malaria results predominantly from a disease-induced dysfunction in hepatic mixed-function oxidase activity (principally CYP 3A) which impairs the conversion of quinine to its major metabolite, 3-hydroxyquinine. The metabolite contributes approximately 5% of the antimalarial activity of the parent compound in malaria, but up to 10% during convalescence.

Adolescent↗
PubMed2005

PET/CT with intravenous contrast can be used for PET attenuation correction in cancer patients.

PURPOSE: If the CT scan of a combined PET/CT study is performed as a full diagnostic quality CT scan including intravenous (IV) contrast agent, the quality of the joint PET/CT procedure is improved and a separate diagnostic CT scan can be avoided. CT with IV contrast can be used for PET attenuation correction, but this may result in a bias in the attenuation factors. The clinical significance of this bias has not been established. Our aim was to perform a prospective clinical study where each patient had CT performed with and without IV contrast agent to establish whether PET/CT with IV contrast can be used for PET attenuation without reducing the clinical value of the PET scan. METHODS: A uniform phantom study was used to document that the PET acquisition itself is not significantly influenced by the presence of IV contrast medium. Then, 19 patients referred to PET/CT with IV contrast underwent CT scans without, and then with contrast agent, followed by an 18F-fluorodeoxyglucose whole-body PET scan. The CT examinations were performed with identical parameters on a GE Discovery LS scanner. The PET data were reconstructed with attenuation correction based on the two CT data sets. A global comparison of standard uptake value (SUV) was performed, and SUVs in tumour, in non-tumour tissue and in the subclavian vein were calculated. Clinical evaluation of the number and location of lesions on all PET/CT scans was performed twice, blinded and in a different random order, by two independent nuclear medicine specialists. RESULTS: In all patients, the measured global SUV of PET images based on CT with IV contrast agent was higher than the global activity using non-contrast correction. The overall increase in the mean SUV (for two different conversion tables tested) was 4.5+/-2.3% and 1.6+/-0.5%, respectively. In 11/19 patients, focal uptake was identified corresponding to malignant tumours. Eight out of 11 tumours showed an increased SUVmax (2.9+/-3.1%) on the PET images reconstructed using IV contrast. The clinical evaluation performed by the two specialists comparing contrast and non-contrast CT attenuated PET images showed weighted kappa values of 0.92 (doctor A) and 0.82 (doctor B). No contrast-introduced artefacts were found. CONCLUSION: This study demonstrates that CT scans with IV contrast agent can be used for attenuation correction of the PET data in combined modality PET/CT scanning, without changing the clinical diagnostic interpretation.

Adult↗
PubMedDate not supplied

Spiral CT for the detection of hepatocellular carcinomas:relative value of arterial- and late-phase scanning.

BACKGROUND: Spiral computed tomography (CT) can image the liver during arterial and late phases of contrast and optimize the evaluation of hypervascular tumor. The objective of this study was to evaluate the relative value of arterial- and late-phase spiral CT in the detection of hepatocellular carcinomas. METHODS: Fifty-eight patients with hepatocellular carcinomas underwent two-phase spiral CT examination with 10-mm collimation at 10 mm/s table speed (Siemens Somatom Plus S), and 120 mL of contrast material (36 g iodine) was injected at the rate of 3 mL/s. CT images of hepatic arterial and late phases were obtained with a 35-s and 180-s delay, respectively. RESULTS: In 58 patients, 111 hepatocellular carcinoma lesions were seen. The arterial phase detected 93 (84%) and the late phase 75 (68%) lesions (p < 0.01). The arterial phase detected more lesions in 11 patients, and the late phase detected more in two patients and an equal number in 45 patients. If lesions larger than 2 cm are excluded, the arterial phase detected 40 (74%) and the late phase 21 (39%) of 54 lesions (p < 0.001). CONCLUSION: The arterial phase of spiral CT greatly improves the detection of hepatocellular carcinoma when compared with the late phase.

Adult↗
PubMedDate not supplied

Helical CT anatomy of pancreatic arteries.

BACKGROUND: To assess the frequency of visualization of pancreatic arteries in the arterial phase of helical computed tomography (CT). METHODS: The visibility of pancreatic and peripancreatic arteries in helical CT images was evaluated in 20 consecutive patients who had no evidence of pancreatic disease. CT examinations were performed by using a continuously rotating CT scanner and intravenous injection of contrast media. The scans were taken 35 s after the start of injection and with a table speed of 3 mm/s. Images were reconstructed in 3-mm section increments. RESULTS: Frequently visualized arteries were the gastroduodenal, anterior and posterior superior pancreaticoduodenal, and right gastroepiploic arteries. Infrequently visualized arteries were the dorsal pancreatic, pancreatica magna, caudal pancreatic, transverse pancreatic, and common, anterior, and posterior inferior pancreaticoduodenal arteries. CONCLUSION: Helical CT enabled us to recognize small pancreatic arteries, and the evaluation of these arteries should be considered in the staging of pancreatic carcinoma.

Arteries↗
PubMedDate not supplied

CT of the mesenteric vascular anatomy.

BACKGROUND: To evaluate the appearance of the arrangement of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) on computed tomography (CT) in normal patients and in patients with abdominal masses. METHODS: One hundred seventy-seven consecutive abdominal CT examinations of 143 adults and two children were reviewed. The relationship of the SMV to the SMA was recorded at four locations: the beginning of the mesenteric vessels and levels 3 cm, 6 cm, and 9 cm caudad to the beginning. The relationship of the SMV to the SMA was divided into four quadrants in relation to the SMA: I, ventral right or directly ventral; II, dorsal right or directly right; III, dorsal left or directly dorsal; and IV, ventral left or directly left. RESULTS: In the beginning of the SMV-SMA complex and levels 3 cm, 6 cm, and 9 cm caudal to the beginning, the SMV was located in quadrant I in 146, 84, 69, and 43 examinations, in quadrant II in 31, 93, 71, and 27 examinations, in quadrant III in zero, zero, five, and three examinations, and in quadrant IV in zero, zero, nine, and 15 examinations, respectively. The cases with SMV inversion had neither malrotation nor adjacent tumor compression. All the cases with an adjacent tumor-induced compression of the SMV-SMA complex had a normal SMV-SMA relationship. CONCLUSION: In the first 3 cm, the SMV is always to the right of the SMA. Caudal to the level of 6 cm, the SMV may be located to the left of the SMA without evidence of malrotation. A midgut nonrotation is more likely to be present when a proximal SMV inversion is coexistent with a rightward direction of the proximal jejunal vessels. A hypothetical depiction of the step-by-step change of the SMV-SMA relationship during embryologic development may explain the arrangement patterns of the mesenteric vessels in normal rotation and midgut nonrotation.

Abdominal Neoplasms↗
PubMedDate not supplied

Intestinal malrotation as an incidental finding on CT in adults.

BACKGROUND: Intestinal malrotation in adults is usually an incidental finding on computed tomography (CT). We present the CT findings of 18 adult patients with malrotation and discuss the clinical implications. METHODS: Abdominal scans of 18 patients (12 women, six men; age range = 15-79 years) with intestinal malrotation were reviewed. Special attention was directed to the location of the superior mesenteric vessels, the location of the small and large bowels, the size of the uncinate process, the situs definition, and additional anomalies. RESULTS: The malrotation was an incidental finding in all but one patient. The malrotation was type Ia in 17 patients and IIc in the one symptomatic patient. The superior mesenteric vessels were vertically oriented in 10, inverted in two, normally positioned in four, and mirror imaged in two cases with situs ambiguus. All patients had aplasia of the pancreatic uncinate process, five had a short pancreas, and two had a preduodenal portal vein. Fourteen patients had a normal situs and four had heterotaxia. Seven patients had polysplenia, six of which with associated inferior vena cava anomalies. CONCLUSIONS: Intestinal malrotation can be diagnosed on CT by the anatomic location of a right-sided small bowel, left-sided colon, an abnormal relationship of the superior mesenteric vessels, and aplasia of the uncinate process. Awareness of these abnormalities is necessary to diagnose this anomaly. It should be sought in patients with a situs problem, inferior vena cava anomalies, polysplenia, or preduodenal portal vein. Although usually an incidental finding, it is important to diagnose such a malrotation because it may cause abdominal symptoms. Also, knowledge of associated vascular anomalies is important when abdominal surgery is planned.

Adolescent↗
PubMed2002

Inadvertent intrathecal use of ionic contrast agent.

Intrathecal administration of ionic contrast media may cause severe and fatal neurotoxic reactions due to their hyperosmolarity and ionic nature. They are therefore strictly contraindicated for all radiologic applications involving the central nervous system (e.g., myelography). We present a case in which ioxitalamate was accidentally injected intrathecally. The patient recovered completely due to a combination of the different therapeutic options reported in the literature, including early mechanical ventilation and neuromuscular paralysis, aggressive control of seizures, elevation of head and trunk to prevent cephalad migration of contrast, steroids, cerebrospinal fluid drainage and lavage and prophylactic antibiotics.

Contrast Media↗
PubMed1998

Cranial CT revisited: do we really need contrast enhancement?

The aim of this study was to define guidelines for intravenous contrast administration in cranial CT, as currently there are no recent guidelines based on a large series of patients. In 1900 consecutive patients (1480 adults and 420 children) pre- and post-contrast scan was analysed in order to assess the contribution of contrast enhancement to the diagnosis. The findings were grouped according to whether abnormalities were seen on the pre- and/or post-contrast scan, or whether no abnormalities were seen at all. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of a pre-contrast scan were used to determine validity. Intravenous contrast enhancement only contributes to the diagnosis if a suspicious abnormality is seen on the unenhanced scan or in the appropriate clinical setting (33.6%). In the remaining patients (65.6%) there is no diagnostic contribution, except for a small number of abnormalities (0.8%). These are often anatomical variants and have no therapeutic impact. The number of contrast-enhanced cranial CT examinations can significantly be reduced by using four general guidelines for contrast administration resulting in considerable cost savings without affecting the quality of service to the patient. These guidelines are defined by the clinical findings/presentation or by the findings on the unenhanced scan. The number of contrast-related complications will be reduced, which may have medicolegal implications. These guidelines can be applied in any radiology department.

Adolescent↗
PubMed2006

Estimating absolute glomerular filtration rate in children.

Normal values of glomerular filtration rate (GFR) in children are often expressed in a value adjusted to adult ideal body surface area. These values work well for many clinical situations, but in infants and children, especially those with atypical body mass, they may not accurately reflect renal function. Most body composition values in children are expressed in developmentally appropriate ranges. Absolute GFR (ml/min) also changes during childhood increasing rapidly in infancy and then gradually with age and body size. Previously, we developed a bedside equation for estimating GFR (ml/min) in children that accounted for changes with age and body size, and which correlated well with steady-state cold iothalamate GFR (ml/min) measurements: GFR (ml/min) = k(*)sqrt[(age(months) + 6)*wt (kg)/serum Cr (mg/dl)], where k=0.95 for females and 1.05 for males. In the present study GFR (ml/min) measured by iothalamate infusion was compared by correlation analysis with estimates calculated from the above equation in 566 children. This equation provides clinicians with a simple bedside method to estimate absolute GFR (ml/min).

Adolescent↗
PubMed1997

Infusion clearance of subcutaneous iothalamate versus standard renal clearance.

Accurate, timed urine collections for the measurement of glomerular filtration rate (GFR) may be impractical in infants or in patients with urological abnormalities. GFR may be measured without urine collection using a constant subcutaneous infusion of iothalamate. We compare the infusion clearance with conventional renal clearance in 14 children and young adults. The mean clearance ratio (infusion clearance/renal clearance +/- 1 SD) was 0.99 +/- 0.1 and the mean discrepancy between the two methods was 8.5% +/- 4.7%. The 95% limits of agreement for the ratio of the two methods are 0.83-1.23. These data indicate that subcutaneous infusion of iothalamate is a practical method for measuring GFR in children without a urine collection.

Adolescent↗
PubMed1998

Renal function in Inuit survivors of epidemic hemolytic-uremic syndrome.

We undertook a case-control study to evaluate the renal health of survivors of hemolytic-uremic syndrome (HUS) from the 1991 Arctic epidemic of Escherichia coli O157:H7 gastroenteritis 4 years after the epidemic. Eighteen children who developed HUS during the 1991 epidemic and 18 age- and sex-matched controls from the same community who had uncomplicated gastroenteritis were compared in 1995 for height, weight, blood pressure, urinalysis, and glomerular filtration rate (GFR), measured using continuous subcutaneous infusion of non-radioactive iothalamate. HUS survivors did not differ from controls in height, weight, systolic (HUS 118 mmHg, control 117 mmHg) or diastolic (HUS 64 mmHg, control 62 mmHg) blood pressures. Hematuria was detected more frequently in HUS survivors (11/18 vs. 4/18, P<0.05), but no child had proteinuria. Mean GFR did not differ between the two groups (HUS 159 ml/min per 1.73 m2, control 147 ml/min per 1.73 m2). Survivors of post-enteritic HUS from the 1991 Arctic E. coli 0157:H7 outbreak have excellent renal function 4 years after the epidemic.

Case-Control Studies↗