Cystic changes in intraabdominal extrahepatic metastases from gastrointestinal stromal tumors treated with imatinib.
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OBJECTIVE: This study was undertaken for the purpose of describing the CT features of intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors in patients who were treated with imatinib. MATERIALS AND METHODS: Eleven patients with intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors, who were treated with imatinib between May 2001 and December 2003, were included in this study. The clinical findings and CT scans were retrospectively reviewed. The metastatic lesions were assessed according to the location, size (greatest diameter), attenuation, and the enhancing pattern before and after imatinib treatment. RESULTS: Prior to the treatment, the sizes and attenuation values of the metastatic lesions ranged from 5 to 20 cm and from 63 to 131 H, respectively. The metastatic lesions showed a heterogeneous enhancement pattern on the contrast-enhanced CT scans. After the treatment, the metastatic lesions became smaller in all 11 patients, and the corresponding attenuation value ranged from 15 to 51 H. The metastatic lesions became homogeneous and cystic in appearance on the follow-up CT scans, mimicking ascites. CONCLUSION: Intra-abdominal extra-hepatic metastases of patients with gastrointestinal stromal tumors treated with imatinib may appear as well-circumscribed cystic lesions on contrast-enhanced CT. These metastases are likely to become smaller and resemble ascites, but may persist indefinitely on the followup CT. (+info)
Performance of different prediction equations for estimating renal function in kidney transplantation.
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Numerous formulas have been developed to estimate renal function from biochemical, demographic and anthropometric data. Here we compared renal function derived from 12 published prediction equations with glomerular filtration rate (GFR) measurement by plasma iohexol clearance as reference method in a group of 81 renal transplant recipients enrolled in the Mycophenolate Mofetil Steroid Sparing (MY.S.S.) trial. Iohexol clearances and prediction equations were carried out in all patients at months 6, 9 and 21 after surgery. All equations showed a tendency toward GFR over-estimation: Walser and MDRD equations gave the best performance, however not more than 45% of estimated values were within +/-10% error. These formulas showed also the lowest bias and the highest precision: 0.5 and 9.2 mL/min/1.73 m2 (Walser), 2.7 and 10.4 mL/min/1.73 m2 (MDRD) in predicting GFR. A significantly higher rate of GFR decline ranging from -5.0 mL/min/1.73 m2/year (Walser) to -7.4 mL/min/1.73 m2/year (Davis-Chandler) was estimated by all the equations as compared with iohexol clearance (-3.0 mL/min/1.73 m2/year). The 12 prediction equations do not allow a rigorous assessment of renal function in kidney transplant recipients. In clinical trials of kidney transplantation, graft function should be preferably monitored using a reference method of GFR measurement, such as iohexol plasma clearance. (+info)
Prevention of contrast-induced nephropathy in vascular patients undergoing angiography: a randomized controlled trial of intravenous N-acetylcysteine.
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OBJECTIVE(S): Apart from proper hydration, only oral N-acetylcysteine (NAC) has shown efficacy in reducing radiographic contrast media (RCM)-induced acute renal failure, though its benefit has been challenged. We investigated the effect of intravenous (i.v.) NAC on renal function in patients with vascular disease receiving RCM for angiography. METHODS: Single-center, randomized, double-blind, placebo-controlled trial. Based on a previous study, a trial with 44 patients each in placebo and treatment arms would give at least 80% power to show a statistically significant difference at the 5% level. Vascular patients undergoing angiography were consented and segregated into those whose serum creatinine (SC) level was normal or raised (men >1.32 mg/dl; women >1.07 mg/dL). All patients received 500 mL i.v. normal saline 6 to 12 hours prior to and then after angiography. Groups with normal SC and raised SC were randomly assigned to either 1 g of NAC with normal saline before and after angiography or nothing (placebo). Main outcome measures were change in SC and creatinine clearance (CrCl) as measured 1, 2, and 7 days postangiography (with comparison between active and placebo groups using unpaired t test) and incidence of acute renal decline (>25% or 0.5 mg/dL rise in SC) at 48 hours (with comparison between active and placebo using the Fisher exact test). RESULTS: Forty-six patients received NAC (29 normal SC, 17 raised SC), and 48 received placebo (27 normal SC, 21 raised SC). There was no significant difference in postangiography SC or CrCl at any of the time points measured between NAC and placebo in patients with either normal or raised SC. In the raised SC group, 3 patients from both the NAC and placebo groups suffered acute renal declines. Importantly, at 48 hours, the impaired SC group had a significant reduction in CrCl (-14% +/- 41% vs +18% +/- 58%: P = .0142) and a significant rise in SC (+7.0 +/- 25% vs -1.6% +/- 10%; P = .0246) when compared with the normal SC group. CONCLUSIONS: NAC (i.v. at 1 g) precontrast and postcontrast does not confer any benefit in preventing RCM-induced nephropathy in vascular patients. Patients with pre-existing raised SC have an increased risk of renal impairment as defined by a fall in CrCl and a rise in SC post-RCM when compared with patients with normal SC who appear to benefit from hydration. (+info)
Accuracy of dynamic perfusion CT with deconvolution in detecting acute hemispheric stroke.
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BACKGROUND AND PURPOSE: Dynamic perfusion CT (PCT) with deconvolution produces maps of time-to-peak (TTP), mean transit time (MTT), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV), with a computerized automated map of the infarct and penumbra. We determined the accuracy of these maps in patients with suspected acute hemispheric stroke. METHODS: Forty-six patients underwent nonenhanced CT and dynamic PCT, with follow-up CT or MR imaging. Two observers reviewed the nonenhanced studies for signs of stroke and read the PCT maps for TTP, MTT, rCBF, and rCBV abnormalities. Sensitivity, specificity, accuracy, and interobserver agreement were compared (Wilcoxon tests). Nonenhanced CT and PCT data were reviewed for stroke extent according to previously reported methods. Sensitivity, specificity, and accuracy of the computerized maps in detecting ischemia and its extent were determined. RESULTS: Compared with nonenhanced CT, PCT maps were significantly more accurate in detecting stroke (75.7-86.0% vs. 66.2%; P <.01), MTT maps were significantly more sensitive (77.6% vs. 69.2%; P <.01), and rCBF and rCBV maps were significantly more specific (90.9% and 92.7%, respectively, vs. 65.0%; P <.01). Regarding stroke extent, PCT maps were significantly more sensitive than nonenhanced CT (up to 94.4% vs. 42.9%; P <.01) and had higher interobserver agreement (up to 0.763). For the computerized map, sensitivity, specificity, and accuracy, respectively, were 68.2%, 92.3%, and 88.1% in detecting ischemia and 72.2%, 91.8%, and 87.9% in showing the extent. CONCLUSION: Dynamic PCT maps are more accurate than nonenhanced CT in detecting hemispheric strokes. Despite limited spatial coverage, PCT is highly reliable to assess the stroke extent. (+info)
Prediction of iopromide reduction rates during haemodialysis using an in vitro dialysis system.
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BACKGROUND: In clinical studies, it has been difficult to evaluate the influence of haemodialysis (HD) parameters on HD clearance (CL(HD)) and reduction rate (RR) of non-ionic contrast medium during HD sessions. We therefore predicted clinical values of CL(HD) and RR of iopromide, a non-ionic contrast medium, from findings obtained from in vitro experiments, and confirmed that these predictive values were comparable with the actual values in clinical cases. METHODS: We developed a correlation equation for predicting CL(HD) on the basis of in vitro HD experiments by varying blood flow rates between 100 and 200 ml/min with a cuprammonium rayon dialyser (AM-SD-10H). Total body clearance of iopromide (CL(PT)) was estimated by the Cockroft-Gault equation. The volume of distribution (V(d)) was obtained from the reported value. By using the HD and three pharmacokinetic parameters (CL(HD), CL(PT) and V(d)), we predicted CL(HD) and RR for seven patients undergoing HD after the administration of iopromide. RESULTS: In the in vitro study, the mean values (+/-SD) of iopromide clearance at blood flow rates of 100, 150 and 200 ml/min were 45.35 (2.54), 53.88 (6.46) and 57.61 (4.72) ml/min, respectively. There were highly significant correlations between clearance and blood flow rate (r = 0.975). Although the predicted CL(HD) showed a tendency towards underestimation, a good correlation was found. Predicted RR values were similar to observed values except for one case. CONCLUSION: The in vitro model used in the present study provides pertinent information about CL(HD) and is helpful for predicting RR during HD in individual patients undergoing HD. (+info)
Assessment of myocardial viability in reperfused acute myocardial infarction using 16-slice computed tomography in comparison to magnetic resonance imaging.
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OBJECTIVES: The aim of this study was to examine if contrast-enhanced multislice spiral computed tomography (MSCT) is comparable to contrast-enhanced magnetic resonance imaging (MRI) for depiction of acute myocardial infarction (MI). BACKGROUND: Delayed-enhancement MRI of MI is well established, but there are no clinical reports about MSCT for this indication. Early perfusion deficit on MSCT has been reported to correlate with the presence of MI. METHODS: A total of 28 consecutive patients (23 men; 55.9 +/- 11.4 years) with reperfused MI underwent contrast-enhanced cardiac 16-slice MSCT. Images were acquired in the arterial phase and the late phase 15 min after administration of 120 ml contrast material. Within 5 days, patients underwent MRI after administration of 0.2 mmol Gd-dimeglumine/kg/bodyweight. All examinations were completed within two weeks after MI. The area of MI was compared between the different imaging techniques using Bland-Altman method and multivariate analysis. Agreement of the contrast enhancement patterns was evaluated with a weighted kappa test. RESULTS: Mean infarct size on MRI was 31.2 +/- 22.5% per slice compared with 33.3 +/- 23.8% per slice for late-enhancement MSCT and 24.5 +/- 18.3% per slice for early-perfusion-deficit MSCT. Bland-Altman data showed a good agreement between late-enhancement MRI and late-enhancement MSCT. Contrast enhancement patterns demonstrated an excellent agreement between late-enhancement MRI and late-enhancement MSCT (kappa = 0.878). The results were worse comparing MRI and early-phase MSCT (kappa = 0.635). CONCLUSIONS: Multislice spiral computed tomography allows for the assessment of acute MI. Late-enhancement MSCT appears to be as reliable as delayed contrast-enhanced MRI in assessing infarct size and myocardial viability in acute MI. (+info)
Incidence of contrast nephropathy in patients receiving comprehensive intravenous and oral hydration.
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BACKGROUND: Contrast-induced nephropathy (CIN) remains a major complication of percutaneous coronary interventions (PCI) and a common cause of acute renal failure. The most effective preventive strategy is unknown. OBJECTIVES: This study sought to estimate the incidence of CIN in patients receiving comprehensive intravenous and oral volume supplementation for PCI during which iopromide (Ultravist 370, Schering, Berlin, Germany) was used. METHODS: We prospectively studied the development of CIN in 425 consecutive patients undergoing PCI, applying comprehensive intravenous and oral hydration in all patients. Baseline renal function was assessed by calculating the glomerular filtration rate (GFR) with the use of the abbreviated Modification of Diet in Renal Disease Study equation. CIN was defined as an increase in serum creatinine of at least 0.5 mg/dl (44 mmol/l) within 48 hours. RESULTS: Mean patients' age (mean +/- SD) was 64 +/- 10 years. A total of 133/425 patients (31%) were 70 years or older, 107 (25%) were women, 70 (16%) were diabetics, 218 (51%) had prior myocardial infarction, and 43 (10%) underwent PCI for an acute ST-segment elevation myocardial infarction. Mean GFR was 89 ml/min/1.73 m2. Glomerular filtration rate was below 60 ml/min/ 1.73 m2 in 43 patients (10%). During PCI 226 +/- 80 ml of iopromide were used. With the comprehensive hydration strategy used, CIN developed in only 6 of 425 (1.4%; 95% confidence interval 0.5-3.1%) patients. No patient required dialysis. CONCLUSIONS: Applying the combination of intravenous and oral volume supplementation results in a very low incidence of CIN following PCI. Hydration remains the cornerstone for the prevention of CIN. (+info)
Liposuction and extravasation injuries in ICU.
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Liposuction is a minimally invasive surgical technique, occasionally used to minimize the risk of devastating soft tissue necrosis following extravasation of noxious substances. Anaesthetists and intensive care physicians frequently use agents that may cause serious tissue injury if extravasated. Therefore, knowledge on how to manage this complication is important. We present two cases of percutaneous extravasation of noxious agents in intensive care patients and discuss their subsequent management. (+info)