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Patient Study (patient + study)
Selected AbstractsN -Acetylcysteine Added to Volume Expansion with Sodium Bicarbonate Does Not Further Prevent Contrast-Induced Nephropathy: Results from the Cardiac Angiography in Renally Impaired Patients StudyJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2009CEZAR S. STANILOAE M.D. We reviewed data from the multicenter CARE (Cardiac Angiography in Renally Impaired Patients) study to see if benefit could be shown for N-acetylcysteine (NAC) in patients undergoing cardiac angiography who all received intravenous bicarbonate fluid expansion. Four hundred fourteen patients with moderate-to-severe chronic kidney disease were randomized to receive intra-arterial administration of iopamidol-370 or iodixanol-320. All patients were prehydrated with isotonic sodium bicarbonate solution. Each site chose whether or not to administer NAC 1,200 mg twice daily to all patients. Serum creatinine (SCr) levels and estimated glomerular filtration rate were assessed at baseline and 2,5 days after receiving contrast. The primary outcome was a postdose SCr increase 0.5 mg/dL (44.2 ,mol/L) over baseline. Secondary outcomes were a postdose SCr increase 25% and the mean peak change in SCr. The NAC group received significantly less hydration (892 ± 236 mL vs. 1016 ± 328 mL; P < 0.001) and more contrast volume (146 ± 74 mL vs. 127 ± 71 mL; P = 0.009) compared with no-NAC group. SCr increases 0.5 mg/dL occurred in 4.2% (7 of 168 patients) in NAC group and 6.5% (16 of 246 patients) in no-NAC group (P = 0.38); rates of SCr increases 25% were 11.9% and 10.6%, respectively (P = 0.75); mean post-SCr increases were 0.07 mg/dL in NAC group versus 0.11 mg/dL in no-NAC group (P = 0.14). In conclusion, addition of NAC to fluid expansion with sodium bicarbonate failed to reduce the rate of contrast-induced nephropathy (CIN) after the intra-arterial administration of iopamidol or iodixanol to high-risk patients with chronic kidney disease. [source] Differences in endoscopic views during biopsy through the right and left lower biopsy channels of the upper gastrointestinal endoscopeDIGESTIVE ENDOSCOPY, Issue 3 2004Naoki Mantani Background:, It has not been established as to which side the biopsy (instrument) channel should be placed in the tip of a front-viewing upper gastrointestinal (GI) endoscope to allow an en-face approach to lesions on various aspects of the stomach wall. Methods:, Using a front-viewing two-channel endoscope, we identi,ed a difference in endoscopic views during biopsy between lower-right and lower-left channels. Colored marks were distributed on the lesser curvature (LC), greater curvature (GC), anterior wall (AW), and posterior wall (PW) in the ,stomach' of a dummy for mock-performance of upper GI endoscopy. When biopsy forceps through the different channels touched the marks, an endoscopic photograph was taken. Furthermore, when biopsy specimens were obtained from PW lesions in several patients, endoscopic views were compared between the two biopsy channels. Results:, In the dummy study, no remarkable difference was detected in targeting the marks on AW, LC, or GC of the stomach. The dummy and the patient study showed that the lower-right approach could target PW lesions with a more adequate endoscopic view than from the lower left. The lower-left approach targeted PW lesions on the higher body with a nearly blinded endoscopic view. Specimens from PW of the upper body, which could be precisely obtained under direct visual control through the lower-right channel, were no smaller than those obtained using the channel on the lower left. Conclusion:, The present study suggests that the lower-right channel may be preferable to the lower-left channel in the tip of a front-viewing upper GI endoscope. [source] Use of cardiac output to improve measurement of input function in quantitative dynamic contrast-enhanced MRIJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2009Jeff L. Zhang PhD Abstract Purpose To validate a new method for converting MR arterial signal intensity versus time curves to arterial input functions (AIFs). Materials and Methods The method constrains AIF with patient's cardiac output (Q). Monte Carlo simulations of MR renography and tumor perfusion protocols were carried out for comparison with two alternative methods: direct measurement and population-averaged input function. MR renography was performed to assess the method's inter- and intraday reproducibility for renal parameters. Results In simulations of tumor perfusion, the precision of the parameters (Ktrans and ve) computed using the proposed method was improved by at least a factor of three compared to direct measurement. Similar improvements were obtained in simulations of MR renography. Volunteer study for testing interday reproducibility confirmed the improvement of precision in renal parameters when using the proposed method compared to conventional methods. In another patient study (two injections within one session), the proposed method significantly increased the correlation coefficient (R) between GFR of the two exams (0.92 vs. 0.83) compared to direct measurement. Conclusion A new method significantly improves the precision of dynamic contrast-enhanced (DCE) parameters. The method may be especially useful for analyzing repeated DCE examinations, such as monitoring tumor therapy or angiotensin converting enzyme-inhibitor renography. J. Magn. Reson. Imaging 2009;30:656,665. © 2009 Wiley-Liss, Inc. [source] Axonal excitability properties in hemifacial spasmMOVEMENT DISORDERS, Issue 9 2007Arun V. Krishnan PhD, FRACP Abstract Hemifacial spasm (HFS) is characterized by involuntary, irregular contractions of muscles innervated by the facial nerve. Whether the facial nerve has a relative predisposition for ectopic activity has not been clarified. Nerve excitability techniques, which provide information about membrane potential and axonal ion channel function, were initially measured in 12 control subjects looking for biophysical differences that may predispose the facial nerve to generate ectopic activity. In a second series of studies, facial nerve excitability was assessed in nine HFS patients. In both series, stimulus,response behavior, threshold electrotonus, a current threshold relationship, and the recovery of excitability following supramaximal stimulation were recorded following stimulation of the facial nerve. When compared to normative data from nerves in the upper and lower limbs, there was a relative "fanning-in" of threshold electrotonus, reduced superexcitability, and increased subexcitability in facial nerve studies from control subjects (P < 0.05), consistent with relative axonal depolarization. These findings may underlie the propensity for the facial nerve to develop ectopic impulse activity in motor axons. In the HFS patient study, there were no significant differences in distal facial nerve excitability properties from the affected side in HFS patients when compared either to the unaffected side or to normative facial nerve data. It is concluded that the impulse generator underlying HFS must consequently be sited more proximally and does not cause a generalized disturbance of motor axon excitability. © 2007 Movement Disorder Society [source] Quantitative coronary arteriography on digital flat-panel systemCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2004Paul L. Van Herck MD Abstract On images acquired with a digital flat-panel (DFP) detector, known for its better image quality, the performance of a validated quantitative coronary arteriography (QCA) software, CAASII (Cardiovascular Angiography Analysis System or CAAS), and a DFP-dedicated QCA algorithm (flat-panel analysis software or FPAS) was compared in a phantom and a patient study. On phantom, FPAS performed with higher accuracy the quantification of the smallest tubes and the calibration of an empty catheter. The overall accuracy and precision for the quantification procedure was better for FPAS (0.07 ± 0.04 mm) than for the CAAS (0.19 ± 0.06 mm; P = 0.03 and P < 0.01, respectively). In the patient study, the main difference between the two algorithms was found in the small diameters: CAAS almost always gave higher values than FPAS for the minimal luminal diameter (P < 0.001) and could only give values up to 70% for diameter stenosis. In conclusion, the FPAS can be considered more appropriate for assessing severe stenoses on digital flat-panel images. Catheter Cardiovasc Interv 2004;63:192,200. © 2004 Wiley-Liss, Inc. [source] | ||||||||||