Assessing observer variability.
Explore the source record for details and available documents.
Observer Variation↗
Biomedical subjects
J Jamart
Publications and source records attributed to J Jamart.
Capsule and mosaic pattern of hepatocellular carcinoma: correlation between CT and MR imaging.
Computed tomography (CT) was compared with magnetic resonance (MR) imaging in depicting the capsule and the mosaic pattern of hepatocellular carcinoma in 34 patients. The kappa statistic was used to compare results from both modalities. For the detection of the capsule, there was a substantial agreement beyond chance between late enhanced CT (more than 5 min after dynamic CT) and MR imaging (kappa = 0.76). Late enhanced CT and MR imaging had almost perfect agreement for the demonstration of the mosaic pattern (kappa = 0.85). These agreements were better than the agreements between unenhanced CT and MR imaging or between early enhanced CT and MR imaging. These results suggest that late enhanced CT compares favorably with MR imaging in depicting the capsule and the mosaic pattern of hepatocellular carcinoma.
Adolescent↗
Initial experience with low-potassium cold blood cardioplegia: a clinical comparative study.
This study presents the results of bypass grafting in 96 patients operated on for triple-vessel coronary artery disease between May 1988 and September 1990. In the first 54 patients a cold crystalloid solution was employed, and in the 42 more recent patients cold blood low-potassium cardioplegia was employed. There were no differences in postoperative cardiac index or left ventricular stroke work index. Yet, in patients with impaired prebypass left ventricular stroke work index, postbypass left ventricular performance correlated negatively with duration of aortic cross-clamping in the cold crystalloid group (r = -0.441, p = 0.045). In contrast, no correlation was found in the cold blood low-potassium group (r = 0.125, p = 0.587). The incidence of myocardial infarction, need for inotropic support, and need for intraaortic balloon counterpulsation were similar among the groups. Release of the myocardial isoenzyme creatine kinase-MB from 12 to 30 hours after operation was significantly less in the low-potassium blood cardioplegia group. The use of low-potassium blood cardioplegia resulted in a marked reduction in the operative administration of fluids (1,527 +/- 87 versus 3,511 +/- 148 mL; p less than 0.001). In conclusion, low-potassium cold blood cardioplegia is a simple and effective method of myocardial protection. The fact that left ventricular stroke work index recovery was not dependent on the duration of aortic occlusion and that release of the MB isoenzyme of creatine kinase was reduced in the low-potassium blood cardioplegia group implies better myocardial protection.
Adult↗
Chance-corrected sensitivity and specificity for three-zone diagnostic tests.
Explore the source record for details and available documents.
Clinical Laboratory Techniques↗
Statistical tests in medical research.
Various propositions have been made to improve the statistical quality of medical journals: using statistical referees, promoting better collaboration between statisticians and researchers, and teaching of basic statistics to clinicians. The most frequent errors found in medical articles are misinterpretation of p-values or non-significant results and confusion between statistical and clinical significance, inappropriate use of tests requiring precise assumptions, inappropriate or not controlled multiple testing and particularly testing of post hoc hypotheses, and overemphasis on p-values. Many errors arising from the misinterpretation of results of statistical hypothesis tests, the basic principles of this methodology are emphasized, and the usual fallacies found in the medical literature are reviewed.
Research↗
Does flow character of cardiopulmonary bypass make a difference?
The influence of pulsatile bypass flow on the performance of the cardiovascular system, fluids and blood balance, acid-base equilibrium, and splanchnic function was investigated. One hundred patients scheduled for elective coronary artery bypass grafting were randomly divided into a group of standard perfusion (NP) and a group of pulsatile perfusion (PP). At the end of the operation, similar cardiac performance developed in both groups that was higher than before bypass: left ventricular stroke work index after bypass, 56.8 +/- 2.7 gm/beat per square meter in the NP group and 56.7 +/- 2.6 gm/beat per square meter in the PP group (not significant). Further determinations did not differ among the groups. After discontinuation of cardiopulmonary bypass, bypass grafts flow measured using an electromagnetic probe did not differ among the groups. During the postbypass period, mean arterial pressure and systemic vascular resistance were similar (mean arterial pressure 86.8 +/- 1.6 mm Hg in the NP group and 88.5 +/- 1.7 in the PP group; systemic vascular resistance 817 +/- 33 dyne.sec/cm5 in the NP group and 881 +/- 34.5 in the PP group), as were further determinations. However, severe hypotension requiring the administration of vasoconstrictors was observed more frequently in PP group of patients (20 versus 6%; p < 0.05). Fluid balance determined at the second postoperative day was similar among the groups (+1307 +/- 239 ml in the NP group and +1535 +/- 266 ml in the PP group). Blood loss was 1122 +/- 120 ml in the NP group and 1263 +/- 119 ml in the PP group during the first postoperative day (p = 0.407). Urine output during bypass was lower in the PP group (261 +/- 25 versus 341 +/- 26 ml/hr; p = 0.028). The creatinine clearance was 96.4 +/- 10.3 ml/min in the NP group and 92.6 +/- 7.0 ml/min in the PP group (not significant); amylase and lipase clearance did not differ among the groups. Finally, no significant difference was detected in arterial lactic acid determinations and acid-base balance assessment between the groups postoperatively. Thus equivalent cardiovascular hemodynamics, a good control of fluids and blood balance, acid-base equilibrium, and a satisfactory protection of the function of kidneys and pancreas were obtained with both types of perfusion.
Cardiopulmonary Bypass↗
Regenerative nodules in hepatic cirrhosis. Value of gradient-echo MR imaging with a surface coil.
To evaluate the accuracy of surface coil gradient-echo (GRE) imaging in the detection of regenerative nodules of hepatic cirrhosis, 53 patients with diffuse liver disease, among whom 31 had cirrhosis, were prospectively investigated. Three GRE sequences acquired with a surface coil were used in the study: a T2*-weighted, a T1-weighted, and a gadopentetate-enhanced sequence. ROC analysis showed that two surface coil GRE sequences were superior to conventional T2-weighted spin-echo imaging acquired with a body coil for the detection of regenerative nodules. The detection of regenerative nodules was also more accurate for the diagnosis of cirrhosis than the measurement of the caudate-to-right lobe ratio. These results suggest that there could be a potential for surface coil GRE imaging in the assessment of the characteristic macroscopic alterations of cirrhosis.
Adult↗
Highly permeable and biocompatible membranes.
Explore the source record for details and available documents.
Amyloidosis↗
Effect of dialysis membrane and patient's age on signs of dialysis-related amyloidosis. The Working Party on Dialysis Amyloidosis.
This 12 center study was designed to assess factors affecting the development and progression of beta 2-microglobulin amyloidosis in long-term dialysis. A total of 221 patients who were on hemodialysis for more than five years, and who were treated the entire time only with AN69, a biocompatible, highly permeable membrane, or cuprophane, a less permeable, poorly biocompatible membrane (Cell) were evaluated for time on dialysis, development of carpal tunnel syndrome, and cystic bone lesions. X-ray documentation was taken in a minimum of four of the six following joints: both hips, wrists and shoulders. The data demonstrate that patients treated solely by AN69 membranes display signs of bone amyloidosis less frequently than do those treated by Cell membranes. Age at onset of dialysis was found to have a striking correlation with the development of carpal tunnel syndrome and bone amyloidosis, while no significant influence was found for hyperparathyroidism, sex or year of first dialysis.
Acrylic Resins↗
Surgery in patients on long-term steroid therapy: a tentative model for risk assessment.
Increased morbidity after operation has been associated with long-term steroid therapy. To determine the correlation between steroid therapy and such morbidity, the perioperative course of 55 steroid-treated patients was reviewed: 27 had bronchopulmonary disorders (group P) and 28 had non-pulmonary diseases (group NP). There were six (11 per cent) deaths, of which three were steroid related. Among the 13 non-lethal postoperative complications, eight were considered to be steroid related in group P and one in group NP. The duration of steroid therapy was for a median of 24 months (range 1-408 months) in group P and for a median of 6 months (range 1-240 months) in group NP (P less than 0.01). In contrast, the daily dose of hydrocortisone or equivalent before operation was significantly lower in group P, with a median of 0.51 mg kg-1 day-1 (range 0.20-2.56 mg kg-1 day-1) than in group NP, with a median of 1.20 mg kg-1 day-1 (range 0.23-7.38 mg kg-1 day-1) (P less than 0.01). In conclusion, bronchopulmonary disorders requiring a long duration of steroid therapy are associated with a higher risk of steroid-related complications after surgery. A convenient mathematical model is proposed which may allow a preoperative assessment of surgical risk, using steroid dose and duration of treatment.
Adult↗
Dynamic spin-echo imaging with Gd-DTPA: value in the differentiation of hepatic tumors.
Thirty patients with hemangiomas (n = 6), benign liver cell tumors (n = 7), and primary or metastatic malignant tumors of the liver (n = 17) underwent dynamic MR imaging with Gd-DTPA to determine the value of the procedure in the differentiation of hepatic tumors. The diagnoses were proved by histology or follow-up. Hemangiomas had a significantly greater mean T2 value (192.1 +/- 34.8 msec) than did both benign liver cell tumors (71.9 +/- 16.9 msec; p less than .01) and primary or metastatic malignant tumors (79.7 +/- 21.2 msec; p less than .01), but the T2 values of benign liver cell tumors and malignant tumors were not significantly different. Both hemangiomas and benign liver cell tumors had a significantly greater mean signal-intensity ratio (1.86 +/- 0.60 and 1.77 +/- 0.26, respectively) than did malignant tumors (1.04 +/- 0.34; p less than .01) in the early phase after Gd-DTPA administration, and hemangiomas had a significantly greater signal-intensity ratio (1.59 +/- 0.21) than did both benign liver cell tumors (1.21 +/- 0.08; p less than .01) and malignant tumors (1.06 +/- 0.26; p less than .01) in the delayed phase. These results suggest that dynamic MR images obtained after administration of Gd-DTPA are useful in differentiating hepatic hemangiomas, benign liver cell tumors, and malignant liver lesions.
Adenoma, Bile Duct↗
Prediction of risk in noncardiac operations after cardiac operations.
To determine the preoperative variables affecting the mortality rate and the development of severe complications in patients who have had myocardial revascularization or a valve replacement and who then undergo a noncardiac operation, we retrospectively studied data from 120 such patients over the 5 years from 1982 through 1986. Thirty-six percent of patients had a noncardiac operation during the first month after the cardiac operation. The mortality rate was 11%, and the morbidity rate was 56%. The statistical comparison of the predictive accuracy of postoperative complications of three simple, widely used classifications (American Society of Anesthesiologists physical status, New York Heart Association classification, Massachusetts General Hospital cardiac risk index) demonstrated the superiority of the simplified three-class cardiac risk index (Massachusetts General Hospital-cardiac risk index; predictive accuracy of 84%). In a multivariate discriminant analysis of 21 variables in this population, five variables (myocardial infarction in previous 6 months, S3 gallop or jugular vein distention, arrhythmia on last preoperative electrocardiogram, emergency operation, delay between cardiac and noncardiac operation) were identified as being the most predictive of a postoperative complication. When these variables were used in the function (DF3) obtained by linear discriminant analysis, the prediction accuracy of a postoperative complication reached 83%. Performance of the new models in a prospective validation population remained satisfactory (75% for Massachusetts General Hospital-cardiac risk index three-class index and 72% for DF3). Extensive statistical analysis of our data tested by a validation study provided simple predictive models based on clinical variables easily available even in emergency situations.
Adult↗
[Radiological diagnosis of pneumatosis cystoides intestinalis. Report of three cases and review of the literature (author's transl)].
Explore the source record for details and available documents.
Adult↗
Pneumatosis cystoides intestinalis. A statistical study of 919 cases.
Pneumatosis cystoides intestinalis, an uncommon disease characterized by the presence of gaseous bubbles in bowel wall, is studied by a review of 919 cases of the world literature. The subserous cysts are more frequently found in the small bowel while the submucous localizations are predominant in the colonic wall. The disease, occurring more frequently in males than in females, is associated with several other lesions: pyloric stenosis and scleroderma for small bowel pneumatosis, chronic cardiopathies and dolichocolon for colonic localizations. Jejunoileal bypass for morbid obesity is an increasing iatrogenic cause. Diagnosis is based on radiology and endoscopy with biopsy but is not yet correctly done in many cases. The treatment is essentially medical.
Adolescent↗
[Surgery of complicated diverticular sigmoiditis. Report of 138 cases (author's transl)].
The authors analyse a series of 138 cases of complicated diverticular sigmoiditis treated surgically. They noted 50% of pyostercoral peritonitis, 32% of persigmoid abscesses, 13% of case of intestinal obstruction, and 5% of cases of fistual or hemorrhage. The overall mortality was 28% and depended mainly more on the surgical management adopted than on the type of complication. In this respect, simple colostomy with drainage of the septic focus had a mortality of 18%. The results suggest surgical operation in two stages, in the form of colonic resection, with, depending on each case, an anastomosis straight away with transverse colostomy or segmental colectomy with bitubular colostomy (Mikulicz procedure) or, in rarer cases, simple colostomy. The authors emphasise the interest of early surgery in sigmoiditis with complications and contrast the mortality of cold surgery which is now about 5% compared with 28% in emergency cases with complications.
Abscess↗
[Heller's operation in the treatment of idiopathic mega-esophagus. Reflections on 22 cases].
Explore the source record for details and available documents.
Adult↗
Magnetic resonance imaging of lower abdominal and pelvic lesions: assessment of oral magnetic particles as an intestinal contrast agent.
To determine the value of oral magnetic particles (OMP) as a superparamagnetic MR contrast agent for the gastrointestinal tract in lower abdominal and pelvic lesions, 30 patients underwent spin-echo imaging before and after ingestion of OMP at a dose of approximately 80 mg of iron in 800 ml water. The preparation was divided into four portions and taken by the patient over a 2-h period. Two readers independently reviewed the MR images. The contrast material was well tolerated and the distribution of the contrast material was good to excellent in the proximal and pelvic small bowel, but was not sufficient in the colon with the dose and timing used in the study. Postcontrast images showed a significantly better delineation of the lesions, the small bowel, and the paraaortic region, but no significant improvement in the delineation of the colon, the iliac vessels area, the bladder or genital tract. Compared with precontrast images, confidence in defining or excluding disease on postcontrast images was better, equal or worse in 40, 60 and 0% of cases, respectively (P less than 0.001) with a substantial agreement between readers (kappa = 0.71). OMP produced susceptibility artefacts of significant intensity in only one case. These results indicate that OMP may be useful in the delineation of lower abdominal and pelvic lesions at MR imaging. Marking of the colon by a contrast agent might improve the results.
Abdominal Neoplasms↗
Proximal femur density in type 1 and 2 diabetic patients.
This study reports on the proximal femur mineral content in 36 Type 1 and 60 Type 2 diabetic patients. Bone mass measurements were performed in the neck, Ward's triangle and in the trochanteric area of the femur, using dual-photon absorptiometry with 153Gd. Bone mineral density (BMD) was significantly decreased in Type 1 diabetic men and women as well in Type 2 men, when compared with a non diabetic matched population. In Type 1 men, neck and Ward's triangle densities were reduced from 0.94 +/- 0.05 to 0.86 +/- 0.11 (p = 0.007) and from 0.87 +/- 0.10 to 0.74 +/- 0.14 g.cm-2 (p = 0.011), respectively. In Type 1 women, BMD was reduced from 0.97 +/- 0.10 to 0.90 +/- 0.10 g.cm-2 (p = 0.023) in the femoral neck. In Type 2 men, BMD in Ward's triangle was also significantly lower than in controls: 0.69 +/- 0.14 vs 0.76 +/- 0.19 g.cm-2, respectively (p = 0.001). In contrast, no bone loss was observed in a group of Type 2 overweight diabetic women. No statistical correlation was observed between bone loss and age, duration of diabetes, body mass index, C-peptide levels, daily insulin doses, HbA1 and the presence of diabetic complications. In conclusion, long-standing Type 1 diabetic men and women and Type 2 diabetic men have a decrease in the proximal femur bone mass. Type 2 diabetic women appear to be protected from diabetic osteopenia.
Adult↗