Comparison of dual-source and electron-beam CT for the assessment of coronary artery calcium scoring.

OBJECTIVE: Cardiac CT allows the detection and quantification of coronary artery calcification (CAC). Electron-beam CT (EBCT) has been widely replaced by high-end CT generations in the assessment of CAC. The aim of this study was to compare the CAC scores derived from an EBCT with those from a dual-source CT (DSCT). METHODS: We retrospectively selected 92 patients (61 males; mean age, 60.7 ± 12 years) from our database, who underwent both EBCT and DSCT. CAC was assessed using the Agatston score by two independent readers (replicates: 1, 2; 3=mean of reading 1 and 2). RESULTS: EBCT scores were on average slightly higher than DSCT scores (281 ± 569 vs 241 ± 502; p<0.05). In regression analysis R(2)-values vary from 0.956 (1) to 0.966 (3). We calculated a correction factor as EBCT=(DSCT+1)(1.026)-1. When stratifying into CAC categories (0, 1-99, 100-399, 400-999 and ≥1000), 79 (86%) were correctly classified. From those with positive CAC scores, 7 out of 61 cases (11%, κ=0.81) were classified in different categories. Using the corrected DSCT CAC score, linear regression analysis for the comparison to the EBCT results were r=0.971 (p<0.001), with a mean difference of 6.4 ± 147.8. Five subjects (5.4%) were still classified in different categories (κ=0.84). CONCLUSION: CAC obtained from DSCT is highly correlated with the EBCT measures. Using the calculated correction factor, agreement only marginally improved the clinical interpretation of results. Overall, for clinical purposes, face value use of DSCT-derived values appears as useful as EBCT for CAC scoring.

Prognostic value of electron-beam computed tomography-derived coronary calcium scores compared with clinical parameters in patients evaluated for coronary artery disease. Prognostic value of EBCT in symptomatic patients.

OBJECTIVE: The electron-beam computed tomography-(EBCT-)derived calcium score provides a measure of coronary atherosclerotic plaque disease which may allow for more precise risk stratification in symptomatic patients. However, it remains unclear if EBCT can add prognostic information compared with the clinical information derived from risk factor assessment, exercise stress testing, and coronary angiography. METHODS AND RESULTS: A cohort of 300 consecutive patients with recent (<3 months) onset of symptoms was retrospectively identified who were examined for possible coronary artery disease (CAD) and who all underwent EBCT. Successful follow-up after 3.5 years was obtained in 255 (85%) patients whose mean age at baseline was 58+/-11 years (n = 181 (71%), males). Four clinical categories with increasing evidence of CAD were constructed on the basis of risk factor assessment, exercise stress testing, coronary angiographic anatomy, and coronary revascularization at baseline. During follow-up, major adverse cardiac events (MACE: myocardial infarction, cardiac death, revascularization) were observed in 40 (16%) patients, including myocardial infarction and cardiac death in 5 patients. The 4 clinical categories were highly predictive of MACE, with a relative risk estimate of 28.3 (95% CI, 6.7-119.1) in the upper vs. the reference category. In univariate analysis, the relative risk estimate of MACE associated with a calcium score > or =100 was 12.0 (95% CI, 4.7-30.6). After adjustment for the clinical categories and for age, this estimate decreased in multivariate analysis, but remained predictive at 4.4 (95% CI, 1.5-12.6). CONCLUSION: In patients with first-time evaluation of possible CAD, EBCT-derived coronary calcium is suggested to provide for independent and additional information compared with the clinically available information.

Reproducibility of two coronary calcium quantification algorithms in patients with different degrees of calcification.

PURPOSE: To evaluate the reproducibility of coronary calcium quantification algorithms by electron beam CT (EBT) in patients with different amounts of calcified plaque using the conventional (Agatston) score and an area score and to demonstrate a potential application of these results for evaluation of follow-up scans. METHODS: In 50 consecutive patients. the conventional calcium score (CCS = Agatston score) and the area score (AS) were summed for each artery and patient. Data were analyzed in four groups according to degrees of calcification: 0 (absent-minimal): CCS 0-9, I (mild): CCS 10-99, II (moderate): CCS 100-399, III (severe): CCS > or = 400. We determined and compared the reproducibility for each algorithm within and among groups. RESULTS: Median percent reproducibility improved with increasing amounts of calcified plaque for the CCS and the AS (p = 0.002 and p = 0.004, respectively). We demonstrate how these reproducibility values can be used to evaluate long-term follow-up studies. The reduction of median reproducibility per patient using the AS vs. the CCS was 32% (13 vs. 19%, respectively). On a vessel-by-vessel basis, the reduction of median reproducibility was 7% (24.3 vs. 22.6%, CCS vs. AS, p < 0.02), which was attributable to a 45% reduction in reproducibility in arteries with mild scores (46.1 vs. 25.5%, CCS vs. AS, p < 0.005). CONCLUSION: The AS has an improved reproducibility compared with the CCS, especially in patients with small amounts of coronary calcifications which may prove clinically useful. Different reproducibility values in different degrees of calcification can be used for an individual assessment of changes in amounts of coronary calcification.

Prevalence and clinical significance of accidental findings in electron-beam tomographic scans for coronary artery calcification.

AIMS: To analyse the prevalence, and diagnostic and therapeutic consequences, of accidental findings in electron-beam tomographic scans performed for evaluation of coronary artery calcification. METHODS AND RESULTS: A total of 1812 consecutive patients with known or suspected coronary artery disease underwent electron-beam tomography. In 583 (32%) of the patients, i.v. contrast was also administered for non-invasive coronary angiography. A total of 2055 non-coronary pathological findings were observed in 953 (53%) of the patients. The prevalence of extra-cardiac disease, as shown in native scans and contrast studies, was assessed separately. In 583 (32%) patients, cardiac structures or the pericardium were affected, in 423 (23%) aortic disease was found. Lung disease was found in 357 (20%), and pathology of other organs in 273 patients (15%). The most frequent findings were aortic calcium in 423 (23%) patients and heart valve calcification in 317 patients (17%). Malignant disease could be detected in three patients. Further diagnostic investigations were done in 191 (11%) patients, 141 (74%) of which concerned the heart. In 22 (1.2%) patients, specific therapy was initiated following electron-beam tomographic findings. CONCLUSION: Accidental non-coronary pathology is a frequent finding in electron-beam tomographic calcium scanning, and often requires diagnostic or therapeutic action. Profound knowledge of the radiological differential diagnosis of the thoracic organs is necessary for reporting electron-beam tomographic scans, in order to avoid misdiagnosis and to receive a high quality interpretation.

Anaphylactic shock from a latex allergy in a patient with spinal trauma.

Allergy to latex is a condition that affects patients as well as health care workers. It is a spectrum of immunologic disorders that ranges from mild hypersensitivity to life-threatening anaphylaxis. Beginning in the early 1970s, the health care community has become more aware of this entity, leading to many improvements in the understanding, diagnosis and treatment of patients with latex allergy. Many hospitals have developed protocols and procedures for patients with latex sensitivity. However, some physicians remain unaware of the logistics of taking care of patients with this disorder. We present a case of a severe anaphylactic reaction to latex in a trauma patient with a spinal cord injury. The difficulty of treating the acutely injured patient with this disorder is illustrated. A list of equipment that may be included in a latex-free emergency kit is provided.

Natural history and topographic pattern of progression of coronary calcification in symptomatic patients: An electron-beam CT study.

Electron-beam CT may assess the progression of coronary atherosclerosis by visualizing changes in calcification. The present investigation analyzes (1) the rate of progression of calcification in symptomatic patients, (2) the topographic pattern, and (3) the influence of baseline plaque burden and risk factors. Progression of calcification during a mean (median) interval of 18 (15) months was measured in 102 symptomatic outpatients (aged 59+/-9 years, 80% male) with calcification. In 4 patient groups with a baseline total score (Agatston criteria) of 1 to 30, >30 to 100, >100 to 400, and >400, the median was 3.1, 26.1, 58.9, and 109.7, respectively, for absolute annual progression of the score (P<0.05) and 57%, 49%, 32%, and 15%, respectively, for relative progression (P<0.05). On the coronary segmental level, changes were largely restricted to typical predilection sites of coronary atherosclerosis. The presence of angiographically defined coronary narrowing influenced absolute, but not relative, progression. Of the risk factors, only low density lipoprotein cholesterol levels showed a trend, although not significant, for predicting progression. These data indicate that baseline plaque burden determines the rate of progression of calcification. This appears to be a coronary systemic process, reflecting the natural history of coronary atherosclerosis.

Assessment of coronary calcification by electron-beam computed tomography in symptomatic patients with normal, abnormal or equivocal exercise stress test.

AIMS: Exercise stress testing is often used as the initial non-invasive diagnostic test in symptomatic patients with suspected obstructive coronary artery disease. Positive standard ECG criteria are quite specific for obstructive coronary artery disease, but there may be a substantial number of false negative tests, including patients with severe coronary artery disease. Also, exercise stress tests frequently yield equivocal results. Instead of detecting the functional consequences, electron-beam computed tomography visualized atherosclerotic plaque disease directly, but its relationship to functional testing has not been clearly delineated. It was the aim of the current study to examine electron-beam computed tomography for the identification of obstructive coronary artery disease in patients with a normal, abnormal, or equivocal exercise stress test. METHODS AND RESULTS: Symptomatic patients referred for coronary angiography were prospectively included in a consecutive manner if they had no prior diagnosis of coronary artery disease and an unremarkable resting ECG. All patients underwent both exercise stress test and electron-beam computed tomography on the day before coronary angiography. Standard protocols and ECG criteria to diagnose inducible ischaemia were used for the exercise stress test. The electron-beam computed tomography-derived total calcium score was computed according to standard Agatston criteria. Of the 323 patients (mean age, 55+/-11 years; 77% male), 179 (55%) had obstructive coronary artery disease, defined angiographically as luminal diameter narrowing >/=50%. A normal exercise stress test was documented in 105 patients (32.5%), an abnormal exercise stress test ('diagnostic for ischaemia') in 113 (35%), and an equivocal exercise stress test ('inadequate exercise or non-diagnostic ECG-changes') in 105 (32.5%). Multivariate analysis indicated that exercise stress test and electron-beam computed tomography yielded independent information for predicting obstructive coronary artery disease. Sensitivity, specificity and overall accuracy of the exercise stress test were 71%, 75% and 73%, respectively, if equivocal tests were not included, and 50%, 84% and 65% if they were included. Irrespective of the cutpoint regarded as 'positive', the overall accuracy of the electron-beam computed tomography-derived calcium score remained approximately 80% in patients with a normal, abnormal or equivocal exercise stress test. In patients with an equivocal and - to a lesser degree - with a normal exercise stress test, electron-beam computed tomography was able to significantly improve classification regarding obstructive coronary artery disease. Electron-beam computed tomography added no incremental predictive value in patients with an abnormal exercise stress test. CONCLUSION: In patients who are judged to have an intermediate post-test probability of disease after exercise stress test, electron-beam computed tomography scanning may be a meaningful strategy for further stratification regarding the likelihood of obstructive coronary artery disease.

Usefulness of topography of coronary calcium by electron-beam computed tomography in predicting the natural history of coronary atherosclerosis.

Electron-beam computed tomography (EBCT) allows for accurate noninvasive detection and quantification of coronary calcium that is representative of underlying atherosclerotic disease. The present study quantitatively analyzes the topography and establishes the natural history of coronary calcium in patients with variable degrees of coronary atherosclerosis. EBCT was performed in 330 consecutive patients aged 56 +/- 12 years (70% men) with recent (<3 months) onset of signs or symptoms of coronary artery disease (CAD) or who were evaluated because of a presumed high risk. Total calcium scores, computed by the Agatston method, were positive in 269 patients (82%) (mean age 58 +/- 11 years, 73% men). These patients were classified into 4 groups, with total calcium scores ranging between 1 and 30, >30 and 100, >100 and 400, and >400, respectively. The presence and amount of calcium was additionally assessed in 10 major segments of the coronary arterial tree, including the major coronary arteries. Of the 72 patients with calcium of only 1 of the major coronary arteries, the left anterior descending coronary artery was involved in 39 patients (54%) and the right coronary artery in 18 patients (25%). Left main stem calcium was observed in only 10 of 139 patients (7%) with 1- or 2-vessel calcium and in 17 of 77 patients (23%) with 3-vessel calcium. Calcium was consistent most frequently in the proximal left anterior descending coronary artery, followed by the proximal left circumflex and right coronary artery segments. A significant decrease of frequency and amount of calcium from the proximal to distal segments was observed in the left coronary system but not in the right coronary artery, where the distribution was more even. With increasing total calcium scores, segmental scores in the more distal segments were enhanced, but the increase was most pronounced in the proximal segments and particularly in the proximal left anterior descending coronary artery. EBCT-derived coronary calcium shows an axial distribution that appears comparable to that of atherosclerotic lesions observed in pathologic and angiographic studies, highlighting the potential role of EBCT for studying the natural history of CAD.

[Security aspects on the Internet]. / Sicherheitsaspekte im Internet.

AIM OF THE STUDY: Is it possible to use the Internet as a secure media for transport of telemedicine? Which risks exist for routine use? In this article state of the art methods of security were analysed. Telemedicine in the Internet has severe risks, because patient data and hospital data of a secure Intranet can be manipulated by connecting it to the Web. CONCLUSIONS: Establishing of a firewall and the introduction of HPC (Health Professional Card) are minimizing the risk of un-authorized access to the hospital server. HPC allows good safety with digital signature and authentication of host and client of medical data. For secure e-mail PGP (Pretty Good Privacy) is easy to use as a standard protocol. Planning all activities exactly as well as following legal regulations are important requisites for reduction of safety risks in Internet.

Coronary arterial stent patency: assessment with electron-beam CT.

PURPOSE: To evaluate electron-beam computed tomography (CT) for stent localization and noninvasive assessment of stent patency in patients with coronary arterial stents and coronary bypass stents. MATERIALS AND METHODS: CT in the single-section volume mode was performed in 202 patients with 321 coronary arterial stents in 221 vessels to localize the stents. Patency was evaluated in the multisection flow mode with an intravenous bolus injection of contrast material. All electron-beam CT images were reviewed by an observer who had no knowledge of the coronary angiographic results. Electron-beam CT findings were then compared with coronary angiographic findings. RESULTS: The stents could be visualized and related to the coronary arterial segments in 216 of 221 vessels with electron-beam CT. Of the 221 vessels, 207 were correctly evaluated with electron-beam CT. Compared with coronary angiography, electron-beam CT permitted the detection of 18 of 23 high-grade stenoses (sensitivity, 78%) and correctly depicted the absence of high-grade stenoses in 189 of 193 vessels with stents (specificity, 98%). Altogether, 18 stenoses were detected correctly at electron-beam CT; the interpretation was false-positive in four vessels (positive predictive value, 82% [18/22 vessels]) and false-negative in five (negative predictive value, 97% [189/194 vessels]). CONCLUSION: Electron-beam CT may be helpful in localizing intracoronary stents and assessing stent patency noninvasively to delay the intervals between catheterizations in an increasing number of patients.

Anatomical analysis and preoperative planning of correctional osteotomies: slipped capital femoral epiphysis (SCFE).

SCFE is defined as the slippage of the femoral head relative to the femoral neck along the proximal femoral growth plate. The femoral head shifts and rotates along the proximal end of the femoral neck, usually posteriorly and interiorly. The pathoanatomical findings are characterised by the changed relationship between the femoral head and femoral metaphysis, and between the femoral head and the acetabulum. A reduced femoral anteversion, a varus deformity of the femur, a shortening of the femoral metaphysis and an anterior metaphyseal prominence are also regularly observed. This may lead to impingement between the femoral metaphysis and the acetabular rim. Potential consequences of this complex 3D deformity are pain, a reduced range of hip motion and an early degenerative joint disease. In moderate and severe cases a redirectional femoral osteotomy is recommended. Different techniques, such as subcapital, base-of-neck, intertrochanteric and subtrochanteric osteotomies, have been described. These correctional osteotomies aim towards a reconstruction of the hip joint geometry, to prevent early arthritic degeneration. Currently, the planning of surgical treatment in these cases is based on measurements on antero-posterior and lateral plain radiographs. The relevant angle for planning of correctional osteotomies is the physis-shaft angle, determined in both plains. These angles describe the degree of slippage, thereby helping the surgeon to indicate and plan a correctional osteotomy. However, plain radiographs are projectional images and therefore carry inaccuracies caused by the overlay of anatomical structures and an incorrect positioning of the patient. 3D reconstructions are more accurate and provide substantial additional information for the surgeon, such as, for example, the anteversion of the acetabulum. We have developed interactive 3D software to measure projected angles, to analyse the geometry of the proximal femur and to determine the orientation of the acetabulum based on 3D reconstructions of CT data-sets. A program was also developed to simulate different techniques of osteotomies and to evaluate the postoperative range of hip motion and the hip-joint geometry. Accurate 3D measurements, additional anatomical information, simulations of different techniques of osteotomies and the evaluation of simulated postoperative results enables the surgeon to determine the best surgical treatment, based on the clinical findings.

Minimally invasive evaluation of coronary stents with electron beam computed tomography: In vivo and in vitro experience.

We sought to describe the value of electron beam computed tomography (EBCT) to detect stent restenoses at follow-up and to identify characteristic EBCT features of coronary stents. Six coronary stents (GRII, Jostent, NIR, PS, Micro, Wiktor) were scanned in vitro (10 1. 5-mm-thick slices, 15-cm FoV, 100-ms AT) before and after inflation with 3.0-, 3.5-, and 4.0-mm balloons to study intensity values and different stent dimensions in comparison to caliper measurements. In 44 patients (60 +/- 10 years, 4 females) we prospectively compared EBCT findings [eight 8-mm-thick slices in the flow mode, 26-cm field of view (FoV), 50 ms acquisition time (AT)] with 6-month angiographic outcome after placement of 86 stents in 49 vessels. For the detection of significant angiographic luminal narrowing (>/=75%) that occurred in 17/49 vessels (35%), we found a sensitivity of 65%, a specificity of 84%, and a positive and negative predictive value of 69% and 82%, respectively. The in vitro data show significant differences in image intensity between the stents and a significant gradual decrease in image intensity with increasing stent diameters. The mean differences between EBCT and caliper measurements for the length and diameter were 0.17 +/- 0.18 mm and -0.32 +/- 0.25mm, respectively. EBCT is currently the only noninvasive technique that allows the assessment of stent dimensions and stent geometry, which may prove useful in patients when intravascular ultrasound cannot be performed. Contrast-enhanced EBCT is a promising tool for minimally invasive stent patency evaluation at follow-up, especially in patients that are unable to exercise. Cathet. Cardiovasc. Intervent. 48:39-47, 1999.

Ultrasound for the detection of intraperitoneal fluid: the role of Trendelenburg positioning.

A prospective, observational study was performed to evaluate the role of Trendelenburg positioning in improving the sensitivity of the single-view ultrasound examination. Hemodynamically stable patients undergoing diagnostic peritoneal lavage (DPL) were assigned to one of two groups: supine or 5 degrees of Trendelenburg positioning. Baseline right intercostal oblique images of Morison's pouch were obtained followed by additional images for each 100 cc of lavage fluid instilled into the peritoneal cavity. The initial volume of fluid required to identify an anechoic stripe was recorded for each patient. Patients were excluded if they had (1) a positive DPL for hemoperitoneum (defined as 10 cc of gross blood or >100,000 red blood cells/microL), (2) positive baseline ultrasound study, (3) hemodynamic instability, or (4) lack of documentation (ie, baseline/subsequent hard copy images were not obtained or inadequately demonstrated anechoic stripe). The mean quantity of fluid for visualization of the anechoic stripe was 443.8 cc in the Trendelenburg group (n = 8) and 668.2 cc in the supine group (n = 11). These means were statistically different (P < .05, t test). The median amount of fluid needed for visualization of the anechoic stripe was 400 cc and 700 cc for the Trendelenburg and supine groups, respectively.

Electron-beam CT in the noninvasive assessment of coronary stent patency.

RATIONALE AND OBJECTIVES: Coronary artery stents reduce the rate of restenosis in patients who have undergone balloon angioplasty; therefore, the implantation of coronary stents represents an important method in the treatment of coronary stenoses. The authors' purpose was to investigate the usefulness of electron-beam computed tomography (CT) as a noninvasive means of assessing the patency of coronary artery stents in patients who had undergone balloon angioplasty and stent placement. MATERIALS AND METHODS: Electron-beam CT was used to assess stent patency in 177 patients with 285 stents. Contrast material-enhanced multisection flow studies were performed, and the images were evaluated by three investigators and compared with the findings of coronary angiography. RESULTS: Cine loop evaluations and time-attenuation curve analysis led to the correct diagnosis in 167 (94.3%) patients, as confirmed with coronary angiography. Stenoses had occurred in 18 of the 194 vessels with stents, and 14 of these were detected with electron-beam CT. CONCLUSION: Electron-beam CT appears to be a valuable imaging modality in the noninvasive assessment of stent patency in coronary arteries.

Myocardial nuclear factor-kappaB activity and nitric oxide production in rejecting cardiac allografts.

BACKGROUND: Nuclear factor-kappaB (NF-kappaB) is a rapid response transcription factor for genes whose products are critical for inflammation and immunity. In a rat model of heterotopic cardiac transplantation, we studied NF-kappaB DNA binding activity and nitric oxide (.NO) production in untreated allografts and whether inhibition of NF-kappaB suppresses .NO production and prolongs graft survival. METHODS: In allograft recipients and isograft controls, NF-kappaB was assayed by electrophoretic mobility shift assay, daily from transplant until rejection. Myocardial .NO was directly detected in explanted allografts by electron spin resonance spectroscopy on day 6 after transplant. The potent inhibitor of NF-kappaB, pyrrolidine dithiocarbamate (PDTC; 250 mg/kg s.c.) was administered daily from transplant until day of rejection. The extent of graft lymphocytic infiltrate was assessed by routine hematoxylin and eosin staining. Immunohistochemical staining of NF-kappaB was per formed to identify the cell type responsible for NF-kappaB activity. RESULTS: A time-dependent increase in myocardial NF-kappaB activity was seen in untreated allografts as compared with isografts as determined by PhosphorImage analysis. Peak NF-kappaB activity occurred in allografts on day 4 with a ninefold increase as compared with isografts (24.0+/-3.7% vs. 2.7+/-0.5; P<0.05). On posttransplant day 6, electron spin resonance spectroscopy analysis of allografts demonstrated .NO identified by a triplet nitrogen signal centered at g=2.012 with hyperfine splitting of 17.5 Gauss, which is consistent with nitrosoheme formation and low-field signals at g=2.08 and g=2.03 consistent with nitrosomyoglobin. These signals were not seen in native hearts of allograft recipients. With PDTC administration, a threefold decrease in NF-kappaB activity within the transplanted heart was observed on posttransplant day 5 as compared with untreated allografts (9.7+/-1.6% vs. 23.5+/-2.5%; P<0.01). PDTC prolonged graft survival as compared with untreated allografts (11.7+/-0.3 vs. 6.6+/-0.2 days; P<0.05) and reduced the intensity of the nitrosoheme and nitrosomyoglobin signals. Allograft mononuclear cell infiltrate correlated with peak NF-kappaB activity with peak infiltrate on posttransplant day 4. PDTC treatment had no effect on the extent of infiltrate. Immunohistochemical staining localized NF-kappaB to the infiltrating mononuclear cells on posttransplant day 5. CONCLUSION: These data support a role for NF-kappaB in allograft rejection.

Is colostomy always necessary in the treatment of open pelvic fractures?

BACKGROUND: Wound management in open pelvic fractures has used fecal diversion, debridement, and closure by secondary intention to prevent pelvic sepsis. Colostomy care and takedown adds to the morbidity and resource utilization of this approach. We reviewed our experience to determine if a selective approach to fecal diversion based on wound location was possible. METHODS: Retrospective analysis of patients admitted to a Level I trauma center during an 8-year period. Fractures were classified as open if the fracture was in continuity with the wound. Wounds were classified as perineal if they involved the rectum, ischiorectal fossa, or genitalia, and as nonperineal if they involved the pubis anteriorly, iliac crest, or anterior thigh. Pelvic sepsis was defined as cellulitis, fasciitis, or infection of a pelvic hematoma. Diversion consisted of loop or end colostomy. RESULTS: Eighteen patients with open fractures were identified. Four died from closed head injury and blood loss. The remaining 14 were treated as follows. Five patients with perineal wounds had diversion of their fecal stream. Their Injury Severity Score was 34 +/- 8.3 and their Revised Trauma Score was 7.69 +/- 0.15. No patient developed pelvic sepsis. Nine patients with nonperineal wounds did not undergo diversion. Their Injury Severity Score was 28.6 +/- 5.3 and their Revised Trauma Score was 7.36 +/- 0.45. No patients developed pelvic sepsis in the nondiverted group. CONCLUSION: No patients with anterior wounds and an intact fecal stream developed pelvic sepsis. Colostomy may not be necessary in all patients with open pelvic fracture. Protocols using fecal diversion based on wound location appear to be safe and may decrease resource utilization and subsequent morbidity related to colostomy closure.

Electron spin resonance analysis of heme-nitrosyl and reduced iron-sulfur centered complexes in allogeneic, heterotopic cardiac transplants: effects of treatment with pyrrolidine dithiocarbamate.

Inhibition of inducible nitric oxide synthase (iNOS) prolongs allograft survival suggesting a role for nitric oxide (.NO) in allograft rejection. Induction of iNOS is regulated by the oxidant-sensitive, nuclear factor kappa B (NF-kappaB) in many cell types. In the present study using electron spin resonance (ESR) spectroscopy, we evaluated whether pyrrolidine dithiocarbamate (PDTC), a metal chelator and antioxidant, might limit .NO production during the development of rejection in cardiac allografts. We performed either isogeneic (Lewis to Lewis) or allogeneic (Wistar-Furth to Lewis) heterotopic abdominal cardiac transplantation. Allograft recipients received daily injections of PDTC or aminoguanidine (a known inhibitor of iNOS). At postoperative days 4 or 6, grafted and native hearts of transplant recipients were flushed with cardioplegic solution to remove blood contamination. ESR data of allografts revealed a triplet nitrogen signal (aN=17.5 G) and centered at g=2.012 and an additional broad signal at g=2.08. This signal was not seen in either isografts or native hearts of either isograft or allograft recipients. Based upon these parameters, these signals are attributed to nitrosomyoglobin. This signal was inhibited by treatment with aminoguanidine or PDTC. Under these conditions, PDTC also prolonged graft survival from 6.6+/-0.2 to 11.7+/-0.3 days. Thus, it is conceivable that nitrosylmyoglobin formation precedes rejection in cardiac allografts and inhibition of nitrosomyoglobin with agents such as PDTC contribute to improved graft survival.

Comparison of electron-beam computed tomography and intracoronary ultrasound in detecting calcified and noncalcified plaques in patients with acute coronary syndromes and no or minimal to moderate angiographic coronary artery disease.

We compared intracoronary ultrasound (ICUS) and electron-beam computed tomography (EBCT) on a coronary segmental basis in 40 consecutive patients with acute coronary syndromes and no or minimal to moderate angiographic disease (53+/-10 years; 34 men, 6 women). ICUS was used to define plaques, and EBCT was used to quantify coronary calcium (using a threshold of a CT density > 130 Hounsfield units in an area > 1.03 mm2). In a site-by-site analysis, coronary segments were defined as normal if both methods were negative, as containing noncalcified plaques if only ICUS was positive, and as containing calcified plaques if both methods were positive. A total of 222 coronary segments were analyzed (5.6+/-1.9 segments per patient). In 36 patients (90%), a total of 95 segments with plaques were identified, whereas in 4 patients (10%), only normal segments were seen. Of the 95 segments with plaques, 61 (64%) were calcified, and 34 (36%) were noncalcified. There was a linear relationship between the number of segments with calcified and with noncalcified plaques (r = 0.86, p <0.0001), but the mean relative frequency of segments with calcified plaques (55+/-38%) was highly variable. Calcium was found in 15 of 16 patients (93%) with 3 or more segments with plaques, while it was found in only 12 of 20 patients (60%) with one or 2 segments with plaques (p = 0.026). Younger age, higher low-density lipoprotein-cholesterol levels, diabetes, and active smoking predicted a higher relative frequency of segments with noncalcified plaques. Thus, in patients with acute coronary syndromes but no angiographically critical stenoses, there is a linear relationship between segments with calcified plaques versus segments with noncalcified plaques. However, while the mean ratio of these segments is close to 1:1, it is highly variable among individual patients.

Measuring the effect of risk factors on coronary atherosclerosis: coronary calcium score versus angiographic disease severity.

OBJECTIVES: This study sought to determine whether noninvasive quantification of coronary calcium is comparable to selective coronary angiography in measuring the effect of cardiovascular risk factors on coronary atherosclerosis. BACKGROUND: Electron beam computed tomography (EBCT) allows the delineation of anatomic coronary atherosclerotic disease and may be useful for noninvasively defining the role of established and new cardiovascular risk factors in selected patient groups. METHODS: A total of 211 consecutive patients, 26 to 79 years old, referred for evaluation of suspected or recently diagnosed coronary artery disease were examined. Selective coronary angiography was used to define five angiographic disease categories: normal coronary arteries, nonobstructive disease and one-, two- or three-vessel disease. EBCT was used to calculate coronary calcium scores, and cardiovascular risk, including lipid variables and fibrinogen levels, was assessed. RESULTS: Coronary calcium score and angiographic disease severity categories were largely predicted by identical risk factors (i.e., age, male gender, total/high density lipoprotein cholesterol ratio, fibrinogen) and, to a lesser degree, hypertension. Only smoking predicted angiographic disease severity but not calcium scores. The risk factors together explained a comparable proportion of the variability in angiographic disease categories and in calcium score quintiles (33% vs. 41%, p=0.16 by bootstrap analysis). An overall risk score composed of these risk factors separated angiographic disease categories and calcium score quintiles with a similar area under the receiver operating characteristic curve ([mean+/-SE] 0.81+/-0.03 vs. 0.83+/-0.03, p=NS). CONCLUSIONS: Quantification of coronary calcium is comparable to selective coronary angiography in measuring the effect of established cardiovascular risk factors on coronary atherosclerosis. Thus, EBCT may be useful for the noninvasive evaluation of the relations between conventional or developing cardiovascular risk factors and coronary atherosclerosis.

Compatible instrumentation for intraoperative MRI: expanding resources.

Steadfast progress has been made from biopsy to surgery with interventional MRI (iMRI). Such image-guided interventions require specialized instrumentation due to the unusual elements of the MR environment. Suppliers/manufacturers of MR-compatible instrumentation were few in 1994, but now there are more than 50. We present fundamental issues of MR compatibility and a list of known suppliers/manufacturers.