RESUMEN

BACKGROUND AND PURPOSE: There is a need for improved risk stratification of patients with TIA/stroke and carotid atherosclerosis. The purpose of this study was to prospectively investigate the potential of integrated (18)F-FDG PET/MDCT in identifying vulnerable carotid plaques. MATERIALS AND METHODS: Fifty patients with TIA/stroke with an ipsilateral carotid plaque causing <70% stenosis and a plaque on the contralateral asymptomatic side underwent integrated (18)F-FDG PET/MDCT within 36.1 ± 20.0 days (range, 9-95 days) of the last symptoms. Carotid plaque (18)F-FDG uptake was measured as both the mean and maximum blood-normalized SUV, known as the TBR. Using MDCT, we assessed volumes of vessel wall and individual plaque components. RESULTS: Mean TBR was only significantly larger in the ipsilateral plaques of patients who were imaged within 38 days (1.24 ± 0.04 [SE] versus 1.17 ± 0.05, P = .014). This also accounted for maximum TBR (1.53 ± 0.06 versus 1.42 ± 0.06, P = .015). MDCT-assessed vessel wall and LRNC volumes were larger in ipsilateral plaques of all patients (982.3 ± 121.3 versus 811.3 ± 106.6 mm(3), P = .016; 164.7 ± 26.1 versus 134.3 ± 35.2 mm(3), P = .026, respectively). CONCLUSIONS: In the present study, (18)F-FDG PET only detected significant differences between ipsilateral and contralateral asymptomatic plaques in patients with TIA/stroke who were imaged within 38 days, whereas MDCT detected larger vessel wall and LRNC volumes, regardless of time after symptoms. In view of the substantial overlap in measurements of both sides, it remains to be determined whether the differences we found will be clinically meaningful.

Asunto(s)

RESUMEN

We evaluated leukocyte counts and levels of CRP, fibrinogen, MPO, and PAPP-A in patients with stable and unstable angina pectoris, acute myocardial infarction, and healthy controls. All biomarkers were analyzed again after 6 months. Leukocyte counts and concentrations of fibrinogen, CRP, MPO, and PAPP-A were significantly increased in patients with acute myocardial infarction. Leukocyte counts and concentrations of MPO were significantly increased in patients with unstable angina pectoris compared with controls. After 6 months, leukocyte counts and MPO concentrations were still increased in patients with acute myocardial infarction when compared to controls. Discriminant analysis showed that leukocyte counts, MPO, and PAPP-A concentrations classified study group designation for acute coronary events correctly in 83% of the cases. In conclusion, combined assessment of leukocyte counts, MPO, and PAPP-A was able to correctly classify acute coronary events, suggesting that this could be a promising panel for a multibiomarker approach to assess cardiovascular risk.

RESUMEN

OBJECTIVE: To assess the adherence to a guideline for additional breast ultrasonography in a cross-sectional survey among hospitals in The Netherlands. Furthermore, consequences of current practice non-adherence for the patient outcome of diagnostic breast imaging were studied. METHODS: Current practice was compared with a guideline made up of three recommendations for the use of ultrasonography after mammography and three recommendations for not using ultrasonography. All patients referred for mammography to the radiology departments of the participating hospitals during 2 months in 2004 were eligible for the study. No data on the gold standard for breast cancer were analysed, but clinical consequences were estimated by using a probability model based on the data of a former prospective clinical study. RESULTS: In total, 17 of the 66 hospitals approached were participating in the study. Of the 13,694 patients assessed for eligibility, 6457 were included. High adherence rates (81-97%, mean 94%) were observed for the recommendations, which indicate additional ultrasonography, whereas lower adherence rates (68-94%, mean 83%) were seen for the recommendations which do not advise additional ultrasonography. Overall, in all included hospitals, non-adherence would result in 27.2 false-positive and 1.1 false-negative imaging results. CONCLUSION: Current daily practice of diagnostic breast imaging in the hospitals in this survey corresponds to a great extent to the guideline proposed. Non-adherence in current practice results in a relatively small number of false-positive and false-negative imaging results.

Asunto(s)

RESUMEN

PURPOSE: In the setting of an increasing workload for radiologists, this study focuses on the feasibility of skill mixing in breast imaging in a hospital radiology department. METHODS: Two radiological technologists with more than 10 years of experience in performing mammograms were trained in prereading mammograms to select the cases that require further evaluation by a radiologist. Mammograms of consecutive patients were independently evaluated by the technologists, next to the standard clinical interpretation by the radiologist on duty. Mammographic findings were recorded and a BI-RADS classification was assigned for each breast. Different prereading scenarios were analysed using clinical decision rules. Two different cut-off points of BI-RADS classifications were applied to the data. Analysis was performed for the overall clinical patient population as well as for a subgroup of patients with no immediate indication for further work-up. RESULTS: Mammograms of 1994 patients were evaluated. In total, 93 breast cancers were found in 91 patients (prevalence 4.6%). Sensitivity and specificity in selecting mammographic findings (cut-off point between BI-RADS 1 and BI-RADS 0, 2-5 and the radiologist's diagnosis as reference standard) was 98% and 74% for technologist 1 and 98% and 78% for technologist 2. In distinguishing normal and benign mammograms from those with abnormalities that are probably benign, suspicious or highly suggestive for malignancy (cut-off point BI-RADS 1-2 and BI-RADS 0, 3-5 and pathology results as reference standard), sensitivity decreased to 89% and 91% respectively. Specificity increased to 82% for both technologists. In a subgroup of 1389 patients with no immediate indication for additional imaging with the involvement of a radiologist, technologists obtained a mean sensitivity and specificity of 98% and 77% in detecting mammographic findings, and a mean sensitivity and specificity of 78% and 88% in detecting suspicious abnormalities. CONCLUSIONS: The employment of technologists in prereading mammograms seems to be an effective working strategy in daily clinical practice. However, its position in clinical practice remains indistinct as a continuous availability of radiologists still needs to be guaranteed. Nevertheless, as a substantial proportion of mammograms could be evaluated without the attention of a radiologist, the employment of technologists in prereading mammograms seems a promising new working strategy.

Asunto(s)

Asunto(s)

RESUMEN

This paper focuses on the legal implications in terms of duties and responsibilities for radiologists and radiologic technologists of independent pre-reading of mammograms by radiologic technologists, so patients could be discharged without being seen by a radiologist. Pre-reading could be effectuated when preconditions are met to perform reserved procedures by unauthorised professionals as stated in the Individual Health Care Professions (IHCP) Act. Furthermore, compliance with a protocol or code of conduct in combination with adequate training and supervision should be sufficient to disprove potential claims. For a wide implementation, pre-reading should be well-embedded in legal rules and should answer the professional standard of care.

Asunto(s)

RESUMEN

BACKGROUND: Several imaging techniques may reveal calcification of the arterial wall or cardiac valves. Many studies indicate that the risk for cardiovascular disease is increased when calcification is present. Recent meta-analyses on coronary calcification and cardiovascular risk may be confounded by indication. Therefore, this meta-analysis was performed with extensive subgroup analysis to assess the overall cardiovascular risk of finding calcification in any arterial wall or cardiac valve when using different imaging techniques. METHODS AND RESULTS: A meta-analysis of prospective studies reporting calcifications and cardiovascular end-points was performed. Thirty articles were selected. The overall odds ratios (95% confidence interval [CI]) for calcifications versus no calcifications in 218,080 subjects after a mean follow-up of 10.1 years amounted to 4.62 (CI 2.24 to 9.53) for all cause mortality, 3.94 (CI 2.39 to 6.50) for cardiovascular mortality, 3.74 (CI 2.56 to 5.45) for coronary events, 2.21 (CI 1.81 to 2.69) for stroke, and 3.41 (CI 2.71 to 4.30) for any cardiovascular event. Heterogeneity was largely explained by length of follow up and sort of imaging technique. Subgroup analysis of patients with end stage renal disease revealed a much higher odds ratio for any event of 6.22 (CI 2.73 to 14.14). CONCLUSION: The presence of calcification in any arterial wall is associated with a 3-4-fold higher risk for mortality and cardiovascular events. Interpretation of the pooled estimates has to be done with caution because of heterogeneity across studies.

Asunto(s)

RESUMEN

Stroke results in considerable morbidity and mortality. Prevention is therefore of particular importance. On the basis of large clinical trials, carotid endarterectomy (CEA) is performed in selected patient groups to prevent stroke. Patient symptomatology and degree of carotid stenosis are the main clinical grounds to perform CEA. However, many individual patients undergo surgery with its attendant risks without taking advantage of it, whereas in others CEA is probably incorrectly withheld. There is therefore an urgent need for new adjuncts to identify high-risk subgroups of patients who particularly benefit from potentially hazardous interventions. Multiple noninvasive imaging modalities have shown their potential to differentiate high-risk, vulnerable carotid plaques from stable plaques. The ultimate goal is to implement one or a combination of these imaging modalities in daily clinical practice. This review gives an up-to-date overview of the clinical potential of these imaging modalities in identifying patients with carotid atherosclerosis who are at high risk for developing stroke. Advantages and limitations of each imaging technique are outlined. Additionally, recommendations for future research are presented.

Asunto(s)

RESUMEN

Despite progress in prevention and early diagnosis, coronary artery disease (CAD) remains one of the leading causes of mortality in the world. For many years, invasive X-ray coronary angiography has been the method of choice for the diagnosis of significant CAD. However, up to 40% of patients referred for elective X-ray coronary angiography have no clinically significant stenoses. These patients still remain subjected to the potential risks of X-ray angiography. As an alternative, magnetic resonance imaging (MRI) is currently one of the most promising techniques for noninvasive imaging of the coronary arteries. Over the past two decades, many technical developments have been implemented that have led to major improvements in coronary MRI. Nowadays, both anatomical and functional information can be obtained with high temporal and spatial resolution and good image quality. In this review we will discuss the technical foundations and current status of clinical coronary MRI, and some potential future applications.

Asunto(s)

RESUMEN

OBJECTIVE: To determine the clinical and economic consequences of replacing duplex ultrasonography (DUS) by contrast-enhanced magnetic resonance angiography (CE-MRA) for the initial diagnostic work-up of patients with peripheral artery disease (PAD). DESIGN: Randomised multicentre study. METHOD: In the period from January 2002 to August 2003, consecutive patients with PAD were randomly assigned to CE-MRA or DUS. The primary outcome measure was the costs. Secondary outcome measures included the confidence with which the specialist could take a therapeutic decision on the basis of the imaging study, the change in disease severity, and the change in quality of life (QOL) assessed during 6 months of follow-up. In addition, all costs of imaging, therapeutic interventions and outpatient visits were calculated. RESULTS: After 6 months of follow-up the data on 352 patients were analysed. Use of CE-MRA reduced the number of additional vascular-imaging procedures by 42% ((69-40)/69) and the specialists felt more confident about their therapeutic decisions. The diagnostic costs of all imaging studies taken together were Euro 167,- higher, on average, in the CE-MRA group (p < 0.001). However, after 6 months of follow-up, no statistically significant differences were found between the two groups with regard to the change in disease severity, the QOL, or the total costs (p > 0.05). CONCLUSION: Based on these findings, a specialist that replaces DUS by CE-MRA will feel more confident about taking a therapeutic decision and will feel less need for additional imaging. However, the diagnostic costs were higher with CE-MRA.

RESUMEN

PURPOSE: To perform a meta-analysis comparing ultrasonography (US), US guided fine needle aspiration cytology (USgFNAC), computed tomography (CT), and magnetic resonance imaging (MRI) in the detection of lymph node metastases in head and neck cancer. METHODS: MEDLINE, EMBASE and Cochrane databases were searched (January 1990-January 2006) for studies reporting diagnostic performances of US, USgFNAC, CT, and MRI to detect cervical lymph node metastases. Two reviewers screened text and reference lists of potentially eligible articles. Criteria for study inclusion: (1) histopathology was the reference standard, (2) primary tumors and metastases were squamous cell carcinoma and (3) data were available to construct 2 x 2 contingency tables. Meta-analysis of pairs of sensitivity and specificity was performed using bivariate analysis. Summary estimates for diagnostic performance used were sensitivity, specificity, diagnostic odds ratios (DOR) (95% confidence intervals) and summary receiver operating characteristics (SROC) curves. RESULTS: From seventeen articles, 25 data sets could be retrieved. Eleven articles studied one modality: US (n=4); USgFNAC (n=1); CT (n=3); MRI (n=3). Six articles studied two or more modalities: US and CT (n=2); USgFNAC and CT (n=1); CT and MRI (n=1); MRI and MRI-USPIO (Sinerem) (n=2); US, USgFNAC, CT and MRI (n=1). USgFNAC (AUC=0.98) and US (AUC=0.95) showed the highest areas under the curve (AUC). MRI-USPIO (AUC=0.89) and CT (AUC=0.88) had similar results. MRI showed an AUC=0.79. USgFNAC showed the highest DOR (DOR=260) compared to US (DOR=40), MRI-USPIO (DOR=21), CT (DOR=14) and MRI (DOR=7). Conclusion USgFNAC showed to be the most accurate imaging modality to detect cervical lymph node metastases.

Asunto(s)

RESUMEN

AIMS/HYPOTHESIS: Mitochondrial dysfunction and increased intramyocellular lipid (IMCL) content have both been implicated in the development of insulin resistance and type 2 diabetes mellitus, but the relative contributions of these two factors in the aetiology of diabetes are unknown. As obesity is an independent determinant of IMCL content, we examined mitochondrial function and IMCL content in overweight type 2 diabetes patients and BMI-matched normoglycaemic controls. METHODS: In 12 overweight type 2 diabetes patients and nine controls with similar BMI (29.4 +/- 1 and 29.3 +/- 0.9 kg/m(2) respectively) in vivo mitochondrial function was determined by measuring phosphocreatine recovery half-time (PCr half-time) immediately after exercise, using phosphorus-31 magnetic resonance spectroscopy. IMCL content was determined by proton magnetic resonance spectroscopic imaging and insulin sensitivity was measured with a hyperinsulinaemic-euglycaemic clamp. RESULTS: The PCr half-time was 45% longer in diabetic patients compared with controls (27.3 +/- 3.5 vs 18.7 +/- 0.9 s, p < 0.05), whereas IMCL content was similar (1.37 +/- 0.30 vs 1.25 +/- 0.22% of the water resonance), and insulin sensitivity was reduced in type 2 diabetes patients (26.0 +/- 2.2 vs 18.9 +/- 2.3 mumol min(-1) kg(-1), p < 0.05 [all mean +/- SEM]). PCr half-time correlated positively with fasting plasma glucose (r (2) = 0.42, p < 0.01) and HbA(1c) (r (2) = 0.48, p < 0.05) in diabetic patients. CONCLUSIONS/INTERPRETATION: The finding that in vivo mitochondrial function is decreased in type 2 diabetes patients compared with controls whereas IMCL content is similar suggests that low mitochondrial function is more strongly associated with insulin resistance and type 2 diabetes than a high IMCL content per se. Whether low mitochondrial function is a cause or consequence of the disease remains to be investigated.

Asunto(s)

RESUMEN

SUMMARY: Spinal cord arteries and veins are difficult to visualize and distinguish by MR angiographic techniques because of their small sizes, similar spatial course, and close vascular anatomy. Contrast-enhanced MR angiography was demonstrated to dynamically resolve the Adamkiewicz artery from the anterior radiculomedullary vein in the thoracolumbar spinal cord. The location of the Adamkiewicz artery and the anterior radiculomedullary vein could be validated in the postmortem specimen of a thoracoabdominal aortic aneurysm patient.

Asunto(s)

RESUMEN

Incidence of atherosclerosis and atherosclerosis-related complications will increase significantly in the coming decennia. Research identified many serum and plasma markers that are associated with cardiovascular disease. However, little is known about the prognostic value of these markers to identify patients at risk for future cardiovascular events. Therefore, we aimed to investigate the prognostic value of three of these markers (soluble CD40 ligand (sCD40L), interleukin-6 (IL-6) and oxidized low-density lipoprotein (oxLDL)) with respect to coronary vascular disease and stroke. For this reason the Medline database was searched for the period January 1999-January 2005. To be selected in our study, concentration of the marker had to be determined at baseline, follow-up period had to be longer than 3 months and an estimate of relative risk had to be available. Based on these criteria, 4 studies for sCD40L, 10 for IL-6 and 2 for oxLDL were selected. Relative risk estimates adjusted for potential confounders varied between 1.9 and 2.8 for sCD40L, between 1.1 and 3.1 for IL-6 and between 1.9 and 3.2 for oxLDL. In conclusion, this systematic review shows that sCD40L, IL-6 and oxLDL are associated with an increased relative risk of developing cardiovascular disease.

Asunto(s)

RESUMEN

The aim of the present study was to conduct a meta-analysis of English literature on the accuracy of preoperative imaging in predicting the two most important risk factors for local recurrence in rectal cancer, the circumferential resection margin (CRM) and the nodal status (N-status). Articles published between 1985 and August 2004 that report on the diagnostic accuracy of endoluminal ultrasound (EUS), computed tomography (CT), or magnetic resonance imaging (MRI) in the evaluation of lymph node involvement were included. A similar search was done for the assessment of the circumferential resection margin in rectal cancer in the period from January 1985 till January 2005. The inclusion criteria were as follows: (1) more than 20 patients with histologically proven rectal cancer were included, (2) histology was used as the gold standard, and (3) results were given in a 2 x 2 contingency table or this table could otherwise be extracted from the article by two independent readers. Based on the results summary receiver operating characteristic (ROC) curves were constructed. Only 7 articles matching inclusion criteria were found concerning the CRM. The meta-analysis shows that MRI is rather accurate in diagnosing a close or involved CRM. For nodal status 84 articles could be included. The diagnostic odds ratio of EUS is estimated at 8.83. For MRI and CT, the diagnostic odds ratio are 6.53 and 5.86, respectively. The results show that EUS is slightly, but not significantly, better than MRI or CT for identification of nodal disease. There is no significant difference between the different modalities with respect to staging nodal status. At present, MRI is the only modality that predicts the circumferential resection margin with good accuracy, making it a good tool to identify high and low risk patients. Predicting the N-status remains a problem for the radiologist for every modality, although considering the new developments in MR imaging, this may change in the near future.

Asunto(s)

RESUMEN

Renal artery stenosis (RAS) is a potentially curable cause of renovascular hypertension (RVH) and is caused by either atherosclerosis or fibromuscular dysplasia (FMD) in the vast majority of patients. Although intra-arterial digital subtraction angiography (IA-DSA) is still considered the standard of reference test for the anatomical diagnosis of RAS, noninvasive techniques such as MR angiography, CT angiography, and color-aided duplex ultrasonography are promising alternatives that also allow functional characterization of RAS. We provide an overview of these techniques and discuss their relative merits and shortcomings. Analysis of high-quality studies shows that both MR and CT angiography are significantly more accurate for the diagnosis of at least 50% atherosclerotic RAS than ultrasonographic techniques. The primary strength of ultrasonography at present is its suggested ability to predict functional recovery based on preinterventional resistance index measurements. A still unresolved issue is the detection of FMD. Because missing RVH may have serious consequences the most important requirement for a screening test is that it has high sensitivity.

Asunto(s)

RESUMEN

Previous studies have shown a relationship between coronary or carotid atherosclerosis and C-reactive protein (CRP) concentrations. In the present investigation, we evaluated the relationship between high-sensitivity CRP (hsCRP) concentrations and the presence of atherosclerotic lesions in the renal arteries and/or abdominal aorta. In 95 hypertensive patients who underwent intra-arterial DSA on suspicion of renovascular disease, blood was sampled during the procedure for measurement of hsCRP. The presence of atherosclerotic lesions was assessed at the level of the renal arteries and the abdominal aorta. Haemodynamically significant renal artery stenosis was diagnosed when 50% or more stenosis was observed. Patients with fibromuscular disease (n = 8) or incomplete data (n = 4) were excluded from analysis. The results revealed that the median hsCRP concentrations were significantly higher among the 57 patients with atherosclerosis of the aorta and/or renal arteries compared to those in the 26 patients without any angiographic lesions (4.6 vs 1.7 mg/l; P < 0.005). Moreover, in patients with renal artery stenosis, levels of hsCRP were higher when the degree of stenosis exceeded 50%. However, the association between hsCRP and the presence of atherosclerosis appeared to be confounded by serum creatinine, creatinine clearance, age and gender. In the whole group a significant inverse relationship was found between creatinine clearance and hsCRP (P < 0.05). In conclusion, hsCRP concentrations are related to atherosclerotic lesions in the renal arteries and the abdominal aorta. While this supports the view that atherosclerotic renal artery stenosis is part of a systemic inflammatory vascular disease, increased concentrations of CRP may also coincide with decreased renal function.

Asunto(s)

RESUMEN

Abundant data now link composition of the vascular wall, rather than the degree of luminal narrowing, with the risk for acute ischemic syndromes in the coronary, central nervous system, and peripheral arterial beds. Over the past few years, magnetic resonance angiography has evolved as a well-established method to determine the location and severity of advanced, lumen-encroaching atherosclerotic lesions. In addition, more recent studies have shown that high spatial resolution, multisequence MRI is also a promising tool for noninvasive, serial imaging of the aortic and carotid vessel wall, which potentially can be applied in the clinical setting. Because of the limited spatial resolution of current MRI techniques, characterization of coronary vessel wall atherosclerosis, however, is not yet possible and remains the holy grail of plaque imaging. Recent technical developments in MRI technology such as dedicated surface coils, the introduction of 3.0-T high-field systems and parallel imaging, as well as developments in the field of molecular imaging such as contrast agents targeted to specific plaque constituents, are likely to lead to the necessary improvements in signal to noise ratio, imaging speed, and specificity. These improvements will ultimately lead to more widespread application of this technology in clinical practice. In the present review, the current status and future role of MRI for plaque detection and characterization are summarized.

Asunto(s)

RESUMEN

BACKGROUND: The achievement of tumour-free margins on excision of nonpalpable breast lesions that have aroused only an intermediate or low level of suspicion before surgery and do turn out to be malignant is a challenge for the surgeon. The purpose of this study was to determine factors that influence the probability of obtaining tumour-free margins after needle-localised excision of a nonpalpable breast carcinoma. METHOD: During a 10-year period all needle-localised breast biopsies (NLBB) carried out in the Department of Surgery were retrospectively analysed. Possible influential factors considered included: age of the patient, year of NLBB, appearance of the lesion on imaging, preoperative diagnostic index, method of localisation, surgeon's level of experience, specimen size and radiology of the specimen, and all these were analysed in a multivariate logistic regression analysis. RESULTS: In all, 400 needle-localised breast biopsies had been performed. Excision with tumour-free margins was more often achieved, and the final intervention less often took the form of a mastectomy, when the lesion was classified preoperatively as malignant (P = 0.02). CONCLUSION: The outcome of treatment of a needle-localised breast cancer excision is better when the breast lesion is known to be malignant before surgery.

Asunto(s)

RESUMEN

AIM: To assess inter-observer variation in the interpretation of chest radiographs of individuals with pneumonia versus those without pneumonia. MATERIALS AND METHODS: Chest radiographs of out-patients with a lower respiratory tract infection (LRTI) were assessed for the presence of infiltrates by radiologists from three local hospitals and were reassessed by one university hospital radiologist. Various measures of inter-observer agreement were calculated. RESULTS: The observed proportional agreement was 218 in 243 patients (89.7%). Kappa was 0.53 (moderate agreement) with a 95% confidence interval of 0.37 to 0.69. The observed positive agreement (59%) was much lower than for negative agreement (94%). Kappa was considerably lower, if chronic obstructive pulmonary disease was present (kappa = 0.20) or Streptococcus pneumoniae (kappa = -0.29) was the infective agent. CONCLUSION: The overall inter-observer agreement adjusted for chance was moderate. Inter-observer agreement in cases with pneumonia was much worse than the agreement in negative (i.e. non-pneumonia) cases. A general practitioner's selection of patients with a higher chance of having pneumonia for chest radiography would thus not improve the observer agreement.

Asunto(s)