Pulmonary 64-MDCT angiography with 50 mL of iodinated contrast material in an unselected patient population: a feasible protocol

Abstract Objective: To propose a protocol for pulmonary angiography using 64-slice multidetector computed tomography (64-MDCT) with 50 mL of iodinated contrast material, in an unselected patient population, as well as to evaluate vascular enhancement and image quality. Materials and Methods: We evaluated 29 patients (22-86 years of age). The body mass index ranged from 19.0 kg/m2 to 41.8 kg/m2. Patients underwent pulmonary CT angiography in a 64-MDCT scanner, receiving 50 mL of iodinated contrast material via venous access at a rate of 4.5 mL/s. Bolus tracking was applied in the superior vena cava. Two experienced radiologists assessed image quality and vascular enhancement. Results: The mean density was 382 Hounsfield units (HU) for the pulmonary trunk; 379 and 377 HU for the right and left main pulmonary arteries, respectively; and 346 and 364 HU for the right and left inferior pulmonary arteries, respectively. In all patients, subsegmental arteries were analyzed. There were streak artifacts from contrast material in the superior vena cava in all patients. However, those artifacts did not impair the image analysis. Conclusion: Our findings suggest that pulmonary angiography using 64-MDCT with 50 mL of iodinated contrast can produce high quality images in unselected patient populations.

Venous thromboembolism and obstruction after pacemaker implantation. - A Prospective Study of 150 Consecutive Cardiac Pacing Device Implantations

Background: Pacemaker implantation (PMI) may predispose to venous thromboembolism (VTE) and obstruction (VO). This prospective study aimed at quantifying changes in venous calibers, and at determining the incidence of symptomatic and asymptomatic VTE/VO after PMI. Further goals included an assessment of the role of transesophageal echocardiography (TEE) in the diagnosis of lead-related central venous thrombi (CVT), and determination of predictors for VTE/VO. Methods: 150 (mean age 67; 61% male) consecutive patients with first PMI were enrolled and followed for 6 months. Contrast venography was performed at baseline and 6 months after PMI to measure venous diameters, and to detect stenosis, total occlusions and thrombi. TEE was conducted in 66 patients. Based on clinical suspicion, work-up for pulmonary embolism (PE) or acute deep vein thrombosis (DVT) were performed as needed. A total of 50 cases underwent longer-term (mean 2.4 years) follow-up venography. All cases with VTE/VO during the initial 6 months, and their matched controls, were selected for a case-control study focused on possible predictive role of laboratory and patient-related factors for the development of VTE/VO. Results: 10 (7 %) patients were found to have baseline venous abnormalities (e.g. 8 obstructions). Mean venous diameters diminished significantly during the first 6 months, but no further reduction occurred in late follow-up. New VO was discovered in 19 patients (14 %; 14 stenosis, 5 total occlusions; all asymptomatic). Small non-obstructive thrombi were found in 20/140 (14 %) 6-month venograms. TEE at 6 months disclosed CVT in 6 (9 %) patients. One (0.7 %) patient had acute symptomatic upper-extremity DVT, and PE was discovered in 5/150 (3.3 %) patients during the first 6 months with no further cases thereafter. At 6 months, the total number of cases with VTE/VO amounted to 47 (31.3 %). Additionally, the later 2-year venograms (n=50) disclosed 4 (8 %) total occlusions and 1 (2 %) stenosis. In the case-control study, no parameter was predictive of venous end-points as a single variable, but there appeared to be significant clustering of traditional VTE risk-factors among the cases. Laboratory parameters showed a definite acute hypercoagulative state induced by PMI, but its degree did not predict subsequent development of VTE/VO. Conclusions: This study shows that VTE/VO is relatively common after PMI with an overall incidence of at least 30 %. Although the majority of the lesions are asymptomatic and clinically benign, cases of PE were also encountered, and totally occluded veins may hamper future upgrading or replacement of pacing system. Venous complications seem difficult to prognosticate as firm predictors were not identified from a wide range of parameters analyzed in this study, although clustering of classic VTE risk factors may be a predisposing factor. Parameters related to implantation procedure or pacing systems and the severity of implantation-induced trauma did not emerge as predictors.

Aplicación de una técnica mínimamente invasiva para la reparación de ruptura del tendón de Aquiles

Introducción Las rupturas agudas del tendón de Aquiles se presentan en pacientes entre 40 y 50 años. Las causas más comunes son actividades deportivas. Se han descrito técnicas mínimamente invasivas, con complicaciones como infección del sitio operatorio, adherencias y la lesión del nervio sural. El propósito de este estudio es determinar el desenlace clínico y funcional, de los pacientes con rupturas agudas del tendón de Aquiles llevados a reparación quirúrgica mínimamente invasiva entre 2011 y 2013 en nuestra institución. Materiales y métodos. Estudio tipo Serie de casos. Se realizó evaluación de fuerza muscular, fatiga muscular, arcos de movilidad con respecto a la extremidad contralateral, la escala AOFAS y se describieron las complicaciones. Resultados. Se evaluaron 21 pacientes de 31 elegibles, diecisiete hombres y cuatro mujeres. Edad promedio de 42,7 años, duración promedio de seguimiento de 17,47 meses. Como complicación hubo una dehiscencia de sutura treinta días después del procedimiento. Los pacientes regresaron a actividades laborales 48 días después de cirugía. El tiempo promedio de retorno a actividades deportivas fue de 8.47 meses. El puntaje promedio en la escala AOFAS fue 90. Los arcos de movilidad del tobillo fueron en promedio de 52° para el lado afectado y 56° en el no intervenido. El número de repeticiones de elevación de talón de la extremidad afectada fue de 58 en promedio. Discusión. Estos resultados sugieren que la técnica mínimamente invasiva para reparación del tendón de Aquiles provee resultados funcionales satisfactorios a corto y mediano plazo con bajas tasas de complicación.

Abordagem diagnóstica dos pacientes com suspeita de trombose venosa profunda dos membros inferiores

Deep venous thrombosis is a relatively common disease, which can present pulmonary embolism as a complication in its acute phase, and later the post-thrombotic syndrome. Thus, diagnosis should be made as soon as possible, in order to prevent or minimize such complications. Several studies have shown that the symptoms and the clinical signs are inaccurate for the deep venous thrombosis diagnosis and that complementary exams are necessary. As an attempt to simplify the patients' assessment, Well et al., in 1997, developed a clinical prediction index that combines symptoms, signs and risk factors for deep venous thrombosis and managed to make a simpler approach through an association of this index with the complementary exams. Phlebography has been considered the gold standard of complementary exams. However, since it is an invasive exam and thus subject to complications, other diagnostic methods were introduced aiming at making the diagnostic approach simpler and less invasive. Doppler ultrasound, duplex scan, impedance plethysmography, computed tomography, and blood tests such as the D-dimer are some of the available methods for assessing the patient with suspicion of deep venous thrombosis. Among them, duplex scan has shown excellent accuracy and it is currently widely accepted as the first choice test for approaching the patient with deep venous thrombosis. Several authors have suggested an association of diagnostic methods to simplify and make the assessment of such patients more cost-effective, leading to the introduction of a wide range of diagnostic strategies. The different diagnostic methods used for assessing deep venous thrombosis are discussed, as well as a review of the literature on the accuracy, advantages and disadvantages of these methods. Copyright © 2005 by Sociedade Brasileira de Angiologia e Cirurgia Vascular.

Avaliação clínica e ultrassonografia tardia de pacientes com trombose venosa profunda, portadores de trombofilia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Summary of the II Brazilian Guideline Update on Acute Heart Failure 2009/2011

In the past two years we observed several changes in the diagnostic and therapeutic approach of patients with acute heart failure (acute HF), which led us to the need of performing a summary update of the II Brazilian Guidelines on Acute Heart Failure 2009. In the diagnostic evaluation, the diagnostic flowchart was simplified and the role of clinical assessment and echocardiography was enhanced. In the clinical-hemodynamic evaluation on admission, the hemodynamic echocardiography gained prominence as an aid to define this condition in patients with acute HF in the emergency room. In the prognostic evaluation, the role of biomarkers was better established and the criteria and prognostic value of the cardiorenal syndrome was better defined. The therapeutic approach flowcharts were revised, and are now simpler and more objective. Among the advances in drug therapy, the safety and importance of the maintenance or introduction of beta-blockers in the admission treatment are highlighted. Anticoagulation, according to new evidence, gained a wider range of indications. The presentation hemodynamic models of acute pulmonary edema were well established, with their different therapeutic approaches, as well as new levels of indication and evidence. In the surgical treatment of acute HF, CABG, the approach to mechanical lesions and heart transplantation were reviewed and updated. This update strengthens the II Brazilian Guidelines on Acute Heart Failure to keep it updated and refreshed. All clinical cardiologists who deal with patients with acute HF will find, in the guidelines and its summary, important tools to help them with the clinical practice for better diagnosis and treatment of their patients.

Sudden Death after Chest Pain: Feasibility of Virtual Autopsy with Postmortem CT Angiography and Biopsy

Purpose:To determine the potential of minimally invasive postmortem computed tomographic (CT) angiography combined with image-guided tissue biopsy of the myocardium and lungs in decedents who were thought to have died of acute chest disease and to compare this method with conventional autopsy as the reference standard.Materials and Methods:The responsible justice department and ethics committee approved this study. Twenty corpses (four female corpses and 16 male corpses; age range, 15-80 years), all of whom were reported to have had antemortem acute chest pain, were imaged with postmortem whole-body CT angiography and underwent standardized image-guided biopsy. The standard included three biopsies of the myocardium and a single biopsy of bilateral central lung tissue. Additional biopsies of pulmonary clots for differentiation of pulmonary embolism and postmortem organized thrombus were performed after initial analysis of the cross-sectional images. Subsequent traditional autopsy with sampling of histologic specimens was performed in all cases. Thereafter, conventional histologic and autopsy reports were compared with postmortem CT angiography and CT-guided biopsy findings. A Cohen k coefficient analysis was performed to explore the effect of the clustered nature of the data.Results:In 19 of the 20 cadavers, findings at postmortem CT angiography in combination with CT-guided biopsy validated the cause of death found at traditional autopsy. In one cadaver, early myocardial infarction of the papillary muscles had been missed. The Cohen κ coefficient was 0.94. There were four instances of pulmonary embolism, three aortic dissections (Stanford type A), three myocardial infarctions, three instances of fresh coronary thrombosis, three cases of obstructive coronary artery disease, one ruptured ulcer of the ascending aorta, one ruptured aneurysm of the right subclavian artery, one case of myocarditis, and one pulmonary malignancy with pulmonary artery erosion. In seven of 20 cadavers, CT-guided biopsy provided additional histopathologic information that substantiated the final diagnosis of the cause of death.Conclusion:Postmortem CT angiography combined with image-guided biopsy, because of their minimally invasive nature, have a potential role in the detection of the cause of death after acute chest pain.© RSNA, 2012.

Thoraxschmerzen bei Kindern und Jugendlichen - das Herz?

Chest pain in children and adolescents is a frequent observation, although potentially relevant disease is rather rare and then found in situations with acute presentation. In children with an inflammatory/infectious clinical context the differential diagnosis is oesophagitis, pleuropneumonia or pericarditis. Potentially dangerous complications may be found in youth with predisposing conditions for aortic dissection, pneumothorax or pulmonary embolism, or even in rare instances for an acute coronary complication. In these cases aggressive diagnostic work-up is mandatory. In the frequent elective outpatient evaluation of teenagers with long-lasting episodes of chest pain, relevant underlying cardiovascular disease only rarely can be found as the cause. In the elective outpatient evaluation for chest pain, usually patient history and clinical examination may be enough to track the problem, the main role of the physician is to provide reassurance with minimal but appropriate testing.

Pulmonary capillary pressure. A review

Pulmonary capillary pressure (Pcap) is the predominant force that drives fluid out of the pulmonary capillaries into the interstitium. Increasing hydrostatic capillary pressure is directly proportional to the lung's transvascular filtration rate, and in the extreme leads to pulmonary edema. In the pulmonary circulation, blood flow arises from the transpulmonary pressure gradient, defined as the difference between pulmonary artery (diastolic) pressure and left atrial pressure. The resistance across the pulmonary vasculature consists of arterial and venous components, which interact with the capacitance of the compliant pulmonary capillaries. In pathological states such as acute respiratory distress syndrome, sepsis, and high altitude or neurogenic lung edema, the longitudinal distribution of the precapillary arterial and the postcapillary venous resistance varies. Subsequently, the relationship between Pcap and pulmonary artery occlusion pressure (PAOP) is greatly variable and Pcap can no longer be predicted from PAOP. In clinical practice, PAOP is commonly used to guide fluid therapy, and Pcap as a hemodynamic target is rarely assessed. This approach is potentially misleading. In the presence of a normal PAOP and an increased pressure gradient between Pcap and PAOP, the tendency for fluid leakage in the capillaries and subsequent edema development may substantially be underestimated. Tho-roughly validated methods have been developed to assess Pcap in humans. At the bedside, measurement of Pcap can easily be determined by analyzing a pressure transient after an acute pulmonary artery occlusion with the balloon of a Swan-Ganz catheter.

Effect of X-ray tube parameters, iodine concentration, and patient size on image quality in pulmonary computed tomography angiography: a chest-phantom-study

OBJECTIVES: The aim of this phantom study was to evaluate the contrast-to-noise ratio (CNR) in pulmonary computed tomography (CT)-angiography for 300 and 400 mg iodine/mL contrast media using variable x-ray tube parameters and patient sizes. We also analyzed the possible strategies of dose reduction in patients with different sizes. MATERIALS AND METHODS: The segmental pulmonary arteries were simulated by plastic tubes filled with 1:30 diluted solutions of 300 and 400 mg iodine/mL contrast media in a chest phantom mimicking thick, intermediate, and thin patients. Volume scanning was done with a CT scanner at 80, 100, 120, and 140 kVp. Tube current-time products (mAs) varied between 50 and 120% of the optimal value given by the built-in automatic dose optimization protocol. Attenuation values and CNR for both contrast media were evaluated and compared with the volume CT dose index (CTDI(vol)). Figure of merit, calculated as CNR/CTDIvol, was used to quantify image quality improvement per exposure risk to the patient. RESULTS: Attenuation of iodinated contrast media increased both with decreasing tube voltage and patient size. A CTDIvol reduction by 44% was achieved in the thin phantom with the use of 80 instead of 140 kVp without deterioration of CNR. Figure of merit correlated with kVp in the thin phantom (r = -0.897 to -0.999; P < 0.05) but not in the intermediate and thick phantoms (P = 0.09-0.71), reflecting a decreasing benefit of tube voltage reduction on image quality as the thickness of the phantom increased. Compared with the 300 mg iodine/mL concentration, the same CNR for 400 mg iodine/mL contrast medium was achieved at a lower CTDIvol by 18 to 40%, depending on phantom size and applied tube voltage. CONCLUSIONS: Low kVp protocols for pulmonary embolism are potentially advantageous especially in thin and, to a lesser extent, in intermediate patients. Thin patients profit from low voltage protocols preserving a good CNR at a lower exposure. The use of 80 kVp in obese patients may be problematic because of the limitation of the tube current available, reduced CNR, and high skin dose. The high CNR of the 400 mg iodine/mL contrast medium together with lower tube energy and/or current can be used for exposure reduction.

Venous thromboembolism and occult malignancy: simultaneous detection during pulmonary CT angiography with CT venography

OBJECTIVE: We explored the potential for patients with proven venous thromboembolism or pulmonary embolism (PE) to have occult malignancies detected during the same CT examination. To verify this, we compared the presence of occult malignancies identified on pulmonary artery CT angiography (CTA) and CT venography (CTV) when venous thromboembolism (VTE) was present. SUBJECTS AND METHODS: Pulmonary artery CTA combined with CTV was performed on a 16-MDCT scanner on 186 adult patients suspected of having pulmonary embolism without any known malignancies. CTV was performed from the diaphragm to the knee 180 seconds after CTA. Two radiologists evaluated the presence of VTE, that is PE or deep venous thrombosis (DVT), and tumor lesions on both examinations in consensus. The malignant nature of the possibly identified tumors was confirmed by pathologic examination. RESULTS: VTE was found in 49 patients (26%). Malignant tumors were detected in 24 patients (13%). Eleven patients with malignant tumors had VTE (46% of patients with malignant tumors; 22% with VTE and 6% of all patients). There was correlation with presence of malignancies between both and DVT and DVT associated with PE but not between presence of malignancies and PE only. Patients with DVT and those with DVT associated with PE had a risk ratio of 3.2 and 3.3, respectively, for having a malignant tumor discovered simultaneously. CONCLUSION: A high number of malignant tumors can be incidentally discovered on pulmonary artery CTA, even more so with additional CTV. Radiologists should scrutinize scans to pick up unknown malignancies, especially in patients with identified VTE.

Patient exposure and image quality of low-dose pulmonary computed tomography angiography: comparison of 100- and 80-kVp protocols

OBJECTIVE: Measures to reduce radiation exposure and injected iodine mass are becoming more important with the widespread and often repetitive use of pulmonary CT angiography (CTA) in patients with suspected pulmonary embolism. In this retrospective study, we analyzed the capability of 2 low-kilovoltage CTA-protocols to achieve these goals. MATERIALS AND METHODS: Ninety patients weighing less than 100 kg were examined by a pulmonary CTA protocol using either 100 kVp (group A) or 80 kVp (group B). Volume and flow rate of contrast medium were reduced in group B (75 mL at 3 mL/s) compared with group A (100 mL at 4 mL/s). Attenuation was measured in the central and peripheral pulmonary arteries, and the contrast-to-noise ratios (CNR) were calculated. Entrance skin dose was estimated by measuring the surface dose in an ovoid-cylindrical polymethyl methacrylate chest phantom with 2 various dimensions corresponding to the range of chest diameters in our patients. Quantitative image parameters, estimated effective dose, and skin dose in both groups were compared by the t test. Arterial enhancement, noise, and overall quality were independently assessed by 3 radiologists, and results were compared between the groups using nonparametric tests. RESULTS: Mean attenuation in the pulmonary arteries in group B (427.6 +/- 116 HU) was significantly higher than in group A (342.1 +/- 87.7 HU; P < 0.001), whereas CNR showed no difference (group A, 20.6 +/- 7.3 and group B, 22.2 +/- 7.1; P = 0.302). Effective dose was lower by more than 40% with 80 kVp (1.68 +/- 0.23 mSv) compared with 100 kVp (2.87 +/- 0.88 mSv) (P < 0.001). Surface dose was significantly lower at 80 kVp compared with 100 kVp at both phantom dimensions (2.75 vs. 3.22 mGy; P = 0.027 and 2.22 vs. 2.73 mGy; P = 0.005, respectively). Image quality did not differ significantly between the groups (P = 0.151). CONCLUSIONS: Using 80 kVp in pulmonary CTA permits reduced patient exposure by 40% and CM volume by 25% compared with 100 kVp without deterioration of image quality in patients weighing less than 100 kg.

Polypharmacy is Associated with an Increased Risk of Bleeding in Elderly Patients with Venous Thromboembolism.

BACKGROUND Polypharmacy, defined as the concomitant use of multiple medications, is very common in the elderly and may trigger drug-drug interactions and increase the risk of falls in patients receiving vitamin K antagonists. OBJECTIVE To examine whether polypharmacy increases the risk of bleeding in elderly patients who receive vitamin K antagonists for acute venous thromboembolism (VTE). DESIGN We used a prospective cohort study. PARTICIPANTS In a multicenter Swiss cohort, we studied 830 patients aged ≥ 65 years with VTE. MAIN MEASURES We defined polypharmacy as the prescription of more than four different drugs. We assessed the association between polypharmacy and the time to a first major and clinically relevant non-major bleeding, accounting for the competing risk of death. We adjusted for known bleeding risk factors (age, gender, pulmonary embolism, active cancer, arterial hypertension, cardiac disease, cerebrovascular disease, chronic liver and renal disease, diabetes mellitus, history of major bleeding, recent surgery, anemia, thrombocytopenia) and periods of vitamin K antagonist treatment as a time-varying covariate. KEY RESULTS Overall, 413 (49.8 %) patients had polypharmacy. The mean follow-up duration was 17.8 months. Patients with polypharmacy had a significantly higher incidence of major (9.0 vs. 4.1 events/100 patient-years; incidence rate ratio [IRR] 2.18, 95 % confidence interval [CI] 1.32-3.68) and clinically relevant non-major bleeding (14.8 vs. 8.0 events/100 patient-years; IRR 1.85, 95 % CI 1.27-2.71) than patients without polypharmacy. After adjustment, polypharmacy was significantly associated with major (sub-hazard ratio [SHR] 1.83, 95 % CI 1.03-3.25) and clinically relevant non-major bleeding (SHR 1.60, 95 % CI 1.06-2.42). CONCLUSIONS Polypharmacy is associated with an increased risk of both major and clinically relevant non-major bleeding in elderly patients receiving vitamin K antagonists for VTE.

Pulmonary intimal sarcoma: a rare differential diagnosis for arterial filling defects on a chest CT

We present a rare case of pulmonary intimal sarcoma mimicking pulmonary embolism in a 40-year-old woman. Although extremely rare, these tumors must be considered in patients who present inappropriate imaging findings that suggest embolism. Chest computed tomography is the modality of choice to determine the extent of the tumor. We present a female patient with suspected embolism that was in fact found to be an endothelial sarcoma of the pulmonary arteries.

Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients.

AIM To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between <0.001 and 0.03), with no difference between the 100-125 and >125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives.