[Low-dose chest CT for preoperative screening for SARS-CoV-2 infection]. / TC torácica de baja dosis de radiación como técnica de cribado preoperatorio de infección por SARS-CoV-2.

Introduction: This study aimed to evaluate the role of chest computed tomography (CT) in complementing reverse transcription polymerase chain reaction (RT-PCR) in asymptomatic candidates for elective surgery in the context of the COVID-19 pandemic. Material and methods: We prospectively included 464 asymptomatic patients who underwent a triple screening workup for SARS-CoV-2 infection (health questionnaire, RT-PCR, and low-dose chest CT) during the 48 hours prior to undergoing elective surgery. A positive RT-PCR and/or CT findings suggestive of COVID-19 (CO-RADS 4 / 5) were considered diagnostic criteria for SARS-CoV-2 infection. Results: Most patients (64.7%) underwent otorhinolaryngology surgery. No patients had positive RT-PCR results or symptoms suggestive of SARS-CoV-2 in the health questionnaire. Only 22 (4.7%) had signs compatible with lung infection; in 20 of these, the CT findings were atypical or indeterminate for COVID-19 (CO-RADS 2 / 3) and in 2 they were compatible with COVID-19 pneumonia in resolution. In the immediate postoperative period, no cases of SARS-CoV-2 infection were confirmed. Conclusion: In our series of asymptomatic patients, low-dose CT did not add any value to the results of RT-PCR and a health questionnaire in preoperative screening for SARS-CoV-2.

[Chest computed tomography findings in different phases of SARS-CoV-2 infection]. / Hallazgos en la tomografía computarizada de tórax en las fases evolutivas de la infección por SARS-CoV-2.

Objective: To compare the findings on chest computed tomography (CT) in patients with COVID-19 during different phases of the disease and to evaluate the reproducibility of a visual radiologic score for estimating the extent of lung involvement. Methods: We retrospectively reviewed chest CT studies from 182 patients with RT-PCR findings positive for SARS-CoV-2. Patients were classified according to the time elapsed from the onset of symptoms, as follows: early (0-4 days), intermediate/progressive (5-9 days), or advanced (≥10 days). We analyzed the frequency of each radiologic finding, as well as the pattern, appearance, and predominant distribution of lung involvement. A visual tomographic score (range, 0-25) was used to estimate the extent of involvement in each lobe and in the total lung volume. Results: The predominant CT finding was the ground-glass pattern (n=110; 60.4%), the most common distribution was peripheral (n = 116; 66.7%), and the most prevalent appearance was typical (n=112; 61.5%). The halo sign was seen most frequently in the early phase (25%), whereas ground-glass opacities were more common in the intermediate/progressive and advanced phases. The median severity score was 10 (IQR: 5-13), and the scores increased as the disease progressed. The interobserver agreement (kappa) was 0.92 for the appearance, 0.84 for the distribution, 0.70 for the predominant pattern, and 0.89 for the visual score. Conclusion: The CT findings in patients with COVID-19 vary with the course of the infection. The proposed visual radiologic score is a simple, reproducible, and reliable tool for assessing lung involvement in COVID-19 pneumonia.

[Cardiovascular magnetic resonance imaging in patients with acute chest pain]. / Resonancia magnética cardiovascular en pacientes con dolor torácico agudo.

Acute chest pain is a common reason for presentation to the emergency department. It can be caused by a wide variety of diseases, some of which are potentially lethal, so it must be diagnosed quickly. The rise of computed tomography to evaluate patients with acute chest pain is noteworthy. However, computed tomography is not without limitations in this context. Cardiovascular magnetic resonance imaging is a potentially useful technique in this group of patients, although its availability and the time required for examinations restrict its use to specific indications.

[Multidetector computed tomography assessment of cardiac comorbidity in patients with chronic obstructive pulmonary disease]. / Valoración de la comorbilidad cardíaca en pacientes con enfermedad pulmonar obstructiva crónica mediante tomografía computarizada multidetector.

Cardiac comorbidity is one of the most important prognostic factors in lung disease, especially in chronic obstructive pulmonary disease (COPD). The imaging techniques available for the study of this systemic manifestation concomitant with COPD include heart catheterization, transthoracic echocardiography, and magnetic resonance imaging. Multidetector computed tomography (MDCT) represents a significant advance in this field because it enables the acquisition of simultaneous studies of the cardiopulmonary anatomy that go beyond anatomic and morphologic analysis to include a functional approach to this condition. In this article, we review the practical aspects necessary to evaluate cardiac comorbidity in patients with COPD, both from the point of view of pulmonary hypertension and of the analysis of ventricular dysfunction and coronary heart disease.

Magnetic resonance in patients with cardiovascular devices. SEC-GT CRMTC/SEC-Heart Rhythm Association/SERAM/SEICAT consensus document.

Magnetic resonance has become a first-line imaging modality in various clinical scenarios. The number of patients with different cardiovascular devices, including cardiac implantable electronic devices, has increased exponentially. Although there have been reports of risks associated with exposure to magnetic resonance in these patients, the clinical evidence now supports the safety of performing these studies under specific conditions and following recommendations to minimize possible risks. This document was written by the Working Group on Cardiac Magnetic Resonance Imaging and Cardiac Computed Tomography of the Spanish Society of Cardiology (SEC-GT CRMTC), the Heart Rhythm Association of the Spanish Society of Cardiology (SEC-Heart Rhythm Association), the Spanish Society of Medical Radiology (SERAM), and the Spanish Society of Cardiothoracic Imaging (SEICAT). The document reviews the clinical evidence available in this field and establishes a series of recommendations so that patients with cardiovascular devices can safely access this diagnostic tool.

Low radiation and low-contrast dose pulmonary CT angiography: Comparison of 80 kVp/60 ml and 100 kVp/80 ml protocols.

AIM: To determine the image quality and diagnostic performance of an optimized pulmonary computed tomography angiography (CTA) protocol in terms of radiation and contrast volume saving. MATERIALS AND METHODS: Seventy consecutive patients weighting ≤80 kg with clinical suspicion of pulmonary embolism (PE) were prospectively enrolled. Two pulmonary CTA protocols (group A: n = 35, 80 kV/60 ml; group B: n = 35, 100 kV/80 ml) were compared. The presence of PE, image quality parameters [contrast attenuation, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR)] and effective radiation dose (mSv) were assessed. RESULTS: PE was found in 11 patients (five of group A, six of group B). The total mean attenuation of the pulmonary arteries was significantly higher in group A (362.4 ± 100.2 HU) than in group B (262.4 ± 134.3 HU), whereas the CNR and SNR did not differ statistically (14.8 ± 7.4 and 16.3 ± 7.5 for group A and 12.5 ± 8.6 and 13.8 ± 9.1 for group B, respectively). The estimated effective radiation dose was significantly lower in group A (1.1 ± 0.7 mSv) than in group B (2.7 ± 1.2 mSv). CONCLUSION: In individuals weighting ≤80 kg, the evaluated pulmonary CTA protocol allows similar image quality to be achieved as compared with the conventional pulmonary CTA protocol while reducing radiation exposure by 60% and contrast media volume by 25%.

Dual source CT: state of the art in the depiction of coronary arteries anatomy, anatomical variants and myocardial segments.

Cardiovascular disease is the leading cause of death in adults in western countries. Coronary angiography remains the gold standard for the diagnosis of coronary artery disease, a procedure that carries risks. Nowadays, a significant number of the coronary angiographies performed every year are only diagnostic. Multidetector computed tomography (MDCT) allows non-invasive evaluation of coronary arteries. It is a continuously developing technique, and actually the top technology is represented by Dual Source CT. This scanner of new conception permits an improvement in image quality, and visualization of distal vessels and small collateral branches. The aim of our work is to illustrate the actual state of the art in non-invasive coronary arteries evaluation represented by Dual Source CT, presenting images of coronary arteries normal anatomy, anatomical variants and myocardial segment.

Accuracy of different reconstruction intervals to quantify left ventricular function and mass in cardiac computed tomography examinations.

PURPOSE: To compare the accuracy of cardiac dual-source CT (DSCT) reconstructions obtained at 5% and 10% of the cardiac cycle and MRI for quantifying global left ventricular (LV) function and mass in heart transplant recipients. MATERIAL AND METHODS: We prospectively included 23 heart transplant recipients (21 male, mean age 60±11.7 years) who underwent cardiac DSCT and MRI examinations. We compared LV parameters on cardiac DSCT reconstructions obtained at 5% (0%-95%) and 10% (0%-90%) intervals of the cardiac cycle and on double-oblique short-axis MR images. We determined ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and myocardial mass using commercially available semiautomated segmentation analysis software for DSCT datasets and conventional manual contour tracing for MR studies. RESULTS: Using different reconstruction intervals to quantify LV parameters at DSCT resulted in non-significant differences (P>.05). Compared to MRI, DSCT slightly overestimated LV-EDV, ESV, and mass when both 5% (11.5±25.1ml, 6.8±10.9ml, and 28.3±21.6g, respectively) and 10% (mean difference 15.3±26.3ml, 7.4±11.5ml, and 29.3±18.7g, respectively) reconstruction intervals were used. DSCT and MRI estimates of EF and SV were not significantly different. CONCLUSION: In heart transplant recipients, DSCT allows reliable quantification of LV function and mass compared with MRI, even using 10% interval reconstructions.

Low-dose chest CT for preoperative screening for SARS-CoV-2 infection.

INTRODUCTION: This study aimed to evaluate the role of chest computed tomography (CT) in complementing reverse transcription polymerase chain reaction (RT-PCR) in asymptomatic candidates for elective surgery in the context of the COVID-19 pandemic. MATERIAL AND METHODS: We prospectively included 464 asymptomatic patients who underwent a triple screening workup for SARS-CoV-2 infection (health questionnaire, RT-PCR, and low-dose chest CT) during the 48 h prior to undergoing elective surgery. A positive RT-PCR and/or CT findings suggestive of COVID-19 (CO-RADS 4/5) were considered diagnostic criteria for SARS-CoV-2 infection. RESULTS: Most patients (64.7%) underwent otorhinolaryngology surgery. No patients had positive RT-PCR results or symptoms suggestive of SARS-CoV-2 in the health questionnaire. Only 22 (4.7%) had signs compatible with lung infection; in 20 of these, the CT findings were atypical or indeterminate for COVID-19 (CO-RADS 2/3) and in 2 they were compatible with COVID-19 pneumonia in resolution. In the immediate postoperative period, no cases of SARS-CoV-2 infection were confirmed. CONCLUSION: In our series of asymptomatic patients, low-dose CT did not add any value to the results of RT-PCR and a health questionnaire in preoperative screening for SARS-CoV-2.

[Radiologists in the emergency department: when and how to use multislice CT]. / El radiólogo de urgencias ante el dolor torácico agudo: cómo y para qué debo utilizar los equipos TC multicorte?

Chest pain is a challenging clinical problem in the emergency department. Despite advances in clinical diagnosis, many patients with atypical chest pain are needlessly hospitalized and others are mistakenly discharged. Faced with the specific clinical situation in which a patient has chest pain, an initially normal or inconclusive electrocardiogram, and normal cardiac biomarkers, multislice CT has proven useful for ruling out the conditions that involve the greatest morbidity and mortality and for establishing the cause of pain. This article reviews the current usefulness of multislice CT in the diagnostic workup of patients presenting at the emergency department with chest pain. We review the technique, define the most appropriate population, describe the acquisition protocols, and discuss the advantages and disadvantages of each study protocol.

Anatomic characteristics of the left atrium in subjects undergoing radiofrequency ablation for atrial fibrillation.

OBJECTIVE: To analyze the anatomic characteristics of the left atrium and pulmonary veins in individuals undergoing ablation for atrial fibrillation and to identify possible anatomic factors related with recurrence. MATERIAL AND METHODS: We retrospectively reviewed the CT angiography studies done to plan radiofrequency ablation for atrial fibrillation in 95 patients (57 men; mean age, 65 ±â€¯10 y). We reviewed the anatomy of the pulmonary veins and recorded the diameters of their ostia as well as the diameter and volume of the left atrium. We analyzed these parameters according to the type of arrhythmia and the response to treatment. RESULTS: In 71 (74.7%) patients, the anatomy of the pulmonary veins was normal (i.e., two right pulmonary veins and two left pulmonary veins). Compared to patients with paroxysmal atrial fibrillation, patients with persistent atrial fibrillation had slightly larger diameter of the left pulmonary veins (left superior pulmonary vein 17.9 ±â€¯2.6 mm vs. 16.7 ±â€¯2.2 mm, p = 0.04; left inferior pulmonary vein 15.3 ± 2 mm vs. 13.8 ±â€¯2.2 mm, p = 0.009) and larger left atrial volume (91.9 ±â€¯24.9 cm3 vs. 70.7 ±â€¯20.3 mm3, p = 0.001). After 22.1 ±â€¯12.1 months' mean follow-up, 41 patients had sinus rhythm. Compared to patients in whom the sinus rhythm was restored, patients with recurrence had greater left atrial volume (81.4 ±â€¯23.0 mm3 vs. 71.1 ±â€¯23.2 mm3, p = 0.03). No significant differences in pulmonary vein diameters or clinical parameters were observed between patients with recurrence and those without. CONCLUSION: The volume of the left atrium is greater in patients with persistent atrial fibrillation and in those who do not respond to ablation.

Chest computed tomography findings in different phases of SARS-CoV-2 infection. / Hallazgos en la tomografía computarizada de tórax en las fases evolutivas de la infección por SARS-CoV-2.

OBJECTIVE: To compare the findings on chest computed tomography (CT) in patients with COVID-19 during different phases of the disease and to evaluate the reproducibility of a visual radiologic score for estimating the extent of lung involvement. METHODS: We retrospectively reviewed chest CT studies from 182 patients with RT-PCR findings positive for SARS-CoV-2. Patients were classified according to the time elapsed from the onset of symptoms, as follows: early (0-4 days), intermediate/progressive (5-9 days), or advanced (≥10 days). We analyzed the frequency of each radiologic finding, as well as the pattern, appearance, and predominant distribution of lung involvement. A visual tomographic score (range, 0-25) was used to estimate the extent of involvement in each lobe and in the total lung volume. RESULTS: The predominant CT finding was the ground-glass pattern (n=110; 60.4%), the most common distribution was peripheral (n = 116; 66.7%), and the most prevalent appearance was typical (n=112; 61.5%). The halo sign was seen most frequently in the early phase (25%), whereas ground-glass opacities were more common in the intermediate/progressive and advanced phases. The median severity score was 10 (IQR: 5-13), and the scores increased as the disease progressed. The interobserver agreement (kappa) was 0.92 for the appearance, 0.84 for the distribution, 0.70 for the predominant pattern, and 0.89 for the visual score. CONCLUSION: The CT findings in patients with COVID-19 vary with the course of the infection. The proposed visual radiologic score is a simple, reproducible, and reliable tool for assessing lung involvement in COVID-19 pneumonia.

Surgical Outcomes in a Lung Cancer-Screening Program Using Low Dose Computed Tomography.

OBJECTIVE: Lung cancer (LC) is the leading cause of death from cancer worldwide. More than 27,000 LCs are diagnosed annually in Spain, and most are unresectable. Early detection and treatment reduce LC mortality. This study describes surgical outcomes in a longstanding LC screening cohort in Spain. METHODS: We conducted a retrospective study of surgical outcomes in a LC screening (LCS) program using low dose computed tomography (LDCT) since the year 2000. A descriptive analysis of clinical and radiological parameters, presence or absence of a preoperative diagnosis, pathological staging, morbidity, mortality, and survival was performed. RESULTS: Ninety-seven (2.5%) LC were diagnosed in 3825 screened. Twenty individuals with LC had no surgery due to advanced stage or small cell histology. Eighty-seven surgical procedures were carried out for suspected or biopsy proven LC, detected by LDCT. Most operated patients were male (57[85%]) aged 64±9.1 years. Nine patients underwent a second operation for a metachronous primary lung cancer. Mean tumor size was 15.2±7.6mm. Eight nodules were benign (9.2%). Lobectomy was performed in 56 cases (83.6%). Adenocarcinoma (n=39; 58.2%) was the most frequent histological type followed by squamous cell carcinoma (n=17; 25.4%). Fifty-nine (88%) tumors were in Stage I. Thirteen patients (15.4%) had 16 complications. The estimated survival rates at 5 and 10 years for stage I were 93% (95% CI: 79%-98%) and 83% (95% CI: 65%-92%), respectively. CONCLUSION: Lung cancer screening was associated with excellent surgical outcomes with 5 and 10-year survival rates exceeding 90 and 80%, respectively.

Cardiac magnetic resonance imaging myocardial perfusion reserve index in heart transplant patients. / Valoración del índice de reserva de perfusión miocárdica por resonancia magnética en pacientes con trasplante cardíaco.

OBJECTIVE: To compare the myocardial perfusion reserve index (MPRI) measured during stress cardiac magnetic resonance imaging (MRI) with regadenoson in patients with heart transplants versus in patients without heart transplants. MATERIAL AND METHODS: We retrospectively compared 20 consecutive asymptomatic heart transplant patients without suspicion of microvascular disease who underwent stress cardiac MRI with regadenoson and coronary computed tomography angiography (CTA) to rule out cardiac allograft vasculopathy versus 16 patients without transplants who underwent clinically indicated stress cardiac MRI who were negative for ischemia and had no signs of structural heart disease. We estimated MPRI semiquantitatively after calculating the up-slope of the first-pass enhancement curve and dividing the value obtained during stress by the value obtained at rest. We compared MPRI in the two groups. Patients with positive findings for ischemia on stress cardiac MRI or significant coronary stenosis on coronary CTA were referred for conventional coronary angiography. RESULTS: More than half the patients remained asymptomatic during the stress test. Stress cardiac MRI was positive for ischemia in two heart transplant patients; these findings were confirmed at coronary CTA and at conventional coronary angiography. Patients with transplants had lower end-diastolic volume index (59.3±15.2 ml/m2 vs. 71.4±15.9 ml/m2 in those without transplants, p=0.03), lower MPRI (1.35±0.19 vs. 1.6±0.28 in those without transplants, p=0.003), and a less pronounced hemodynamic response to regadenoson (mean increase in heart rate 13.1±5.4 bpm vs. 28.5±8.9 bpm in those without transplants, p <0.001). CONCLUSION: Stress cardiac MRI with regadenoson is safe. In the absence of epicardial coronary artery disease, patients with heart transplants have lower MPRI than patients without transplants, suggesting microvascular disease. The hemodynamic response to regadenoson is less pronounced in patients with heart transplants than in patients without heart transplants.

Safety of regadenoson for vasodilation in cardiac MRI stress tests. / Seguridad del empleo de regadenosón como fármaco vasodilatador en resonancia magnética cardíaca de estrés.

OBJECTIVE: To determine the safety of regadenoson for vasodilation in cardiac MRI stress tests to detect myocardial ischemia. MATERIAL AND METHODS: We retrospectively analyzed cardiac MRI studies done in 120 patients (mean age, 67±11.6 years; 88 men) with suspected ischemic heart disease or known coronary disease who had clinical indications for cardiac MRI stress tests. All studies were done on a 1.5 T scanner (MAGNETOM Aera, Siemens Healthineers) using regadenoson (5ml, 0.4mg) for vasodilation. We recorded cardiovascular risk factors, medications, and indications for the test as well as vital signs at rest and under stress and the symptoms and adverse effects induced by the drug. RESULTS: No symptoms developed in 52.6% of patients. The most common symptoms were central chest pain (25%) and dyspnea (12%). At peak stress, the mean increase in heart rate was 23.9±11.4 beats per minute and the mean decreases in systolic and diastolic blood pressure were 7.1±18.8mmHg and 5.3±9.2mmHg, respectively (p <0.001). The response to regadenoson was less pronounced in obese and diabetic patients. The increase in heart rate was greater in symptomatic patients (27.4±11.2 bpm vs. 20.6±10.7 bpm in asymptomatic patients, p=0.001). No severe adverse effects were observed. CONCLUSION: Regadenoson is well tolerated and can be safely used for cardiac MRI stress tests.

[Global evaluation of the heart in heart transplant recipients using dual-source computed tomography]. / Valoración global del corazón en el paciente con transplante cardiaco mediante tomografía computarizada de doble fuente.

In routine clinical practice surveillance of heart transplant recipients is usually performed using echocardiography and conventional coronary angiography. The latter permits diagnosis and follow-up of coronary allograft vasculopathy. However, this procedure is invasive and is not free of complications. Conventional multislice computed tomography (MSCT) has been shown to be a useful non-invasive tool for ruling out coronary artery disease and evaluating cardiac function. However, due to its limited temporal resolution betablocker administration is required, and its usefulness in certain patient populations with restricted response to this medication, such as heart transplant recipients, may therefore be limited. Dual-source CT (DSCT) allows evaluation of the coronary arteries in all individuals independent of their heart rate. In the case presented here, we demonstrate that DSCT may be useful for evaluating cardiac function and ruling out coronary allograft vasculopathy in heart transplant recipients.

[Quantification of left ventricular function and mass in dual-source CT (DSCT).]. / Cuantificación de la función y masa ventricular izquierda mediante tomografía computarizada de doble fuente.

OBJECTIVES: To evaluate the interobserver agreement in quantifying left ventricular function and mass and to assess the accuracy of conventional manual contour tracing compared to semiautomatic segmentation analysis software. MATERIAL AND METHODS: Twenty consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Two different multiphase image reconstructions were done in 5% steps throughout the entire cardiac cycle (0-95% of the R-R interval) with effective slice thickness of 1mm in the axial plane and 8mm in the short-axis orientation. Left ventricular function and mass were calculated by two independent observers, tracing endocardial and epicardial borders manually and using a semiautomatic software tool (Circulation II, Siemens). Ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), cardiac output (CO), and myocardial mass were evaluated by two independent observers blind to each other's assessments. The interobserver agreement and the reliability of the different segmentation methods were calculated. The time required for manual contouring and semiautomatic contour tracing was also registered. RESULTS: We found an excellent correlation (r>0.94; p<0.05) between the two independent observers for the quantification of left ventricular function and mass. Left ventricular functional parameters derived from semiautomatic contour software and conventional manual tracing method were not significantly different (p>0.05). The semiautomatic contour detection algorithm overestimated LV mass significantly compared with the manual contouring method (mean difference 29.45+/-1.64g; p<0.05). The time needed to calculate these parameters with the semiautomatic tool was significantly lower (248.85+/-99.8s) than with manual contouring (452.7+/-73.92s) (p<0.05). CONCLUSIONS: Interobserver agreement for quantifying left ventricular function and mass using DSCT is excellent. Despite overestimating left ventricular mass, the semiautomatic software tool allows cardíac parameters to be quantified with the same reliability as the conventional manual method in half the time.

[Left ventricular function, volumes, and mass in MRI studies using SFPP versus FLASH sequences in an animal model.]. / Función, volúmenes y masa ventricular izquierda por resonancia magnética en estudios realizados en un modelo animal con secuencias SSFP y FLASH: comparación de los resultados.

OBJECTIVE: To compare the accuracy of two cine-gradient-echo sequences to quantify left ventricular function, volumes, and mass in an animal model. MATERIAL AND METHODS: We studied ten Gottingen miniature pigs (seven male, three female; mean weight 49.8+/-10.65kg; range: 35-65kg) with a 1.5 Tesla MRI scanner using free-breathing SSFP and FLASH sequences. We used 8-mm short-axis images to estimate left ventricular ejection fraction (EF), volumes (end-diastolic (EDV), end-systolic (ESV), and stroke volume (SV)), mass, and signal-to-noise ratio (SNR) on SSFP and FLASH sequences. We analyzed the correlation and concordance of the two sequences for each variable. RESULTS: Using the SSFP sequence, the mean estimated EF was 77.35+/-3.13%; mean EDV 61.55+/-8.64ml; mean ESV 13.83+/-1.92ml; mean SV 47.72+/-7.78ml; and mean myocardial mass 75.87+/-11.44g. Using the FLASH sequence, the mean EF was 81.87+/-2.22%; mean EDV 55.4+/-8.08ml; mean ESV 10.03+/-1.87ml; mean SV 45.38+/-6.83ml; and mean myocardial mass 87.74+/-15.21g. The correlation between SSFP and FLASH to quantify EDV, SV, and myocardial mass was excellent (r>0.8) and moderate (r>0.4) for quantifying ESV and EF. The SNR in the SSFP sequence was significantly higher than in the FLASH sequence (mean difference 120.94+/-42.94). CONCLUSIONS: In the SSFP sequence, ventricular volumes are slightly higher and ventricular mass is slightly lower than in the FLASH sequence, probably because of the higher SNR on SSFP sequences.

Global cardiac evaluation without heart rate control: preliminary experience with dual source CT (DSCT).

AIM: The aim of this work was to assess the role of dual source computed tomography (DSCT) in global cardiac evaluation without heart rate control, assessing the effect of average heart rate on coronary image quality, optimal reconstruction interval, ventricular function, and evaluation of left chamber valves. METHODS: Fifteen consecutive patients under-went coronary CT angiography. For coronary evaluation, data sets were reconstructed in 5% steps from 30% to 80% of the RR interval. For the assessment of cardiac function, image were reconstructed with a slice thickness of 2.0 mm and 2.0 mm increment, at 10% steps from 0% to 90% of the RR interval. Two blinded independent readers assessed the image quality of the coronary arteries and left chamber valves. RESULTS: The mean heart rate during the scan was 73+/-11.8 bpm (range 56-97). At the best reconstruction interval excellent diagnostic image quality (score 4) was achieved in 95.5% (43/45) of coronary arteries. Excellent inter-observer agreement was observed for image quality rating (k=0.82). No significant correlation was found between the average heart rate and the mean quality scores (rho=0.29). Comparison of image quality of the coronary arteries in systolic and diastolic reconstructions in each patient showed no statistically significant differences. CONCLUSION: DSCT is an excellent technique for global cardiac imaging, as it allows to obtain coronary arteries of excellent quality and evaluate ventricular function and valvular area independent of the heart rate.

Could stress magnetic resonance imaging be useful in patients with a low probability of ischemic heart disease? / ¿Podría ser útil la resonancia magnética de estrés en pacientes con baja probabilidad de cardiopatía isquémica?

OBJECTIVE: To assess the usefulness of cardiac stress magnetic resonance imaging (MRI) with adenosine in the detection of ischemic heart disease in patients with a low pretest probability of disease. MATERIAL AND METHODS: We used the probability ratio to analyze the usefulness of cardiac stress MRI in a selection of patients with a low pretest probability of ischemic heart disease (low or moderate cardiovascular risk, atypical chest pain, or absence of prior ischemic heart disease). RESULTS: We included 295 patients followed up for a median of 28 (19-36) months. A total de 60 patients had an event. Cardiac stress MRI was more useful in patients with a low pretest probability: atypical chest pain (probability ratio [PR] positive 8.56), absence of prior ischemic heart disease (PR positive 4.85), and low or moderate cardiovascular risk (PR positive 3.87). CONCLUSIONS: Cardiac stress MRI can be useful in the diagnosis of ischemic heart disease in patients with a low pretest probability.