Quantitative analysis of pulmonary perfusion with dual-energy CT angiography: comparison of two quantification methods in patients with pulmonary embolism.

The study aimed to evaluate a quantification method of pulmonary perfusion with Dual-Energy CT Angiography (DE-CTA) normalized by lung density in the prediction of outcome in acute pulmonary embolism (PE). In this prospective study with CTA scans acquired with different breathing protocols, two perfusion parameters were calculated: %PBV (relative value of PBV, expressed per unit volume) and PBVm (PBV normalized by lung density, expressed per unit mass). DE-CTA parameters were correlated with simplified pulmonary embolism severity index (sPESI) and with outcome groups, alone and in combinationwith tomographic right-to-left ventricular ratios (RV/LV). PBVm showed significant correlation with sPESI. PBVm presented higher accuracy than %PBV In the prediction of ICU admission or death in patients with PE, with the best performance when combined with RV/LV volumetric ratio.

Lobar pulmonary perfusion quantification with dual-energy CT angiography: Interlobar variability and relationship with regional clot burden in pulmonary embolism.

Purpose: Semi-automated lobar segmentation tools enable an anatomical assessment of regional pulmonary perfusion with Dual-Energy CTA (DE-CTA). We aimed to quantify lobar pulmonary perfusion with DE-CTA, analyze the perfusion distribution among the pulmonary lobes in subjects without cardiopulmonary diseases and assess the correlation between lobar perfusion and regional endoluminal clots in patients with acute pulmonary embolism (PE). Methods: We evaluated 151 consecutive subjects with suspected PE and without cardiopulmonary comorbidities. DE-CTA derived perfused blood volume (PBV) of each pulmonary lobe was measured applying a semi-automated lobar segmentation technique. In patients with PE, blood clot location was assessed, and CT-based vascular obstruction index of each lobe (CTOIlobe) was calculated and classified into three groups: CTOIlobe= 0, low CTOIlobe (1-50%) and high CTOIlobe (>50%). Results: Among patients without PE (103/151, 68.2%), median lobar PBV was 13.7% (IQR 10.2-18.0%); the right middle lobe presented lower PBV when compared to all the other lobes (p < .001). In patients with PE (48/151, 31.8%), lobar PBV was 12.6% (IQR 9.6-15.7%), 13.7% (IQR 10.1-16.7%) and 6.5% (IQR 5.1-10.2%) in the lobes with CTOIlobe= 0, low CTOIlobe and high CTOIlobe scores, respectively, with a significantly decreased PBV in the lobes with high CTOIlobe score (p < .001). ROC analysis of lobar PBV for prediction of high CTOIlobe score revealed AUC of 0.847 (95%CI 0.785-0.908). Conclusion: Pulmonary perfusion was heterogeneously distributed along the pulmonary lobes in patients without cardiopulmonary diseases. In patients with PE, the lobes with high vascular obstruction score (CTOIlobe> 50%) presented a decreased lobar perfusion.

Stent evaluation by coronary computed tomography angiography: a comparison between Iopamidol-370 and Ioversol-320 hypo-osmolar iodine concentration contrasts.

OBJECTIVE: Qualitative and quantitative image analysis between Iopamidol-370 and Ioversol-320 in stents´ evaluation by coronary computed tomography angiography (CTA). METHODS: Sixty-five patients with low-risk stable angina undergoing stent follow-up with coronary CTA were assigned to Iopamidol I-370 (n = 33) or Ioversol I-320 (n = 32) in this prospective, double-blind, non-inferiority, randomized trial. Stent lumen image quality was graded by 5-point Likert Scale. Lumen mean attenuation was measured at native coronary segments: pre-stent, post-stent, distal segments and at coronary plaques. Lumen attenuation increase (LAI) ratio was calculated for all stents. Heart rate (HR) variation, premature heart beats (PHB), heat sensation (HS), blooming and beam hardening were also assessed. RESULTS: Image quality was similar between groups, with no significant difference (Likert score 4.48 ± 0.75 vs 4.54 ± 0.65, p = 0.5). There were similarities in LAI ratio between I-370 and I-320 (0.39 ± 0.42 vs 0.48 ± 0.44 HU, p = 0.08). Regarding lumen mean attenuation at native coronary segments, a significant difference was observed, with I-320 presenting lower values, including contrast mean attenuation in distal segments. After statistical multivariate analysis, three variables correlated with stent image quality: 1) stent diameter, 2) HR variation and 3) stent lumen LAI ratio. CONCLUSIONS: There was no significant difference between Iopamidol-370 mgI ml-1 and Ioversol-320 mgI ml-1 contrasts regarding overall stent lumen image quality, which was mainly influenced by stent diameter, HR and LAI ratio.Advances in knowledge:Coronary CTA allows adequate stents' visualization and image quality is influenced by stent diameter, HR variation and LAI ratio.Stents' image quality showed no difference between different concentration contrasts (I-370 vs. I-320); however, higher concentration contrasts may provide an improved overall visualization, especially regarding coronary distal segments.

Cambios hemodinámicos posligadura con bandas de varices esofágicas: un estudio de cohortes / No disponible

INTRODUCCIÓN: existe controversia sobre la necesidad de mantener el tratamiento vasoconstrictor tras lograr una adecuada hemostasia mediante ligadura endoscópica, en la hemorragia aguda por varices esofágicas. Dado que es muy complejo hacer un gradiente "pre y posligadura urgente" en el sangrante por varices, nuestro objetivo es conocer las variaciones hemodinámicas tras la terapia endoscópica, midiendo un gradiente venoso hepático "pre" y otro 24 horas "posprocedimiento" en los cirróticos con ligadura programada como profilaxis de la hemorragia varicosa. MATERIAL Y MÉTODOS: estudio prospectivo, de cohorte, unicéntrico. Los pacientes, en protocolo de erradicación endoscópica, fueron sometidos a un gradiente de presión venosa hepática basal (GPVH PRE), sin modificar su tratamiento habitual con beta-bloqueantes. Después, se procedió a ligadura endoscópica, según guías de práctica clínica. Tras 24 horas del procedimiento, se realizó una segunda medida de presiones (GPVH POST). RESULTADOS: 30 pacientes. Las medianas de los GPVH PRE y POST ligadura fueron 16,5 mmHg (14-20) y 19,5 mmHg (17-21) respectivamente, con un aumento significativo tras el procedimiento (p < 0,001). Las variaciones porcentuales de presión portal, según cifra de gradiente basal (12, 16 y 20 mmHg), eran mayores en pacientes con menor GVPH frente a mayor GPVH basal en cualquiera de las categorías comparadas (p = 0,087, p = 0,016 y p < 0,001, respectivamente). En nuestra serie, el 36,7 % de los pacientes presentó un incremento de gradiente ≥ 20 % tras la ligadura. CONCLUSIÓN: la ligadura con bandas de varices esofágicas condiciona un aumento de presión portal, al menos transitorio, objetivado mediante gradiente de presión venosa hepática

No disponible

Hemodynamic changes after endoscopic variceal ligation: a cohort study.

BACKGROUND: there is controversy about the need to maintain vasoconstrictor treatment after adequate haemostasis is achieved through endoscopic band ligation (EBL) in bleeding esophageal varices (BEV). Measuring a "before and after urgent-EBL" hepatic venous pressure gradient (HVPG) in acute variceal hemorrhage is very difficult. Thus, the goal of this study was to determine hemodynamic variations after an EBL session. A "before" HVPG (PRE) was performed and another one 24 hours "after-ligation" (POST), in cirrhotic patients undergoing endoscopic band ligation as BEV prophylaxis. PATIENTS AND METHODS: this was a single-center, cohort, prospective study. Patients followed a program of repeated sessions of EBL until eradication of their varices and underwent a basal hepatic venous pressure gradient (PRE HVPG), without changing their usual treatment with beta-blockers. Subsequently, an endoscopic ligation session was performed, following the clinical practices guidelines. A second pressure measurement (POST HVPG) was taken 24 hours after the endoscopic treatment. RESULTS: 30 patients were included. PRE and POST HVPG median results were 16.5 mmHg (14-20) and 19.5 mmHg (17-21), respectively, with a significant increase after the procedure (p < 0.001). Percentage variations in portal pressure, based on the baseline gradient values (12, 16 and 20 mmHg), were higher for patients with a lower basal HVPG versus a higher HVPG for any of the categories compared (p = 0.087, p = 0.016 and p < 0.001, respectively). In our series, 36.7 % of patients showed a ≥ 20 % gradient increase after ligation. CONCLUSION: endoscopic band ligation causes an increase in portal pressure, at least for a transitional period, determined by the hepatic venous pressure gradient.

Association between perivascular inflammation and downstream myocardial perfusion in patients with suspected coronary artery disease.

AIMS: To investigate the association between pericoronary adipose tissue (PCAT) computed tomography (CT) attenuation derived from coronary computed tomography angiography (CTA) and coronary flow reserve (CFR) by positron emission tomography (PET) in patients with suspected coronary artery disease (CAD). METHODS AND RESULTS: PCAT CT attenuation was measured in proximal segments of all major epicardial coronary vessels of 105 patients with suspected CAD. We evaluated the relationship between PCAT CT attenuation and other quantitative/qualitative CT-derived anatomic parameters with CFR by PET. Overall, the mean age was 60 ± 12 years and 93% had intermediate pre-test probability of obstructive CAD. Obstructive CAD (≥50% stenosis) was detected in 37 (35.2%) patients and impaired CFR (<2.0) in 32 (30.5%) patients. On a per-vessel analysis (315 vessels), obstructive CAD, non-calcified plaque volume, and PCAT CT attenuation were independently associated with CFR. In patients with coronary calcium score (CCS) <100, those with high-PCAT CT attenuation presented significantly lower CFR values than those with low-PCAT CT attenuation (2.47 ± 0.95 vs. 3.13 ± 0.89, P = 0.003). Among those without obstructive CAD, CFR was significantly lower in patients with high-PCAT CT attenuation (2.51 ± 0.95 vs. 3.02 ± 0.84, P = 0.021). CONCLUSION: Coronary perivascular inflammation by CTA was independently associated with downstream myocardial perfusion by PET. In patients with low CCS or without obstructive CAD, CFR was lower in the presence of higher perivascular inflammation. PCAT CT attenuation might help identifying myocardial ischaemia particularly among patients who are traditionally considered non-high risk for future cardiovascular events.

Feasibility and safety of pulmonary vein isolation by high-power short-duration radiofrequency application: short-term results of the POWER-FAST PILOT study.

PURPOSE: Pulmonary vein (PV) isolation (PVI) by point-by-point radiofrequency application (PPRF) results in longer procedures than that achieved by single-shot ablation techniques. In addition, it is associated with significant risk of oesophageal injury. The POWER-FAST pilot study evaluated the feasibility and safety of PVI by high-power short-duration (HPSD) PPRF. METHODS: HPSD PPRF around the PVs was done in 48 consecutive patients with atrial fibrillation. Fifty watts was delivered until a predefined lesion index value was reached (LSI ≥ 5 or Abl-I ≥ 350) and 60 W during 7-10 s in the first 18 and last 30 patients, respectively. A control group of 47 consecutive patients who had undergone PVI before the HPSD group with conventional PPRF (30 W for 30 s) was included for reference. Echocardiography and oesophageal endoscopy was performed shortly after ablation in all patients. RESULTS: PVI of all targeted veins was achieved in 98% and 100% of patients of the conventional and HPSD groups, respectively (p = 0.59). Total radiofrequency time was 34 ± 11, 24 ± 8, and 15 ± 5 min in groups 30 W, 50 W, and 60 W (p < 0.001). Audible steam pops occurred in 4 out of 48 (8%) patients in the HPSD group, accounting for 4 (0.08%) out of 5 269 HPSD radiofrequency applications. No patient in the HPSD group developed pericardial effusion. The incidence of oesophageal lesions was 28%, 22%, and 0% in groups 30 W, 50 W, and 60 W, respectively (p = 0.007) CONCLUSIONS: PVI can be achieved with HPSD PPRF in most patients. This approach appears safe and associated with low risk of esophageal damage.

Clinical evaluation of left ventricular function and morphology using an accelerated k-t sensitivity encoding method in cardiovascular magnetic resonance.

OBJECTIVES: To provide clinical validation of a recent 2D SENSE-based accelerated cardiovascular magnetic resonance (CMR) sequence (accelerated k-t SENSE), investigating whether this technique accurately quantifies left ventricle (LV) volumes, function, and mass as compared to 2D cine steady-state free precession (2D-SSFP). METHODS: Healthy volunteers (n = 16) and consecutive heart failure patients (n = 26) were scanned using a 1.5 T MRI system. Two LV short axis (SA) stacks were acquired: (1) accelerated k-t SENSE (5-6 breath-holds; temporal/spatial resolution: 37 ms/1.82 × 1.87 mm; acceleration factor = 4) and (2) standard 2D-SSFP (10-12 breath-holds; temporal/spatial resolution: 49 ms/1.67 × 1.87 mm, parallel imaging). Ascending aorta phase-contrast was performed on all volunteers as a reference to compare LV stroke volumes (LVSV) and validate the sequences. An image quality score for SA images was used, with lower scores indicating better quality (from 0 to 18). RESULTS: There was a high agreement between accelerated k-t SENSE and 2D-SSFP for LV measurements: bias (limits of agreement) of 2.4% (- 5.4% to 10.1%), 6.9 mL/m2 (- 4.7 to 18.6 mL/m2), - 1.5 (- 8.3 to 5.2 mL/m2), and - 0.2 g/m2 (- 11.9 to 12.3 g/m2) for LV ejection fraction, end-diastolic volume index, end-systolic volume index, and mass index, respectively. LVSV by accelerated k-t SENSE presented good agreement with aortic flow. Interobserver and intraobserver variabilities for all LV parameters were also high. CONCLUSION: The accelerated k-t SENSE CMR sequence is clinically feasible and accurately quantifies LV volumes, function, and mass, with short acquisition time and good image quality.

Radiation dose reduction by adjusting bolus tracking parameters in a 320-detector row scanner.

BACKGROUND: The importance of bolus tracking (BT) regarding total effective radiation dose (ERD) in the era of advanced coronary computed tomography angiography (CTA) has been ignored. We aimed to investigate whether adjusting BT parameters reduces ERD. METHODS: Adults consecutively referred to CTA (n = 289) in a 320 detector-row scanner were distributed into four BT protocols according to delay time and time between intermittent scans, as follows: A (n = 70, delay 10s, intermittent scans 1s); B (n = 79, delay 10s, intermittent scans 2s); C (n = 68, delay 15s, intermittent scans 1s); and D (n = 72, delay 15s, intermittent scans 2s). Image quality was assessed. RESULTS: The overall ERD in BT and AP were 0.32 ±â€¯0.14 mSv and 6.06 ±â€¯0.66 mSv, respectively. ERD in BT was different among protocols (A:0.44 ±â€¯0.14 mSv; B:0.32 ±â€¯0.10 mSv; C:0.28 ±â€¯0.14 mSv; D:0.23 ±â€¯0.09 mSv; p < 0.001), with no loss in image quality. Adjusted for potential confounders (heart rate, tube current and acquisition window), protocol D provided the highest reduction in total ERD (ß = -0.33, p = 0.004). CONCLUSION: Delaying initiation of BT images (and acquiring them less frequently) reduces radiation dose and does not impair image quality.

Endoscopic submucosal injection of adipose-derived mesenchymal stem cells ameliorates TNBS-induced colitis in rats and prevents stenosis.

BACKGROUND: Mesenchymal stem cells have potential applications in inflammatory bowel disease due to their immunomodulatory properties. Our aim was to evaluate the feasibility, safety and efficacy of endoscopic administration of adipose-derived mesenchymal stem cells (ASCs) in a colitis model in rats. METHODS: Colitis was induced in rats by rectal trinitrobenzenesulfonic acid (TNBS). After 24 h ASCs (107 cells) or saline vehicle were endoscopically injected into the distal colon. Rats were followed for 11 days. Daily weight, endoscopic score at days 1 and 11, macroscopic appearance at necropsy, colon length and mRNA expression of Foxp3 and IL-10 in mesenteric lymph nodes (MLN) were analyzed. RESULTS: Endoscopic injection was successful in all the animals. No significant adverse events or mortality due to the procedure occurred. Weight evolution was significantly better in the ASC group, recovering initial weight by day 11 (- 0.8% ± 10.1%, mean ± SD), whereas the vehicle group remained in weight loss (- 6.7% ± 9.2%, p = 0.024). The endoscopic score improved in the ASC group by 47.1% ± 5.3% vs. 21.8% ± 6.6% in the vehicle group (p < 0.01). Stenosis was less frequent in the ASC group (4.8% vs. 41.2%, p < 0.01). Colon length significantly recovered in the ASC group versus the vehicle group (222.6 ± 17.3 mm vs. 193.6 ± 17.9 mm, p < 0.001). The endoscopic score significantly correlated with weight change, macroscopic necropsy score and colon length. Foxp3 and IL-10 mRNA levels in MLN recovered with ASC treatment. CONCLUSIONS: ASC submucosal endoscopic injection is feasible, safe and ameliorates TNBS-induced colitis in rats, especially stenosis.

Myocardial T1 mapping and extracellular volume quantification in patients with left ventricular non-compaction cardiomyopathy.

Aims: From pathophysiological mechanisms to risk stratification and management, much debate and discussion persist regarding left ventricular non-compaction cardiomyopathy (LVNC). This study aimed to characterize myocardial T1 mapping and extracellular volume (ECV) fraction by cardiovascular magnetic resonance (CMR), and investigate how these biomarkers relate to left ventricular ejection fraction (LVEF) and ventricular arrhythmias (VA) in LVNC. Methods and results: Patients with LVNC (n = 36) and healthy controls (n = 18) were enrolled to perform a CMR with T1 mapping. ECV was quantified in LV segments without late gadolinium enhancement (LGE) areas to investigate diffuse myocardial fibrosis. Patients with LVNC had slightly higher native T1 (1024 ± 43 ms vs. 995 ± 22 ms, P = 0.01) and substantially expanded ECV (28.0 ± 4.5% vs. 23.5 ± 2.2%, P < 0.001) compared to controls. The ECV was independently associated with LVEF (ß = -1.3, P = 0.001). Among patients without LGE, VAs were associated with higher ECV (27.7% with VA vs. 25.8% without VA, P = 0.002). Conclusion: In LVNC, tissue characterization by T1 mapping suggests an extracellular expansion by diffuse fibrosis in myocardium without LGE, which was associated with myocardial dysfunction and VA, but not with the amount of non-compacted myocardium.

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET.

OBJECTIVES: Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography (82RbPET) MPI. Thus, this study aimed to evaluate agreement between 82RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients. METHODS: Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software. RESULTS: There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv). CONCLUSIONS: There was a significant agreement between dipyridamole stress 320-CT MPI and 82RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure. KEY POINTS: • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

Late incidental diagnosis of intrapericardial teratoma - A case report. / Diagnóstico incidental tardio de teratoma intrapericárdico ­ relato de caso.

We report a case of intrapericardial teratoma, which is a rare primary cardiac tumor usually found in newborns and infants. Cardiac teratomas can cause respiratory failure, large accumulations of pericardial fluid and cardiac compression leading to death in the intrauterine or neonatal period. The case described is rare because it is of a 16-year-old asymptomatic girl with an intrapericardial tumor as an incidental echocardiographic finding. Cardiac magnetic resonance imaging showed a complex pericardial cyst. Due to the potential for malignant evolution, she was referred for surgery to remove the tumor and a diagnosis of teratoma was confirmed by histopathology. Clinical follow-up had a good outcome.

On the search of arterial geometry heritability.

BACKGROUND: Geometrical risk factors for CAD have been previously proposed before. To date, however, the effect of those factors is not conclusive, and remains as an open research field. Here, we hypothesize that some of these factors have a genetic component explaining inter-individual variability. OBJECTIVE: To detect heritability indicators of the coronary arterial geometry. MATERIALS AND METHODS: A patient sample of 48 individuals, consisting of 24 siblings, was used. Three dimensional geometry of the LAD, LCx and RCA were reconstructed from standard CCTA. Arterial models were characterized in terms of 20+ geometric descriptors (phenotypes). A comprehensive statistical analysis to detect potential heritability of such phenotypes was employed. Heritability was assessed by means of several statistical indexes. Finally, the association of phenotypes to stenotic lesion is also reported. RESULTS: The RCA scored positive indications for heritability in 15+ phenotypes, while the LAD in 10 and the LCx in only 3 phenotypes. Association between presence of lesion and phenotypes was higher in the LAD, 10+ phenotypes, while for the LCx only 2 phenotypes were significantly associated, and none association was found for the RCA. CONCLUSION: The RCA showed potential heritability for the largest number of phenotypes, followed by the LAD. The LCx presents the weaker association of morphology among siblings. Regarding lesion-geometry associations, the there are hints of an underlying relation in the LAD, the LCx featured a weaker association and the RCA showed none. This difference could be related to the different hemodynamic environments in these arteries.

Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block / Perfusão Miocárdica de Estresse com Dipiridamol por Tomografia Computadorizada em Pacientes com Bloqueio de Ramo Esquerdo

Abstract Background: Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective: To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Methods: Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee. Results: The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). Conclusion: The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

Resumo Fundamentos: Testes funcionais possuem limitada acurácia para identificar isquemia miocárdica em pacientes com bloqueio de ramo esquerdo (BRE). Objetivo: Utilizando tomógrafo com 320 detectores foi avaliado a acurácia diagnóstica da perfusão miocárdica de estresse com dipiridamol pela tomografia (PMT) em pacientes com BRE utilizando a angiografia coronária quantitativa invasiva (QCA) (estenose ≥ 70%) como referência. Procurou-se também investigar o valor adicional da PMT sobre a angiotomografia coronariana (ATC) comparando a acurácia com a cintilografia perfusional miocárdica (SPECT). Métodos: Trinta pacientes com BRE e SPECT prévio em investigação de doença arterial coronariana foram encaminhados para realização do protocolo de estresse na tomografia. Observadores independentes realizaram avaliação por paciente e por território coronariano. Todos os pacientes assinaram um termo de consentimento livre e esclarecido aprovado pelo Comitê de Ética da Instituição. Resultados: A média de idade foi 62 ± 10 anos. A dose média de radiação do protocolo de tomografia foi 9,3 ± 4,6 mSv. Em relação a PMT, na análise por paciente, a sensibilidade, especificidade, valores preditivos positivos e negativos e acurácia foram, respectivamente, 86%, 81%, 80%, 87%, 83% p = 0,001. Na análise por território os valores foram, respectivamente, 63%, 86% a 65%, 84%, 79% p < 0,001. Em ambas as análises, a adição da PMT a ATC determinou maior acurácia diagnóstica para detecção de isquemia miocárdica quando comparado com o SPECT (p < 0,001). Conclusão: O uso do protocolo de estresse na tomografia é viável e tem boa acurácia diagnóstica na pesquisa de isquemia miocárdica nos pacientes com BRE.

Myocardial tissue characterization in Chagas' heart disease by cardiovascular magnetic resonance.

BACKGROUND: Chagas' heart disease is an important public health problem in South America. Several aspects of the pathogenesis are not fully understood, especially in its subclinical phases. On pathology Chagas' heart disease is characterized by chronic myocardial inflammation and extensive myocardial fibrosis. The latter has also been demonstrated by late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR). In three clinical phases of this disease, we sought to investigate the presence of LGE, myocardial increase in signal intensity in T2-weighted images (T2W) and in T1-weighted myocardial early gadolinium enhancement (MEGE), previously described CMR surrogates for myocardial fibrosis, myocardial edema and hyperemia, respectively. METHODS: Fifty-four patients were analyzed. Sixteen patients with the indeterminate phase (IND), seventeen patients with the cardiac phase with no left ventricular systolic dysfunction (CPND), and twenty-one patients with the cardiac phase with left ventricular systolic dysfunction (CPD). All patients underwent 1.5 T CMR scan including LGE, T2W and MEGE image sequences to evaluate myocardial abnormalities. RESULTS: Late gadolinium enhancement was present in 72.2 % of all patients, in 12.5 % of IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001). Myocardial increase in signal intensity in T2-weighted images (T2W) was present in 77.8 % of all patients, in 31.3 % of the IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001). T1-weighted myocardial early gadolinium enhancement (MEGE) was present in 73.8 % of all patients, in 25.0 % of the IND, 92.3 % of the CPND and 94.1 % of the CPD (p < 0.0001). A good correlation between LGE and T2W was observed (r = 0.72, and p < 0.001). CONCLUSIONS: Increase in T2-weighted (T2W) myocardial signal intensity and T1-weighted myocardial early gadolinium enhancement (MEGE) can be detected by CMR in patients throughout all phases of Chagas' heart disease, including its subclinical presentation (IND). Moreover, those findings were parallel to myocardial fibrosis (LGE) in extent and location and also correlated with the degree of Chagas' heart disease clinical severity. These findings contribute to further the knowledge on pathophysiology of Chagas' heart disease, and might have therapeutic and prognostic usefulness in the future.