A review of the anatomy of the middle cerebral artery for the era of thrombectomy: A radiologic tool based on CT angiography and perfusion CT.

The middle cerebral artery (MCA) is one of the principal intracranial vessels. It is also the one that is most often involved in ischemic cerebrovascular disease, which accounts for a significant volume of brain imaging tests. With recent updates in the management of ischemic stroke (including intravascular treatment in increasingly distal vessels and in an increasingly widening spectrum of patients), it is becoming more important to know the details of the cerebral vascular anatomy to reach accurate diagnoses quickly and thereby improve patients' prognoses. For these reasons, we present this anatomic review of the MCA, reviewing its segments and anatomic limits, its branching patterns, and its anatomic variants. We also provide a radiologic tool based on correlations between CT angiography and perfusion CT to facilitate the identification of the points of occlusion within the branches of the MCA, taking into account its different variants.

A review of the anatomy of the middle cerebral artery for the era of thrombectomy: a radiologic tool based on CT angiography and perfusion CT. / Repaso anatómico de la arteria cerebral media en la era de la trombectomía: una herramienta radiológica basada en la angio-TC y la TC perfusión.

The middle cerebral artery (MCA) is one of the principal intracranial vessels. It is also the one that is most often involved in ischemic cerebrovascular disease, which accounts for a significant volume of brain imaging tests. With recent updates in the management of ischemic stroke (including intravascular treatment in increasingly distal vessels and in an increasingly widening spectrum of patients), it is becoming more important to know the details of the cerebral vascular anatomy to reach accurate diagnoses quickly and thereby improve patients' prognoses. For these reasons, we present this anatomic review of the MCA, reviewing its segments and anatomic limits, its branching patterns, and its anatomic variants. We also provide a radiologic tool based on correlations between CT angiography and perfusion CT to facilitate the identification of the points of occlusion within the branches of the MCA, taking into account its different variants.

Pulmonary embolisms in patients with COVID-19: a prevalence study in a tertiary hospital. / Tromboembolismo pulmonar en pacientes con COVID-19: estudio de prevalencia en un hospital terciario.

INTRODUCTION: SARS-CoV-2, the virus responsible for the current pandemic, predominantly affects the respiratory tract, and a growing number of publications report the predisposition of patients with COVID-19 to develop thrombotic phenomena. OBJECTIVE: To determine the prevalence of pulmonary embolism in patients with COVID-19; to determine the possible relationship between the severity of pulmonary involvement and D-dimer levels; to analyze the location of pulmonary embolisms in patients with COVID-19 and to compare it with the location in patients without COVID-19. METHODS: This retrospective study analyzed all CT angiograms of the pulmonary arteries done in patients with suspected pulmonary embolisms between March 15 and April 30, 2020 and compared them with studies done in the same period one year earlier. RESULTS: We included 492 pulmonary CT angiograms (342 (69.9%) in patients with COVID-19 and 147 (30.1%) in patients without COVID-19). The prevalence of pulmonary embolisms was higher in patients with COVID-19 (26% vs. 16.3% in patients without COVID-19, p=0.0197; relative risk=1.6). The prevalence of pulmonary embolisms in the same period in 2019 was 13.2%, similar to that of the group of COVID-19-negative patients in 2020 (p=0.43). There were no significant differences in D-dimer levels or the location of pulmonary embolisms between the two groups. CT showed moderate or severe pulmonary involvement in 78.7% of the patients with COVID-19. CONCLUSIONS: Patients with COVID-19 have an increased prevalence of pulmonary embolisms (26%), and most (78.7%) have moderate or severe lung involvement on CT studies. The location of pulmonary embolisms and the degree of elevation of D-dimer levels does not differ between patients with COVID-19 and those without.

Clinical and radiological diagnosis of pulmonary thromboembolism. / Diagnóstico clínico y radiológico de la tromboembolia de pulmón.

Pulmonary thromboembolism has poorly specific clinical symptomatology, which increases the diagnostic suspicion, multiplying the number of patients who will need to undergo imaging tests to confirm the diagnosis. In recent years, pulmonary angiography using multidetector scanners (CT angiography) has been the most widely used imaging test due to its availability and accuracy, which exceeds that of lung ventilation-perfusion (V/Q) scintigraphy. However, CT angiography is not without risks and is also expensive. Its use should therefore be restricting without reducing the diagnostic efficacy, given its enormous prognostic importance and implication. We therefore need to base our approach on previously validated strategies that, taking into account the clinical probability and using highly sensitive diagnostic tests such as D-dimer, will enable us to exclude many patients from undergoing this imaging test. In this article, we review the diagnostic techniques and strategies that are applied for diagnosing pulmonary thromboembolism in hemodynamically stable and unstable outpatients, hospitalised patients, patients with a history of venous thromboembolism and pregnant women.

Additional cardiac investigation prior to the introduction of the CAD-RADS classification in coronary computed tomography angiography reports.

INTRODUCTION: The CAD-RADSTM classification was recently introduced in an attempt to standardize coronary computed tomography angiography (CCTA) reports and to provide recommendations for further management. The aim of this study was to assess how additional cardiac investigations were being ordered before the introduction of the CAD-RADS classification in a tertiary hospital's CCTA reports. METHODS: We conducted a single-center retrospective analysis of 200 patients (103 women, mean age 59±13 years) who underwent CCTA for suspected or known coronary artery disease prior to the systematic introduction of the CAD-RADS classification in the reports. For each case, we assessed whether further cardiac investigation was requested after CCTA and what type of test was performed (functional testing, invasive coronary angiography or viability testing). RESULTS: The majority of patients (n=158; 79%) were classified as CAD-RADS 0-2. In patients with lower (0-2) or higher (4 or 5) scores, further testing was in accordance with CAD-RADS recommendations in 98% of cases (n=168). In patients with CAD-RADS 3 (intermediate stenosis), functional testing was requested as recommended in only 36% of cases (n=5), while 50% (n=7) proceeded directly to invasive coronary angiography. In patients in whom CCTA was non-diagnostic, most did not undergo further cardiac investigation. CONCLUSION: In patients with CAD-RADS classifications at the ends of the spectrum, additional cardiac investigation after CCTA was almost always in accordance with the recommendations. However, in patients with intermediate scores, invasive coronary angiography prevailed over functional testing.

Imaging techniques used in the diagnostic workup of acute venous thromboembolic disease. / Técnicas de imagen diagnósticas empleadas en la presentación aguda de la enfermedad tromboembólica venosa.

Early diagnosis is one of the most important factors affecting the prognosis of pulmonary embolism (PE); however, the clinical presentation of PE is often very unspecific and it can simulate other diseases. For these reasons, imaging tests, especially computed tomography angiography (CTA) of the pulmonary arteries, have become the keystone in the diagnostic workup of PE. The wide availability and high diagnostic performance of pulmonary CTA has led to an increase in the number of examinations done and a consequent increase in the population's exposure to radiation and iodinated contrast material. Thus, other techniques such as scintigraphy and venous ultrasonography of the lower limbs, although less accurate, continue to be used in certain circumstances, and optimized protocols have been developed for CTA to reduce the dose of radiation (by decreasing the kilovoltage) and the dose of contrast agents. We describe the technical characteristics and interpretation of the findings for each imaging technique used to diagnose PE and discuss their advantages and limitations; this knowledge will help the best technique to be chosen for each case. Finally, we comment on some data about the increased use of CTA, its clinical repercussions, its "overuse", and doubts about its cost-effectiveness.

Diagnosis of gynecological pseudoaneurysms and embolization with cyanoacrylate. / Diagnóstico y embolización con cianoacrilato de pseudoaneurismas de origen ginecológico.

Pseudoaneurysms of the uterine artery are an uncommon cause of severe gynecological bleeding secondary to surgical manipulation of the pelvis or to instrumental delivery. The different imaging techniques are of vital importance in the diagnosis. Angiography is the technique used for confirmation and also for treatment in many cases. Endovascular treatment by embolizing the pseudoaneurysm has become established as the treatment of choice, making it possible to avoid hysterectomy in women of childbearing age. This article presents two cases of gynecological bleeding due to pseudoaneurysms (one secondary to surgery and one secondary to childbirth) that were embolized in a novel way using cyanoacrylate.

Recent Scientific Evidence and Technical Developments in Cardiovascular Computed Tomography.

In recent years, coronary computed tomography angiography has become an increasingly safe and noninvasive modality for the evaluation of the anatomical structure of the coronary artery tree with diagnostic benefits especially in patients with a low-to-intermediate pretest probability of disease. Currently, increasing evidence from large randomized diagnostic trials is accumulating on the diagnostic impact of computed tomography angiography for the management of patients with acute and stable chest pain syndrome. At the same time, technical advances have substantially reduced adverse effects and limiting factors, such as radiation exposure, the amount of iodinated contrast agent, and scanning time, rendering the technique appropriate for broader clinical applications. In this work, we review the latest developments in computed tomography technology and describe the scientific evidence on the use of cardiac computed tomography angiography to evaluate patients with acute and stable chest pain syndrome.

Factors associated with in-hospital delays in treating acute stroke with intravenous thrombolysis in a tertiary centre. / Identificación de los factores que influyen en el retraso intrahospitalario del inicio de trombólisis intravenosa en el ictus agudo en un hospital terciario.

OBJECTIVE: This study aims to determine which factors are associated with delays in door-to needle (DTN) time in our hospital. This will help us design future strategies to shorten time to treatment with intravenous thrombolysis (IVT). METHODS: Retrospective analysis of a prospective cohort of patients with ischaemic stroke treated with IVT in our hospital between 2009 and 2012. We analysed the relationship between DTN time and the following variables: age, sex, personal medical history, onset-to-door time, pre-hospital stroke code activation, blood pressure and blood glucose level, National Institutes of Health Stroke Scale (NIHSS), computed tomography angiography (CTA) and/or doppler/duplex ultrasound (DUS) performed before IVT, time to hospital arrival, and day of the week and year of stroke. RESULTS: Our hospital treated 239 patients. Median time to treatment in minutes (IQR): onset-to-door, 84 (60-120); door-to-CT, 17 (13-24.75); CT-to needle, 34 (26-47); door-to-needle, 52 (43-70); onset-to-needle, 145 (120-180). Door-to-needle time was significantly shorter when code stroke was activated, at 51 vs. 72min (P=0.008), and longer when CTA was performed, at 59 vs. 48.5min (P=0.004); it was also longer with an onset-to-door time<90min, at 58 vs. 48min (P=0.003). The multivariate linear regression analysis detected 2 factors affecting DTN: code stroke activation (26.3% reduction; P<0.001) and onset-to-door time (every 30min of onset-to-door delay corresponded to a 4.7min increase in DTN time [P=0.02]). On the other hand, CTA resulted in a 13.4% increase in DTN (P=0.03). No other factors had a significant influence on door-to-needle time. CONCLUSIONS: This study enabled us to identify CTA and the «3-hour effect¼ as the 2 factors that delay IVT in our hospital. In contrast, activating code stroke clearly reduces DTN. This information will be useful in our future attempts to reduce door-to-needle times.

Performance of traditional risk factors in identifying a higher than expected coronary atherosclerotic burden.

OBJECTIVE: To evaluate the performance of traditional cardiovascular (CV) risk factors in identifying a higher than expected coronary atherosclerotic burden. METHODS: We assessed 2069 patients undergoing coronary CT angiography, with assessment of calcium score (CS), for suspected coronary artery disease. A higher than expected atherosclerotic burden was defined as CS >75th percentile (CS >P75) according to age and gender-adjusted monograms. The ability of traditional CV risk factors to predict a CS >P75 was assessed in a customized logistic regression model ("Clinical Score") and by the calculation of SCORE (Systemic Coronary Risk Evaluation). The population attributable risk (PAR) of risk factors for CS >P75 was calculated. RESULTS: The median CS was 3.0 (IQR 0.0-98.0); 362 patients had CS >P75. The median SCORE was 3.0 (IQR 1.0-4.0). With the exception of hypertension, all traditional CV risk factors were independent predictors of CS >P75: diabetes, dyslipidemia, smoking and family history (OR 1.3-2.2, p≤0.026). The areas under the ROC curves for CS >P75 were 0.64 for the Clinical Score (95% CI 0.61-0.67, p<0.001) and 0.53 for SCORE (95% CI 0.50-0.56, p=0.088). About a quarter of patients with CS >P75 were in the two lower quartiles of the Clinical Score. Altogether, the traditional risk factors explain 56% of the prevalence of CS >P75 (adjusted PAR 0.56). CONCLUSION: Despite the association of CV risk factors with a higher than expected atherosclerotic burden, they appear to explain only half of its prevalence. Even when integrated in scores, the predictive power of these risk factors was modest, exposing the limitations of risk stratification based solely on demographic and clinical risk factors.

[SPECT, coronary angio-CT, invasive coronary angiography and fusion images in stable coronary disease]. / SPECT, angio-TC coronaria, coronariografía invasiva e imágenes de fusión en la cardiopatía isquémica estable.

OBJECTIVES: To evaluate the usefulness of the information obtained with SPECT, coronary angio-CT and fusion images, in patients with stable ischemic disease who need invasive coronary angiography (IA). MATERIAL AND METHODS: Forty-six patients (65.98±8.3 years) with coronary disease were prospectively included. The fusion images generated after undergoing IA were used to evaluate the performance of these techniques in the diagnosis of multi-vessel coronary disease, the detection of the culprit vessel and the therapeutic management of these patients. RESULTS: In the IA, 29 of the 46 patients (63%) had multi-vessel disease. SPECT could detect it in 48.2% and coronary angio-CT could detect it in 89.6%. Concordance between coronary angio-CT and IA in the diagnosis of the culprit vessel was 77% (kappa 0.6), and between SPECT and IA it was 73% (kappa 0.56). Although fusion images could have been obtained prior to IA, they would not have changed the therapeutic approach derived from SPECT and IA. CONCLUSIONS: Coronary angio-CT has a high ability for the diagnosis of multi-vessel disease and the culprit lesion, and SPECT is a good functional complement of the IA in the detection of the most ischemic territory. However, the performance of fusion images in patients with stable ischemic disease, who have undergone a SPECT as the first non-invasive study and need IA, does not seem indicated because they would not have changed the therapeutic management derived from SPECT and IA information.

Role of cardiac multidetector computed tomography in the exclusion of ischemic etiology in heart failure patients.

INTRODUCTION AND AIMS: Differentiation of ischemic from non-ischemic etiology in heart failure (HF) patients has both therapeutic and prognostic implications. One possible approach to this differentiation is direct visualization of the coronary tree. Multidetector computed tomography (MDCT) has emerged as an alternative to invasive coronary angiography (ICA), but its performance and additional clinical value are still not well validated in patients with left ventricular (LV) dysfunction. We aimed to assess the value of coronary MDCT angiography (CTA) in the exclusion of ischemic etiology in HF patients and to determine whether the Agatston calcium score could be used as a gatekeeper for CTA in this context. METHODS: We retrospectively selected symptomatic HF patients with LV ejection fraction (LVEF) <50%, as assessed by echocardiography, referred for CTA between April 2006 and May 2013. Patients with previously known CAD or valvular disease were excluded. The performance of MDCT in the detection of coronary artery disease (CAD) and/or exclusion of an ischemic etiology for HF was studied. Obstructive CAD was defined as the presence of ≥50% luminal stenosis in at least one epicardial coronary artery as assessed by CTA and was assumed in patients with an Agatston coronary artery calcium (CAC) score >400. In patients referred for ICA, an ischemic etiology was assumed in the presence of ≥75% stenosis in two or more epicardial vessels or ≥75% stenosis in the left main or proximal left anterior descending artery. RESULTS: During this period 100 patients (mean age 57.3±10.5 years, 64% men) with HF and systolic dysfunction were referred for MDCT to exclude CAD. Median effective radiation dose was 4.8 mSv (interquartile range 5.8 mSv). Mean LVEF was 35±7.7% (range 20-48%) and median CAC score was 13 (interquartile range 212). Seven patients were in atrial fibrillation. Almost half of the patients (40%) had no CAC and none of these had significant stenosis on CTA. In an additional group of 33 patients CTA was able to confidently exclude obstructive CAD. Twenty-seven patients were classified as positive for CAD (16 due to CAC >400 and 11 with ≥50% stenosis) and were associated with lower LVEF (p=0.004). Of these, 21 patients subsequently underwent ICA: obstructive CAD was confirmed in nine and only six had criteria for ischemic cardiomyopathy. CONCLUSION: In our HF population, MDCT was able to exclude an ischemic etiology in 73% of cases in a single test. According to our results the Agatston calcium score may serve as a gatekeeper for CTA in patients with HF, with a calcium score of zero confidently excluding an ischemic etiology.

Large artery occlusion diagnosed by computed tomography angiography in acute ischaemic stroke: frequency, predictive factors, and safety.

INTRODUCTION: Demonstrating artery occlusion in ischaemic stroke has gained importance due to the increasing availability of endovascular therapies. This study evaluates the frequency of artery occlusion, its associated factors, and complications following the use of CT-angiography in acute stroke. METHODS: We retrospectively analysed a cohort of patients who suffered acute ischaemic stroke between July and-December 2011. RESULTS: We included 157 patients (mean age, 74±11; mean NIHSS score, 5 [2-13]). Of that total, 56.7% of the patients were admitted to hospital during the first 8hours. CT-angiography was performed in 71 cases (45.2%); arterial large-vessel occlusion was detected in 37 (52.1%) of these cases, and the most frequent site was M1 (40%). Univariate analysis showed that the NIHSS score (17 vs 7, P<.001) and atrial fibrillation (64% vs 32%, P=.006) were associated with artery occlusion. A logistic regression analysis was performed subsequently, confirming these associations. There were no cases of contrast-induced nephropathy. Door-to-needle time for intravenous thrombolysis was 61.2±24.5minutes in patients who underwent CT-angiography, and 53.5±34.3minutes in those who did not (P=.495). CONCLUSIONS: Arterial occlusions are seen in 23.6% of patients, especially in those who are admitted during the first few hours. NIHSS score serves as a useful predictive factor.

Active extravasation of contrast within the hemorrhage (spot sign): a multidetector computed tomography finding that predicts growth and a worse prognosis in non-traumatic intracerebral hemorrhage / Extravasamento ativo de contraste no interior da hemorragia (spot sign): um achado de TCMD que prediz crescimento e pior prognostico nas hemorragias intraparenquimatosas cerebrais nao traumaticas

Intracerebral hemorrhage (ICH) causes high rates of disability and neurological sequelae Objective To evaluate spot signs as predictors of expansion and worse prognosis in non-traumatic ICH in a Brazilian cohort. Method We used multidetector computed tomography angiography to study 65 consecutive patients (40 men, 61.5%), with ages varying from 33 to 89 years (median age 55 years). Clinical and imaging findings were correlated with the findings based on the initial imaging. Results Of the individuals who presented a spot sign, 73.7% died (in-hospital mortality), whereas in the absence of a spot sign the mortality rate was 43.0%. Although expansion of ICH was detected in 75% of the patients with a spot sign, expansion was observed in only 9.0% of the patients who did not present a spot sign. Conclusions The spot sign strongly predicted expansion in non-traumatic ICH and an increased risk of in-hospital mortality. .

A hemorragia intraparenquimatosa cerebral (HIC) apresenta altas taxas de incapacidade e sequela neurológica. Objetivo Avaliar a presença de spot sign como preditor de expansão e pior prognóstico no follow-up de HIC não-traumática em brasileiros. Método Usamos a ângio-tomografia para estudar prospectivamente 65 pacientes consecutivos (40 homens 61,5%), com idades variando de 33 a 89 anos (mediana 55 anos). Evolução clínica e achados de imagem foram correlacionados com a interpretação dos achados do exame inicial. Resultados 73,7% dos indivíduos com spot sign no estudo tomográfico inicial evoluíram para óbito e, na sua ausência, a taxa de mortalidade foi 43,0%. Enquanto a expansão da HIC foi detectada em 75% dos pacientes com spot sign, ela foi notada em 9% daqueles sem este sinal. Conclusão O spot sign mostrou-se forte preditor de expansão da HIC não traumática e representa maior risco de morte hospitalar nesta coorte de pacientes. .

Estudio vascular renal por TC multidetector de 64 canales / 64-Multidetector row CT for the Renal Vascular Study

Objetivo: Mostrar las diversas variantes anatómicas vasculares tanto arteriales como venosas en el estudio angiográfico renal por tomografìa computada multidetector (TCMD) de 64 canales, dada su implicancia en un eventual planeamiento quirúrgico. Material y métodos: Evaluamos retrospectivamente 26 estudios realizados con tomógrafo Philips Brilliance de 64 canales. Se obtuvieron secuencias sin contraste y postcontraste e.v. en fases arterial y venosa, administrado con bomba inyectora doble cabezal. Para una fase arterial apropiada se utilizó técnica de bolus track. Las imágenes fueron posteriormente procesadas en Workstation Philips Brilliance 190P en un tiempo promedio de 30 minutos y reconstruidas con técnicas MIP y volumétrica. Resultados: Dentro de las variantes anatómicas arteriales, encontramos: bifurcaciones prehiliares (n=3), arterias accesorias (n=4) y arterias polares (n=9). Dentro de las variantes venosas fueron halladas: venas renales múltiples (n=5), venas circumaórticas (n=2), retroaórticas (n=2) y vena tributaria lumbar prominente (n=1). Conclusión: El estudio vascular renal adquiere importancia en el planeamiento quirúrgico en casos de nefrectomías parciales, laparoscópicas y en el transplante renal. Esto otorga suma utilidad al estudio de TCMD de 64 canales por su eficacia diagnóstica, dada la alta calidad de las reconstrucciones obtenidas, llegando a igualar a la angiografía digital, sin ser un método invasivo.

Purpose: To show the wide range of anatomical vascular variants, arterial and venous, that can be seen in the angiographic renal study using 64-multidetector-row computed tomography (64-MDCT), due to its importance in an eventual surgical planning. Material and Methods: We have evaluated retrospectively 26 studies that have been done using a 64 channels Philips Brilliance CT scanner. We have obtained non enhanced and both in arterial and venous enhanced sequences. For the injection of the contrast material we have used a double head injector bomb. The arterial phase was acquired using the bolus track technique. The raw data has then been post processed in a 190P Philips Brilliance workstation in a mean time of 30 minutes. The reconstructions have been obtained both with MIP and volumetric technique. Conclusion: The renal vascular study has importance for the surgical planning in cases of parcial nephrectomies or laparoscopic nephrectomies as well as in renal transplant. This makes the 64-MDCT a very useful non invasive imaging tool due to its high accuracy similar to digital angiography.