Alvaro Huete

Primary Aldosteronism and Hypertensive Disease

Abstract—Recent studies in hypertensive populations that have used the serum aldosterone (SA) to plasma renin activity (PRA) ratio as a screening test have demonstrated a high prevalence of primary aldosteronism (PA). This frequency is higher than that previously described when hypokalemia was used as a screening tool. However, other factors, such as the characteristics of hypertensive disease, could also influence the prevalence of PA. We studied 609 essential hypertensive patients, classified according to the Joint National Committee VI (JNC VI), in 3 different stages depending on the severity of their hypertensive disease. We measured SA and PRA and calculated the SA-PRA ratio for all patients. An SA-PRA ratio >25 was detected in 63 of 609 patients, and the fludrocortisone test confirmed the PA diagnoses in 37 of 609 (6.1%) cases. PA prevalence according to hypertension stage was as follows: stage 1, 6 of 301 cases (1.99%); stage 2, 15 of 187 cases (8.02%); and stage 3, 16 of 121 cases (13.2%). PA patients were slightly younger than the other hypertensive patients (48.4±10.5 vs 53.6±10.2 years; P <0.05). Serum potassium levels were normal in 36 of 37 PA patients; only 1 patient had minor hypokalemia. Computed tomography scans showed bilateral adrenal enlargement in 7 and an adrenal nodule in 2 cases. In summary, we found a high frequency of PA in essential hypertensives classified in stages 2 and 3 according to the JNC VI. The low frequency of computed tomography scan abnormalities and hypokalemia suggests that the diagnosis for most PA patients corresponds to attenuated forms of the disease.

Gastric Cancer after Roux-en-Y Gastric Bypass

Roux-en-Y gastric bypass (RYGBP) is one of the most commonly performed surgical procedures for morbid obesity. Several complications that may develop in the short- and long-term have been reported. We present a patient who presented with cancer in the bypassed stomach 8 years after RYGBP. Although the development of this lesion is rare and only a few cases have been reported, there are aspects worthy of discussion. Several monitoring, diagnostic and therapeutic alternatives are analyzed.

Portal biliopathy: a multitechnique imaging approach

Portal biliopathy (PB) is a disorder characterized by biliary ductal and gallbladder wall abnormalities seen in patients with extrahepatic portal vein obstruction. These abnormalities consist mainly of bile duct compression and tethering, stenoses, fibrotic strictures and dilatation of both extrahepatic and intrahepatic bile ducts, as well as gallbladder varices. In this pictorial essay, we describe the imaging findings of PB, which allow differentiation of this entity from other diseases that may have similar imaging findings including cholangiocarcinoma, extrinsic compression of the bile duct caused by metastatic adenopathy or sclerosing cholangitis.

Incidental venous thromboembolism detected by PET-CT in patients with cancer: Prevalence and impact on survival rate

INTRODUCTION People with cancer are at increased risk of incidental venous thromboembolism (VTE) and PET-CT imaging is commonly used in this population. However, the prevalence of incidental VTE detected by PET-CT in patients with cancer and its impact on survival are unknown. MATERIALS AND METHODS This retrospective study was approved by the local Institutional Review Board. 1331 consecutive adult patients with cancer who underwent PET-CT examination between 2009 and 2012 were included in the study (mean age: 57 ± 15 years). PET-CT reports were reviewed to identify patients with incidental VTE at the time of examination. Survival rates were assessed with Kaplan-Meier curves. The Cox proportional hazards model was used to determine the association between incidental VTE and overall survival, after controlling for clinical variables. RESULTS Incidental VTE was detected in 19 patients (1.4%). Patients with genitourinary malignancies, colorectal cancer and lung cancer had the highest rates of incidental VTE at PET-CT. At multivariate analysis, incidental VTE detected by PET-CT was associated with worse overall survival independently of patient age, hospitalization status at time of PET-CT examination, and the presence of metastatic disease (Hazard ratio=2.03; 95% confidence interval=1.08-3.81, p=0.028). CONCLUSION Incidental VTE was detected in 1.4% of adult patients with cancer undergoing PET-CT imaging. Diagnosis of incidental VTE at PET-CT imaging was associated with worse overall survival in this population.

Multimodality Imaging of Liver Infections: Differential Diagnosis and Potential Pitfalls

Imaging plays an important role in the diagnosis, characterization, and management of infectious liver disease. In clinical practice, the main contributions of imaging are in detecting early disease, excluding other entities with a similar presentation, establishing a definitive diagnosis when classic findings are present, and guiding appropriate antimicrobial, interventional, or surgical treatment. The most common imaging features of bacterial, viral, parasitic, and fungal hepatic infections are described, and key imaging and clinical manifestations are reviewed that may be useful to narrow the differential diagnosis and avoid pitfalls in image interpretation. Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging allow accurate detection of most hepatic infections and, in some circumstances, may provide specific signs to identify the underlying pathogen and exclude other entities with similar imaging features. In bacterial and parasitic infections, specific imaging features may be enough to exclude a neoplasm and, occasionally, to identify the underlying infectious agent. US and CT are important means to guide percutaneous aspiration or drainage when needed. In viral infections, imaging is critical to exclude entities that may manifest with similar clinical and laboratory findings. Disseminated fungal infections require early detection at imaging because they can be fatal if not promptly treated. Familiarity with the epidemiology, pathogenesis, clinical manifestations, imaging features, and treatment of hepatic infections can aid in radiologic diagnosis and guide appropriate patient care. (©)RSNA, 2016.

Rendimiento de la colangiografía por resonancia magnética en el diagnóstico de coledocolitiasis

Magnetic resonance cholangiopancreatography MRCP) is a non-invasive diagnostic method for choledocholithiasis. Aim: To evaluate the results of MRCP in the diagnosis of choledocholithiasis. Patients and methods: Retrospective review of MRCP reports performed between October 2001 and December 2004. We included patients with suspected choledocholithiasis who were studied with MRCP and some other confirmatory test such as endoscopic retrograde cholangiopancreatography ERCP), surgical common bile duct exploration or transcystic colangiography TC). Results: One hundred and twenty five patients aged 58±20 years 70 females) were included. In 54 patients 43%) we compared the results of MRCP with the findings of surgical common bile duct exploration or TC and in 71 57%) we did so with ERCP. MRCP suggested choledocholithiasis in 93 patients and in 32 it was negative. Eighty six 67%) patients had choledocholithiasis according to TC or ERCP, including 3 patients who had a negative MRCP. Therefore the sensibility was 97%, specificity 74% positive predictive value 89%, negative predictive value 90% and accuracy of MRCP was 90% for the diagnosis of choledocholithiasis. Conclusions: MRCP has a high accuracy for the diagnosis of choledocholithiasis

Imaging of Hydatid Disease with a Focus on Extrahepatic Involvement

Hydatid disease (HD) is a parasitic infection caused by the larvae of a tapeworm that is endemic to many regions around the world-South America, Africa, and Asia, in particular. Humans are infected as intermediate hosts in the parasites life cycle; thus, HD can be seen in persons living in areas where animal husbandry is practiced. However, owing to the varied patterns of migration and immigration during the past several decades, HD can be diagnosed in individuals living anywhere. The liver is the most common organ involved, with hepatic HD accounting for the majority of published cases. However, HD can affect multiple organs and tissues other than the liver, including the spleen, kidneys, lungs, heart, peritoneum, muscles, and brain. Knowledge of the route of spread, clinical findings at presentation, and possible complications involving each extrahepatic location can be useful for the radiologist when evaluating imaging findings in patients suspected of having HD. The ultrasonographic, computed tomographic, and magnetic resonance imaging findings of extrahepatic hydatid lesions frequently simulate those of hepatic HD, as long as rupture, bleeding, and/or superimposed bacterial infection has not occurred. Specific features of HD seen at different extrahepatic sites can help tailor the diagnosis. The differential diagnoses that can mimic HD at every nonhepatic location should be considered, as many of these entities are common, especially in nonendemic areas. ©RSNA, 2017.

Resonancia magnética cardíaca con perfusión stress: Utilidad clínica y relación con coronariografía convencional

Resumen: Introduccion: La resonancia magnetica cardiaca (RMC) es una herramienta no invasiva, libre de radia-cion que permite una evaluacion global del corazon. Una de las potencialidades son los estudios de perfu-sion miocardica con stress. Objetivo: Presentar nuestra experiencia de RMC con stress (RMCS) su correlacion con la coronariografia convencional (CC) y su relacion con eventos clinicos. Metodo: En forma prospectiva se incluyeron en un re-gistro todos los pacientes sometidos a RMCS en nues-tro servicio entre Enero 2007 y Abril 2009.Todos los pacientes fueron sometidos a RMCS anali-zando anatomia, estructura, funcion global y segmen-taria, perfusion stress/reposo y viabilidad miocardica. Los examenes fueron realizados en resonadores 1.5 T, en apnea de ± 10 segundos, con gatilleo ECG retros-pectivo y con uso de Gadolinio endovenoso para las fases de perfusion y viabilidad El estudio de stress se realizo con inyeccion de adenosina ev (140ug/kg/min) tras lo cual se adquirieron las imagenes y comparadas con la fase de reposo. El estudio de viabilidad se realizo a continuacion de la fase de reposo. Se consideraron como RMCS positivas aquellas con areas de hipoper-fusion en stress que se recuperaron en reposo. En aque-llos pacientes que fueron sometidos a CC dentro de los 3 meses de realizado la RMCS, se realizo correlacion entre ambos metodos, considerando presencia y loca-lizacion de la enfermedad coronaria. Se consideraron significativas las lesiones ≥70% de estenosis luminal.

The boundaries of mild chronic obstructive pulmonary disease (COPD): design of the searching clinical COPD onset (SOON) study

Introduction Clinical onset of chronic obstructive pulmonary disease (COPD) is the point at which the disease is first identifiable by physicians. It is a poorly defined stage which seems to include both mild spirometric and non-spirometric disease, and could be described as early grade COPD, for practical purposes. While dyspnoea; chronic bronchitis and CT imaging evidence of emphysema and airway disease may be present very early, the lone significance of dyspnoea, the most relevant symptom in COPD in identifying these individuals, has been scarcely assessed. The Searching Clinical COPD Onset (SOON) Study was designed primarily to detect clinical, physiological and structural differences between dyspnoeic and non-dyspnoeic individuals with early grade COPD. It is hypothesised that presence of dyspnoea in early disease may identify a subtype of individuals with reduced exercise capacity, notwithstanding of their spirometry results. In addition, dyspnoeic individuals will share worse quality of life, lower physical activity, greater lung hyperinflation greater emphysema and airway thickness and reduced peripheral muscle mass than their non-dyspnoeic counterpart. Methods and analysis SOON is a monocentric study, with a cross sectional design aimed at obtaining representative samples of current or ex-smoker-adults aged ≥45 and ≤80 years. Two hundred and forty participants will be enrolled into four strata, according to normal spirometry or mild spirometric obstruction and presence or not of dyspnoea modified Medical Research Council score ≥1. The primary outcome will be the difference between dyspnoeic and non-dyspnoeic individuals on the 6-min walk test performance, regardless of their spirometry results. To account for the confounding effect of heart failure on dyspnoea, stress echocardiography will be also performed. Secondary outcomes will include clinical (quality of life, physical activity), physiological (exercise testing) and structural characteristics (emphysema, airway disease and peripheral muscle mass by CT imaging). Ethics and dissemination The Institutional Ethics Committee from Pontificia Universidad Católica de Chile has approved the study protocol and signed informed consent will be obtained from all participants. The findings of the trial will be disseminated through relevant peer-reviewed journals and international conference presentations. Trial registration number NCT03026439.

Resonancia magnética cardíaca (RMC) en miocardiopatías

La no compactacion del VI (VINC) es una patologia estructural congenita que se produce por la detencion del proceso normal de coalescencia de las trabeculas durante la embriogenesis. Este proceso de “compactacion” ocurre normalmente desde la base hacia el apex del ventriculo y desde el septum hacia la cara lateral. Desde el punto de vista imagenologico, una relacion entre la zona no compactada y la compactada >2:1, y la presencia de profundos recesos inter-trabeculares, son criterios diagnosticos. El VINC es una entidad de reciente reconocimiento, cuyo diagnostico ha ido en aumento con el desarrollo de tecnicas de imagen de alta resolucion espacial, siendo por tanto su real incidencia desconocida. En algunos pacientes, el VINC progresaria a un estado de dilatacion y disfuncion ventricular, denominandose miocardiopatia no compactada (MCNC). Es importante diferenciar estas dos entidades (VINC y MCNC) ya que no es infrecuente encontrar en pacientes sanos con funcion ventricular conservada pequenas areas de no compactacion. El pronostico de los pacientes con MCNC es reservado, siendo la falla cardiaca, las arritmias malignas y la trombosis, complicaciones frecuentes. Aunque la Ecocardiografia suele ser la primera herramienta en la sospecha del diagnostico, la RMC, por su alta resolucion espacial es capaz de ofrecer una mejor diferenciacion entre las capas compactadas y no compactadas, facilitando asi el diagnostico de esta entidad (Fig.1). Ha sido demostrado en estudios funcionales la disminucion de la reserva coronaria en las zonas de trabeculacion, y ademas, estudios patologicos han demostrado la presencia de fibrosis y necrosis, tanto en las zonas compactadas como no compactadas. Lo anterior explicaria la captacion de Gadolinio en los estudios de realce tardio (viabilidad). La extension de las zonas de realce ha sido postulada como un marcador de la severidad de la MCNC (Fig. 2). Es importante recalcar la utilidad de la RMC en aquellos pacientes con insuficiencia cardiaca cuya etiologia no esta clara, dado el potencial de analisis morfologico y funcional. Imagenes en Cardiologia