Diagnosis and quantification of fibrosis, steatosis, and hepatic siderosis through multiparametric magnetic resonance imaging. / Diagnóstico y cuantificación de fibrosis, esteatosis y hepatosiderosis por medio de resonancia magnética multiparamétrica.

BACKGROUND: The presence of liver fibrosis is the common denominator in numerous chronic liver diseases that can progress to fibrosis and hepatocellular carcinoma. Most important, with respect to frequency, are viral hepatitis and non-alcoholic fatty liver disease, the prevalence of which is increasing in epidemic proportions. Liver biopsy, albeit imperfect, continues to be the criterion standard, but in many clinical situations tends to be replaced with noninvasive imaging methods. OBJECTIVES: The aim of the present article was to describe our imaging department experience with magnetic resonance elastography and to analyze and discuss recently published results in gastroenterology, hepatology, and radiology from other authors in the literature, complemented with a PubMed search covering the last 10 years. RESULTS AND CONCLUSIONS: Magnetic resonance elastography is an efficacious, noninvasive method with results that are concordant with liver biopsy. It is superior to ultrasound elastography because it evaluates a much greater volume of hepatic tissue and shows the often heterogeneous lesion distribution. The greatest advantage of the magnetic resonance protocol described is the fact that it quantifies fibrosis, fat content, and iron content in the same 25min examination specifically directed for that purpose, resulting in a favorable cost-benefit ratio for the patient and/or institution.

Liver-specific gadoxetic acid-enhanced magnetic resonance for focal lesion evaluation.

Gadolinium-enhanced magnetic resonance for the evaluation of hepatic lesions is increasingly being used in clinical practice, especially in patients with suspicious focal lesions, whether benign or malignant. In regard to hepatocellular carcinoma, the diagnostic performance of magnetic resonance through the «conventional¼ protocols and multi-detector computerized tomography consisting of multiphase evaluation with intravenous contrast, largely depends on the size of the lesion. They are more reliable in lesions>2cm. However, in lesions measuring 1-2cm, establishing the definitive diagnosis is a real challenge, with sensitivity values of 45-65%, but generally with excellent specificity (>95%). Furthermore, if the lesion has a diameter<1cm, diagnosis is usually unreliable. In these last 2 settings, the complementary use of liver-specific contrast agents can be advantageous. The aim of our article was to review the current evidence on the usefulness of this new non-invasive diagnostic method in hepatic lesions.

A case of tracheal varices: an unusual but important cause of mural nodules in the trachea.

Tracheal varices (TV) are uncommon but can be an important source of massive or recurrent haemoptysis. We present a case of TV in a 32-year-old patient with a history of Glenn-Fontan surgery, for congenital tricuspid atresia, and portal hypertension owing to cardiac cirrhosis. We discuss TV presenting as tracheal nodules in the presence of extensive mediastinal collateral circulation.

Methods for measuring abdominal obesity in the prediction of severe acute pancreatitis, and their correlation with abdominal fat areas assessed by computed tomography.

BACKGROUND: Obesity increases the risk for severe acute pancreatitis, although abdominal obesity may be a better prognostic marker. AIM: To determine if a single anthropometric parameter best predicts severe acute pancreatitis and correlates with intra-abdominal fat. METHODS: Ninety-nine patients with acute pancreatitis were studied prospectively. Anthropometry included body mass index (BMI) and girths (umbilical/minimum waist, iliac/trochanter hip, thigh). Several waist-to-hip/waist-to-thigh ratios (WHR/WTR) were constructed. A CT-scan with calculation of cross-sectional abdominal fat areas was obtained in 37 cases. RESULTS: Severe acute pancreatitis occurred in 25 patients. Waist circumference (WC), WHR and WTR - all using the umbilical reference - most accurately predicted severe acute pancreatitis. Only umbilical WC was retained in multivariate analysis: the risk for severe acute pancreatitis increased 16% with every 1 cm (OR 1.16, 95%CI: 1.1-1.3). Abdominal obesity caused a 6-fold increase in risk. Umbilical WC correlated best with subcutaneous fat area (r = 0.791, P < 0.001), whereas WHR with intra-abdominal (r = 0.594, P < 0.001). CONCLUSIONS: Abdominal obesity according to umbilical WC is a better predictor for development of severe acute pancreatitis than BMI, minimum WC, WHR and WTR. The protocol for anthropometry must be standardized as it may affect results. Both subcutaneous and intra-abdominal fat appears to affect the likelihood of a severe outcome.

[Bioterrorism: notes for an agenda in case of the unexpected]. / Bioterrorismo: apuntes para una agenda de lo inesperado.

UNLABELLED: The vulnerability of human populations to chemical, biological, radiological, and nuclear terrorism has been widely discussed but insufficiently studied. Current public health policies are not guided by solid and relevant information to design cost-effective programs for preventing or controlling this kind of incidents in the future. Governmental budgets are insufficient to respond to bioterrorist attacks. To face these threats, developing countries like Mexico should frame strategies and devise specific preventive actions that consider the transmission dynamics of potential infectious agents likely to be used in a bioterrorist attack. PROPOSALS: The international reaction to a biological attack must be supported by international agreements that ban the use of biological agents for warfare and/or defense purposes, as well as on academic and technological exchange for the prevention of bioterrorist attacks. At the national level, the recommendations in the event of a biological attack are: a) establishing a legal defense strategy against bioterrorism; b) implementing education programs as a key strategy for defense against bioterrorism; c) devising a national program of interinstitutional anti-bioterrorist coordination that includes medical emergency assistance and collection of medical forensic evidence; d) including a biological weapon registry in epidemiological surveillance systems; e) implementing a laboratory for biological material analysis related to terrorist incidents; f) devising public health information campaigns, g) assuring the supply of diagnostic testing, special protection, and emergency treatment materials; h) decentralizing alert systems for the timely detection of bioterrorist attacks; i) responding to bioterrorist actions addressed against animals and plants, and j) organizing Ethics Committees in case of urgent events derived from a biological attack. CONCLUSIONS: The proper response to sudden and unexpected events of emergent or unusual infectious diseases involved in a bioterrorist attack requires an adequate public health infrastructure. Modern technology allows the timely identification of multiple infectious agents by nucleic acid analyses and should be widely available in reference laboratories. All these measures require sufficient funding to respond to this potential threat. Resource allocation to respond to bioterrorist attacks must be consonant with their potential public health consequences.