Esther Rodriguez

MRI of subendocardial perfusion deficits in isolated left ventricular noncompaction.

Ventricular noncompaction is a rare unclassified cardiomyopathy due to intrauterine arrest of compaction of the loose interwoven meshwork. It is characterized by markedly irregular endocardial surfaces with prominent trabeculations and intertrabecular recesses. Patients are asymptomatic or present with depressed ventricular function, ventricular arrhythmia, and systemic embolism. Areas of restricted myocardial perfusion have been previously documented by scintigraphy and positron emission tomography. This report documents a case of isolated left ventricular noncompaction with subendocardial perfusion deficits on MRI.

Magnetic resonance imaging of delayed enhancement in hypertrophic cardiomyopathy: relationship with left ventricular perfusion and contractile function.

Purpose: The aim of the study was to analyze the relationship between myocardial delayed enhancement, first-pass perfusion, and contractile function in hypertrophic cardiomyopathy (HCM) patients, using MR. Methods: Fifty-three patients diagnosed with HCM were prospectively examined using a 1.5-T MR unit. Multiphase gradient-echo sequences were performed to study global left ventricular function, wall thickness, and left ventricular mass. Myocardial tissue tagging was conducted to evaluate contractile function. T1-weighted inversion-recovery sequences were obtained at rest to study myocardial contrast enhancement at first pass and delayed enhancement 10 minutes later. Results: Delayed enhancement found in 30 patients (56.6%) was most commonly seen in hypertrophic segments. Nine patients exhibited delayed enhancement in segments with normal wall thickness (<15 mm). Sixteen patients (30.1%) showed first-pass perfusion defects at rest, which were associated with significantly lower stroke volume (P < 0.05) and lower cardiac output (P < 0.01). The hypokinetic segments found in 16 patients (30.1%) were significantly thicker at end diastole (P < 0.01). Delayed enhancement correlated positively with perfusion defects (r = 0.5, P < 0.01) and hypokinetic segments (r = 0.3, P < 0.05). Conclusion: Delayed myocardial enhancement is most commonly found in hypertrophic segments but also can be seen in segments with normal wall thickness. Perfusion defects at rest and impaired contractile function are related abnormalities with delayed myocardial enhancement. Further studies are necessary to assess the role of myocardial tagging, first-pass perfusion, and delayed enhancement in risk stratification for patients with HCM.Abbreviations: MCH = hypertrophic cardiomyopathy, FOV = field of view

CT Attenuation Values and Enhancing Characteristics of Thoracoabdominal Lymphomatous Adenopathies

Objective Thoracoabdominal lymphomatous adenopathies have been described as homogeneous and typically showing little enhancement on postcontrast CT. After observing pronounced adenopathic contrast enhancement in one patient with lymphoma, we prospectively investigated the CT enhancing characteristics and attenuation values of pathologic thoracic and abdominal lymph nodes in 25 patients with lymphoma. Materials and Methods Unenhanced CT of the chest, abdomen and pelvis was performed in all cases. The enhancing characteristics and attenuation values of the largest node or group of nodes were evaluated at 1, 2, 5, and 10 min after a 100 ml intravenous bolus injection of contrast medium. Results On unenhanced CT the nodes were of soft-tissue attenuation (42 ± 5 HU) in 23 cases and of low attenuation (31 and 28 HU) in 2 cases. The maximum enhancement was achieved at 1 or 2 min postinjection and was low (16 ± 6 HU) or moderate (31 ± 6 HU) in 21 cases and pronounced (61 ± 5 HU) in 4. The patterns of enhancement were classified as homogeneous (no. = 23) inhomogeneous (no. = 1), and peripheral (no. = 1). Conclusion Thoracic and abdominal lymphomatous adenopathies are usually of soft-tissue attenuation on unenhanced CT and can show slight, moderate, or even pronounced enhancement on postcontrast CT.

MR imaging in inferior vena cava thrombosis.

PURPOSE To prospectively evaluate the efficacy of MR imaging in inferior vena cava (IVC) thrombosis; to differentiate acute from non-acute thrombus, and to identify the presence of changes in the morphology and signal intensity during medical treatment. METHODS AND MATERIALS Seventeen patients with suspected IVC thrombosis underwent 30 MR examinations. The IVC thromboses were subdivided into two groups (acute and non-acute) according to onset of clinical symptoms. MR imaging of the IVC was analyzed and when an IVC thrombus was identified, a qualitative and quantitative assessment of the thrombus on spin-echo sequences with magnitude and phase reconstruction was performed to evaluate the relationship between signal intensity and the time elapse since the onset of clinical symptoms. Venography and/or CT scan proof was available in all cases. RESULTS IVC thrombus was correctly identified in 19 MR examinations which showed the size, localization and the degree of lysis during follow-up. No differences were found in the signal intensity of the thrombus related to time. The pattern of the signal intensity was homogeneous in six (86%) acute thrombus and heterogeneous in nine (75%) thrombus of more than 1 week duration. A significant statistical relationship (P < 0.01) existed between the thrombus age and differences in the pattern of signal intensity. CONCLUSIONS MR imaging is accurate to assess the localization and size of IVC thrombus, similar to the imaging techniques of reference. In addition, MR also provides useful information about the age and the morphological variations of thrombus during medical treatment.

Agenesis of the dorsal pancreas with polysplenia syndrome : CT features

We report two cases of agenesis of the dorsal pancreas associated with multiple spleens and interruption of the inferior vena cava with azygoshemiazygos continuation.

Monte Carlo Simulation of Visible Light Diffuse Reflection in Neonatal Skin

Neonatal jaundice is a medical condition that happens commonly in newborns as result of desbalance between the production and the elimination of the bilirubin. Around 50% of newborns in term and something more of 60% of the near‐term becomes jaundiced in the first week of life. This excess of bilirubin in the blood is exhibited in the skin, the sclera of the eyes and the mucous of mouth like a characteristic yellow coloration. In this work we make several numerical simulations of the spectral diffuse reflection for the skin of newborns that present different values of the biological parameters (bilirubin content, grade of pigmentation and content of blood) that characterize it. These simulations will allow us to evaluate the influence of these parameters on the experimental determination of bilirubin by noninvasive optical methods. The simulations are made in the spectral range of 400–700 nm using the Monte Carlo code MCML and two programs developed in LabVIEW by the authors. We simulated the diffuse refl...