Lipotoxicity in Obesity and Coronary Artery Disease. Studies by PET, CT and MR

Lipotoxicity is a condition in which fatty acids (FAs) are not efficiently stored in adipose tissue and overflow to non-adipose tissue, causing organ damages. A defect of adipose tissue FA storage capability can be the primary culprit in the insulin resistance condition that characterizes many of the severe metabolic diseases that affect people nowadays. Obesity, in this regard, constitutes the gateway and risk factor of the major killers of modern society, such as cardiovascular disease and cancer. A deep understanding of the pathogenetic mechanisms that underlie obesity and the insulin resistance syndrome is a challenge for modern medicine. In the last twenty years of scientific research, FA metabolism and dysregulations have been the object of numerous studies. Development of more targeted and quantitative methodologies is required on one hand, to investigate and dissect organ metabolism, on the other hand to test the efficacy and mechanisms of action of novel drugs. The combination of functional and anatomical imaging is an answer to this need, since it provides more understanding and more information than we have ever had. The first purpose of this study was to investigate abnormalities of substrate organ metabolism, with special reference to the FA metabolism in obese drug-naïve subjects at an early stage of disease. Secondly, trimetazidine (TMZ), a metabolic drug supposed to inhibit FA oxidation (FAO), has been for the first time evaluated in obese subjects to test a whole body and organ metabolism improvement based on the hypothesis that FAO is increased at an early stage of the disease. A third objective was to investigate the relationship between ectopic fat accumulation surrounding heart and coronaries, and impaired myocardial perfusion in patients with risk of coronary artery disease (CAD). In the current study a new methodology has been developed with PET imaging with 11C-palmitate and compartmental modelling for the non-invasive in vivo study of liver FA metabolism, and a similar approach has been used to study FA metabolism in the skeletal muscle, the adipose tissue and the heart. The results of the different substudies point in the same direction. Obesity, at the an early stage, is associated with an impairment in the esterification of FAs in adipose tissue and skeletal muscle, which is accompanied by the upregulation in skeletal muscle, liver and heart FAO. The inability to store fat may initiate a cascade of events leading to FA oversupply to lean tissue, overload of the oxidative pathway, and accumulation of toxic lipid species and triglycerides, and it was paralleled by a proportional growth in insulin resistance. In subjects with CAD, the accumulation of ectopic fat inside the pericardium is associated with impaired myocardial perfusion, presumably via a paracrine/vasocrine effect. At the beginning of the disease, TMZ is not detrimental to health; on the contrary at the single organ level (heart, skeletal muscle and liver) it seems beneficial, while no relevant effects were found on adipose tissue function. Taken altogether these findings suggest that adipose tissue storage capability should be preserved, if it is not possible to prevent excessive fat intake in the first place.

Advanced epithelial ovarian cancer – studies on preoperative [18F] FDG PET/CT and HE4 profile during primary chemotherapy

Epithelial ovarian cancer (EOC) is usually diagnosed in an advanced stage. The prognosis depends highly on the amount of the residual tumor in surgery. In patients with extensive disease, neoadjuvant chemotherapy (NACT) is used to diminish the tumor load before debulking surgery. New non-invasive methods are needed to preoperatively evaluate the disease dissemination and operability. [18F] FDG PET/CT (Positron emission tomography/computed tomography) is a promising method for cancer diagnostics and staging. The biomarker profiles during treatment can predict patient’s outcome. This prospective study included 41 EOC patients, 21 treated with primary surgery and 20 with NACT and interval surgery. The performances of preoperative contrast enhanced PET/CT (PET/ceCT) and diagnostic CT (ceCT) were compared. Perioperative visual estimation of tumor spread was studied in primary and interval surgery. The profile of the serum marker HE4 (Human epididymis 4) during primary chemotherapy was evaluated. In primary surgery, surgical findings were found to form an adequate reference standard for imaging studies. After NACT, the sensitivity for visual estimation of cancer dissemination was significantly worse. Preoperative PET/ceCT was more effective than ceCT alone in detecting extra-abdominal disease spread. The high number of supradiaphragmatic lymph node metastases detected by PET/ceCT at the time of diagnosis brings new insight in EOC spread patterns. The sensitivity of both PET/CT and ceCT remained modest in intra-abdominal areas important to operability. The HE4 profile was in concordance with the CA125 profile during primary chemotherapy. Its role in the evaluation of EOC chemotherapy response will be clarified in further studies.

Computed tomography findings of hepatic veno-occlusive disease caused by Sedum aizoon with histopathological correlation

This study investigated the value of computed tomography (CT) in the diagnosis and treatment of hepatic veno-occlusive disease (HVOD) caused by Sedum aizoon (SA). The clinical manifestations, treatment results, imaging findings, and histological findings of the liver were analyzed in 39 patients with HVOD caused by SA. Hepatomegaly, liver dysfunction, abdominal effusion, and geographic density changes on liver CT scans were found in all 39 patients. The pathological findings of histological liver examination included swelling and point-like necrosis of liver cells, significant expansion and congestion of the sinuses, endothelial swelling, and wall thickening with incomplete lumen occlusion of small liver vessels. CT geographic density changes were confirmed by histological examination of the liver in 18 patients. Sixteen patients with small amounts of ascites that started within 4 weeks of treatment recovered completely or significantly improved after symptomatic and supportive treatment. However, only 43.75% of the patients with larger amounts of ascites improved following symptomatic and supportive treatment. In conclusion, liver CT examination is a valuable, safe, and noninvasive tool for the diagnosis of HVOD caused by SA. In selected cases, liver CT examination may replace liver biopsy and histological analysis.

Accuracy of Periapical Radiography and Cone-Beam Computed Tomography Scans in Diagnosing Apical Periodontitis Using Histopathological Findings as a Gold Standard

Introduction: The aim of this study was to evaluate the accuracy of two imaging methods in diagnosing apical periodontitis (AP) using histopathological findings as a gold standard. Methods: The periapex of 83 treated or untreated roots of dogs` teeth was examined using periapical radiography (PR), cone-beam computed tomography (CBCT) scans, and histology. Sensitivity, specificity, predictive values, and accuracy of PR and CBCT diagnosis were calculated. Results: PR detected AP in 71% of roots, a CBCT scan detected AP in 84%, and AP was histologically diagnosed in 93% (p = 0.001). Overall, sensitivity was 0.77 and 0.91 for PR and CBCT, respectively. Specificity was 1 for both. Negative predictive value was 0.25 and 0.46 for PR and CBCT, respectively. Positive predictive value was 1 for both. Diagnostic accuracy (true positives + true negatives) was 0.78 and 0.92 for PR and CBCT (p = 0.028), respectively. Conclusion: A CBCT scan was more sensitive in detecting AP compared with PR, which was more likely to miss AP when it was still present. (J Endod 2009;35:1009-1012)

C5 and C6 human dermatomes: a clinical, electromyographical, imaging and surgical findings

There is substantial controversy in literature about human dermatomes. In this work, C5 and C6 superior limb dermatomes were studied. The method consisted of comparing clinical signs and symptoms with conduction studies, electromyographical data, neurosurgical findings, and imaging findings obtained by computerized tomography (CT) or magnetic resonance imaging (MRI), for each patient. Data analysis from superior members in 18 patients suggests that C5 is located in the lateral aspect of the shoulder and arm, and C6 in the lateral aspect of the forearm and 1(st), 2(nd), and 3(rd) fingers. To our knowledge this is the first time that C5 and C6 human dermatomes have been studied by all the following methods together: clinical, electromyographical, CT and MR imaging, and surgical findings.

L4-L5-S1 human dermatomes: a clinical, electromyographical, imaging and surgical findings

There is substantial controversy in literature about human dermatomes. We studied L4, L5, and S1 inferior limb dermatomes by comparing clinical signs and symptoms with conduction studies, electromyographical data, neurosurgical findings, and imaging data from computerized tomography (CT) or magnetic resonance imaging (MRI). After analyzing 60 patients, we concluded that L4 is probably located in the medial aspect of the leg, L5 in the lateral aspect of the leg and foot dorsus, and S1 in the posterior aspect of the backside, tight, leg and plantar foot skin. This is the first time that these human dermatomes have been evaluated by combined analysis of clinical, electromyographical, neurosurgical, and imaging data.

Ultrasonographic, computed tomographic, and operative findings in dogs infested with giant kidney worms (Dioctophyme renale)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Wavelet-based algorithm to the evaluation of contrasted hepatocellular carcinoma in CT-images after transarterial chemoembolization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Multidetector CT Evaluation of the Postoperative Pancreas

Several pancreatic diseases may require surgical treatment, with most of these procedures classified as resection or drainage. Resection procedures, which are usually performed to remove pancreatic tumors, include pancreatoduodenectomy, central pancreatectomy, distal pancreatectomy, and total pancreatectomy. Drainage procedures are usually performed to treat chronic pancreatitis after the failure of medical therapy and include the Puestow and Frey procedures. The type of surgery depends not only on the patient's symptoms and the location of the disease, but also on the expertise of the surgeon. Radiologists should become familiar with these surgical procedures to better understand postoperative changes in anatomic findings. Multidetector computed tomography is the modality of choice for identifying normal findings after surgery, postoperative complications, and tumor recurrence in patients who have undergone pancreatic surgery. (C)RSNA, 2012 . radiographics.rsna.org

Dentomaxillofacial manifestations of Gaucher's disease: preliminary clinical and radiographic findings

Objectives: A wide variety of manifestations is presented in patients with Gaucher's disease (GD), including bone, haematology and visceral disturbances. This study was conducted to ascertain the main maxillofacial abnormalities by means of clinical survey, panoramic and cone beam CT (CBCT); to compare the patient's group with an age-sex matched control group; and to correlate clinical and radiological data. Methods: Ten patients previously diagnosed with GD were submitted to clinical and radiological surveys (CBCT and panoramic radiographs). The examination consisted of anamnesis, extra- and intraoral examinations and analyses of each patient's records. Imaging data were collected from the point of view of 3 observers, and the results compared with a healthy group (20 individuals) by means of statistical analysis (Fisher's exact test). Results: Gaucher patients had significantly more manifestations than otherwise healthy carriers. The most prevalent findings were enlarged marrow spaces, generalized osteopenia and effacement of jaw structures (mandibular canal, lamina dura and mental foramen). Here we describe a case in which thickening of the maxillary sinus mucosa was observed on CBCT rather than opacification of the sinus as seen on panoramic radiographs. Pathological fractures, root resorption and delay on tooth eruption were not observed. Conclusions: A poor relationship could be observed between clinical and radiological data. Patients showed important bone manifestations, which require careful diagnostic and surgical planning whenever necessary. Although panoramic radiographs have shown significant differences, CBCT is more effective in pointing out differences between patients and a control group, thus showing it as an important tool for evaluation of Gaucher patients. Dentomaxillofacial Radiology (2012) 41, 541-547. doi: 10.1259/dmfr/143023353

Radiopaque stomach contents in postmortem CT in suicidal oral medication intoxication: report of three cases

In clinical medicine, plane radiography is used for detecting the remains of medications in the stomach in oral medication intoxication cases. Since postmortem computed tomography (CT), performed prior to autopsy, is currently intensively entering the forensic routine, the technique was applied to three fatal cases of oral medication intoxication. Here we report CT and autopsy findings for these cases. In all three cases, hyperdense areas within the stomach content were documented. The measurement of Hounsfield Units (HU) beyond 74HU showed mean values of 338, 88 and 98HU. Postmortem CT also showed brain edema and pulmonary aspiration in one case. At autopsy, tablet remains in the stomach were detected microscopically in all three cases. The ex vivo CT scans of the ingested medicaments showed similar HU values. Despite the fact that further case studies are necessary beyond this one, and in spite of its limitations, postmortem CT was found to be a useful screening and documentation method for stomach contents in oral medication intoxication.

Minimally invasive post-mortem CT-angiography in a case involving a gunshot wound

Non-contrast post-mortem computed tomography (pm-CT) is useful in the evaluation of bony pathologies, whereas minimally invasive pm-CT-angiography allows for the detection of subtle vascular lesions. We present a case of an accidentally self-inflicted fatal bullet wound to the chest where pm-CT-angiography revealed a small laceration of the anterior interventricular branch of the left coronary artery and a tiny disruption of the right ventricle with pericardial and pleural effusion. Subsequent autopsy confirmed our radiological findings. Post-mortem CT-angiography has a great potential for the detection of vascular lesions and can be considered equivalent to autopsy for selected cases in forensic medicine.

Pros and cons of post-mortem CT imaging on aspiration diagnosis

Recently, the field of forensics has experienced a rapid increase in the use of modern cross-sectional imaging in forensic investigations. We examined the value of post-mortem computed tomography (CT) imaging relative to autopsy for distinguishing aspiration into the lungs from airways, from lung alterations due to other causes, and for identifying the aspirated material. We selected 54 bodies submitted to whole-body CT scanning prior to autopsy. All cases had autopsy findings of blood (31 cases), fresh water (12 cases), or gastric content (11 cases) aspiration. The radiological images were retrospectively analyzed for airway and lung aspiration. In all cases, CT imaging detected pulmonary abnormalities suggestive of aspiration. Nevertheless, analysis of the CT images alone was not able to identify the aspirated material or to distinguish pulmonary findings of aspiration from lung changes due to other causes, except for a few cases of hemo-aspiration. However, due to its ability to visualize the entire parenchyma, CT imaging was superior to autopsy in providing additional data about the distribution and severity of the aspiration as well as in detecting small abnormalities. Post-mortem CT imaging should be considered as a superior tool for forensic investigations of aspiration due to its ability to document diagnostic conclusions and to guide the forensic pathologist during lung tissue examination.

Postmortem imaging-guided biopsy as an adjuvant to minimally invasive autopsy with CT and postmortem angiography: a feasibility study

Although postmortem CT suffices for diagnosing most forms of traumatic death, the examination of natural death is, to date, very difficult and error prone. The introduction of postmortem angiography has led to improved radiologic diagnoses of natural deaths. Nevertheless, histologic changes to tissues, an important aspect in traditional examination procedures, remain obscure even with CT and CT angiography. For this reason, we examined the accuracy of a minimally invasive procedure (i.e., CT angiography combined with biopsy) in diagnosing major findings and the cause of death in natural deaths.

Computed tomography (CT) virtual autopsy and classical autopsy discrepancies: radiologist's error or a demonstration of post-mortem multi-detector computed tomography (MDCT) limitation?

Modern imaging technologies, such as computed tomography (CT) techniques, represent a great challenge in forensic pathology. The field of forensics has experienced a rapid increase in the use of these new techniques to support investigations on critical cases, as indicated by the implementation of CT scanning by different forensic institutions worldwide. Advances in CT imaging techniques over the past few decades have finally led some authors to propose that virtual autopsy, a radiological method applied to post-mortem analysis, is a reliable alternative to traditional autopsy, at least in certain cases. The authors investigate the occurrence and the causes of errors and mistakes in diagnostic imaging applied to virtual autopsy. A case of suicide by a gunshot wound was submitted to full-body CT scanning before autopsy. We compared the first examination of sectional images with the autopsy findings and found a preliminary misdiagnosis in detecting a peritoneal lesion by gunshot wound that was due to radiologist's error. Then we discuss a new emerging issue related to the risk of diagnostic failure in virtual autopsy due to radiologist's error that is similar to what occurs in clinical radiology practice.