Asbestos-related Disease Progression of Parenchymal Abnormalities on High-resolution CT

Purpose: To evaluate the changes over time in the pattern and extent of parenchymal abnormalities in asbestos-exposed workers after cessation of exposure and to compare 3 proposed semiquantitative methods with a careful side-by-side comparison of the initial and the follow-Lip computed tomography (CT) images. Materials and Methods: The study included 52 male asbestos workers (mean age SD, 62.2y +/- 8.2) who had baseline high-resolution CT after cessation of exposure and follow-up CT 3 to 5 years later. Two independent thoracic radiologists quantified the findings according to the scoring systems proposed by Huuskonen, Gamsu, and Sette and then did a side-by-side comparison of the 2 sets of scans without awareness of the dates of the CT scans. Results: There was no difference in the prevalence of the 2 most common parenchymal abnormalities (centrilobular small dotlike or branching opacities and interstitial lines) between the initial and follow-up CT scans. Honeycombing (20%) and traction bronchiectasis and bronchiolectasis (50%) were seen more commonly on the follow-up CT than on the initial examination (10% and 33%, respectively) (P = 0.01). Increased extent of parenchymal abnormalities was evident on side-by-side comparison in 42 (81%) patients but resulted in an increase in score in at least 1 semiquantitative system in only 16 (31%) patients (all P > 0.01, signed test). Conclusions: The majority of patients with previous asbestos exposure show evidence of progression of disease on CT at 3 to 5 years follow-up but this progression is usually not detected by the 3 proposed semiquantitative scoring schemes.

IMAGE QUANTIFICATION FOR RADIATION DOSE CALCULATIONS-LIMITATIONS AND UNCERTAINTIES

Radiation dose calculations in nuclear medicine depend on quantification of activity via planar and/or tomographic imaging methods. However, both methods have inherent limitations, and the accuracy of activity estimates varies with object size, background levels, and other variables. The goal of this study was to evaluate the limitations of quantitative imaging with planar and single photon emission computed tomography (SPECT) approaches, with a focus on activity quantification for use in calculating absorbed dose estimates for normal organs and tumors. To do this we studied a series of phantoms of varying complexity of geometry, with three radionuclides whose decay schemes varied from simple to complex. Four aqueous concentrations of (99m)Tc, (131)I, and (111)In (74, 185, 370, and 740 kBq mL(-1)) were placed in spheres of four different sizes in a water-filled phantom, with three different levels of activity in the surrounding water. Planar and SPECT images of the phantoms were obtained on a modern SPECT/computed tomography (CT) system. These radionuclides and concentration/background studies were repeated using a cardiac phantom and a modified torso phantom with liver and ""tumor"" regions containing the radionuclide concentrations and with the same varying background levels. Planar quantification was performed using the geometric mean approach, with attenuation correction (AC), and with and without scatter corrections (SC and NSC). SPECT images were reconstructed using attenuation maps (AM) for AC; scatter windows were used to perform SC during image reconstruction. For spherical sources with corrected data, good accuracy was observed (generally within +/- 10% of known values) for the largest sphere (11.5 mL) and for both planar and SPECT methods with (99m)Tc and (131)I, but were poorest and deviated from known values for smaller objects, most notably for (111)In. SPECT quantification was affected by the partial volume effect in smaller objects and generally showed larger errors than the planar results in these cases for all radionuclides. For the cardiac phantom, results were the most accurate of all of the experiments for all radionuclides. Background subtraction was an important factor influencing these results. The contribution of scattered photons was important in quantification with (131)I; if scatter was not accounted for, activity tended to be overestimated using planar quantification methods. For the torso phantom experiments, results show a clear underestimation of activity when compared to previous experiment with spherical sources for all radionuclides. Despite some variations that were observed as the level of background increased, the SPECT results were more consistent across different activity concentrations. Planar or SPECT quantification on state-of-the-art gamma cameras with appropriate quantitative processing can provide accuracies of better than 10% for large objects and modest target-to-background concentrations; however when smaller objects are used, in the presence of higher background, and for nuclides with more complex decay schemes, SPECT quantification methods generally produce better results. Health Phys. 99(5):688-701; 2010

Helminthic Diseases in the Abdomen: An Epidemiologic and Radiologic Overview

Helminthic diseases have a worldwide distribution. They affect billions of people in endemic areas and can result in serious clinical complications. Some parasites have a human gastrointestinal life cycle with resultant abdominal manifestations. However, the symptoms of helminthic diseases are usually nonspecific. Radiologic imaging, along with the identification of risk factors, may help narrow the differential diagnosis. To avoid diagnostic delays, radiologists should be familiar with the geographic distribution, transmission cycle, and characteristic and atypical manifestations of common helminthic diseases at abdominal imaging with radiography, computed tomography, magnetic resonance imaging, and ultrasonography. Awareness of the clinical, epidemiologic, and pathogenic characteristics of these diseases also may be helpful for narrowing the diagnosis when imaging features are nonspecific. (c) RSNA, 2010 . radiographics.rsna.org

Repetitive transcranial magnetic stimulation improve tinnitus in normal hearing patients: a double-blind controlled, clinical and neuroimaging outcome study

Background and purpose: Tinnitus is a frequent disorder which is very difficult to treat and there is compelling evidence that tinnitus is associated with functional alterations in the central nervous system. Targeted modulation of tinnitus-related cortical activity has been proposed as a promising new treatment approach. We aimed to investigate both immediate and long-term effects of low frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) in patients with tinnitus and normal hearing. Methods: Using a parallel design, 20 patients were randomized to receive either active or placebo stimulation over the left temporoparietal cortex for five consecutive days. Treatment results were assessed by using the Tinnitus Handicap Inventory. Ethyl cysteinate dimmer-single photon emission computed tomography (SPECT) imaging was performed before and 14 days after rTMS. Results: After active rTMS there was significant improvement of the tinnitus score as compared to sham rTMS for up to 6 months after stimulation. SPECT measurements demonstrated a reduction of metabolic activity in the inferior left temporal lobe after active rTMS. Conclusion: These results support the potential of rTMS as a new therapeutic tool for the treatment of chronic tinnitus, by demonstrating a significant reduction of tinnitus complaints over a period of at least 6 months and significant reduction of neural activity in the inferior temporal cortex, despite the stimulation applied on the superior temporal cortex.

Peritumoral brain edema in benign meningiomas: correlation with clinical, radiologic, and surgical factors and possible role on recurrence

Background: Approximately 60% of meningiomas are associated with peritumoral edema. Various causative factors have been discussed in the literature. The objective of this study was to investigate the correlation of PTBE with clinical, radiologic, and surgical aspects and recurrence of meningiomas. Methods: Sixty-one patients with benign meningiomas were chosen for surgical treatment by the Group of Brain Tumors and Metastasis of the Department of Neurosurgery. All patients underwent complete surgical resection (Simpson grades I and 2), and those with atypical and malignant histopathologic grades were excluded. Tumors located in the cavernous sinus, tuberculum sellae, foramen magnum, ventricles, and petroclival region were excluded. Results: Edema extension had a positive correlation with the higher recurrence rates (P=.042) and with the presence of irregular margins (P<.011) on bivariate analysis. Meningiomas with larger edema sizes also showed correlation with large meningiomas (P=.035), and the ones with smaller edema sizes correlated with the tentorial location (P=.032). Multivariate analysis showed an association between PTBE and the presence of seizures (odds ratio, 3.469), large meningiomas (odds ratio, 15.977), and for each cubic centimeter added to its size, the risk of edema increased 1.082 times (odds ratio). Conclusion: Peritumoral brain edema may be related to the invading potential of meningiomas and may play a role in the recurrence potential of the tumor. As a consequence, it is reasonable to consider the presence of edema as an additional factor to be taken into account when mapping out strategies for the treatment of meningiomas. (C) 2008 Elsevier Inc. All rights reserved.

Preaortic Iliac Confluence (Marsupial Vena Cava): Report of 4 Cases

Congenital anomalies of the inferior vena cava (IVC) call represent a difficult for abdominal surgeries, and the radiologist must be aware even of the less common of these anatomical variations. Preaortic iliac venous confluence, also known as marsupial vena cava, is a rare congenital anomaly of the development of the IVC in which the IVC or the left common iliac vein is located anterior to the aortic bifurcation or the right common iliac artery. We report 4 cases of marsupial vena cava detected on multidetector computed tomography examinations in asymptomatic patients and discuss that this congenital anomaly can be recognized more frequently with the use of this new technique based on thinner images.

A Comparison of the Consensus and Clinical Definitions of Pancreatitis With a Proposal to Redefine Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis

Objectives: We evaluated the correlation between the consensus and clinical definitions of pancreatitis following endoscopic retrograde cholangiopancreatography (ERCP), with the objective of updating and revising the definition of post-ERCP pancreatitis (PEP). Methods: Three hundred patients were subjected to serial serum amylase & lipase levels testing and abdominal computed tomography scan for abdominal pain after ERCP. Main outcome measures included the correlation between consensus and clinical definitions. Results: Using consensus criteria, 25 patients had acute pancreatitis (11 of mild and 14 of moderate severity). Forty-three patients had acute pancreatitis using the clinical definitions (18 of mild and 25 of moderate severity). At 4 hours, serum hyperamylasemia of under 1.5-fold and at 12 hours a serum hyperamylasemia of under 2-fold had a negative predictive value of 0.94 for development of PEP. Serum hyperamylasemia following ERCP had a poor positive predictive value for PEP. Conclusions: Clinical and consensus definitions are poorly correlated; use of the latter leads to significant underrecognition of PEP. The adoption of clinical definition results in uniformity of diagnosis of pancreatitis for clinical care and research. Serum amylase levels at 4 and 12 hours after ERCP have a high negative predictive value for PEP.

Prospective evaluation of EUS versus CT scan for staging of ampullary cancer

Background: Malignancies of the biliary and pancreatic systems are associated with a poor prognosis. However, ampullary cancer carries a better prognosis and is often diagnosed when curative treatment is still possible. Accurate staging is important for the determination of the most appropriate treatment option. Objectives: (1) To determine the test performance characteristics of EUS and CT in loco-regional staging of ampullary neoplasms, and (2) to determine the impact of CT scan results on the test performance characteristics of EUS. Design and Setting: Prospective single-arm intervention study performed in 2 academic hospitals. Results and Main Outcome Measurements: Thirty-seven patients were screened and 33 staged with EUS and CT A total of 27 patients (13 men; mean age, 69.5 years; mean serum bilirubin level, 12.6 mg/dL) with locally advanced disease completed the protocol with EUS and CT and underwent surgical resection. Tumor classifications were as follows: 2 patients (7.4%), T1 tumors; 13 patients (48.1%), T2 tumors; and 12 patients (44.4%), T3 tumors, as per surgical pathology. Seventeen tumors (62.9%) were classified as NO and 10 (37.1%) as NI. The difference in proportion of correct tumor (74.1% vs 51.8%; P =.15, 95% CI, -0.06-0-50) and lymph node (81.4% vs; 55.5%; P =.07, 95% Cl, -0.01-0.53) staging by EUS and CT, respectively, was not statistically significantly different. However, the strength of tumor (kappa 0.51 vs 0.11) and nodal (kappa 0.59 vs 0.05) agreement with pathology was statistically significantly higher for EUS than for CT (P <.05). EUS was more sensitive and specific than CT for tumor and nodal staging, and the association of CT to EUS data did not improve the final test accuracy Limitation: Low number of T1 tumors. Conclusions: EUS is in accurate diagnostic test and exhibits a high level of agreement with surgical pathology. CT findings do not improve the test performance characteristics of EUS. Therefore, the evaluation for metastatic disease should not be compromised by CT protocols that aim to perform tumor and nodal staging. Further studies to determine the role of specialized CT protocols in patients with ampullary malignancies are needed. (Gastrointest Endosc 2009;70:290-6.)

Lead Poisoning by Intradiscal Firearm Bullet A Case Report

Study Design. The report of a rare case of lead poisoning by an intradiscal firearm bullet is presented. Objective. To describe and discuss the clinical and radiologic features (by computed tomography and magnetic resonance imaging) of a gunshot wound in the L2-L3 space which caused lead poisoning 5 years afterwards. Summary of Background Data. Lead poisoning from firearm bullets is rare, but the possibility should be investigated in the case of bullets lodged in the joints. Methods. A 30-year-old man presented to the emergency room with an intense lumbar pain complaint, colic, intestinal constipation, insomnia, and progressive headache for 20 days. He had a history of a gunshot wound 5 years previously, and the bullet was left in situ, in the intravertebral disc between L2 and L3, as confirmed by radiographs, computed tomography, and magnetic resonance imaging. The hypothesis of lead poisoning was confirmed by the laboratory results. Chelation treatment with calcium versenate (disodium ethylenediaminetetraacetate, or CaNa (2) EDTA) was indicated. The patient was admitted and treated once again, before surgical removal of the bullet. Results. After removal of the bullet, the patient had an episode of recurrence, and a new chelation cycle was performed, with complete resolution. Conclusion. Lead poisoning can result in severe clinical disorders that require rapid treatment. In this case, both clinical and surgical treatments led to complete resolution of the symptoms.

EVALUATION OF CENTRIFUGED OSTEOGENIC BONE MARROW IN FRACTURE CONSOLIDATION IN RABBITS

Objective The purpose of this study was to evaluate the efficacy of a centrifuged osteogenic bone marrow aspirate to stimulate healing in rabbit fibular osteotomies Methods Ten white New Zealand rabbits were used A transverse medial diaphyseal fibular osteotomy was performed on the right fibula where an absorbable collagen sponge embedded in osteogenic centrifuged bone marrow aspirate obtained from the ipsilateral iliac bone was inserted The left fibula was used as the control group where the collagen absorbable sponge was inserted without the osteogenic centrifuged aspirate The rabbits were sacrificed four weeks after surgery to evaluate bone callus formation Analyses of results were performed with DEXA bone densitometry to evaluate callus mineral mass multislice computed tomography to evaluate callus volume and histomorphometry to evaluate the relative rate of tissue formation Results The employment of centrifuged osteogenic bone marrow aspirate resulted in a 40 3% increase of callus bone mineral mass and increased relative quantity of bone tissue formation by 9 4% without a significant increase in the relative quantities of cartilage fibrous tissue or in callus volume Conclusions This study shows that the centrifuged osteogenic bone marrow aspirate was able to improve the healing of experimental fibular osteotomies in rabbits

Intracardiac Cavopulmonary Connection in Patients with Univentricular Heart Using Intra-atrial Lateral Tunnel and Intra-atrial Conduit Techniques

Background: In this study, we analyzed the time course of hemodynamic efficiency and follow-up in Fontan candidates who underwent the bidirectional Glenn procedure for staged intracardiac cavopulmonary connection (ICPC). Methods: Between 1991 and 2008, 52 patients with univentricular heart (mean age, 3.3 years; range, 2-8 years; 27 female patients [51.9%]) underwent ICPC. The cardiac malformations were as follows: tricuspid atresia, 25 cases (48.0%); common ventricle, 16 cases (30.7%); and pulmonary atresia with intact ventricular septum, 11 cases (21.1%). The intracardiac cavopulmonary procedure was indicated for all 52 cases. In 42 patients (80.7%), an intra-atrial lateral tunnel was constructed with a bovine pericardium patch. In the last 10 consecutive cases (19.3%), we performed a modified surgical technique in which we implanted an intra-atrial corrugated bovine pericardium tube sutured around the superior and inferior vena cava ostium. In all cases, a 4-mm fenestration was made to reduce the intratunnel pressure. All 52 patients had previously undergone a Glenn operation. Results: There were 2 hospital deaths (3.8%) and no recorded late deaths. During the follow-up, all patients were medicated with antiplatelet drugs. To evaluate the hemodynamic performance, we used Doppler echocardiography, computed tomography, and magnetic nuclear resonance studies. There were no prosthesis thromboses during this follow-up period. To evaluate cardiac arrhythmias, we conducted a Holter study. The last 10 patients with an intra-atrial conduit (IAC) presented with sinus rhythm and no arrhythmias during the last 4 years. The 50 surviving patients (96.1%) have been followed up for 6 to 204 months; all these patients are free of reoperation. Conclusion: The Glenn operation, which is performed at an early age, prepares the pulmonary bed to receive the ICPC. The midterm results of the intracardiac Fontan procedure seem to be good. The modified surgical procedure (IAC) can be a good alternative technique to the Fontan procedure in suitable patients.

Vascular diseases and old age mental disorders: an update of neuroimaging findings

Purpose of review To review neuroimaging findings that have been reported in samples of patients with cardiovascular disorders and their association with the onset of Alzheimer`s disease, vascular dementia, depression and bipolar disorder in the elderly and to highlight the implications of these findings to the knowledge about the pathophysiology of psychiatric disorders in old age, as well as their potential clinical implications. Recent findings Vascular risk factors, such as hypertension, diabetes, dyslipidemia, smoking habits and heart failure, have all been associated with signs of cerebrovascular dysfunction, including structural MRI findings of signal hyperintensities, lacunes and stroke and functional imaging findings of brain regional hypoperfusion and hypometabolism. Such brain abnormalities have been found to increase the risk of onset of psychiatric disorder (depression, bipolar and dementia) in old age. Summary As vascular risk factors are potentially modifiable when detected in midlife, the early characterization of brain changes associated with the presence of cardiovascular diseases holds promise to afford clinical applications in psychiatry, providing new perspectives for the prevention of old age psychiatric disorders.

Primary ciliary dyskinesia: evaluation using cilia beat frequency assessment via spectral analysis of digital microscopy images

Olm MA, Kogler JE Jr, Macchione M, Shoemark A, Saldiva PH, Rodrigues JC. Primary ciliary dyskinesia: evaluation using cilia beat frequency assessment via spectral analysis of digital microscopy images. J Appl Physiol 111: 295-302, 2011. First published May 5, 2011; doi:10.1152/japplphysiol.00629.2010.-Ciliary beat frequency (CBF) measurements provide valuable information for diagnosing of primary ciliary dyskinesia (PCD). We developed a system for measuring CBF, used it in association with electron microscopy to diagnose PCD, and then analyzed characteristics of PCD patients. 1 The CBF measurement system was based on power spectra measured through digital imaging. Twenty-four patients suspected of having PCD (age 1-19 yr) were selected from a group of 75 children and adolescents with pneumopathies of unknown causes. Ten healthy, nonsmoking volunteers (age >= 17 yr) served as a control group. Nasal brush samples were collected, and CBF and electron microscopy were performed. PCD was diagnosed in 12 patients: 5 had radial spoke defects, 3 showed absent central microtubule pairs with transposition, 2 had outer dynein arm defects, 1 had a shortened outer dynein arm, and 1 had a normal ultrastructure. Previous studies have reported that the most common cilia defects are in the dynein arm. As expected, the mean CBF was higher in the control group (P < 0.001) and patients with normal ultrastructure (P < 0.002), than in those diagnosed with cilia ultrastructural defects (i.e., PCD patients). An obstructive ventilatory pattern was observed in 70% of the PCD patients who underwent pulmonary function tests. All PCD patients presented bronchial wall thickening on chest computed tomography scans. The protocol and diagnostic techniques employed allowed us to diagnose PCD in 16% of patients in this study.

High-fat diet: A trigger of non-alcoholic steatohepatitis? Preliminary findings in obese subjects

Objective: We correlated dietary profile and markers of visceral and somatic obesities in nonalcoholic fatty liver disease. Methods: Patients with histologically proven fatty infiltration of the liver (n = 25, 52 +/- 11 y of age, 64% women) underwent abdominal computed tomography, bioelectrical impedance, and anthropometric measurements. Insulin resistance was evaluated (homeostasis model assessment) and dietary intake of macronutrients was estimated by 24-h recall. Main outcome measurements were correlation of carbohydrate and fat ingestion with liver histology. Results: Metabolic syndrome was present in 72% of the population, and increased waist circumference and low high-density lipoprotein cholesterol occurred in 66%. Total body fat (bioimpedance) and dietary intake of lipids were higher in patients with non-alcoholic steatohepatitis (P < 0.05), but not in diabetic subjects who exhibited more steatosis than non-alcoholic steatohepatitis. Waist circumference exhibited a good correlation with homeostasis model assessment, total energy intake, and ingestion of specific fatty acids. Body mass index correlated well with somatic and visceral adiposities. Conclusion: Energy intake and visceral adiposity were predisposing factors for fatty liver disease. Lipid input correlated with non-alcoholic steatohepatitis in the entire group and after stratification for diabetes. These findings suggest that lipid intake may play a greater role in non-alcoholic steatohepatitis than hitherto suspected. (C) 2008 Elsevier Inc. All rights reserved.

Giant multilocular thymic cyst in an HIV-infected adolescent

A girl with vertically acquired HIV infection presented with a 6-month history of dyspnea and chest pain. Computed tomography of the thorax showed a heterogenous mass measuring 13 x 9 x 17 cm located in the anterior mediastinum. Complete surgical resection was accomplished with no complications. The final diagnosis was multilocular thymic cyst, a distinct pathologic entity that is morphologically distinguishable and unrelated to congenital thymic cyst. (C) 2011 Elsevier Inc. All rights reserved.