984 resultados para computed tomography scanner


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BACKGROUND: Intraabdominal adipose tissue (IAAT) is the body fat depot most strongly related to disease risk. Weight reduction is advocated for overweight people to reduce total body fat and IAAT, although little is known about the effect of weight loss on abdominal fat distribution in different races. OBJECTIVE: We compared the effects of diet-induced weight loss on changes in abdominal fat distribution in white and black women. DESIGN: We studied 23 white and 23 black women, similar in age and body composition, in the overweight state [mean body mass index (BMI; in kg/m(2)): 28.8] and the normal-weight state (mean BMI: 24.0) and 38 never-overweight control women (mean BMI: 23.4). We measured total body fat by using a 4-compartment model, trunk fat by using dual-energy X-ray absorptiometry, and cross-sectional areas of IAAT (at the fourth and fifth lumbar vertebrae) and subcutaneous abdominal adipose tissue (SAAT) by using computed tomography. RESULTS: Weight loss was similar in white and black women (13.1 and 12.6 kg, respectively), as were losses of total fat, trunk fat, and waist circumference. However, white women lost more IAAT (P < 0.001) and less SAAT (P < 0.03) than did black women. Fat patterns regressed toward those of their respective control groups. Changes in waist circumference correlated with changes in IAAT in white women (r = 0.54, P < 0.05) but not in black women (r = 0.19, NS). CONCLUSIONS: Despite comparable decreases in total and trunk fat, white women lost more IAAT and less SAAT than did black women. Waist circumference was not a suitable surrogate marker for tracking changes in the visceral fat compartment in black women.

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ABSTRACT: BACKGROUND: Chest wall syndrome (CWS), the main cause of chest pain in primary care practice, is most often an exclusion diagnosis. We developed and evaluated a clinical prediction rule for CWS. METHODS: Data from a multicenter clinical cohort of consecutive primary care patients with chest pain were used (59 general practitioners, 672 patients). A final diagnosis was determined after 12 months of follow-up. We used the literature and bivariate analyses to identify candidate predictors, and multivariate logistic regression was used to develop a clinical prediction rule for CWS. We used data from a German cohort (n = 1212) for external validation. RESULTS: From bivariate analyses, we identified six variables characterizing CWS: thoracic pain (neither retrosternal nor oppressive), stabbing, well localized pain, no history of coronary heart disease, absence of general practitioner's concern, and pain reproducible by palpation. This last variable accounted for 2 points in the clinical prediction rule, the others for 1 point each; the total score ranged from 0 to 7 points. The area under the receiver operating characteristic (ROC) curve was 0.80 (95% confidence interval 0.76-0.83) in the derivation cohort (specificity: 89%; sensitivity: 45%; cut-off set at 6 points). Among all patients presenting CWS (n = 284), 71% (n = 201) had a pain reproducible by palpation and 45% (n = 127) were correctly diagnosed. For a subset (n = 43) of these correctly classified CWS patients, 65 additional investigations (30 electrocardiograms, 16 thoracic radiographies, 10 laboratory tests, eight specialist referrals, one thoracic computed tomography) had been performed to achieve diagnosis. False positives (n = 41) included three patients with stable angina (1.8% of all positives). External validation revealed the ROC curve to be 0.76 (95% confidence interval 0.73-0.79) with a sensitivity of 22% and a specificity of 93%. CONCLUSIONS: This CWS score offers a useful complement to the usual CWS exclusion diagnosing process. Indeed, for the 127 patients presenting CWS and correctly classified by our clinical prediction rule, 65 additional tests and exams could have been avoided. However, the reproduction of chest pain by palpation, the most important characteristic to diagnose CWS, is not pathognomonic.

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A right heart metastasis of a small-cell lung cancer was found on the whole-body F-fluoro-deoxy-glucose positron emission tomography/computed tomography (F-FDG-PET/CT) of a 69-year-old smoker investigated for a right pulmonary mass discovered on chest radiography after a fracture of the right humerus. The PET scan showed an increased FDG uptake by the mass in the right lung and an intense, atypical focal activity of the right ventricle strongly suggestive of a neoplastic process. CT-guided lung biopsy revealed a small-cell lung cancer and myocardial biopsy confirmed the presence of a cardiac metastasis. The patient was treated with six cycles of chemotherapy followed by radiation therapy, which included the heart lesion. At follow-up PET/CT 2 months after the end of treatment, the abnormal cardiac uptake had disappeared, whereas increased FDG uptake persisted in the pulmonary residual mass.

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BACKGROUND: Laparoscopic enucleation for neuroendocrine pancreatic tumors has become a feasible technique, with a reported incidence of pancreatic fistula ranging from 13 to 29 %.1 (-) 3 This report describes the first successful case of laparoscopic pancreatic enucleation with resection of the main pancreatic duct followed by end-to-end anastomosis. METHODS: A 41-year-old woman was admitted to the authors' hospital for repeated syncope. Hypoglycemia also was noted. A contrast-enhanced computed tomography examination showed a highly enhanced tumor measuring 22 mm in diameter on the ventral side of the pancreatic body adjacent to the main pancreatic duct. The patient's blood insulin level was elevated, and her diagnosis was determined to be pancreatic insulinoma. Laparoscopic pancreatic enucleation was performed. Approximately 2 cm of the main pancreatic duct was segmentally resected, and a short stent (Silicone tube: Silastic, Dow Corning Corporation, Midland, MI) was inserted. The direct anastomosis of the main pancreatic duct was performed using four separate sutures with an absorbable monofilament (6-0 PDS). RESULTS: The operation time was 166 min, and the estimated blood loss was 100 mL. The postoperative course was uneventful, and the patient was discharged from hospital on postoperative day 7. The pathologic findings showed a well-differentiated insulinoma and a negative surgical margin. A computed tomography examination performed 1 month after the operation showed a successful anastomosis with a patent main pancreatic duct. CONCLUSIONS: Laparoscopic segmental resection of the main pancreatic duct and end-to-end anastomosis can be performed safely with the insertion of a short stent. This technique also can be used for a central pancreatectomy.

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Traditionally, thoracic aortic rupture, suspected after blunt thoracic trauma, is characterized by a chest radiograph showing a widened mediastinum. The diagnostic machinery consecutively activated still depends heavily on the pressure as additional traumatic lesions. A patient with additional cranio-cerebral trauma would typically undergo contrast-enhanced computed tomography or magnetic resonance imaging of head, chest, and other regions. In a number of patients these analyses would confirm the presence of blood in the mediastinum without formal proof of an aortic disruption. This is because mediastinal hematomas may be caused not only by an aortic rupture, but also by numerous other blood sources including fractures of the spine and other macro- and microvascular lesions providing similar images. Therefore, aortic angiography became our preferred diagnostic tool to identify or rule out acute traumatic lesions of not only the aorta but with great vessels. However recently, a number of traumatic aortic transsections have been identified by transoesophageal echocardiography (TEE). TEE has the additional advantage of being a bed-side procedure providing additional information about cardiac function. The latter analysis allows for identification and quantification of cardiac contusions, post-traumatic myocardial infarctions, and valvar lesions which are of prime importance to develop an adequate surgical strategy and to assess the risk of the numerous emergency procedures required in patients with polytrauma. The standard approach for repair of isthmic aortic rupture is through a lateral thoracotomy. Distal and proximal control of the aorta can be achieved in a substantial number of cases before complete aortic rupture occurs and a higher proportion of direct suture repair can be achieved under such circumstances. Most proximal descending aortic procedures are performed without cardiopulmonary bypass (clamp and go) but paraplegia may occur before, during, or after the procedure. Ascending aortic lesions and disruption of the aortic arch, the supra-aortic vessels, the main pulmonary arteries, the great veins as well as cardiac lesions are best approached through a sternotomy, which may have to be extended. Cardiopulmonary bypass allowing for deep hypothermia and circulatory arrest is often required and carries its own complications. It is not clear whether the increasing proportion of ascending aortic and cardiac lesions which are observed nowadays are due to a change in trauma mechanics (i.e., speed limits, seat belts, air-bags), an improvement of the diagnostic tools or both.

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BACKGROUND CONTEXT: Kyphotic deformities with sagittal imbalance of the spine can be treated with spinal osteotomies. Those procedures are known to have a high incidence of neurological complications, in particular at the thoracic level. Motor evoked potentials (MEPs) have been widely used in helping to avoid major neurological deficits postoperatively. Previous reports have shown that a significant proportion of such cases present with important transcranial MEP (Tc-MEP) changes during surgery with some of them being predictive of postoperative deficits. PURPOSE: Our aim was to study Tc-MEP changes in a consecutive series of patients and correlate them with clinical parameters and radiological changes. STUDY DESIGN/SETTING: Retrospective case notes study from a prospective patient register. PATIENT SAMPLE: Eighteen patients undergoing posterior shortening osteotomies (nine at thoracic and nine at lumbar levels) for kyphosis of congenital, degenerative, inflammatory, or post-traumatic origin were included. OUTCOME MEASURES: Loss of at least 80% of Tc-MEP signal expressed as the area under the curve percentual change, of at least one muscle. METHODS: We studied the relation between outcome measure (80% Tc-MEP loss in at least one muscle group) and amount of posterior vertebral body shortening as well as angular correction measured on computed tomography scans, occurrence of postoperative deficits, intraoperative blood pressure at the time of the osteotomy, and hemoglobin (Hb) change. RESULTS: All patients showed significant Tc-MEP changes. In particular, greater than 80% MEP loss in at least one muscle group was observed in five of nine patients in the thoracic group and four of nine patients in the lumbar group. No surgical maneuver was undertaken as a result of this loss in an effort to improve motor responses other than verifying the stability of the construct and the extent of the decompression. Four patients developed postoperative deficits of radicular origin, three of them recovering fully at 3 months. No relation was found between intraoperative blood pressure, Hb changes, and Tc-MEP changes. Severity of Tc-MEP loss did not correlate with postoperative deficits. Shortening of more than 10 mm was linked to more severe Tc-MEP changes in the thoracic group. CONCLUSIONS: Transcranial MEP changes during spinal shortening procedures are common and do not appear to predict severe postoperative deficits. Total loss of Tc-MEP (not witnessed in our series) might require a more drastic approach with possible reversal of the correction and wake-up test.

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Pyogenic liver abscess is a severe condition and a therapeutic challenge. Treatment failure may be due to an unrecognized ingested foreign body that migrated from the gastrointestinal tract. There has recently been a marked increase in the number of reported cases of this condition, but initial misdiagnosis as cryptogenic liver abscess still occurs in the majority of cases. We conducted the current study to characterize this entity and provide a diagnostic strategy applicable worldwide. To this end, data were collected from our case and from a systematic review that identified 59 well-described cases. Another systematic review identified series of cryptogenic-and Asian Klebsiella-liver abscess; these data were pooled and compared with the data from the cases of migrated foreign body liver abscess. The review points out the low diagnostic accuracy of history taking, modern imaging, and even surgical exploration. A fistula found through imaging procedures or endoscopy warrants surgical exploration. Findings suggestive of foreign body migration are symptoms of gastrointestinal perforation, computed tomography demonstration of a thickened gastrointestinal wall in continuity with the abscess, and adhesions seen during surgery. Treatment failure, left lobe location, unique location (that is, only 1 abscess location within the liver), and absence of underlying conditions also point to the diagnosis, as shown by comparison with the cryptogenic liver abscess series. This study demonstrates that migrated foreign body liver abscess is a specific entity, increasingly reported. It usually is not cured when unrecognized, and diagnosis is mainly delayed. This study provides what we consider the best available evidence for timely diagnosis with worldwide applicability. Increased awareness is required to treat this underestimated condition effectively, and further studies are needed.

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Objectives: Nasopalatine duct cysts (NPDCs) are the most common developmental, epithelial and non-odontogenic cysts of the maxillae. The present study describes the clinicopathological characteristics of 22 NPDCs and discusses their etiology, incidence, treatment and prognosis, with a review of the literature on the subject. Study design: A retrospective observational study was made comprising a period of 36 years (1970-2006), and yielding a series of 22 patients with histopathological confirmation of NPDC. Surgical treatment was carried out under local anesthesia and comprised the dissection and removal of the cyst adopting a usually palatine approach, with the preparation of an enveloping flap from 1.4 to 2.4. Results: No statistically significant correlation was observed between the size of the lesion and patient age, although the size of the cyst differed according to patient gender, with a mean NPDC diameter of 16 mm in males and 12 mm in females. In no case did we observe root reabsorption or loss of vitality of the upper incisors following surgery. The X-ray image was rounded in 15 cases and heart-shaped in the remaining 7 cases. In the majority of cases panoramic X-rays and periapical and occlusal X-rays sufficed to identify the lesion, though computed tomography was used in cases of doubt. Conclusions: The etiology of NPDC is unclear. Simple surgical resection is recommended, followed by clinical and radiological control to ensure correct resolution of the case.

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Idiopathic pulmonary fibrosis (IPF) is the most frequent of the idiopathic interstitial pneumonias. It is a progressive disorderwith a poor prognosis. Its diagnosis requires the careful exclusion of potential causes, and a pattern of usual interstitial pneumonia at high-resolution computed tomography or video-assisted surgical lung biopsy. Several recent randomized trials have profoundly modified the therapeutic management of IPF. The combination of prednisone and azathioprine, often prescribed until recently, has been shown to be harmful and is no longer indicated. N-acetylcystein, also used in the past decade, failed to show an efficacy. However, two new antifibrotic drugs, pirfenidone and nintedanib, have for the first time proven effective in slowing disease progression.

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Objective: To report a single-center experience treating patients with squamous- cell carcinoma of the anal canal using helical Tomotherapy (HT) and concurrent chemotherapy (CT).Materials/Methods: From October 2007 to February 2011, 55 patients were treated with HT and concurrent CT (5-fluorouracil/capecitabin and mitomycin) for anal squamous-cell carcinoma. All patients underwent computed- tomography-based treatment planning, with pelvic and inguinal nodes receiving 36 Gy in 1.8 Gy/fraction. Following a planned 1-week break, primary tumor site and involved nodes were boosted to a total dose 59.4 Gy in 1.8 Gy/fraction. Dose-volume histograms of several organs at risk (OAR; bladder, small intestine, rectum, femoral heads, penile bulb, external genitalia) were assessed in terms of conformal avoidance. All toxicity was scored according to the CTCAE, v.3.0. HT plans and treatment were implemented using the Tomotherapy, Inc. software and hardware. For dosimetric comparisons, 3D RT and/or IMRT plans were also computed for some of the patients using the CMS planning system, for treatment with 6-18 MV photons and/or electrons with suitable energies from a Siemens Primus linear accelerator equipped with a multileaf collimator.Locoregional control and survival curves were compared with the log-rank test, and multivariate analysis by the Cox model.Results: With 360-degree-of-freedom beam projection, HT has an advantage over other RT techniques (3D or 5-field step-and-shot IMRT). There is significant improvement over 3D or 5-field IMRT plans in terms of dose conformity around the PTV, and dose gradients are steeper outside the target volume, resulting in reduced doses to OARs. Using HT, acute toxicity was acceptable, and seemed to be better than historical standards.Conclusions: Our results suggest that HT combined with concurrent CT for anal cancer is effective and tolerable. Compared to 3D RT or 5-field step-andshot IMRT, there is better conformity around the PTV, and better OAR sparing.

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Nationwide surveys on radiation dose to the population from medical radiology are recommended in order to follow the trends in population exposure and ensure radiation protection. The last survey in Switzerland was conducted in 1998, and the annual effective dose from medical radiology was estimated to be 1 mSv y(-1) per capita. The purpose of this work was to follow the trends in diagnostic radiology between 1998 and 2008 in Switzerland and determine the contribution of different modalities and types of examinations to the collective effective dose from medical x-rays. For this reason, an online database (www.raddose.ch) was developed. All healthcare providers who hold a license to run an x-ray unit in the country were invited to participate in the survey. More than 225 examinations, covering eight radiological modalities, were included in the survey. The average effective dose for each examination was reassessed. Data from about 3,500 users were collected (42% response rate). The survey showed that the annual effective dose was 1.2 mSv/capita in 2008. The most frequent examinations are conventional and dental radiographies (88%). The contribution of computed tomography was only 6% in terms of examination frequency but 68% in terms of effective dose. The comparison with other countries showed that the effective dose per capita in Switzerland was in the same range as in other countries with similar healthcare systems, although the annual number of examinations performed in Switzerland was higher.

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OBJECTIVES: The purpose of this study was to assess the effectiveness of a novel radiation-independent aiming device for distal locking of intramedullary nails in a human cadaver model. METHODS: A new targeting system was used in 25 intact human cadaver femora for the distal locking procedure after insertion of an intramedullary nail. The number of successful screw placements and the time needed for this locking procedure were recorded. The accuracy of the aiming process was evaluated by computed tomography. RESULTS: The duration of the distal locking process was 8.0 ± 1.8 minutes (mean ± SD; range, 4-11 minutes). None of the screw placements required fluoroscopic guidance. Computed tomography revealed high accuracy of the locking process. The incidence angle (α) of the locking screws through the distal locking holes of the nail was 86.8° ± 5.0° (mean ± SD; range, 80°-96°). Targeting failed in 1 static locking screw because of a material defect in the drilling sleeve. CONCLUSIONS: This cadaver study indicated that an aiming arm-based targeting device is highly reliable and accurate. The promising results suggest that it will help to decrease radiation exposure compared with the traditional "free-hand technique."

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PURPOSE: To evaluate the technical quality and the diagnostic performance of a protocol with use of low volumes of contrast medium (25 mL) at 64-detector spiral computed tomography (CT) in the diagnosis and management of adult, nontraumatic subarachnoid hemorrhage (SAH). MATERIALS AND METHODS: This study was performed outside the United States and was approved by the institutional review board. Intracranial CT angiography was performed in 73 consecutive patients with nontraumatic SAH diagnosed at nonenhanced CT. Image quality was evaluated by two observers using two criteria: degree of arterial enhancement and venous contamination. The two independent readers evaluated diagnostic performance (lesion detection and correct therapeutic decision-making process) by using rotational angiographic findings as the standard of reference. Sensitivity, specificity, and positive and negative predictive values were calculated for patients who underwent CT angiography and three-dimensional rotational angiography. The intraclass correlation coefficient was calculated to assess interobserver concordance concerning aneurysm measurements and therapeutic management. RESULTS: All aneurysms were detected, either ruptured or unruptured. Arterial opacification was excellent in 62 cases (85%), and venous contamination was absent or minor in 61 cases (84%). In 95% of cases, CT angiographic findings allowed optimal therapeutic management. The intraclass correlation coefficient ranged between 0.93 and 0.95, indicating excellent interobserver agreement. CONCLUSION: With only 25 mL of iodinated contrast medium focused on the arterial phase, 64-detector CT angiography allowed satisfactory diagnostic and therapeutic management of nontraumatic SAH.

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BACKGROUND: Leptomeningeal collaterals improve outcome after stroke, including reduction of hemorrhagic complications after thrombolytic or endovascular therapy, smaller infarct size, and reduction in symptoms at follow-up evaluation. The purpose of this study was to determine the demographic and clinical variables that are associated with a greater degree of cerebral collaterals. METHODS: Clinical data of patients presenting with M1 occlusions of the middle cerebral artery (MCA) and associated computed tomography angiography studies after admission from 3 separate institutions were retrospectively compiled (n = 82). Occluded hemispheres were evaluated against the intact hemisphere for degree of collateralization in the MCA territory. Regression analysis of variance was conducted between clinical variables and collateral score to determine which variables associate with greater collateral development. RESULTS: Smaller infarct size corresponded to greater collateral scores, whereas older age and statin use corresponded to lower collateral scores (P < .001). CONCLUSIONS: Cerebral collateralization is influenced by age and statin use and influences infarct size.

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OBJECTIVE: Despite dramatic advances in all medical era, cerebral vasospasm is still the major complication in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to assess the influence of intraarterial (IA) nimodipine in the treatment of symptomatic vasospasm and in preventing neurological disabilities. MATERIALS AND METHODS: We retrospectively reviewed 10 patients of SAH who received IA nimodipine in 15 procedures. The decision to perform angiography and endovascular treatment was based on the neurological examination, brain computed tomography (CT) and CT-angiography. The procedure reports, anesthesia records, neurological examination before and after the procedure, brain imaging and short- and long-term outcome were studied. RESULTS: The average dose of nimodipine was 2 mg. The median change in mean arterial pressure at 10 min was -10 mmHg. No significant change of heart rate was observed at 10 min. There was radiological improvement in 80% of the procedures. Neurological improvement was noted after eight out of 12 procedures when nimodipine was used as the sole treatment and after 10 out of 15, overall. Six patients clinically improved after the treatment and had good outcome. In one patient, an embolus caused fatal anterior and middle cerebral arteries infarction. There was no other neurological deficit or radiological abnormality due to the nimodipine treatment itself. CONCLUSION: Low-dose IA nimodipine is a valid adjunct for the endovascular treatment of cerebral vasospasm. Beneficial effects are achieved in some patients, prompting a prospective control study.