19 resultados para CT scan
em Université de Lausanne, Switzerland
Resumo:
A 67-year-old woman was referred for staging of a mucosa-associated lymphoid tumor lymphoma involving the left conjunctiva. CT scan had shown paravertebral and pelvic masses, and a breast nodule. FDG PET/CT demonstrated moderately increased uptake in the left ocular conjunctiva and confirmed the paravertebral and pelvic masses and the breast nodule. Moreover, abnormal FDG uptake was shown in 2 breast nodules, the flank, the gluteus maximus, and the gastric cardia. The patient received 6 cycles of rituximab-bendamustine chemotherapy with a complete clinical and metabolic response at the 6-month follow-up PET/CT and remained relapse-free without visual acuity problem after a 36-month follow-up.
Resumo:
Objective: Postmortem radiology had in recent years appeared in the field of forensic medicine and is now considered by some authors as a good replacement for conventional autopsy and by others as a complementary examination. Although postmortem CT radiological imaging is very useful in demonstrating traumatic lesions, its utility is still quite limited in the cardiovascular field. This limitation could be minimized by the introduction of postmortem angiography. At the University Center of Legal Medicine of Lausanne, CT scans and postmortem multiphase CTangiography are used in cases with a suspicion of ischemic heart disease.Method: The goal of this presentation is to demonstrate some correlations between postmortem CT, CTangiography and conventional autopsy examination in cases of ischemic heart disease.Results: We observed that the native CT scan can show only some pathological findings as cardiac tamponade and calcifications of coronary arteries. However, postmortem angiography allows a better visualization of coronary arteries and evaluation of stenosis and occlusion as well as better imaging of soft tissue.Conclusion: The interpretation of postmortem modern radiology is a new field for both forensic pathologists and radiologists who have to learn to read the postmortem modified images. The information obtained from both parties can help to further the understanding of CT and CT angiography in postmortem cases.
Resumo:
PURPOSE: To evaluate a diagnostic strategy for pulmonary embolism that combined clinical assessment, plasma D-dimer measurement, lower limb venous ultrasonography, and helical computed tomography (CT). METHODS: A cohort of 965 consecutive patients presenting to the emergency departments of three general and teaching hospitals with clinically suspected pulmonary embolism underwent sequential noninvasive testing. Clinical probability was assessed by a prediction rule combined with implicit judgment. All patients were followed for 3 months. RESULTS: A normal D-dimer level (<500 microg/L by a rapid enzyme-linked immunosorbent assay) ruled out venous thromboembolism in 280 patients (29%), and finding a deep vein thrombosis by ultrasonography established the diagnosis in 92 patients (9.5%). Helical CT was required in only 593 patients (61%) and showed pulmonary embolism in 124 patients (12.8%). Pulmonary embolism was considered ruled out in the 450 patients (46.6%) with a negative ultrasound and CT scan and a low-to-intermediate clinical probability. The 8 patients with a negative ultrasound and CT scan despite a high clinical probability proceeded to pulmonary angiography (positive: 2; negative: 6). Helical CT was inconclusive in 11 patients (pulmonary embolism: 4; no pulmonary embolism: 7). The overall prevalence of pulmonary embolism was 23%. Patients classified as not having pulmonary embolism were not anticoagulated during follow-up and had a 3-month thromboembolic risk of 1.0% (95% confidence interval: 0.5% to 2.1%). CONCLUSION: A noninvasive diagnostic strategy combining clinical assessment, D-dimer measurement, ultrasonography, and helical CT yielded a diagnosis in 99% of outpatients suspected of pulmonary embolism, and appeared to be safe, provided that CT was combined with ultrasonography to rule out the disease.
Resumo:
Rapport de Synthése : Introducfíon : la maladie diverticulaire est devenue un problème majeur de santé communautaire et occupe la cinquième place en termes de coûts des maladies digestives. La diverticulite représente sa complication la plus fréquente chez environ 20-25% des patients avec une maladie diverticulaire. Son taux de récidive après un premier épisode de diverticulite est estimé à 20%. Historiquement, il était accepté que le taux de complications et d'échec du traitement conservateur de la diverticulite soient plus élevés lors de récidive qu'après un épisode initial. Ceci a amené la communauté médicale ä un consensus qui est de proposer une sigmoidectomie élective suite à un 2ème épisode de diverticulite. De nouvelles données et réinterprétations de travaux antérieurs ont remis en question ce consensus. Par ces faits, les dernières recommandations de la société américaine de chirurgie colorectale restent encore évasives dues au manque d'évidence. Le but de cette thèse est de déterminer si la récidive de diverticulite a une présentation clinique et radiologique différente d'un épisode initiale et si le risque d'échec du traitement est réellement plus élevé. Méthode : étude rétrospective .de 271 patients consécutifs admis dans le service. de chirurgie viscérale CHUV pour diverticulite, confirmée par CT-scan, de 2001 à 2004. 202 patients présentaient un épisode initial (groupe I), et 69 une récidive (groupe R). Au total 20 paramètres cliniques et 15 radiologiques ont été analysés et comparés entre les 2 groupes, dont le taux de prise en charge chirurgicale, la présentation clinique initiale, la réponse au traitement, les complications, les paramètres de laboratoires, la présence de liquide libre, d'abcès ou de pneumopéritoine au scanner. Une analyse statistique univariée a été effectuée. Résultats : aucun des paramètres cliniques ou radiologiques n'étaient différents entre les deux groupes. Concernant la chirurgie, 15.8% des patients dans le groupe I ont nécessité une prise en charge chirurgicale à l'admission comparé à 5.8% dans le groupe R (p=0.04). Le taux d'échec du traitement conservateur dans les deux groupes était similaire (10.7% vs 10.0% ; p=0.84). Le taux de mortalité à 30 jours était de 3% dans le groupe I et 0% dans le groupe R (p= 0.34). Conclusion : selon les résultats de cette étude, la récidive de diverticulite n'entraîne pas plus de complications ni d'échec du traitement conservateur. De plus, le taux de prise en charge chirurgicale à l'admission du patient est moins fréquent en cas de récidive. Ces résultats remettent en questions le consensus actuel de prise en charge chirurgicale élective.
Resumo:
According to the hypothesis of Traub, also known as the 'formula of Traub', postmortem values of glucose and lactate found in the cerebrospinal fluid or vitreous humor are considered indicators of antemortem blood glucose levels. However, because the lactate concentration increases in the vitreous and cerebrospinal fluid after death, some authors postulated that using the sum value to estimate antemortem blood glucose levels could lead to an overestimation of the cases of glucose metabolic disorders with fatal outcomes, such as diabetic ketoacidosis. The aim of our study, performed on 470 consecutive forensic cases, was to ascertain the advantages of the sum value to estimate antemortem blood glucose concentrations and, consequently, to rule out fatal diabetic ketoacidosis as the cause of death. Other biochemical parameters, such as blood 3-beta-hydroxybutyrate, acetoacetate, acetone, glycated haemoglobin and urine glucose levels, were also determined. In addition, postmortem native CT scan, autopsy, histology, neuropathology and toxicology were performed to confirm diabetic ketoacidosis as the cause of death. According to our results, the sum value does not add any further information for the estimation of antemortem blood glucose concentration. The vitreous glucose concentration appears to be the most reliable marker to estimate antemortem hyperglycaemia and, along with the determination of other biochemical markers (such as blood acetone and 3-beta-hydroxybutyrate, urine glucose and glycated haemoglobin), to confirm diabetic ketoacidosis as the cause of death.
Resumo:
The incidental discovery of a solitary pulmonary nodule while performing a CT scan of the chest is a very common clinical problem. The differential diagnosis is large but the main clinical challenge is to exclude or ascertain a neoplasia. The evaluation of preexisting risk factors and the analysis of morphological characteristics of the nodule allow the clinician to solve this challenge in a significant number of cases. When the nature of the lesion remains indeterminate a careful follow-up with volumetric determination is necessary for decision making.
Resumo:
The trans-apical aortic valve implantation (TA-AVI) is an established technique for high-risk patients requiring aortic valve replacement. Traditionally, preoperative (computed tomography (CT) scan, coronary angiogram) and intra-operative imaging (fluoroscopy) for stent-valve positioning and implantation require contrast medium injections. To preserve the renal function in elderly patients suffering from chronic renal insufficiency, a fully echo-guided trans-catheter valve implantation seems to be a reasonable alternative. We report the first successful TA-AVI procedure performed solely under trans-oesophageal echocardiogram control, in the absence of contrast medium injections.
Resumo:
To make a comprehensive evaluation of organ-specific out-of-field doses using Monte Carlo (MC) simulations for different breast cancer irradiation techniques and to compare results with a commercial treatment planning system (TPS). Three breast radiotherapy techniques using 6MV tangential photon beams were compared: (a) 2DRT (open rectangular fields), (b) 3DCRT (conformal wedged fields), and (c) hybrid IMRT (open conformal+modulated fields). Over 35 organs were contoured in a whole-body CT scan and organ-specific dose distributions were determined with MC and the TPS. Large differences in out-of-field doses were observed between MC and TPS calculations, even for organs close to the target volume such as the heart, the lungs and the contralateral breast (up to 70% difference). MC simulations showed that a large fraction of the out-of-field dose comes from the out-of-field head scatter fluence (>40%) which is not adequately modeled by the TPS. Based on MC simulations, the 3DCRT technique using external wedges yielded significantly higher doses (up to a factor 4-5 in the pelvis) than the 2DRT and the hybrid IMRT techniques which yielded similar out-of-field doses. In sharp contrast to popular belief, the IMRT technique investigated here does not increase the out-of-field dose compared to conventional techniques and may offer the most optimal plan. The 3DCRT technique with external wedges yields the largest out-of-field doses. For accurate out-of-field dose assessment, a commercial TPS should not be used, even for organs near the target volume (contralateral breast, lungs, heart).
Resumo:
Early admission to hospital with minimum delay is a prerequisite for successful management of acute stroke. We sought to determine our local pre- and in-hospital factors influencing this delay. Time from onset of symptoms to admission (admission time) was prospectively documented during a 6-month period (December 2004 to May 2005) in patients consecutively admitted for an acute focal neurological deficit presented at arrival and of presumed vascular origin. Mode of transportation, patient's knowledge and correct recognition of stroke symptoms were assessed. Physicians contacted by the patients or their relatives were interviewed. The influence of referral patterns on in-hospital delays was further evaluated. Overall, 331 patients were included, 249 had an ischaemic and 37 a haemorrhagic stroke. Forty-five patients had a TIA with neurological symptoms subsiding within the first hours after admission. Median admission time was 3 hours 20 minutes. Transportation by ambulance significantly shortened admission delays in comparison with the patient's own means (HR 2.4, 95% CI 1.6-3.7). The only other factor associated with reduced delays was awareness of stroke (HR 1.9, 95% CI 1.3-2.9). Early in-hospital delays, specifically time to request CT-scan and time to call the neurologist, were shorter when the patient was referred by his family or to a lesser extent by an emergency physician than by the family physician (p < 0.04 and p < 0.01, respectively) and were shorter when he was transported by ambulance than by his own means (p < 0.01). Transportation by ambulance and referral by the patient or family significantly improved admission delays and early in-hospital management. Correct recognition of stroke symptoms further contributed to significant shortening of admission time. Educational programmes should take these findings into account.
Resumo:
PURPOSE: To investigate current practices and timing of neurological prognostication in comatose cardiac arrest patients. METHODS: An anonymous questionnaire was distributed to the 8000 members of the European Society of Intensive Care Medicine during September and October 2012. The survey had 27 questions divided into three categories: background data, clinical data, decision-making and consequences. RESULTS: A total of 1025 respondents (13%) answered the survey with complete forms in more than 90%. Twenty per cent of respondents practiced outside of Europe. Overall, 22% answered that they had national recommendations, with the highest percentage in the Netherlands (>80%). Eighty-nine per cent used induced hypothermia (32-34 °C) for comatose cardiac arrest patients, while 11% did not. Twenty per cent had separate prognostication protocols for hypothermia patients. Seventy-nine per cent recognized that neurological examination alone is not enough to predict outcome and a similar number (76%) used additional methods. Intermittent electroencephalography (EEG), brain computed tomography (CT) scan and evoked potentials (EP) were considered most useful. Poor prognosis was defined as cerebral performance category (CPC) 3-5 (58%) or CPC 4-5 (39%) or other (3%). When prognosis was considered poor, 73% would actively withdraw intensive care while 20% would not and 7% were uncertain. CONCLUSION: National recommendations for neurological prognostication after cardiac arrest are uncommon and only one physician out of five uses a separate protocol for hypothermia treated patients. A neurological examination alone was considered insufficient to predict outcome in comatose patients and most respondents advocated a multimodal approach: EEG, brain CT and EP were considered most useful. Uncertainty regarding neurological prognostication and decisions on level of care was substantial.
Resumo:
The objective of this work was to develop an easily applicable technique and a standardized protocol for high-quality post-mortem angiography. This protocol should (1) increase the radiological interpretation by decreasing artifacts due to the perfusion and by reaching a complete filling of the vascular system and (2) ease and standardize the execution of the examination. To this aim, 45 human corpses were investigated by post-mortem computed tomography (CT) angiography using different perfusion protocols, a modified heart-lung machine and a new contrast agent mixture, specifically developed for post-mortem investigations. The quality of the CT angiographies was evaluated radiologically by observing the filling of the vascular system and assessing the interpretability of the resulting images and by comparing radiological diagnoses to conventional autopsy conclusions. Post-mortem angiography yielded satisfactory results provided that the volumes of the injected contrast agent mixture were high enough to completely fill the vascular system. In order to avoid artifacts due to the post-mortem perfusion, a minimum of three angiographic phases and one native scan had to be performed. These findings were taken into account to develop a protocol for quality post-mortem CT angiography that minimizes the risk of radiological misinterpretation. The proposed protocol is easy applicable in a standardized way and yields high-quality radiologically interpretable visualization of the vascular system in post-mortem investigations.
Resumo:
Purpose: The aim of this educational poster is to introduce the technical principles of cerebral perfusion CT and to provide examples of its clinical applications and potential limitations in the everyday emergency practice. Methods and materials: Cerebral perfusion CT is a well established investigatory tool for many vascular and parenchymal brain dysfunctions. CT perfusion maps allow a semiquantitative assessment of cerebral perfusion. Results: Currently, cerebral perfusion CT has a pivotal role in differentiating reversible from irreversible ischemic parenchymal insult besides its integral role in grading vasospasm after subarachnoid hemorrhage. Furthermore, cerebral perfusion CT can be coupled to acetazolamide administration in order to assess the cerebrovascular reserve capacity before performing extra-/intra-cranial bypass surgery in patients with cerebral vascular insufficiency. Cerebral perfusion CT can also identify diffuse abnormalities of cerebral perfusion in children with traumatic brain injury showing a low initial GCS in order to predict the final outcome regarding the late occurrence of irreversible parenchymal damage. Cerebral Perfusion CT is also able to detect focal parenchymal perfusion abnormalities in acute epileptic seizures. Conclusion: Cerebral perfusion CT can be integrated in the management of many vascular, traumatic and functional disorders of the brain.