Search results for " Medical imaging"
showing 10 items of 1067 documents
An adapted optical flow algorithm for robust quantification of cardiac wall motion from standard cine-MR examinations
2012
International audience; This paper presents a method for local myocardial motion estimation from a conventional steady-state free precession cine-MRI sequence using a modified phase-based optical flow (OF) technique. Initially, the technique was tested on synthetic images to evaluate its robustness with regards to Rician noise and to brightness variations. The method was then applied to cardiac images acquired on 11 healthy subjects. Myocardial velocity is measured in centimeter per second in each studied pixel and visualized as colored vectors superimposed on MRI images. The estimated phase-based OF results were compared with a reference OF method and gave similar results on synthetic imag…
3D CT scan for perioperative identification of anatomical variations of lungs.
2016
Aim: The aim of this study is to investigate anatomical lung variations and vascular patterns using volumetric 3D computed tomography (CT) representations. Methods & results: We considered 24 major thoracic surgery performed in our ward. In these, we discovered some interesting anatomical variations of the main pulmonary fissures. These findings were not visible on the plain x-ray or during routine examination of a preoperative CT scan. After re-examination of 3D CT scan reconstruction the anatomical variations were detected. Discussion: General thoracic surgeons must familiarize themselves with anatomical variations in lungs. 3D images may aid the general thoracic surgeon in performin…
Amide-to-triazole switch vs. in vivo NEP-inhibition approaches to promote radiopeptide targeting of GRPR-positive tumors
2017
Abstract Introduction Radiolabeled bombesin (BBN)-analogs have been proposed for diagnosis and therapy of gastrin-releasing peptide receptor (GRPR)-expressing tumors, such as prostate, breast and lung cancer. Metabolic stability represents a crucial factor for the success of this approach by ensuring sufficient delivery of circulating radioligand to tumor sites. The amide-to-triazole switch on the backbone of DOTA-PEG 4 -[Nle 14 ]BBN(7–14) ( 1 ) was reported to improve the in vitro stability of resulting 177 Lu-radioligands. On the other hand, in-situ inhibition of neutral endopeptidase (NEP) by coinjection of phosphoramidon (PA) was shown to significantly improve the in vivo stability and …
Model-Based Dose Calculation Algorithms for Brachytherapy Dosimetry
2019
The purpose of this study was to review the limitations of dose calculation formalisms for photon-emitting brachytherapy sources based on the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) report and to provide recommendations to transition to model-based dose calculation algorithms. Additionally, an overview of these algorithms and approaches is presented. The influence of tissue and seed/applicator heterogeneities on brachytherapy dose distributions for breast, gynecologic, head and neck, rectum, and prostate cancers as well as eye plaques and electronic brachytherapy treatments were investigated by comparing dose calculations based on the TG-43 formalism …
Comparison between MRI and pathology in the assessment of tumour regression grade in rectal cancer
2017
Background: Limited data exist regarding the correlation between MRI tumour regression grade (mrTRG) and pathological TRG (pTRG) in rectal cancer. Methods: mrTRG and pTRG were compared in rectal cancer patients from two phase II trials (EXPERT and EXPERT-C). The agreement between radiologist and pathologist was assessed with the weighted κ test while the Kaplan–Meier method was used to estimate survival outcomes. Results: One hundred ninety-one patients were included. Median time from completion of neoadjuvant treatment to pre-operative MRI and surgery was 4.1 weeks (interquartile range (IQR): 3.7–4.7) and 6.6 weeks (IQR: 5.9–7.6), respectively. Fair agreement was found between mrTRG and pT…
Multifocal Biliary Cystadenocarcinoma of the Liver: CT and Pathological Findings
2006
Biliary cystadenocarcinoma is a rare tumor that originates from the hepatobiliary epithelium. Although this tumor can affect any portion of the biliary tree, intrahepatic location is more common. It is usually a slow growing tumor and often asymptomatic until it reaches a considerable size. The lesion is most often solitary and large when discovered; multiple lesions or metastases within the liver are very rare. A 63-year-old man was referred to our institute for weight loss, abdominal discomfort, worsening bulky symptoms in the right upper abdominal quadrant, and an increase in serum aminotransferases that had been present for several months. Spiral CT of the abdomen demonstrated two lesi…
Sequential boost in neoadjuvant irradiation for T3N0-1 rectal cancer: long-term results from a single-center experience.
2016
Purpose To evaluate the influence of radiation dose on tumor regression grade (TRG) and sphincter preservation rate in a series of cT3N0-1 rectal cancer patients treated with neoadjuvant chemoradiotherapy (CT-RT) with or without a sequential radiation boost. Materials and methods Between May 2002 and September 2013, 116 cases were eligible for retrospective evaluation. Radiotherapy was delivered for a total dose of 45 Gy (no boost arm) or 50.4 Gy (boost arm). TRG was evaluated with the Dworak scale. Results Median follow-up was 62 months (range, 12-138 months). The 5-year overall survival and local control rates were 72% and 93%, respectively. Fifty-five patients (47%) were treated with a s…
Postoperative Radiation Therapy in Patients with Extracranial Chondrosarcoma: A Joint Study of the French Sarcoma Group and Rare Cancer Network
2020
International audience; PurposePostoperative radiation therapy (poRT) of intracranial/skull base chondrosarcomas (CHSs) is standard treatment. However, consensus is lacking for poRT in extracranial CHS (eCHS) owing to their easier resectability and intrinsic radioresistance. We assessed the practice and efficacy of poRT in eCHS.Methods and MaterialsThis multicentric retrospective study of the French Sarcoma Group/Rare Cancer Network included patients with eCHS who were operated on between 1985 and 2015. Inverse propensity score weighting (IPTW) was used to minimize poRT allocation biases.ResultsOf 182 patients, 60.4% had bone and 39.6% had soft-tissue eCHS. eCHS were of conventional (31.9%)…
A DOTA based bisphosphonate with an albumin binding moiety for delayed body clearance for bone targeting
2016
Radiolabeled bisphosphonates are commonly used in the diagnosis and therapy of bone metastases. Blood clearance of bisphosphonates is usually fast and only 30%-50% of the injected activity is retained in the skeleton, while most of the activity is excreted by the urinary tract. A longer blood circulation may enhance accumulation of bisphosphonate compounds in bone metastases. Therefore, a chemically modified macrocyclic bisphosphonate derivative with an additional human albumin binding entity was synthesized and pharmacokinetics of its complex was evaluated. The DOTA-bisphosphonate conjugate BPAMD was compared against the novel DOTAGA-derived albumin-binding bisphosphonate DOTAGA(428-d-Lys)…
Perfusion of surgical cavity wall enhancement in early post-treatment MR imaging may stratify the time-to-progression in glioblastoma
2017
Objective To determine if perfusion in surgical cavity wall enhancement (SCWE) obtained in early post-treatment MR imaging can stratify time-to-progression (TTP) in glioblastoma. Materials and methods This study enrolled 60 glioblastoma patients with more than 5-mm-thick SCWEs as detected on contrast-enhanced MR imaging after concurrent chemoradiation therapy. Two independent readers categorized the shape and perfusion state of SCWEs as nodular or non-nodular and as having positive or negative perfusion compared with the contralateral grey matter on arterial spin labeling (ASL). The perfusion fraction on ASL within the contrast-enhancing lesion was calculated. The independent predictability…