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Objectifs Savoir regler les sequences de rehaussements tardifs (reglage du temps d’inversion, quelles sequences pour quels patients, delai injection – acquisition). Connaitre la dose de contraste a injecter. Connaitre les autres moyens pour mettre en evidence le rehaussement d’une structure cardiaque. Connaitre la possibilite d’utiliser le scanner pour mettre en evidence un rehaussement tardif. Messages a retenir L'IRM est la technique de reference qui permet de mettre en evidence un rehaussement tardif. La visualisation du rehaussement tardif est possible en scanner. Le reglage et la qualite de la sequence sont les parametres les plus importants en IRM. La quantite de produit de contraste et le delai entre l’injection et l’acquisition sont les deux parametres les plus importants pour la qualite d’image en scanner. Resume Les sequences de rehaussement tardif en IRM representent la technique de reference pour la mise en evidence d’une zone de fibrose ou de necrose dans le myocarde. L’optimisation de cette technique depend premierement de l’optimisation de la sequence. Les sequences de rehaussement tardif necessitent un reglage du temps d’inversion precis pour eviter les artefacts. D’autre part, les differents constructeurs proposent des solutions pour les patients arythmiques ou incapables de tenir une apnee. Deuxiemement, le produit de contraste utilise a un interet majeur dans ces reglages, seuls les produits extracellulaires doivent etre utilises et la dose ainsi que le delai entre l’injection et l’acquisition des images doivent etre adaptes en fonction des pathologies. Les sequences de mesure du Tl ainsi que les sequences cinetiques peuvent etre utilisees dans certains cas difficiles. Recemment le scanner est apparu comme une technique prometteuse pour la realisation des sequences de rehaussement tardif et doit aussi beneficier de reglage precis pour etre reproductible et efficace.

Purpos To determine the efficacy and safety of urokinase in the management of occluded PICC lines. Materials and Methods A total of 587 PICC lines were placed over an 11 month period. During this period, 28 PICC lines (4.8%) became occluded: 12 occluded PICC lines were successfully managed by simple flushing with normal saline while 16 PICC lines were thrombolyzed with urokinase. Results After urokinase, 93.8% (15/16) of occluded PICC lines were completely patent. A single infusion of urokinase, 20 000 IU over 30 minutes, was used in all cases. No secondary occlusion or complication was noted after urokinase. Conclusion Urokinase is effective and safe to restore patency to occluded PICC lines. The procedure is simple, and could be performed at the bedside by nursing staff after medical prescription. It is an alternative to over the wire PICC line exchange, that could reduce the risk of complication related to manipulations, patient discomfort and cost.

Virtual interventional radiology: Evaluation of performances as a function of experience Purpose. To determine the value of an angioplasty simulation to differentiate the users based on their level of experience. To determine the perceived usefulness of an angioplasty simulation program. Materials and methods. Forty-six radiologists performed a renal angioplasty on a VIST simulator (Mentice Corporation, Gothenburg, Sweden); the procedure was completed by 41 radiologists. The radiologists were divided into two groups based on the level of experience. Quantitative variables analyzed included procedure duration time and fluoroscopy time. The radiologists then completed a questionnaire evaluating the simulation program. Results. Radiologists with more than 2 years of clinical experience (n = 14) performed the procedures faster (20.4 min vs 27.4 min, p Conclusion. Procedure duration time and duration of fluoroscopy were criteria able to differentiate the users based on their level of experience. The educational value of the simulation program was perceived as helpful by the users.

Imaging plays a chief role in the care and monitoring of patients in cervico-facial oncology. The radiologist must know the anatomy of different lymph nodes as well as signs of malignancy (hypertrophy, enhancement, necrosis, capsular rupture, etc.). CT is still the first-line examination because of its high reliability, its accessibility and its ability to make an assessment of the upper aero digestive ways at the same time. Ultrasound is very accuracy, and allows the realization of cytoponction, but does not provide a complete exploration of the neck. MRI does not appear to be indicated for the first intention, but the new rapid sequences (STIR, diffusion) seem interesting. The PET-CT is useful in post-therapeutic management of patients, and probably in the initial staging, but its accessibility is poor.

Nasopharyngeal carcinoma Nasopharyngeal carcinoma is relatively common. Undifferentiated Carcinomas of Nasopharyngeal Type (UNCT) are endemic Epstein-Barr virus (EBV)-related tumors. They are mainly radiosensitive. The role of imaging is to assess locoregional extension, TNM classification and adjust the radiation fields. MRI is essential to determine the initial extension. CT is useful to confirm the presence of bone involvement and evaluate nodal status. MRI and CT are necessary for the post-treatment follow-up.

Prospective evaluation of PICC line related complications Purpose. To report the occurrence of complications following placement of peripherally inserted central catheters (PICC). Materials and methods. A total of 127 PICC lines were placed in 115 patients for TPN (n=54), long-term antibiotics (n=29), chemotherapy (n=14) or miscellaneous intravenous therapy (n=18). Results. All PICC lines were successfully inserted. PICC lines were used for a mean duration of 16 days (1-166 days). The following complications were recorded: occlusion (7%), rupture (1.6%), accidental withdrawal (2.4%), infection (3.1%) and venous thrombosis (2.4%). Conclusion. PICC lines are a simple, safe and effective alternative to conventional central venous catheters. The occurrence of complications, typically “mechanical”, must be reduced and prevented by strict management of this type of central line by the treating team.

Resume Objectif Evaluer l’interet du scanner dans l’exploration des infections de protheses totales de hanches. Patients et methodes Un scanner a ete realise sur dix sept hanches de quatorze patients presentant une suspicion d’infection de prothese totale de hanche. Nous recherchons dans les parties molles peri-prothetiques la presence d’abces, d’epanchements articulaires et de fistules cutanees et au niveau de l’interface os-materiel prothetique, la presence de liseres radio-clairs ou d’erosions osseuses. Nous etudions la faisabilite du scanner malgre les artefacts metalliques generes par les protheses. Resultats Dix hanches sont septiques. Nous retrouvons un abces dans les parties molles chez huit patients sur dix, associe dans sept cas a un epanchement articulaire suspect de surinfection. Un trajet fistuleux inflammatoire est retrouve dans huit cas. L’analyse de l’interface osseuse revele la presence de liseres chez dix patients, dont sept sont septiques et d’erosions chez quatre patients dont deux sont septiques. Les artefacts metalliques ne sont pas un obstacle dans la visualisation des abces des parties molles. Conclusions Le scanner permet le diagnostic d’abces des parties molles au cours des infections de protheses de hanches. Cet examen permet d’orienter l’intervention chirurgicale ou une surveillance si un traitement medical seul est envisage.

Arrhythmogenic right ventricular dysplasia (ARVD) is a cardiomyopathy of unknown etiology responsible for 20% of cases of sudden death in young adults secondary to arrhythmia. It is characterized histologically by fatty or fibro-fatty infiltration of the right ventricular myocardium. Diagnostic criteria have been proposed for diagnosing ARVD. Imaging, especially MRI, plays an important role. MR imaging must be performed using cardiac gating, and should include both cine-MR sequences for evaluation of segmental and global right ventricular function or any morphological change of the right ventricular shape, and anatomic sequences to detect fatty or fibro-fatty infiltration of the right ventricular myocardium.

CT, MRI and transesophageal echocardiography have become the standard of reference for evaluation of the thoracic aorta. Angiography is mainly performed as a presurgical procedure. Congenital pathologies observed during adulthood include coarctation, patent ductus arteriosus, and aberrant retroesophageal subclavian arteries. Imaging plays a major role for diagnosis and management of patients with acute aortic syndromes: intramural hematoma, dissection, penetrating ulcer and nondissecting aneurysms. Cross sectional imaging of the thoracic aortic wall allows evaluation of inflammatory diseases of the aorta or aortitis.

The purpose of this article is to 1) review the basic models characterizing myocardial enhancement on MR and CT, 2) review the main characteristics of available iodinated and Gadolinium-based contrast agents and, 3) review the literature on emerging MR contrast agents to assess myocardial viability. The intensity of enhancement following infarction is the result of two processes: 1) the increased interstitial space (15 + or - 2% in normal myocardium and 80 + or - 3% in necrotic tissue) secondary to cell necrosis and 2) perfusion abnormalities secondary to absent revascularization or impaired microvascularization. The equation described by Kety was used to create models of contrast material kinetics within myocardium or enhancement of the different components of the myocardium (viable myocardium, necrosed myocardium, fibrosis, with no-reflow zone, hibernating or stunned myocardium).

Peripherally inserted central catheters (PICC): a promising technique To describe technical features and benefits from PICC lines.

The authors report the clinical and imaging features of a patient with rupture of an aortoiliac graft successfully treated by endovascular approach. The endovascular treatment is easy to perform and effective. The main pitfall of this technique is the limited availability of stent-grafts.

To determine the efficacy and safety of urokinase in the management of occluded PICC lines.A total of 587 PICC lines were placed over an 11 month period. During this period, 28 PICC lines (4.8%) became occluded: 12 occluded PICC lines were successfully managed by simple flushing with normal saline while 16 PICC lines were thrombolyzed with urokinase.After urokinase, 93.8% (15/16) of occluded PICC lines were completely patent. A single infusion of urokinase, 20,000 IU over 30 minutes, was used in all cases. No secondary occlusion or complication was noted after urokinase.Urokinase is effective and safe to restore patency to occluded PICC lines. The procedure is simple, and could be performed at the bedside by nursing staff after medical prescription. It is an alternative to over the wire PICC line exchange, that could reduce the risk of complication related to manipulations, patient discomfort and cost.

This evaluation of clinical practices (pulmonary embolus) was performed to evaluate the quality of CT pulmonary angiograms for suspected acute pulmonary embolus.Five validated criteria evaluating both the acquisition technique and the quality of image interpretation were selected: slice thickness, pulmonary arterial enhancement over 250 HU, caudocranial acquisition, visualization of fifth order pulmonary arterial branches, and right-left ventricular ratio in the presence of pulmonary embolus. Forty CT pulmonary angiograms were reviewed before and after implementation of a practice quality improvement program: modification of acquisition protocol, training of medical and paramedical staff, and implementation of a standardized radiology report.Thin collimation was already implemented. The implementation of two other technical parameters significantly improved the technical quality of the examinations. The detection of findings with adverse clinical outcome was also significantly improved. Only the accuracy of detection of embolus involving fifth order pulmonary arterial branches could not be improved, a criteria allowing formal exclusion of pulmonary embolus.This study resulted in an improvement in the quality of CT pulmonary angiograms and increased awareness of radiologists for the prognostic value of right ventricular dilatation. It has also underscored the need for quality control of a CT pulmonary angiogram prior to interpretation.

To determine the impact of exposing medical students to medical imaging during the first year of the second cycle of medical school (DCEM1) on their perception of this medical specialty and the acquisition of its basic concepts.All students in the 2007-2008 graduation class entering into the first year of the second cycle of medical school were anonymously enrolled into this project that included pre-rotation and post-rotation questionnaires, theory classes followed by clinical rotations with clearly predetermined objectives.A total of 108 students were enrolled, with 70% being females. The parents of the students had a medical or paramedical profession in 46.3% of cases. Before the rotation, 61.6% of students perceived a difference between a hospital-based practice and private practice. Fifty-two percent of students had a clear idea of their professional future prior to the rotation. Five students (4.7%) believed prior to the rotation that it might have an impact on their professional future, versus 63% after the rotation (P0.0001). The students whose parents work in the medical or paramedical field do not have a better defined idea of their professional future; on the other hand, they have more interest for radiology (73.6% with high or very high interest versus 52.8%, P=0.03). After the rotation, there was a significant increase in the number of students with high or very high interest for radiology (77.8% versus 66.7%, P=0.023). A student noted that he would redirect his career to radiology. There was also a significant increase in the number of students perceiving a difference between a hospital-based practice and private practice (82.2% versus 61.6%, P=0.003). With regards to radiology knowledge before and after the rotation, there was a significant increase of mean scores (P0.001). Eighty-eight percent of students were satisfied or very satisfied with the radiology rotation. Overall, the students believe that 70% of the objectives were achieved. The only criticism from the students was that the clinical instructors were overworked.Early exposure of medical students to radiology increases their level of interest for the specialty and increases the perception of differences between a hospital-based practice and private practice. The overall knowledge of students about radiology was improved, but the workload of clinical instructors impaired the quality of the rotation.

To determine the value of an angioplasty simulation to differentiate the users based on their level of experience. To determine the perceived usefulness of an angioplasty simulation program.Forty-six radiologists performed a renal angioplasty on a VIST simulator (Mentice Corporation, Gothenburg, Sweden); the procedure was completed by 41 radiologists. The radiologists were divided into two groups based on the level of experience. Quantitative variables analyzed included procedure duration time and fluoroscopy time. The radiologists then completed a questionnaire evaluating the simulation program.Radiologists with more than 2 years of clinical experience (n=14) performed the procedures faster (20.4 min vs 27.4 min, p0.01) using less fluoroscopy time (7.8 min vs 11.2 min, p0.05) than others. Radiologists performing more than 2 procedures per month (n=14) performed the procedures faster (19.4 min vs 27.9 min, p0.01) using less fluoroscopy time (7.4 min vs 11.3 min, p0.05) than other (n=27). The participating radiologists indicated that the simulation was realistic.Procedure duration time and duration of fluoroscopy were criteria able to differentiate the users based on their level of experience. The educational value of the simulation program was perceived as helpful by the users.

Imaging plays a chief role in the care and monitoring of patients in cervico-facial oncology. The radiologist must know the anatomy of different lymph nodes as well as signs of malignancy (hypertrophy, enhancement, necrosis, capsular rupture, etc.). CT is still the first-line examination because of its high reliability, its accessibility and its ability to make an assessment of the upper aero digestive ways at the same time. Ultrasound is very accuracy, and allows the realization of cytoponction, but does not provide a complete exploration of the neck. MRI does not appear to be indicated for the first intention, but the new rapid sequences (STIR, diffusion) seem interesting. The PET-CT is useful in post-therapeutic management of patients, and probably in the initial staging, but its accessibility is poor.

Nasopharyngeal carcinoma is relatively common. Undifferentiated Carcinomas of Nasopharyngeal Type (UNCT) are endemic Epstein-Barr virus (EBV)-related tumors. They are mainly radiosensitive. The role of imaging is to assess locoregional extension, TNM classification and adjust the radiation fields. MRI is essential to determine the initial extension. CT is useful to confirm the presence of bone involvement and evaluate nodal status. MRI and CT are necessary for the post-treatment follow-up.

To describe technical features and benefits from PICC lines.

To report the occurrence of complications following placement of peripherally inserted central catheters (PICC). Materials and methods. A total of 127 PICC lines were placed in 115 patients for TPN (n=54), long-term antibiotics (n=29), chemotherapy (n=14) or miscellaneous intravenous therapy (n=18).All PICC lines were successfully inserted. PICC lines were used for a mean duration of 16 days (1-166 days). The following complications were recorded: occlusion (7%), rupture (1.6%), accidental withdrawal (2.4%), infection (3.1%) and venous thrombosis (2.4%).PICC lines are a simple, safe and effective alternative to conventional central venous catheters. The occurrence of complications, typically "mechanical", must be reduced and prevented by strict management of this type of central line by the treating team.

The authors report the clinical and imaging features of a patient with rupture of an aortoiliac graft successfully treated by endovascular approach. The endovascular treatment is easy to perform and effective. The main pitfall of this technique is the limited availability of stent-grafts.

To evaluate the ability of CT imaging to detect infectious lesions in total hip prosthesis.CT was performed in 17 cases of suspected total hip prosthesis infection. Images were reviewed to evaluate for the presence of soft tissue abscess, hip joint effusion or fistula and peri-prosthetic lucency or erosion at bone window setting. The feasibility of CT imaging is assessed with regards to metallic artifacts.Infection was confirmed in 10 hips. A soft tissue abscess was present in 8 of these cases, in association to a joint effusion, presumably septic, in 7 cases. A fistula was identified in 8 cases. A peri-prosthetic lucency was present in 10 cases, 7 of which with infection, and erosions were noted in 4 patients, 2 of which with infection. Metallic artifacts reduced image quality but did not prevent detection of soft tissue abscesses.CT is useful for detection of soft tissue abscesses in patients with infected hip prosthesis. CT is useful for surgical planning or follow-up of patients treated conservatively.

CT, MRI and transesophageal echocardiography have become the standard of reference for evaluation of the thoracic aorta. Angiography is mainly performed as a presurgical procedure. Congenital pathologies observed during adulthood include coarctation, patent ductus arteriosus, and aberrant retroesophageal subclavian arteries. Imaging plays a major role for diagnosis and management of patients with acute aortic syndromes: intramural hematoma, dissection, penetrating ulcer and nondissecting aneurysms. Cross sectional imaging of the thoracic aortic wall allows evaluation of inflammatory diseases of the aorta or aortitis.

Arrhythmogenic right ventricular dysplasia (ARVD) is a cardiomyopathy of unknown etiology responsible for 20% of cases of sudden death in young adults secondary to arrhythmia. It is characterized histologically by fatty or fibro-fatty infiltration of the right ventricular myocardium. Diagnostic criteria have been proposed for diagnosing ARVD. Imaging, especially MRI, plays an important role. MR imaging must be performed using cardiac gating, and should include both cine-MR sequences for evaluation of segmental and global right ventricular function or any morphological change of the right ventricular shape, and anatomic sequences to detect fatty or fibro-fatty infiltration of the right ventricular myocardium.

The diagnosis of chronic sinusitis is based on clinical presentation, nasal endoscopy and CT scan. As a matter of fact, the CT scan of the paranasal sinuses is absolutely necessary to characterise the lesions, to visualise anatomic variations which are risk factors for the endoscopic surgery and to follow up treated and/or operated patients with recurrent symptoms. Nowadays, plain films of paranasal sinuses do not have any indication. MR Imaging may be indicated in selected cases of complicated sinusitis and of pseudotumors associated to sinusitis.

The imaging anatomy of the paranasal sinuses presents some complexity. The paranasal sinuses develop within facial and cranial bones. They communicate with one another and with the nasal cavity. Knowledge of normal anatomy is mandatory for accurate diagnosis of sinonasal pathology. The most frequent anatomical variants should be identified to decrease surgical risks. CT is the main imaging modality for the evaluation of sinonasal pathology.to review the normal sinonasal anatomy and its frequent anatomical variants at CT imaging.

The detection and the clinical and pathological findings of kidney tumors have much progressed over the last 15 years. The incidence of asymptomatic renal masses has increased up to 30% during this time. This is mostly due to advances in ultrasound and computed tomography imaging. So, the therapeutic management of these masses has also been significantly changed. A better knowledge of their clinical and anatomical features allowed a more efficient mutlidisplinary approach and a better assessment of their prognosis.

Objectifs Connaitre les indications de l’IRM en imagerie post-mortem. Connaitre les sequences IRM utilisables en pratique dans cette indication. Connaitre la semiologie elementaire des lesions du systeme nerveux central, des parenchymes pleins et des gros vaisseaux. Messages a retenir L’IRM sans injection de contraste est superieure a la TDM en imagerie post-mortem pour la detection et la caracterisation des lesions du systeme nerveux central. L’IRM permet la detection et la caracterisation des lesions des parenchymes pleins, notamment hepatique et splenique. L’IRM peut detecter des ruptures des gros vaisseaux, notamment de l’isthme aortique. L’examen IRM doit etre oriente par l’examen de la levee de corps et par l’examen TDM realise au prealable. Resume Nous presentons des cas pratiques de confrontations entre la TDM, l’IRM et l’examen autopsique, et ou l’IRM a ete d’un apport determinant dans la recherche des causes de la mort. L’IRM permet la detection des lesions traumatiques des parenchymes hepatique ou splenique, la visualisation d’hematomes epiduraux cervicaux, la mise en evidence de rupture isthmique de l’aorte thoracique. Toutes ces lesions n’etaient pas visibles sur l’examen TDM en contraste spontane realise au prealable. L’examen IRM doit neanmoins etre oriente par les constatations de la levee de corps et par l’examen TDM du corps entier.

Erdheim-Chester disease is a non-langerhans cell histiocytosis. It is a rare and plurifocal disease. Retroperitoneal involvement manifests as a mass associated with fibrosis, which is well visualized on CT scan and MRI. This disease is characterized by its potential to involve the whole retroperitoneum. We report a case of this disease that developed over twenty years, consisting of renal arteries stenosis, bilateral ureteral stenosis and evolutive adhesive capsulitis.