[A new modality for dentomaxillofacial imaging: cone beam CT]. / Nouveauté en radiologie dento-maxillofaciale: la tomographie volumétrique à faisceau conique.

Cone beam CT is an imaging technique used worldwide. It is a reliable and credible alternative to CT scan for dentomaxillofacial imaging. Radiation exposure may vary from one machine to another, but it remains definitely lower than CT dose levels. This technique is compatible with dental implant software. The major diagnostic advantage is the exquisite spatial resolution. The main pitfall is the poor contrast of face and neck soft tissues, due to a lower density resolution compared to CT scan.

[Dental implant news: from help to diagnosis to help to surgery]. / Nouveautés en implantologie: de l'aide au diagnostic à l'aide à la chirurgie.

Imaging has always been a part of dental implant procedures from its beginning. Initially, imaging was performed by dentists. The introduction of CT scan at the end of the seventies was revolutionary. Radiologists then played a major role in image generation and distribution. For the last two years, a revolution is occurring with the availability of "cone beam" CT machines in dental offices with implant planning software. The dentist can sometimes administer the entire delivery of care: choice of imaging technique, generation and distribution of imaging data, implant planning and treatment. The radiologist's role is now only conceivable as a specialist in dental imaging, attuned to the evolution of dental implant techniques.

[Digital volume tomography using the NewTom system: advantages of this new technique in children]. / La tomographie volumétrique numérisée par le système NewTom: intérêt de ce nouvel examen d'imagerie médicale chez l'enfant.

In some cases, after preliminary clinical examination, medical imaging can provide indispensable complementary information for the care of young patients. Volume imaging using two- and three-dimensional reconstructions provides the most complete information possible. Problems involving the superposition of anatomical structures, which can occur with conventional X-rays, are a thing of the past, and this technique represents the future in this field. In high-density tissue such as bone or teeth, tomodensitometry is the preferred examination as it can give a three-dimensional approach to the study. However, because of the high radiation dose required, scanner is still a second intention examination. Development of digital volume tomography using NewTom system, designed for maxillofacial exploration, produces the same type of image for a very much reduced X-ray dose, and at low cost. Although the use of this new examining technique is developing rapidly in Europe and throughout the world since its recent introduction, France is lagging behind as to date there are only seven machines in the entire country. The main uses in children, illustrated by original clinical cases, relate to preoperative surgery planning, post-trauma diagnostic workups, orthodontic checkups, postoperative follow-up and TMJ examinations. The purpose of this article is to inform dental surgeons, paediatricians and doctors about this new medical imaging examination, which will most definitely have a place in the battery of diagnostic tools available to us. After weighing the advantages/risks involved, it should be possible to reduce the number of tomodensitometry exams in favour of this new examination technique in children according to the clinical examination data and diagnostic information required.

[Intraductal papillary mucinous tumor of the pancreas discovered after diagnosis of diabetes mellitus and acute pancreatitis]. / Tumeur intracanalaire papillaire mucineuse du pancréas révélée par une pancréatite aiguë et un diabète.

INTRODUCTION: Imaging of the pancreas soon after diagnosis of diabetes can help screen for tumors. CASE: A 45 year-old man with recently diagnosed insulin-dependent diabetes and no other notable history was found to have intraductal papillary mucinous tumour of the pancreas (IPMTP), a month after an unexplained and benign acute pancreatitis. DISCUSSION: The histology of IPMTP differs from that of the adenocarcinomas usually described in these circumstances, and they are far rarer. Because they carry the risk of malignant degeneration, early diagnosis is important. Surgery is the only curative treatment and should therefore be discussed.

[The fat halo sign in the small intestine: diagnostic implications?]. / Le signe du halo graisseux iléal: quelle signification lui accorder?

The fat halo sign in the small intestine may sometimes be observed in patients with chronic inflammatory bowel diseases, but it can represent a normal finding that is possibly related to obesity. The authors report two cases showing these findings.

[Retrospectively detectable carcinomas: review of the literature]. / Cancers rétrospectivement visibles: revue de la littérature.

Retrospectively visible cancers are defined as interval cancers or screen-detected cancers (missed cancers) which are judged visible on prior screening mammogram. There are two kinds of retrospectively visible cancers: "actionable" cancers and nonspecific findings that do not warrant recall in normal practice. Nonspecific findings are twice more frequent than actionable cancers. The rate of missed breast cancers in screening is estimated at 25% (13-41%). Missed breast cancers are masses or calcifications. Masses are twice more frequent than calcifications. Missed breast cancers result from detection errors (location in retroglandular region or at the edge of glandular tissue, architectural distorsion) and interpretation errors (findings judged as benign). Detection errors could be limited by double reading and CAD, interpretation errors by better knowledge of BIRADS classification which needs specific training.

[Diagnosis of periventricular ependymal enhancement in MRI in adults]. / Diagnostic d'un rehaussement épendymaire et périventriculaire en irm chez l'adulte.

Periventricular enhancement in adults at MRI is a significant finding since it often indicates the presence of an underlying disease requiring prompt medical attention. From a review of patients with periventricular enhancement, the main imaging features based on the underlying infectious or tumoral etiology will be described. The presented differential diagnosis is based on the immune status of the patient, type of enhancement, and response to a trial therapy. In immunocompromised patients, the main considerations are lymphoma and viral ependymitis. The pattern of enhancement is important. The presence of thin linear enhancement suggests a viral etiology (cytomegalovirus or varicella-zoster virus) that can be confirmed at CSF evaluation whereas the presence of nodular enhancement suggests a diagnosis of primary CNS lymphoma that can be confirmed by the presence of lymphomatous cells in the CSF or, more frequently, at stereotactic surgical biopsy performed after failure of response to anti-toxoplasmosis treatment. The presence of band enhancement is less specific and can be seen with viral, lymphomatous and even tuberculous involvement. In immunocompetent patients, a clinical context of infection will suggest bacterial or tuberculous ventriculitis and the presence of cystic lesions will suggest cysticercosis; in the absence of constitutional symptoms, the presence of nodular enhancement will suggest a tumoral process (lymphoma, ependymoma, germ cell tumor, or metastases). Rarely, linear enhancement will be due to sarcoidosis or Whipple's disease.

[Input of coronary artery calcium score assessed by computed tomography in the screening of diabetic coronaropathy]. / Intérêt du score calcique coronaire par scanner multicoupes dans le dépistage de la coronaropathie diabétique.

The poor prognosis of coronary artery disease along with the inaccuracy of available testing methods have favoured the development of new screening techniques. One such innovation involves measuring the coronary artery calcium score (CAC). Through computed tomography, this test quantifies the amount of calcium deposited in coronary arteries, itself a reflection of the degree of atherosclerosis. This investigation is a prospective study of 48 diabetic subjects comparing the performance of CAC score with the gold standard testing methods. The results of our study showed that, due to its high negative predictive value, 5 invasive tests were performed needlessly as these subjects had very low CAC scores. At this time, the CAC score is not recommended for every patient but rather on a case-by-case basis. However, it may soon emerge as the next step after the ECG in the evaluation of coronary artery disease. This would alleviate the need for more invasive tests in those patients for whom such investigations are deemed unnecessary. The CAC score, when matched for age, sex and other variables, could also serve as an indication for prescribing medications such as statins, along with other therapeutic interventions. Diabetologists, cardiologists and radiologists must work together in order to gain a better understanding of these new techniques. This may facilitate the emergence of a new approach to the treatment of coronary artery disease.

[Importance of transesophageal echocardiography and computed tomography in the differential diagnosis of a case of papillary fibroelastoma revealed by a neurologic accident]. / Intérêt de l'échocardiographie transoesophagienne et du scanner multicoupes dans la démarche diagnostique d'un cas de fibroélastome papillaire révélé par un accident neurologique.

In the light of a new case revealed by a stroke, the authors confirm the importance of transesophagal echocardiography (TEE), and show that multislide computered tomography can be used as a new efficient tool for the diagnosis of cardiac papillary fibroelastoma (CPF). These benign tumours of endocardium are rare and case reports have been published sporadically. Stroke is an usual clinical complication and the most frequent symptom associated with CPF. Transesophageal echocardiography is the reference for diagnosis of CPF when transthoracic echocardiography is normal. When TEE is contraindicated or technically impossible, multislide computered tomography appears as an interesting alternate solution for diagnosis because of its fast acquisition and high spatial resolution. Symptomatology may be connected to either tumoral embolisation or cruoric emboli. Surgery is required for any symptomatic tumour.

[Pulsating exophtalmos and contralateral carotid-cavernous fistula]. / Exophtalmie pulsatile contralatérale à une fistule carotido-caverneuse résolutive après traitement médical.

A rare case of spontaneous carotid-cavernous fistula with contralateral clinical signs (ocular discomfort, pulsating exophthalmos, chemosis, ptosis) is reported. It was associated with partial thrombosis of the ipsilateral cavernous sinus. It was cured with conservative treatment after six months. Anatomical knowledge of the cavernous sinus remains essential for better understanding of this original clinical presentation.

[Metastasis in pulmonary arteries]. / Métastases néoplasiques intra-artérielles pulmonaires.

We report two cases of pulmonary tumor emboli. The first patient had a chondroblastic osteosarcoma of the pelvis while the second patient had a seminoma. The possibility of tumor emboli should be entertained in patients with prior history of malignancy presenting with enlargement of the pulmonary arteries and thrombus enhancement on delayed scans.