Imaging decisions (Berlin, Germany)最新文献

Computed tomography (CT) has made its introduction in the diagnostic work-up for pulmonary embolism (PE) since 1992. Initially only larger thrombi could be visualized, gradually smaller thrombi were also found. This is mainly due to technical development in CT and the introduction of the multidetector CT. Today CT is an integral part of the diagnostic work-up for PE. In this article an overview is given from the literature from 1998 until 2006 about the performance of CT in the detection of PE, especially regarding the diagnostic accuracy and clinical value of CT in the diagnosis of PE.

In pregnant and postpartum patients, the incidence of venous thromboembolism (VTE) is increased three to fivefold compared with non-pregnant women of the same age, and deep venous thrombosis (DVT) and pulmonary embolism (PE) are leading causes of maternal mortality during pregnancy and postpartum. Early and accurate diagnosis is essential as unnecessary anticoagulation is not without risk. However, the diagnosis of VTE among these women is complicated by difficulties in clinical diagnosis and the concerns regarding radiation exposure of the fetus. Many of the common diagnostic tests, including D-dimer, compression ultrasonography, ventilation-perfusion scintigraphy and helical computed tomography that have been extensively investigated in non-pregnant patients, have not been appropriately validated in pregnancy. This article will review the role of various diagnostic tests in case of suspected VTE in pregnancy and puerperium, and issues such as radiation risk are discussed. Recommendations for the use of D-dimer and imaging techniques in pregnant and postpartum patients with a clinically suspected DVT or PE are provided.

The use of the D-dimer concentration for the exclusion of venous thromboembolism (VTE) has been evaluated circumstantially in many clinical studies and meta-analyses with different kinds of assays and tests. The sensitivity and specificity depend upon the prevalence of the VTE in the patient population and this explains the variety of results of the different studies. With a combination of studies in meta-analyses, more reliable results and conclusions can be obtained. The quantitative assays have a higher sensitivity, but a lower specificity than the qualitative tests, but no assay or test is sensitive enough for a safe exclusion of VTE.

In patients with clinically suspected pulmonary embolism (PE) many diagnostic tests are available and have been widely evaluated. An integrated diagnostic approach is the most efficient way to make management decisions. This is best accomplished by the use of a diagnostic algorithm consisting of a dichotomous decision rule, D-dimer testing and computed tomographic pulmonary angiography (CTPA), or as alternative V-Q lung scanning. Such an algorithm can guide treatment decisions with a low risk for false negative outcome in patients in whom tests indicate that PE is ruled out. No further diagnostic testing is necessary in patients with unlikely clinical probability in combination with a normal D-dimer test result. CTPA or V/Q scans can safely rule out PE in patients with a likely pre-test probability or elevated D-dimer test result.

Head and neck cancers are rising in incidence. In the diagnosis of malignant head and neck cancer, conventional morphological imaging methods, i.e. ultrasonography, radiography, computerised tomography (CT) and magnetic resonance imaging (MR) play a routine role besides clinical investigation. Despite these diverse techniques, the primary tumour often cannot be found. Furthermore, for staging purposes as well as for the detection of tumour recurrence after chemotherapy and/or radiotherapy, morphological examination techniques such as CT and MR are of limited accuracy. Due to promising results in the literature, 18F-fluorodeoxyglucose-positron emission tomography has been playing an increasing role in the assessment of malignant head and neck cancer. The authors present a literature review as well as their own data in comparison to conventional imaging methods.

This case report shows that fusion of positron emission tomography (PET)/computerized tomography (CT) with radiotherapy planning CT offers the possibility to give high total doses with minimized morbidity specifically in patients with head and neck cancer.

PET/CT plays an important role in the evaluation and follow up of patients with various head and neck neoplasms.

The role of PET/CT in the management of a wide variety of head and neck cancers varies based on the TNM tumour stage. Futhermore, because there is a large overlap between tumour and physiologic FDG uptake, interpretation of malignancies in the head and neck on PET/CT can be confusing/unclear.

Thus, it is essential to have knowledge of the patient's prior history, including relevant surgical procedures as well as prior chemo and radiation treatment for proper interpretation of head and neck malignancies.

This article examines how FDG PET/CT is utilized in squamous cell carcinoma of the nasopharyax and larynx.

Magnetic resonance imaging (MRI) plays an important role in pre-treatment assessment of tumours of the head and neck region. Because of its excellent soft tissue contrast it renders pivotal information in staging and serves as a basis for surgery planning or primary chemo- and/or radiotherapy. Primary tumours are best seen on T2WI with fat saturation or contrast-enhanced images. Morphologic criteria used for lymph node imaging depend on size and shape, and thus MRI is limited in differentiation of normal size malignant nodes or hyperplastic benign nodes. Necrosis is a more specific sign of malignancy.

In this review, imaging technique and imaging of tumours in the head and neck region in general and for specific areas are covered with the emphasis on MR imaging features of the primary tumours and their spread including perineural and lymphatic dissemination. Uncooperative or claustrophobic patients, however, should undergo staging by computerized tomography instead of MRI.