The British journal of radiology
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To evaluate the additional value of contrast-enhanced multiphase CT in comparison with low-dose non-contrast CT in combined positron emission tomography (PET)/CT protocols for oncological imaging, we retrospectively analysed 100 patients with different malignant tumours. All patients underwent a PET/CT consisting of a multiphase CT protocol including a low-dose non-enhanced attenuation scan and an arterial and portal-venous contrast-enhanced scan followed by a whole-body PET. PET/CT studies were analysed by different categories to determine the added value of contrast-enhanced CT. ⋯ The benefit of diagnostic CT was influenced by the tumour type demonstrating the highest impact in gastrointestinal, lung and neuroendocrine tumours. Diagnostic CT changed clinical management in 21 patients (21%). Diagnostic multiphase CT as part of the combined PET/CT protocol has the potential to provide considerable additional value in specific clinical conditions with resultant change of management in a substantial proportion of patients.
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The objective of the study was to determine the proportion of patients with missed lesions on plain chest radiographs compared with high-resolution computed tomography (HRCT) in 49 human immunodeficiency virus (HIV) infected patients with community-acquired pneumonia (CAP). Patients underwent plain chest radiography and HRCT scans of the chest at admission. Microbiological investigations for CAP were performed. ⋯ The proportion of patients with missed lesions on plain chest radiographs in HIV infected patients with CAP was high. This has important implications for management and prognosis. HRCT scans correlate well with the microbiological diagnosis when reported by an experienced radiologist.
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The purpose of this study was to evaluate the interbreath-hold reproducibility of the tumour (gross tumour volume, GTV) position and relative reduction of the internal target volume (ITV) using a voluntary breath-hold method with a spirometer in a clinical setting of stereotactic radiotherapy (SRT) for lung tumours 11 patients with 14 lung tumours were enrolled in this study. CT scans were performed once at the free breathing phase and five times at the breath holding phase before the first treatment day. Patients held their breath at the end-expiration phase under spirometer-based monitoring. ⋯ The interbreath-hold reproducibility of the tumour position was 1.3+/-1.3 mm, 1.4+/-1.8 mm, 2.1+/-1.6 mm and 3.3+/-2.2 mm in CC, LR and AP directions and vectors, respectively. ITV at the breath-holding phase was significantly smaller than that at the free breathing phase (P<0.01). In conclusion, the voluntary breath-hold method with a spirometer is feasible, with relatively good reproducibility of the tumour position for SRT in the clinical setting.
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Routine anatomical imaging with CT and MRI does not reliably indicate the true extent or the most malignant areas of gliomas and cannot identify the functionally critical parts of the brain. The aim of the study was to see if the use of MR spectroscopic imaging (MRSI) along with functional MRI (fMRI) can better define both the target and the critical structures to be avoided to improve radiation delivery in gliomas. 12 patients with gliomas underwent multivoxel MRS and functional imaging using GE processing software. The choline to creatine ratio (Cho:Cr), which represents the degree of abnormality for each individual voxel on MRSI, was derived, converted into a grayscale grading system, fused to the MRI images and then transferred to the planning CT images. ⋯ However, MRSI defined Cho:Cr > or =3 was smaller by 40% compared with post-contrast T1 weighted MRI defined GTV volumes. fMRI helped in optimizing the orientation of the beams. In conclusion, both MRSI and fMRI provide additional information to conventional imaging that may guide dose painting in treatment planning of gliomas. A Phase I IMRT dose intensification trial in gliomas using this information is planned.
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Castleman's disease (CD) appears at ubiquitous lymph nodes. To date, detection of the lesion focus for CD has mainly been carried out by physical examination and radiological findings, such as X-ray analysis, CT and MRI. 18F-FDG PET visualizes the active focus of glucose metabolism and the clinical value has been investigated for many different tumours. ⋯ In this paper, we report two cases of CD, one with unicentric CD and one with multicentric CD. We demonstrate that the use of 18F-FDG PET for the detection and monitoring of patients with CD, especially multicentric CD, would be effective.