Multimodal imaging

To evaluate the diagnostic and prognostic role of fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in comparison to morphological imaging such as computed tomography in primary adrenal malignancies. In this multicenter retrospective study, 68 patients with adrenal malignancy were included. All patients had histologically proven diagnosis of primary adrenal malignancy (adrenocortical carcinoma, malignant pheochromocytoma, neuroblastoma and lymphoma), one whole body (18)F-FDG PET/CT scan and one whole-body contrast enhancement computed tomography (CECT) scan acquired within one month and were followed clinically and by performing morphological tests for at least 12 months. Overall sensitivity, specificity, accuracy, positive and negative predictive values for CECT and (18)F-FDG PET/CT were respectively, 59%, 100%, 65%, 100%, 27% and 75%, 100%, 82%, 100% and 63%. For adrenocortical carcinomas, (18)F-FDG PET/CT showed a better accu...

Fever of unknown origin (FUO) is an uncommon disease, and its underlying etiology may include a number causes, i.e., infections, malignancies, autoimmune conditions. Diagnosis is often a difficult task, and usually physician spend time and money in order to define the etiology of FUO. We report a case of patient who presented with FUO and headache, and positron emission tomography (PET) with 2-deoxy-2-[fluorine-18] fluoro-D-glucose (18F-FDG) allowed to reveal the presence of a large vessel vasculitis. 18F-FDG PET may represent an useful tool in patients with FUO, since it can early depict an hypermetabolic activity due to inflammation and so help to achieve a final diagnosis in some cases of FUO.

Simultaneous PET/MRI is an emerging hybrid modality for clinical and pre-clinical imaging. The static magnetic field of the MRI device affects the trajectory of the positrons emitted by the PET radioisotopes. This effect translates into an improvement of the spatial resolution in transaxial images. However, due to the elongation of the positron range distribution along the magnetic field B0, the axial resolution worsens and "shine-through" artifacts might appear. These artifacts can lead to misinterpretation and overstaging. The aim of this work was to study the relevance of this effect. Measurements were carried out in a 3T PET/MR scanner. A 1-cm(2) piece of paper, soaked with a radioisotope and placed in air, was scanned; the magnitude of the shine-through was quantified from the PET images for various radioisotopes. Additionally, PET/MR and PET/CT images of a larynx with trachea, and the lungs of a deceased swine were also obtained after injecting a mixture of NiSO4 and...

Gallium 68 ((68)Ga) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE, GaTate) positron emission tomography (PET)/computed tomography (CT) is an imaging technique for detecting and characterizing neuroendocrine tumors (NETs). GaTate, a somatostatin analog, has recently been accorded orphan drug status by the U.S. Food and Drug Administration, thereby increasing interest in and availability of this radiotracer. GaTate PET/CT allows whole-body imaging of cell surface expression of somatostatin receptors (SSTRs) and is rapidly evolving as the new imaging standard of reference for the detection and characterization of NETs. The authors discuss the normal appearance at GaTate PET/CT and the utility of this modality in a variety of these tumors, including gastrointestinal, pancreatic, and bronchial NETs as well as pheochromocytoma, paraganglioma, meningioma, and oncogenic osteomalacia. In addition, they discuss potential causes of false-positive findings...

First described about three decades ago by D. Frank Benson and occasionally referred to as Benson's disease, posterior cortical atrophy (PCA) is a rare, debilitating, progressive neurodegenerative condition characterized mainly by declining visuoperceptual/spatial capabilities, and structurally by occipito-temporal/parietal lobe atrophy. Although research evidence suggests a 5% incidence of PCA amongst people diagnosed with Alzheimer's disease, standard epidemiological data for PCA remains relatively scarce, possibly due to a lack of clinical awareness of the condition and an under-recognition plus under-reporting of its variable phenotypic presentation. There also appears to be difficulties in consistency with the classification, as well as a lack of proper validation of congruous diagnostic criteria with regards to PCA. This case report describes the clinical presentation of a 55-year-old Caucasian female diagnosed with PCA and the management strategy. The report also highlights the role of multimodal imaging and neuropsychology in arriving at a potential diagnosis.