AJR. American journal of roentgenology
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AJR Am J Roentgenol · Dec 2013
ReviewSomatostatin receptor-based PET/CT of intracranial tumors: a potential area of application for 68 Ga-DOTA peptides?
Similar to neuroendocrine tumors (NETs) at other sites, a wide array of intracranial tumors also express somatostatin receptors (SSTRs). This expression can be exploited for both imaging and therapy. The introduction of (68)Ga-labeled tetraazacyclododecanetetraacetic acid (DOTA)-peptide PET/CT has given new dimension to SSTR-based imaging because of its improved sensitivity and excellent spatial resolution. ⋯ However, in contrast to gastropancreatic and bronchopulmonary NETs, limited literature is available regarding the use of (68)Ga-DOTA-peptide PET/CT in intracranial tumors. Here, we briefly review the available literature and highlight the potential role that (68)Ga-DOTA-peptide PET/CT can play in the management of intracranial tumors.
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AJR Am J Roentgenol · Dec 2013
ReviewDiagnostic imaging of fetal and pediatric orbital abnormalities.
The orbit contains structures from which a wide spectrum of disease can arise. This article focuses on orbital anatomy and a simple compartmental approach to evaluating the orbit on diagnostic imaging. The characteristic findings of key fetal structural diseases and a wide spectrum of pediatric orbital disorders, including inflammatory disorders and developmental lesions, and the differential diagnosis of benign versus malignant masses will be discussed. ⋯ Orbital abnormalities in fetuses may be recognized using ultrasound and MRI. Anophthalmia, hypertelorism, and hypotelorism either may be part of a genetic syndrome or may be related to a developmental abnormality of the fetal skull. In the pediatric population, cross-sectional imaging with CT and MRI offers a means to assess which compartments of the orbit are affected. Aggressive masses have characteristic features and must be evaluated for intracranial extension.
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AJR Am J Roentgenol · Dec 2013
Comparative StudyAdaptive iterative dose reduction 3D versus filtered back projection in CT: evaluation of image quality.
The purpose of this study was to evaluate image quality with filtered back projection (FBP) and adaptive iterative dose reduction 3D (AIDR 3D). ⋯ AIDR 3D performs better than FBP with regard to noise and LCD, resulting in better image quality, and performs similarly with respect to spatial resolution. The evaluation of image quality of clinical CT scans was consistent with the objective assessment of image quality with a phantom. The amount of dose reduction should be investigated for each clinical indication in studies with larger numbers of patients.
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AJR Am J Roentgenol · Nov 2013
Comparative StudyComparison of the accuracy of PET/CT and PET/MRI spatial registration of multiple metastatic lesions.
The purpose of this study was to compare the accuracy of the spatial registration of conventional PET/CT with that of hybrid PET/MRI of patients with FDG-avid metastatic lesions. ⋯ PET/MRI T1-weighted gradient-echo images with a radial stack-of-stars trajectory and T2-weighted images had more accurate spatial registration than PET/CT images. This may be because that the whole-body PET/MRI system used can perform simultaneous acquisition, whereas the PET/CT system acquires data sequentially. However, the EPI-based b0 DWI datasets were significantly misregistered compared with the PET/CT datasets, especially in the thorax. Radiologists reading PET/MR images should be aware of the potential for misregistration on images obtained with EPI-based DWI sequences because of inherent spatial distortion associated with this type of MRI acquisition.