The dual energy CT (DECT) technology has been recently employed in the form of two X-ray sources of different energies to enhance the contrast between adjacent structures. Its use in the cardiac arena has been widely highlighted due to the higher temporal resolution. However, it may also be used in the craniocervical and peripheral vasculature for better differentiation between contrast-enhanced vascular lumina and calcified plaques, in the characterisation of ureteric stones, and in the evaluation of hepatic lesions. The objective of this paper is to revisit DECT physics, review the literature and discuss its use in CT neuroangiography with case illustrations from our institution, and impact on dose savings.
Cerebral Angiography ; Constriction, Pathologic ; diagnosis ; Humans ; Image Interpretation, Computer-Assisted ; Intracranial Aneurysm ; diagnosis ; Radiation Dosage ; Radiography, Dual-Energy Scanned Projection ; methods ; Review Literature as Topic ; Tomography, X-Ray Computed ; methods

INTRODUCTIONWe reviewed the clinical features, brain and spinal cord magnetic resonance (MR) imaging findings and associated abnormalities in six patients with spinal cavernous malformations (CMs).

METHODSLesions were defined on gradient-recalled echo (GRE) images but measured on T2-weighted images performed on 1.5- and 3-tesla clinical scanners.

RESULTSFour patients had associated multiple cranial CMs and one patient had multiple spinal CMs. All spinal CMs were predominantly hypointense on GRE images, and most were predominantly hyperintense and surrounded by hypointense edge on T2-weighted images. Other associations included asymptomatic vertebral body and splenic haemangiomas.

CONCLUSIONWe conclude that intramedullary spinal CMs typically have 'mulberry' or 'popcorn' appearances similar to those of cranial CM. The presence of associated haemangioma or familial cranial CM syndrome on MR imaging may suggest the correct diagnosis without requiring invasive investigations.

Adult ; Aged ; Brain Neoplasms ; pathology ; Central Nervous System Vascular Malformations ; pathology ; Child, Preschool ; Diagnosis, Differential ; Female ; Hemangioma, Cavernous, Central Nervous System ; pathology ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neoplastic Syndromes, Hereditary ; pathology ; Retrospective Studies ; Spinal Cord Diseases ; pathology ; Spinal Cord Neoplasms ; pathology

Around 50% of the population harbour thyroid nodules on ultrasonography, up to 7% of which may be malignant irrespective of size. While fine-needle aspiration biopsy is reliable, subjecting every thyroid nodule to this procedure is not cost-effective. Hence, ultrasonography is used primarily to characterise thyroid nodules, whereas nodules that have suspicious features are subject to a fine-needle aspiration biopsy. The presence of microcalcifications, macrocalcifications, irregular margins, 'taller-than-wide' shape, marked hypoechogenicity and intrinsic vascularity are features that render a thyroid nodule suspicious for malignancy. Spongiform appearance and the presence of colloid plugs or purely cystic nodules are considered features of benignity. In this article, these aforementioned sonographic features of malignancy and benignity are pictorially illustrated and a basic approach to dealing with solitary and multiple thyroid nodules is highlighted.
Humans ; Predictive Value of Tests ; Thyroid Neoplasms ; diagnosis ; diagnostic imaging ; Thyroid Nodule ; diagnosis ; diagnostic imaging ; Ultrasonography