Dual-energy computed tomography angiography for evaluating the renal vascular variants.
(21/31)
BACKGROUND: Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery. This study aimed to investigate the renal vascular variants with dual-energy computed tomography (DECT) angiography to provide valuable information for surgery. METHODS: A total of 378 patients underwent DECT. The number, size, course and relationships of the renal vessels were retrospectively observed from the scans. Anomalies of renal arteries and veins were recorded and classified. Multiplanar reformations (MPR), maximum intensity projections (MIP), and volume renderings (VR) were used for analysis. RESULTS: In 378 patients (756 kidneys), renal artery variations were discovered and recorded in 123 kidneys (16.3%, 123/756) of 106 patients (28.0%, 106/378). Type IB (early branches of the only one main renal artery) and IC (accessory renal artery with only one main renal artery) were found most frequently with an incidence of 11.4% (43/378) and 14.5% (55/378). The incidence of renal artery variations in the left kidney was not statistically different than in the right kidney (12.4% vs. 11.1%). The incidence of renal vein variations was detected in 104 patients (27.5%, 104/378). The incidence of venous variants in the right kidney was higher than in the left kidney (20.1% vs. 7.4%), but left renal vein variations were more complex. Variants of the left renal vein were detected in 28 patients including type 1 (circumaortic left renal vein) in eight cases, type 2 (retroaortic left renal vein) in seven cases, type 3 (abnormal reflux) in six cases, type 4 (late venous confluence of left renal vein) in five cases, and type 5 (rare type) in two cases. The frequency of left renal vein variation associated with the left renal accessory artery was significantly higher than with early branches of the left renal artery (P = 0.037). CONCLUSIONS: The renal vascular variants are rather common and complex. DECT angiography can demonstrate the precise anatomy of the renal vessels, which is a benefit for renal transplantation or other renal operations. (+info)
Gastric cancer staging with dual energy spectral CT imaging.
(22/31)
Novel clinical applications of dual energy computed tomography.
(23/31)
Dual energy CT (DECT) was conceived at the very beginning of the computed tomography era. However the first DECT scanner was developed in 2006. Nowadays there are three different types of DECT available: dual-source CT with 80(100) kVp and 140 kVp tubes (Siemens Medical Solution); dual-layer multi-detector scanner with acquisition 120 or 140kVp (Philips Healthcare); CT unit with one rapid kVp switching source and new detector based on gemstone scintillator materials (GE Healthcare). This article describes the physical background and principles of DECT imaging as well as applications of this innovative method in routine clinical practice (renal stone differentiation, pulmonary perfusion, neuroradiology and metallic implant imaging). The particular applications are illustrated by cases from author's material. (+info)
Dual energy computed tomography angiography for the rapid diagnosis of reversible cerebral vasoconstriction syndromes: report of a case.
(24/31)
PURPOSE: Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by segmental vasoconstriction and dilatation of intracranial arteries, typically affecting bilateral medium-sized intracranial arteries and their branches. The diagnosis usually relies both on clinical presentations and cerebral vascular imaging such as magnetic resonance angiography or conventional angiography. Dual energy computed tomography angiography (CTA) could provide high-quality imaging and is usually immediately available for the diagnosis at the emergency department. CASE REPORT: A 37-year-old previously healthy woman was admitted to the neurology ward for recurrent episodes of headaches within 3 days. She was diagnosed as having RCVS presenting with thunderclap headaches. Dual energy CTA provided high-quality imaging and almost immediately available for diagnosis at the emergency department (ER). CT perfusion showed adequate brain perfusion. Transcranial Doppler disclosed increased arterial velocities at bilateral middle cerebral arteries. We treated the patient with oral diclofenac and nimodipine. After a few days, she had great improvement of headaches. The follow-up CTA 3 months after her initial presentation disclosed complete resolution of the constrictions of these intracranial arteries. CONCLUSION: Brain magnetic resonance imaging (MRI) with magnetic resonance angiography (MRA) and MR venography is the choice for initial investigation; however, CTA is an alternative diagnostic tool when MRI is not readily available. Dual energy CTA has the great advantage in providing high-resolution imaging, high speed scanning with a lower radiation dose. (+info)