DECT Scans Research Articles

Spectral parametric segmentation of contrast-enhanced dual-energy CT to detect bone metastasis: feasibility sensitivity study using whole-body bone scintigraphy

Dual-energy computed tomography (DECT) images may be underutilized for the evaluation of skeletal metastasis. Spectral parametric segmentation of DECT can produce bone-iodine separated images, which have the potential to detect bone metastases. To evaluate the potential of bone-iodine separation in the detection of bone metastasis with spectral parametric segmentation of DECT images which are acquired at clinical follow-up for patients with prior malignancy. The institutional review board approved the protocol of this retrospective review. Chest DECT scans using fast kV-switching between 80 and 140 kVp were included in this study. Bone-iodine separated reformatted images were produced by spectral parametric segmentation of synthesized monochromatic images. All chest CT images of 702 metastatic lesions from 54 patients were retrospectively evaluated in terms of visualization of metastatic lesions compared with (99m)Tc-MDP (methylene diphosphonate) whole-body bone scintigraphy (WBBS) as reference standard of diagnosis. Spectral parametric segmentation images of DECT visualized metastatic lesions in 92.3% (n = 648/702). Osteoblastic metastases were delineated as subtle enhancing lesions on DECT in comparison to WBBS. Spectral parametric segmentation of iodine from cortical and medullary bone allowed visualization of bone metastasis. DECT might be utilized for the screening or detection of bone metastases.

Technical limitations of dual-energy CT in neuroradiology: 30-month institutional experience and review of literature

BackgroundDual-energy CT (DECT) has been shown to be a useful modality in neuroradiology.ObjectiveTo assess failure modes and limitations of DECT in different neuroimaging applications.Patients and methodsDual-source DECT scans were performed...

Dual Energy CT Myelography after Lumbar Osteosynthesis

The purpose of this study was to evaluate the benefits of CT myelography in the DE technique in patients with lumbar osteosynthesis. In 30 patients a DE-CT scan of the spine with tube voltages of 80 kV and 140 kV was performed and a virtual monochromatic series of 120 kV was generated after intrathecal contrast injection. The impact of metal artifacts on the spinal canal and the spinal foramina was evaluated. The visualization of nerve roots was compared between a VRT series of the dural sac and conventional myelography. With tube voltages of 140 kV, the artifacts were least pronounced. As no overlay disturbance was present, VRT visualization of the nerve roots was more reliable than conventional myelography. In patients after osteosynthesis, CT in the DE technique provides minimal artifact disturbance using a tube voltage of 140 kV. "Virtual myelography" seems to be superior to conventional myelography for the evaluation of nerve roots. This could reduce additional conventional radiography, may shorten the entire examination and radiation time and diminish unnecessary painful movements for the patient.

Dual-Energy CT in the Evaluation of Intracerebral Hemorrhage of Unknown Origin: Differentiation between Tumor Bleeding and Pure Hemorrhage

Detection of underlying tumor in patients with unknown-origin acute ICH may be difficult because acute hematoma may mask enhancement of tumor on postcontrast CT. We intended to investigate the clinical utility of DECT in differentiating tumor bleeding from pure ICH. Using a dual-source CT scanner, we obtained TNC single-energy and postcontrast DECT scans for 56 patients with unknown-origin spontaneous ICH. From the 2 sets of postcontrast DECT images obtained with different tube energy, EA (equivalent to conventional postcontrast CT), VNC, color-coded iodine overlay, fusion images of iodine overlay and VNC images were produced. The diagnostic performances of fusion, EA, and combined EA and TNC images for detecting underlying tumors were compared. Of the 56 patients, 17 had primary or metastatic tumors (18 lesions) and 39 had nontumorous ICH. The sensitivities of fusion, EA, and combined EA and TNC images for detecting brain tumors were 94.4%, 61.1%, and 66.7%, respectively, and their specificities were 97.4%, 92.3%, and 89.7%, respectively. The areas under the ROC curves were 0.964, 0.786, and 0.842, respectively. Overall, the diagnostic performance of fusion images was significantly superior to EA (P = .006) and combined EA and TNC (P = .011) images. DECT may be useful in detecting underlying tumors in patients with unknown-origin ICH.

Dual-energy CT in the evaluation of solitary pulmonary nodules by virtual non-enhanced images:initial experience

Objective To determine the accuracy and radiation dose of dual-energy computed tomography (CT) in evaluating solitary pulmonary nodules (SPNs) by virtual non-enhanced images.Methods Sixty-one patients with SPNs including 39 malignant and 18 benign nodules proved by pathology underwent DECT scans. The CT values of SPNs on enhanced weighted average and virtual non-enhanced images were compared by using Liver VNC processing unit in terms of their diagnostic accuracy for distinguishing malignant and benign nodules with a 20 HU threshold. Diagnostic accuracy was compared. In 28 patients of all patients, image noise and quality score of the non-enhanced and virtual non-enhanced images were compared, and radiation doses of each patient were recorded. The paired t test was used to analyze the noise difference between the plain scan and virtual non-enhanced scan. The Mann-Whitney U test was used to analyze statistically significant differences of the image quality score and radiation dose between the non-enhanced scan and virtual non-enhanced scan. Results The sensitivity, specificity and accuracy for distinguishing benign and malignant nodules by using the virtual non-enhanced image of were 89. 7％(35/39), 72.2％ (13/18), 84.2％ (48/57)respectively. The noise of common CT and virtual nonenhanced images were(8. 49 ± 1. 94) HU and( 10. 14 ± 2. 18 ) HU, and there were statistically difference (t＝9.45,P＜0. 01 ). The quality scores of common CT and virtual non-enhanced images were (4.71 ±0. 46 ) and ( 4.42 ± 0. 57 ), and there were no statistical difference ( U ＝ 290. 00, P ＞ 0. 05 ). The radiation doses of common CT and DECT were ( 3. 72 ± 0. 48 ) mSv and ( 3.78 ± 0. 45 ) mSv, and there were no statistical difference ( U ＝ 350. 50,P ＞ 0. 05 ). Conclusion DECT by using virtual non-enhanced images is useful tool to distinguish the benign and malignant SPN without additional radiation dose. Key words: Coin lesion pulmonary; Tomography, X-ray computed; Image processing,computed-assisted