Dual-source Computed Tomography Imaging Research Articles

Usefulness of the spectral shaping dual-source computed tomography imaging technique in posterior corrective fusion for adolescent idiopathic scoliosis.

Since childhood exposure to radiation has been demonstrated to increase cancer risk with increase in radiation dose, reduced radiation exposure during computed tomography (CT) evaluation is desired for adolescent idiopathic scoliosis (AIS). Therefore, this retrospective study aimed to investigate the radiation dose of dual-source CT using a spectral shaping technique and the accuracy of the thoracic pedicle screw (TPS) placement for posterior spinal fusion (PSF) in patients with AIS. Fifty-nine female patients with thoracic AIS who underwent PSF using CT-guided TPSs were included and divided into two groups comprised of 23 patients who underwent dual-source CT (DSCT) with a tin filter (DSCT group) and 36 who underwent conventional multislice CT (MSCT group). We assessed the CT radiation dose using the CT dose index (CTDIvol), effective dose (ED), and accuracy of TPS insertion according to the established Neo's classification. The DSCT and MSCT groups differed significantly (p < 0.001) in the mean CTDIvol (0.76 vs. 3.31mGy, respectively) and ED (0.77 vs. 3.47mSv, respectively). Although the correction rate of the main thoracic curve in the DSCT group was lower (65.7% vs. 71.2%) (p = 0.0126), the TPS accuracy (Grades 0-1) was similar in both groups (381 screws [88.8%] vs. 600 screws [88.4%], respectively) (p = 0.8133). No patient required replacement of malpositioned screws. Spectral shaping DSCT with a tube-based tin filter allowed a 75% radiation dose reduction while achieving TPS insertion accuracy similar to procedures based on conventional CT without spectral shaping.

Differential Diagnosis of Preinvasive Lesions in Small Pulmonary Nodules by Dual Source Computed Tomography Imaging.

This study was aimed to explore the differential diagnosis value of preinvasive lesions/minimally invasive adenocarcinoma and invasive adenocarcinoma manifesting as small pulmonary nodules under dual source computed tomography (DSCT) imaging. The patients with nodular manifestations of adenocarcinoma in situ (AIS)/microinfiltrating adenocarcinoma (MIA) were selected as group X, including 14 cases. A total of 31 cases with nodular infiltrating adenocarcinoma were selected as group Y. The enhanced dual-energy image obtained by DSCT dual-energy scan was transferred to the software to obtain the energy image and iodine distribution map. SPSS 18.0 was used for statistical analysis. P < 0.05 was considered statistically significant. All measurements were labeled as mean x͞±S standard deviation. In the CT findings of microinfiltrating adenocarcinoma and infiltrating adenocarcinoma, lobulation sign, burr sign, vacuole sign, and pleural depression sign can help the diagnosis of infiltrating adenocarcinoma. The results showed that lobulation sign, burr sign, vacuole sign, and pleural depression sign could be used as the distinguishing feature of preinvasive lesion/microinvasive adenocarcinoma and invasive adenocarcinoma. Receiver-operating characteristic (ROC) curve analysis showed that the critical value, sensitivity, and specificity of lesion diameter ≥1.4 cm and CT value ≥14.14HU for diagnosis of invasive lung adenocarcinoma were 1.32 and 14.14, 88.4% and 94.4%, and 67.3% and 75.8%, respectively. There were substantial differences in CT values between the two groups under low energy level (42-99 kev) (P < 0.05). DSCT dual-energy imaging can quantitatively identify preinvasive pulmonary nodules with multiple parameters.

Complex Congenital Heart Disease with Common Atrium: A Rare Entity

Common atrium (CA) is a rare congenital cardiac anomaly characterized by complete lack of interatrial septal tissue. It is commonly associated with atrioventricular valve malformations and other extracardiac anomalies. Hereby, we report a case of a term neonate with complex congenital heart disease with CA and panorama of dual-source computed tomography imaging findings in the patient.

Protocol Optimization and Implementation of Dual-Energy and Dual-Source Computed Tomography in Clinical Practice: Field of View, Speed, or Material Separation?

Clinical use of dual-energy computed tomography (DECT) and dual-source computed tomography (DSCT) has been well established for more than a decade. Improved software and decreased postprocessing time have increased the advantages and availability of DECT and DSCT imaging. In this article, we will provide a practical guide for implementation of DECT and DSCT in clinical practice and discuss automated processing and selection of CT protocols in neurologic, cardiothoracic, vascular, body, and musculoskeletal imaging.

In a Heartbeat: An Assessment of Dynamic Dose Variation to Cardiac Structures Using Dual Source Computed Tomography

To assess radiation dose variation to the left anterior descending artery (LAD), left main coronary artery (LMCA), left ventricle (LV), and whole heart (WH) during the cardiac cycle using dual source computed tomography (DSCT). The present prospective study included patients with left-side breast cancer planned to undergo tangential radiation therapy. An electrocardiogram-synchronized contrast-injected DSCT scan was obtained with the patient in the treatment position, in deep-inspiration breath-hold, using retrospective sequential acquisition. The WH, LV, LMCA, and proximal, middle, and distal LAD segments were contoured on each phase of the cardiac cycle. The maximum, minimum, and mean Hausdorff distance between each structure and the tangential fields was assessed in ventricular systole and diastole. Four-dimensional dose-volume histograms were used to compare the systolic and diastolic dosimetric data. Ten patients were enrolled. The average maximum, minimum, and mean Hausdorff distance variation from systole to diastole was ≤4mm for the LV and LMCA and ≤3mm for the WH and LAD segments. WH maximum dose and volume receiving 5Gy were decreased in systole compared with diastole (42.9Gy versus 44.5Gy, P=.03, and 21.7cm3 versus 27.7cm3, P=.01), but the mean dose remained similar throughout the cycle. The maximum and mean dose to the distal LAD was 21.2Gy versus 26.6Gy(P=.005) and 8.6Gy versus 13.2Gy(P=.006) in systole versus diastole, respectively. The maximum and mean dose to the middle LAD was 18.4Gy versus 25.1Gy(P=.005) and 8.5Gy versus 10.2Gy in systole versus diastole (P=.005). The maximum dose to the LV was lower in systole than in diastole (21.5Gy vs 26.7Gy; P=.005). In addition to deep-inspiration breath-hold, systolic irradiation is associated with a reduction in dose to the LAD, LV, and WH. In addition to its potential use in radiation planning for cardiac gating, DSCT imaging can be used to help define a planning organ at risk volume for clinically important cardiac substructures.

Diagnostic Accuracy of Dual-Source Computerized Tomography Coronary Angiography in Symptomatic Patients Presenting to a Referral Cardiovascular Center During Daily Clinical Practice.

BackgroundThere are numerous studies that address the diagnostic value of dual-source computed tomography (DSCT) as an alternative to conventional coronary angiography (CCA). However, the benefit of application of DSCT in a real world clinical setting should be evaluated.ObjectivesTo determine the diagnostic accuracy of DSCT technique compared with CCA as the gold standard method in detection of coronary artery stenosis among symptomatic patients who are presented to a referral cardiovascular center during daily clinical practice.Patients and MethodsEvaluating the medical records of a tertiary care referral cardiovascular center, 47 patients who had undergone DSCT and CCA, and also met the inclusion and exclusion criteria of the study were selected. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios (LRs) of the DSCT imaging technique were calculated.ResultsIn total, 97.8% of the segments (628/642) could be visualized with diagnostic image quality via DSCT coronary angiography. The mean heart rate during DSCT was 69.2 ± 12.2 bpm (range: 39 - 83 bpm), and the mean Agatston score was 507.7 ± 590.5 (range: 0 - 2328). Per segment analysis of the findings revealed that the sensitivity, specificity, PPV, NPV, positive LR (PLR) and negative LR (NLR) of DSCT technique for evaluation of patients with coronary artery disease were 93.7%, 96.8%, 92.7%, 97.2%, 29.4, and 0.066, respectively. Also per vessel, analysis of the findings showed a sensitivity of 97.1%, a specificity of 94.0%, PPV of 95.3%, NPV of 96.3%, PLR of 16.1, and NLR of 0.030.ConclusionOur results indicate that DSCT coronary angiography provides high diagnostic accuracy for the evaluation of CAD patients during daily routine practice of a referral cardiovascular setting.

The value of using iodine maps in distinguishing the benign and malignant thyroid nodule with dual-source CT by dual energy

Objective To investigate the clinical application of iodine-enhanced image of dual-source computed tomography(DSCT)in distinguishing benign and malignant thyroid nodules. Methods Thirty patients with thyroid nodules underwent DSCT imaging with dual-source computed tomography. All thyroid nodules were confirmed by operation or biopsy. Iodine concentration in the thyroid nodule and normal thyroid tissue were calculated and not enhanced. A receiver operator characteristic curve in SPSS software was utilized to select critical value of optimum sensitivity and specificity. The data were retrospectively analyzed. Results There were 30 patients with 40 thyroid nodules(17 malignant nodules, 23 benign nodules). The range of iodine concentration in malignant nodules was -2.4-0.9 mg/ml(median -0.5 mg/ml), and that in normal thyroid tissue was -0.9-2.2 mg/ml(median 0.7 mg/ml). The range of iodine concentration in benign nodules was 1.5-4.4 mg/ml(median 2.4 mg/ml), and that in normal thyroid tissue was 1.5-4.3 mg/ml(median 2.6 mg/ml). Among them, the iodine concentration in the solid part of benign nodules was significantly higher than that in malignant nodules, the difference was statistically significant(Z=-3.23, P=0.21). When critical value was 0.15 mg/ml, sensitivity was 82.40%, specificity was 81.00%. Conclusion Iodine-enhanced images with DSCT in non-enhanced weighted images may be an implement tool for differential diagnosis of benign and malignant nodules of the thyroid gland. (Chin J Endocrinol Metab, 2015, 31: 333-336) Key words: Thyroid nodule; Tomography, X-ray computed; Iodine image

A new method for computer-assisted detection, definition and differentiation of the urinary calculi

Purpose: Urinary stones are common and can be diagnosed with computed tomography (CT) easily. In this study, we aimed to specify the opacity characteristics of various types of calcified foci that develop through the urinary system by using an image analysis program. With this method, we try to differentiate the calculi from the non-calculous opacities and also we aimed to present how to identify the characteristic features of renal and ureteral calcules. Materials and methods: We obtained the CT studies of the subjects (n = 48, mean age = 41 years) by using a dual source CT imaging system. We grouped the calculi detected in the dual-energy CT sections as renal (n = 40) or ureteric (n = 45) based on their locations. Other radio-opaque structures that were identified outside but within close proximity of the urinary tract were recorded as calculi “mimickers”. We used ImageJ program for morphological analysis. All the acquired data were analyzed statistically. Results: According to thorough morphological parameters, there were statistically significant differences in the angle and Feret angle values between calculi and mimickers (p < 0.001). Multivariate logistical regression analysis showed that Minor Axis and Feret angle parameters can be used to distinguish between ureteric (p = 0.003) and kidney (p = 0.001) stones. Conclusions: Computer-based morphologic parameters can be used simply to differentiate between calcular and noncalcular densities on CT and also between renal and ureteric stones.

Diagnostic Performance of Dual-Energy CT for the Detection of Traumatic Bone Marrow Lesions in the Ankle: Comparison with MR Imaging

To evaluate prospectively the performance of noncalcium images reconstructed from dual-energy (DE) computed tomography (CT) for the diagnosis of bone marrow lesions in patients with acute ankle joint trauma in comparison with magnetic resonance (MR) images. The study had local ethics board approval, and written informed consent was obtained. Thirty consecutive patients (15 women; mean age, 34 years±11.8 [standard deviation]) underwent dual-source DE CT (80 kVp and 140 kVp with tin filter) and MR imaging within 1 day following acute ankle trauma. DE CT data were postprocessed by using a three-material decomposition algorithm for generating noncalcium images. MR and noncalcium images were graded by two blinded, independent readers using a four-point system (1=distinct bone marrow lesion, 4=no lesion); CT numbers in noncalcium images were calculated by a third reader. MR imaging interpretations served as the reference standard. Interreader agreement for qualitative grading of DE CT images was substantial (κ=0.66). The respective sensitivity, specificity, positive predictive value, and negative predictive value of DE CT for depicting distinct bone marrow lesions for both readers were 90.0% each, 80.5% and 81.6%, 25.4% and 26.5%, and 99.1% each. In regions without abnormality, CT numbers in noncalcium images gradually increased from proximal to distal location (P<.001). Significant differences in CT numbers were found in regions positive for bone marrow lesions compared with those that were negative (P<.001). CT numbers for the diagnosis of distinct bone marrow lesions according to MR imaging revealed areas under the receiver operating characteristic curve of 0.973, 0.813, and 0.758 for ankle mortise, talar dome, and talar body/head, respectively. Compared with MR images, distinct traumatic bone marrow lesions of the ankle joint can be diagnosed on noncalcium images reconstructed from DE CT with high sensitivity and excellent negative predictive value, but with moderate specificity and low positive predictive value.

Reduction of radiation dose using 80 kV tube voltage: a feasible strategy?

Reduction of radiation dose using 80 kV tube voltage: a feasible strategy?

Features of the dual energy technique with dual-source computed tomography for anterior cruciate ligament injuries

To explore the diagnostic value of the dual-energy technique with dual-source computed tomography (DSCT) for anterior cruciate ligament injuries. The clinical data of 8 patients with arthroscopic results were retrospectively reviewed. All patients underwent two- and three-dimensional imaging by multiplanar reconstruction, volume rendering, and tendon mode on DSCT. Dual-energy characteristics were compared with arthroscopic results. Six patients who were arthroscopically diagnosed as anterior cruciate ligament injuries, all of them were also correctly diagnosed by DSCT. Two patients who were arthroscopically diagnosed as normal, one was also diagnosed as normal by DSCT and the other was misdiagnosed. The overall agreement rate was 87.5% (7/8) . Under the dual energy tendon mode, the dual energy staining of the injured anterior cruciate ligament was lower than that of the contralateral normal cruciate ligament of the patient. The staining diminution in DSCT imaging may be a new feature that can be used to effectively diagnose anterior cruciate ligament injury.

100 kV versus 120 kV: effective reduction in radiation dose?

100 kV versus 120 kV: effective reduction in radiation dose?

Effect of dual-source cardiac computed tomography on patient radiation dose in a clinical setting: Comparison to single-source imaging

Dual-source computed tomography (DSCT) was introduced with significant hardware and software changes compared with single-source CT (SSCT), resulting in improved temporal resolution (83 ms) and the potential for improved image quality. The effect of these changes on radiation dose requirements for coronary CT angiography in clinical practice has not been investigated. We evaluated patient radiation dose and image quality of electrocardiogram (ECG)-gated helical techniques, using DSCT compared with SSCT for clinical imaging of the coronary arteries. DSCT data from 160 patients were evaluated; 82 patients (DSCT group 1) were imaged with early software, and 78 patients (DSCT group 2) were imaged with a later software version. Patients imaged with SSCT (n = 124) were the control group. Effective radiation dose values were estimated for all patients. Image noise was measured, and image quality was evaluated on a 5-point scale. Effective dose values for DSCT group 2 (11.7 +/- 4.0 mSv) were not different from those for SSCT group (10.9 +/- 2.9 mSv); the highest doses, 13.2 +/- 3.2 mSv, were recorded for DSCT group 1 (P < 0.001). A decrease in image noise was observed for DSCT compared with SSCT (P <or= 0.001) as was an increase in image quality (P < 0.01). With optimized DSCT imaging, lower dose values were associated with (1) shorter scan range, (2) lower maximum tube current, and (3) lower fraction of R-R interval receiving maximum tube current. ECG-gated helical DSCT can provide images of the coronary arteries with improved image quality and decreased noise without an increase in radiation dose compared with SSCT in clinical patient groups.

Dual Source Computed Tomography: A Novel Technique to Determine Stone Composition

Dual source computed tomography (CT), a novel technology that employs two different x-ray sources, may provide an image resolution that has not been possible with conventional single source CT. We tested the ability of dual source CT imaging to distinguish calcium oxalate (CaOx) stones from calcium phosphate (CaP) stones, and both types of calciferous stones from uric acid (UA) stones. CaOx, CaP, and UA stones were placed in a tissue phantom and imaged with dual source multidetector CT at both 80kV and 140 kV. Hounsfield units (HU) of each stone were recorded for the 140 kV and the 80 kV datasets by drawing regions of interest by circle, hand-drawing, and using a volume calculation method. The differences between, and the ratios of, the HU obtained by the two energy sources were compared among the stone groups. Between CaOx and CaP stones, HU differences (80kV-140kV difference, hand-drawing technique: CaOx = 270.7; CaP = 369.5; UA = 11.45; P = 0.020 for CaOx vs. CaP; P < 0.001 for CaOx and CaP vs. UA) as well as ratios (140kV:80kV ratio, hand-drawing technique: CaOx = 1.44; CaP = 1.51; UA = 1.04; P = 0.001 for CaOx vs. CaP; P < 0.001 for CaOx and CaP vs. UA) were significantly different. There were no significant differences in stone size among the groups. Dual source CT has the ability to distinguish not only between calciferous stones and uric acid stones, but also among stones composed of different calcium salts. Further studies are warranted to confirm these findings in a clinical setting.

Incidental dual source computed tomography imaging of ductal aortic coarctation, left subclavian artery stenosis and bicuspid aortic valve in a patient admitted for atypical chest pain

A case of incidental ductal aortic coarctation with left subclavian artery stenosis at the origin, severely calcified and stenotic bicuspid aortic valve, and normal coronary arteries demonstrated by single breath hold dual source computed tomography angiography in a 46-year-old man admitted for acute chest pain is presented.

Myocardial Ischemia Diagnosed by Dual-Energy Computed Tomography

For decades, dual-energy imaging has been used for tissue differentiation with several x-ray–based imaging modalities, exploiting the fact that the tissues in the human body show different absorption characteristics when penetrated with different x-ray spectra, spectra that are typically generated by different kV settings of the x-ray tube. Recently, dual-source computed tomography (CT) with 2 x-ray tubes and 2 detector arrays mounted in the same gantry has become available.1 After experience with earlier experimental prototypes, this dual-source CT for the first time enables the clinical acquisition of dual-energy CT studies simultaneously with a single scan. We used a dual-source CT scanner (Definition, Siemens, Forchheim, Germany) in dual-energy mode for performing coronary CT angiography in a 74-year–old woman with suspected coronary artery disease and prior abnormal nuclear rest/stress single-photon emission CT (SPECT). The CT scan was acquired with retrospective ECG-gating and the following scan parameters: 330-ms gantry rotation, pitch 0.2, and 32×2×0.6-mm …

Dual-source computed tomography imaging in a patient with atrial fıbrillation and left atrial thrombus

f c F t v A 54-year-old man was admitted to the hospital with the ymptoms of palpitation, dyspnea, and chest pain. Electroardiography showed atrial fibrillation, and dual-source CT oronary angiography imaging was performed (Somatom efinition; Siemens, Germany). The average heart rate was 7 beats/minute (range, 60–139 beats/minute), and the canning time was 9 seconds in a single breath-hold. With ual-source CT examination, the left atrial dimensions were easured as 12 11 cm. Almost one third of the huge left trium was filled with thrombus (Figs. 1 and 2). The mitral alve was calcific and stenotic with a valve area of 1 cm. he ejection fraction of the left ventricle was 35%. In hree-dimensional cine images, the apex and anterolateral all of the left ventricle were hypokinetic. A severe stenosis as detected in the proximal segment of the left anterior escending artery (Fig. 3). The newest dual-source CT offers a temporal resolution f 83 milliseconds independent of the heart rate. Thus, a econstruction of diagnostic systolic and diastolic images is ossible for a wide range of heart rates, even in patients with rrhythmia such as atrial fibrillation, allowing accurate