No abstract available.
*Cardiac-Gated Imaging Techniques ; Coronary Vessel Anomalies/*radiography ; Female ; Humans ; Male ; Sinoatrial Node/*radiography ; Tomography, X-Ray Computed/*methods

OBJECTIVE: To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. MATERIALS AND METHODS: Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 +/- 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. RESULTS: There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 +/- 0.306 [group A] vs. 1.084 +/- 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 +/- 0.16 mSv in group A and 7.1 +/- 1.05 mSv in group B (p = 0.001). CONCLUSION: In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.
Arrhythmias, Cardiac/*diagnosis ; Artifacts ; *Cardiac-Gated Imaging Techniques ; *Coronary Angiography ; *Electrocardiography ; Female ; *Heart Rate ; Humans ; Male ; Middle Aged ; *Tomography, Spiral Computed

OBJECTIVE: To assess the performance of a high-definition CT (HDCT) for imaging small caliber coronary stents (< or = 3 mm) by comparing different scan modes of a conventional 64-row standard-definition CT (SDCT). MATERIALS AND METHODS: A cardiac phantom with twelve stents (2.5 mm and 3.0 mm in diameter) was scanned by HDCT and SDCT. The scan modes were retrospective electrocardiography (ECG)-gated helical and prospective ECG-triggered axial with tube voltages of 120 kVp and 100 kVp, respectively. The inner stent diameters (ISD) and the in-stent attenuation value (AVin-stent) and the in-vessel extra-stent attenuation value (AVin-vessel) were measured by two observers. The artificial lumen narrowing (ALN = [ISD - ISDmeasured]/ISD) and artificial attenuation increase between in-stent and in-vessel (AAI = AVin-stent - AVin-vessel) were calculated. All data was analyzed by intraclass correlation and ANOVA-test. RESULTS: The correlation coefficient of ISD, AVin-vessel and AVin-stent between the two observers was good. The ALNs of HDCT were statistically lower than that of SDCT (30 +/- 5.7% versus 35 +/- 5.4%, p < 0.05). HDCT had statistically lower AAI values than SDCT (15.7 +/- 81.4 HU versus 71.4 +/- 90.5 HU, p < 0.05). The prospective axial dataset demonstrated smaller ALN than the retrospective helical dataset on both HDCT and SDCT (p < 0.05). Additionally, there were no differences in ALN between the 120 kVp and 100 kVp tube voltages on HDCT (p = 0.05). CONCLUSION: High-definition CT helps improve measurement accuracy for imaging coronary stents compared to SDCT. HDCT with 100 kVp and the prospective ECG-triggered axial technique, with a lower radiation dose than 120 kVp application, may be advantageous in evaluating coronary stents with smaller calibers (< or = 3 mm).
Analysis of Variance ; Cardiac-Gated Imaging Techniques/methods ; Coronary Disease/*radiography/*therapy ; Humans ; Phantoms, Imaging ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted ; *Stents ; Tomography, Spiral Computed/*methods

Azygous vein aneurysm is a rare congenital lesion that needs to be differentiated from mediastinal mass lesions. Although almost of these anomalies are asymptomatic lesions, we experienced an interesting case in which a thrombus within an azygous vein aneurysm in a 75-year-old woman caused pulmonary thromboembolism. The patient was managed by medical treatment for one month and then the thrombus within both the azygous vein aneurysm and the pulmonary arteries completely resolved.
Aged ; Aneurysm/complications/*radiography ; *Azygos Vein ; *Cardiac-Gated Imaging Techniques ; Female ; Humans ; *Multidetector Computed Tomography ; Pulmonary Embolism/etiology/*radiography ; Thrombosis/complications/*radiography

In keeping with the increasing utilization of CT examinations, the greater concern about radiation hazards from examinations has been addressed. In this regard, CT radiation dose optimization has been given a great deal of attention by radiologists, referring physicians, technologists, and physicists. Dose-saving strategies are continuously evolving in terms of imaging techniques as well as dose management. Consequently, regular updates of this issue are necessary especially for radiologists who play a pivotal role in this activity. This review article will provide an update on how we can optimize CT dose in order to maximize the benefit-to-risk ratio of this clinically useful diagnostic imaging method.
Body Size ; Cardiac-Gated Imaging Techniques/methods ; Humans ; *Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted ; Radiometry ; Risk Assessment ; Tomography, X-Ray Computed/*methods

OBJECTIVETo assess the image quality, diagnostic accuracy and effective radiation dose of prospectively ECG- triggered high-pitch spiral double scanning (Double Flash) mode of computed tomography coronary angiography (CTCA) using dual-source CT for the diagnosis of significant coronary stenoses.

METHODSPatients underwent both CTCA in Double Flash mode and conventional coronary angiography (CAG) and were divided into two groups according to heart rate (HR), namely group A with HR <65/min (62 cases) and group B with HR between 65 and 80/min (52 cases). All the coronary segments were evaluated by two blinded and independent observers for image quality on a four-point scale and for the presence of significant coronary stenoses (defined as a diameter narrowing exceeding 50%). CAG served as the reference standard for analyzing the diagnostic accuracy of Double Flash mode images on the level of both patients and vessels. Radiation dose values were calculated using the dose-length product.

RESULTSA total of 114 patients were enrolled and 1725 vessel segments were displayed. In terms of image quality, the diagnosable segments accounted for 98.5% (919/933) in group A and 97.3% (770/792) in group B. In the per-patient analysis, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 100%, 90.5%, 88.2%, 100% and 96.7% in group A and were 100%, 88.5%, 94.5%, 100% and 96.2% in group B, respectively. The mean effective radiation dose was 1.63∓0.52 mSv.

CONCLUSIONDouble Flash spiral protocol of dual-source CTCA can acquire good image quality and yield high diagnostic accuracy for assessment of coronary artery stenoses at a low radiation dose in patients with HR between 65 and 80/min.

Aged ; Cardiac-Gated Imaging Techniques ; Coronary Angiography ; Coronary Stenosis ; diagnosis ; diagnostic imaging ; pathology ; physiopathology ; Coronary Vessels ; diagnostic imaging ; Female ; Heart Rate ; Humans ; Male ; Middle Aged ; Radiation Dosage ; Sensitivity and Specificity ; Tomography, Spiral Computed

The purpose of this study was to explore the clinical value of ECG-gated dual-source CT angiography (DSCTA) in evaluating coarctation of aorta (CoA). 23 patients suspected with CoA underwent DSCTA and transthoracic echocardiography (TTE). Surgical results were taken as reference standard. 23 patients were diagnosed with CoA, 12 cases had focal stenosis of aorta, while 11 had tubular stenosis. 19 cases were associated with other cardiovascular malformations, including 5 cases of hypoplastic aortic arch, 5 of patent ductus arteriosus, 10 of ventricular septal defect, 2 of bicuspid aortic valve, 4 of collateral arteries, 2 of aberrant left subclavian artery and 2 of persistent left superior vena cava, respectively. The mean diameter of stenotic segment of aorta was (7.0 +/- 3.7) mm. In 9 patients with tubular CoA, the diameter and length of stenotic segment of aorta were (6.2 +/- 7. 3) mm and (29.2 +/- 5.9) mm, respectively. The accuracies of DSCTA and TTE in the diagnosis of CoA were 100% and 91.3% (P > 0.05), respectively. It is well concluded that ECG-gated DSCTA could accurately evaluate CoA and associated cardiovascular malformations, and provide detailed anatomic information before surgery.
Adolescent ; Adult ; Angiography ; methods ; Aortic Coarctation ; diagnostic imaging ; surgery ; Cardiac-Gated Imaging Techniques ; methods ; Child ; Child, Preschool ; Contrast Media ; Echocardiography ; Electrocardiography ; methods ; Female ; Humans ; Infant ; Male ; Tomography, X-Ray Computed ; methods ; Young Adult

OBJECTIVE: The ventriculus terminalis (VT) in adults is a rare pathology. We report various MR imaging features of the adult VT. MATERIALS AND METHODS: Ten patients were included in this retrospective review.. All patients had undergone magnetic resonance (MR imaging with a surface coil that used two different 1.5T MR systems. All patients had undergone initial and follow-up MR imaging with contrast enhancement using gadopentate dimeglumine. Three patients underwent additional MR imaging using the echocardiogram-gated spatial modulation of magnetization (SPAMM) technique. If a shift in tagging band during the systolic phase was less than half of the band space, it was defined as a "non-pulsatile fluid". Two neuroradiologists independently reviewed these images, while clinical symptoms and outcomes were statistically analyzed between the treated and non-treated group. RESULTS: All cases presented an intramedullary cystic lesion in the conus medullaris and showed the same signal intensity as CSF. Three VTs had intracystic septation and cord edema, which were pathologically confirmed after surgery; two of these were associated with kyphotic deformity and spinal arteriovenous malformation. SPAMM-MRI of 3 patients demonstrated non-pulsatile fluid motion within the VT. In the treated group, clinical symptoms improved better than the non-treated group. CONCLUSION: The adult VT shows some unusual imaging features, including septation, cord edema, and coexistence of a spinal AVM, as well as the typical findings. Surgical maneuvers may be considered as a treatment option in adult VT with progressive neurological symptoms.
Adult ; Cardiac-Gated Imaging Techniques ; Contrast Media/diagnostic use ; Cysts/*diagnosis/physiopathology ; Diagnosis, Differential ; Female ; Gadolinium DTPA/diagnostic use ; Humans ; Magnetic Resonance Imaging/*methods ; Male ; Retrospective Studies ; Spinal Cord Diseases/*diagnosis/physiopathology

Objective: To investigate the dynamic change of the secundum atrial septal defect (ASD) throughout the cardiac cycle, and assess its impact on occluder selection. Methods: This study retrospectively analyzed 35 patients with ASD who received electrocardiogram-gated coronary CT angiography (CCTA) throughout the cardiac cycle as well as interventional closure therapy in Fuwai Hospital from December 2016 to December 2019. The raw data were reconstructed into 20 phasic images of RR intervals (RRI) ranging from 0 to 95% in an increment of 5% and transmitted to a workstation for postprocessing. For each phase image, CT virtual endoscopy reconstruction technique (CTVE) was used to provide views of ASD. Axial sequence assisted CT volumetric measurement (CTAS) was used to calculate the maximum dimensions in axial planes (D_a) and in superior-inferior direction (D_b). Using a formula for converting circumference to diameter, the equivalent circle dimensions were calculated (D_e, D_e=minor axis+2 (major axis-minor axis)/3). Taking the data of 75% RRI phase, the patients were divided into D_a75%RRI≥D_b75%RRI group and D_a75%RRIb75%RR group. According to the postoperative chest X-ray, the waist diameter of the occluder in the left anterior oblique plain film was measured, and its correction value (CR-POD_laoc) was calculated with the correction formula. Scatter plots of the changes of the mean values of D_a, D_b and D_e with the cardiac cycle were presented. The change and ratio of measured values of D_a and D_e at 35% and 75% RRI was calculated. The ratio of D_e change to D_a change in D_a75%RRI≥D_b75%RRI group and D_a75%RRIb75%RR group was calculated, respectively, and compared between groups. Pearson correlation analysis was used to explore the correlation between CR-POD_laoc and D_e35%RRI and D_e75%RRI. Results: A total of 35 patients, aged (42.7±15.0) years, including 10 males, were included. Among 35 patients, 8 cases were divided into group D_a75%RRI≥D_b75%RRI and 27 cases into group D_a75%RRIb75%RRI. Both D_a and D_b regularly changed at each phase throughout the cardiac cycle. The D_a changed significantly, with a maximum at phase of 35%-45% of RRI, and a minimum between phases of 90% and 0 of RRI. While the D_b showed insignificant changes during phases of 10%-90% RRI, and increased at 0-10% of RRI, then reduced in the remaining phases. The change of D_a was (6.35±2.46) mm, and the ratio of D_a values at 35% and 75% RRI was 0.77±0.08. The change of D_e was (2.28±1.32) mm, and the ratio of D_e at 35% and 75% RRI was 0.93±0.05. The ratio of D_e change to D_a change in the D_a75%RRI≥D_b75%RRI group was 0.67±0.13; while the ratio was 0.34±0.05 in D_a75%RRIb75%RR group, and there was significant difference between the two groups (P=0.02). CR-POD_laoc was positively correlated with D_{e35% RRI} (r=0.99, P<0.001) and D_{e75% RRI} (r=0.98, P<0.001). Conclusions: Most secundum ASDs show oval shape with D_b>D_a. D_b is basically constant while D_a changes significantly during cardiac cycle (10%-90% RRI). Nonetheless, both values peak and maintain the maximum status at end-systolic phase (35%-45% RRI). For patients with huge ASD, occluder selection should be based on the D_e at 35% RRI phase, which is helpful for the successful intervention.
Adult ; Cardiac-Gated Imaging Techniques ; Computed Tomography Angiography ; Coronary Angiography ; Electrocardiography/methods* ; Female ; Heart Septal Defects, Atrial/surgery* ; Humans ; Imaging, Three-Dimensional ; Male ; Middle Aged ; Retrospective Studies ; Septal Occluder Device

OBJECTIVE: To evaluate, on a retrospective basis, the anatomic characteristics of the arterial supply to the sinoatrial node (SAN) in the Korean population using an ECG-gated multi-detector CT (MDCT). MATERIALS AND METHODS: The electrocardiographic-gated MDCTs of 500 patients (258 men and 242 women; age range, 17-83 years; mean age, 58.6 +/- 12.04 years) were analyzed retrospectively. In each case, the SAN artery (arteries) was named according to a special nomenclature with regard to origin, course, and termination. RESULTS: A total of 516 SAN arteries were visualized in 496 patients. The SAN was supplied by a single artery in 476 (96.4%) cases and by 2 arteries in 18 (3.6%) cases. The SAN originated from the right coronary artery in 265 (53.4%) cases and from the left circumflex in 213 (43%) cases. CONCLUSION: This study can provide basic data on variations of the SAN artery in the Korean population.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; *Cardiac-Gated Imaging Techniques ; Coronary Vessel Anomalies/*radiography ; Female ; Humans ; Male ; Middle Aged ; Republic of Korea ; Retrospective Studies ; Sinoatrial Node/*radiography ; Tomography, X-Ray Computed/*methods