Subjective and objective image differences in pediatric computed tomography cardiac angiography using lower iodine concentration

Interventional Treatment of Bronchiectasis Macrosomia Based on Multirow CT Tomography Monitoring

We present in this paper an in-depth study and analysis of bronchiectasis haemoptysis by multirow CT tomography and a multifaceted treatment and analysis of the interventions monitored by the scan. Although coronary CT is of great clinical value in the diagnosis and monitoring of coronary artery disease, the potential radiation damage caused by coronary CT should not be underestimated because CT imaging is based on X-rays and the actual effective dose is 5-30 mSv, which is reported in the literature to be high when using conventional imaging modalities for coronary CT. Although there is no direct evidence of a definite causal relationship between X-ray exposure during CT examinations and tumorigenesis, theoretically, even small doses of radiation exposure may pose some potential health risk. Therefore, in clinical practice, coronary CT examinations should be performed in strict compliance with the radiation protection rule "as low as reasonably achievable" (ALARA) recognized by the radiation industry. For longitudinal openings in the range of 0° to 59° and transverse openings in the range of 0° to 44°, the CB2 catheter is significantly more stable than the MIK catheter, and for longitudinal openings in the range of 60° to 119° and transverse openings in the range of 0° to 44°, the CB2 catheter is more stable than the MIK catheter. For longitudinal openings from 0° to 120° and lateral openings from 45° to 90°, there was no significant difference in cannulation stability between the CB2 and MIK catheters. There was a potential tendency for MIK cannulation stability to be higher than CB2 for longitudinal openings in the range of 120° to 180° and lateral openings in the range of 45° to 90°, but there was no significant difference.

Cardiothoracic CTA in Infants Referred for Aortic Arch Evaluation-Retrospective Comparison of Iomeprol 350, Ioversol 350, Iopromide 370 and Iodixanol 320

Background: Computed tomography angiography (CTA) in infants is considered one of the most challenging radiological examinations due to difficulties in balancing start delay, contrast agent (CA) volume and flow in order to achieve optimal opacification of the large vessels. This study aimed to compare the contrast enhancement achieved by four CAs when taking into consideration CA injection parameters and patient characteristics. Methods: We performed a retrospective assessment of forty-eight consecutive cardiothoracic CTAs performed for aortic arch evaluation on children aged 0–1 year. All examinations were performed using the same 64-slice scanner and power injector using the bolus tracking technique. Axial 0.6 mm slices were used to measure large vessel enhancement using regions of interest at the level of the main pulmonary artery, ascending and descending aorta. The recorded variables included anthropometric measurements, CA type, flow rate, volume, and the average Hounsfield unit (HU) values of the blood pool. Descriptive statistics are presented as averages and standard deviations (SD) for normal distributed data or otherwise as medians and interquartile ranges (IQRs). Results: We found no statistically significant differences between age and anthropometric parameters when looking at different CAs. The median CA volume was 7 (IQR, 7–9) mL with the average flow rate of 0.94 (SD, 0.23) mL/s. Ascending aorta average HU values were 605.9 (SD, 177.23) for Iomeprol 350, 626 (SD, 183.83) for Ioversol 350, 530.83 (SD, 175.56) for Iopromide 370 and 354.91 (SD, 115.81) for Iodixanol 320. The difference in HU value for Iodixanol 320 compared to the other CAs was statistically significant. Similar differences were found for the other vascular structures. Conclusion: In CTA of infants suspected of aortic arch hypoplasia/coarctation, Iodixanol 320 provided up to 40% less enhancement of the great vessels when compared to Iomeprol 350, Ioversol 350 and Iopromide 370.

Chest CTA in children younger than two years - a retrospective comparison of three contrast injection protocols

To obtain the highest diagnostic information with least side effects when performing thoracic CT angiography (CTA) is challenging in young children. The current study aims to compare three contrast agent (CA) injection protocols regarding image quality and CA characteristic: a standard CTA, a fixed-bolus delay protocol, and the “microbolus technique (MBT)” developed in our institution. Seventy chest CTA scans of patients (<2 years) were divided into three groups. MBT was applied in group I, the standard protocol in group II and a fixed bolus delay in group III. Objective image quality was assessed by measuring peak enhancement, image noise, signal-to-noise (SNR) and contrast-to-noise ratios (CNR). Two observers scored subjective image quality and artifacts. Significantly lower amounts of CA (mean ± SD) were used in the MBT group compared to Group II (9.0 ± 3.7 ml vs. 12.9 ± 4.5 ml). A lower, but still diagnostic (>400 HU) enhancement was registered in all major thoracic vessels in group I without significant differences regarding SNR and CNR in most regions (p < 0.05). The best scores for image quality and artifacts were reached in group I. All three chest CTA contrast injection protocols offered diagnostic vessel enhancement in young patients. MBT was associated with reduced image artifacts and less injected CA.

Development and validation of image quality scoring criteria (IQSC) for pediatric CT: a preliminary study

OBJECTIVE

To develop and assess the value and limitations of an image quality scoring criteria (IQSC) for pediatric CT exams.

METHODS

IQSC was developed for subjective assessment of image quality using the scoring scale from 0 to 4, with 0 indicating desired anatomy or features not seen, 3 for adequate image quality, and 4 depicting higher than needed image quality. Pediatric CT examinations from 30 separate patients were selected, five each for routine chest, routine abdomen, kidney stone, appendicitis, craniosynostosis, and ventriculoperitoneal (VP) shunt. Five board-certified pediatric radiologists independently performed image quality evaluation using the proposed IQSC. The kappa statistics were used to assess the interobserver variability.

RESULTS

All five radiologists gave a score of 3 to two-third (67%) of all CT exams, followed by a score of 4 for 29% of CT exams, and 2 for 4% exams. The median image quality scores for all exams were 3 and the interobserver agreement among five readers (acceptable image quality [scores 3 or 4] vs sub-optimal image quality ([scores 1 and 2]) was moderate to very good (kappa 0.4-1). For all five radiologists, the lesion detection was adequate for all CT exams.

CONCLUSIONS

The image quality scoring criteria covering routine and some clinical indication-based imaging scenarios for pediatric CT examinations has potential to offer a simple and practical tool for assessing image quality with a reasonable degree of interobserver agreement. A more extensive and multi-centric study is recommended to establish wider usefulness of these criteria.

Comparison of image quality of abdominopelvic CT in paediatric patients: low osmolar contrast media versus less iodine-containing iso-osmolar contrast media at different peak kilovoltages

AIM

To evaluate the effect of iso-osmolar contrast media (IOCM) at different tube voltages on image quality for abdominal computed tomography (CT) in paediatric patients.

MATERIALS AND METHODS

The low osmolar contrast media (LOCM) group and IOCM group consisted of 101 and 102 CT examinations, respectively, in patients <18 years old. Images were reviewed retrospectively. Objective measurement of the contrast enhancement and noise were analysed and contrast-to-noise ratios (CNRs) of the abdominal aorta, portal vein, and liver were calculated. Four radiologists participated in subjective analysis using a four-point scale system to evaluate degrees of contrast enhancement, image noise, beam-hardening artefact, and overall image quality. Reader performance for correctly differentiating the two kinds of contrast media was evaluated.

RESULTS

Regarding the objective measurement, contrast enhancement was significantly higher in the LOCM group (p<0.05). In subjective analysis, only CT using 120 kVp showed significantly stronger enhancement in the LOCM group (p=0.002), and sensitivity to differentiate the IOCM was 80.6%. Overall sensitivity and specificity for correctly differentiating IOCM were 57.1%, and 56.9%, respectively.

CONCLUSION

The application of IOCM was found to be feasible for performing paediatric abdominopelvic CT with a low tube voltage protocol. Although objective measurements of contrast enhancement were significantly lower in the IOCM group, subjective contrast enhancement and image quality assessments were not statistically different between groups.

Contrast Administration in CT: A Patient-Centric Approach

Patient-centric care has garnered the attention of the radiology community. The authors describe a patient-centric approach to iodinated contrast administration designed to optimize the diagnostic yield of contrast-enhanced CT while minimizing patient iodine load and exposure to ionizing radiation, thereby enhancing patient safety while providing reasonable diagnostic efficacy. Patient-centric CT hardware settings and contrast media administration are important considerations for clinical CT quality and safety.