Introduction
Anatomical and physiological differences between pediatric and adults require special attention when imaging pediatric patients. Before performing a pediatric CT examination, it is essential to fully evaluate the risks, radiation dose and benefits of the requested examination. Systematic efforts can be used to drive process and quality improvement in terms of optimizing CT radiation dose while maintaining image utility. The other challenge was the imaging without sedation and breath hold. Image quality is a key factor because these images are routinely used for clinical evaluation as well as for pre-operative surgical planning. Technologies have evolved and will continue to develop innovations that follow the ALARA (as low as reasonably achievable) principle.
Prospective
Below are some novel clinical examples where the lowest radiation dose was achieved by using technologies such as CARE Dose 4D, CARE kV, Turbo flash, Sub-second rotation and ADMIRE iterative reconstruction(IR) algorithm.
MPR image with VRT clearly delineating hepatic focal lesion showing residual hypodensity
Pediatric Case Study #1 - DLP: 4 mGy x cm.
Achieved effective dose level of 0.12 msv
History - 7-month-old male infant presented for follow up study of invasive fungal infection treated with 6 weeks of antifungals.
Examination Protocol - • 70 kV • 10 mAs/rot • Dedicated single acquisition ultra-fast pediatric protocol for chest, abdomen and pelvis • CARE Dose 4D and CARE kV • DLP: 4 mGy x cm. Achieved effective dose level of 0.12MsV(Conversion Factor abdo pelvis k=0.030) with superior image quality.
Diagnosis - Follow up CT imaging depicts the appreciable therapeutic response and resolution of the previously seen right para tracheal and retro caval lymph nodes. The mid bilateral basal pleural effusion and basal atelectatic bands are no longer visible in the current study. The liver is still seen mildly enlarged with resolution of the previously seen enhancing hepatic focal lesion showing residual hypodensity.
MPR image with VRT clearly delineating heterogeneously enhancing
mass like lesion involving the upper and lower lobes of right lung
Pediatric Case Study #2 - DLP: 8 mGy x cm.
Achieved effective dose level of 0.2msv
History - 9-month-old female child presented for CT scan chest with right upper zone haziness and a query of mediastinal mass. Suspecting hepatoblastoma and further evaluation of staging.
Examination Protocol - • 70 kV • 18 mAs/rot • Dedicated single acquisition ultra-fast pediatric protocol for chest two phase (P+C) • CARE Dose 4D and CARE kV • DLP: 8 mGy x cm. Achieved effective dose level of 0.20 msv (Conversion Factor chest 1 year k=0.026) superior image quality.
Diagnosis - Evidence shows last heterogeneously enhancing mass like lesion involving the upper and lower lobes of right lung. The lesion shows air bronchogram and multiple low attenuation areas. The features most likely represent infective etiology (necrotizing pneumonia).
MPR image with VRT clearly delineating heterogeneously enhancing mass like lesion involving the upper and lower lobes of right lung
Pediatric Case Study #3 - DLP: 15 mGy x cm.
Achieved effective dose level of 0.73 msv
History - 6-month-old boy presented for CT scan chest and abdomen with a query of pulmonary nodule and hepatic mass. Suspecting hepatoblastoma and further evaluation of staging.
Examination Protocol - • 70 kV • 24 mAs/rot • Dedicated single acquisition ultra-fast pediatric protocol for chest and abdomen • CARE Dose4D and CARE kV • DLP: 15 mGy x cm. Achieved effective dose level of 0.73 MsV (Conversion Factor abdo pelvis 0-year k=0.049) superior image quality.
Diagnosis - Both the lung fields appear to be normal and there is no evidence of sizable pulmonary nodule large hepatic infiltrative neoplastic mass lesion. Likely hepatoblastoma.
MPR image with VRT clearly delineating the large hepatic infiltrative
neoplastic mass lesion
Pediatric Case Study #4 - DLP: 19 mGy x cm.
Achieved effective dose level of 0.38 msv
History - 5-year-old boy presented for CT scan. Follow up study of Burkitt’s lymphoma post-chemo.
Examination Protocol - • 70 kV • 30 mAs/rot • Dedicated single acquisition ultra-fast pediatric protocol for chest two phase (P+C) • CARE Dose 4D and CARE kV • DLP: 19 mGy x cm. Achieved effective dose level of 0.38 Msv (Conversion Factor abdo pelvis 5-year k=0.020) with superior image quality.
Diagnosis - Post CT compared images are evidence of B cell lymphoma showing residual short segmental small bowel mural thickening with significant proximal small bowel dilation. Mild hepatomegaly and sub centimetric mesenteric lymph nodes are visible.
Conclusion
Adapting new CT technologies opens doors to a decisive factor in critical emergency situations and complex pediatric imaging. It helps us to perform CT studies without the need for breath-hold with high-quality diagnostic imaging. This is the case for trauma patients as well as for very young or elderly patients who are unable to hold their breath either at all or for longer periods of time.
Here, fast scans eliminate the potential need for sedation or intubation, and thereby save additional costs. For those patients who still require an anesthetic, fast scans also reduce the associated risks. The SOMATOM Force CT scan can scan the entire thorax in sub seconds, and it can scan the thorax, abdomen, and pelvis in 1 second in high-pitch mode. This leads to significantly reduced motion artifacts. Pediatric imaging presents specific challenges that range from reducing X-ray doses to creating an anxiety-free environment during imaging procedures. Innovative concepts and new technologies can help address all these challenges.