Is it time to eliminate CT after EVAR as routine follow-up?

Growing concerns regarding radiation exposure, contrast induced nephropathy and increasing costs lead us to reconsider the necessity of CTA for all EVAR patients. The purpose of this study is to compare the results of different follow-up imaging modalities with the aim of finding a rationale to the optimal follow-up imaging protocol. We reviewed recent literature regarding post EVAR imaging modalities and compared it to our experience with different follow-up protocols. Modalities compared were CTA, DUS, CEUS, and plain abdominal X-ray with regard to detection of complications, cost, overall impact to the patient, and on decision making regarding reintervention. CTA is related to increased follow-up costs and a much higher exposure to radiation compared to other modalities. The cumulative radiation dose can have a significant impact on the attributable lifetime cancer risk of patients. Renal function deterioration during post EVAR follow-up is higher compared to open repair. Plain abdominal X-ray is the best manageable modality and a well established tool in documenting migration kinking and stent fracture. Plain X-Ray cannot be used as a standalone imaging modality since it doesn't allow direct detection of endoleaks. As far as detection of endoleaks is concerned recent meta-analyses show a sensitivity of 66-77% for DUS and 81-98% for CEUS, respectively. Most endoleaks missed by DUS and CEUS are type II endoleaks with no need for reintervention. Our data in a cohort of 62 patients do show a sensitivity of 66.7% for DUS, and do correlate with current literature. No endoleaks requiring reintervention were missed. A follow-up protocol comprising of DUS/CEUS and plain abdominal X-ray gives a wide range of information covering EVAR related risks and is associated with less radiation exposure, avoidance of renal function deterioration due to repeated contrast agent application and an important decrease in the cost of EVAR follow-up. CTA should be reserved for cases of inconclusive ultrasound, signs of complications and unfavourable anatomy.

Iatrogenic and fatal arterial air embolism during the CT scan

Systemic and fatal arterial air embolism during the computed tomography (CT) scan is rarely reported in English-based literature. Iatrogenic air embolism happening during the CT scan is often related to the injector, usually venous air embolism and asymptomatic. We report one fatal and extensive systemic arterial air embolism because of one error that happened during a brain CT scan. The mechanism is different from the reported cases in the literature. The possible mechanism and pathogenesis are well discussed to alert clinicians and prevent the recurrence of such complication.

[Radiation hygiene in medical X-ray imaging: part 2: Assessment of radiation exposure and radiation protection measures]

In order to secure and continually improve radiation protection standards in the field of medical X-ray imaging, the German X-Ray Ordinance requires that each individual examination be properly justified and that any procedure undertaken be optimized. Diagnostic reference levels have been introduced in Germany as a measure of optimization for common and/or high-dose X-ray procedures, and are regularly checked for compliance by the competent Medical Experts Office. A prerequisite for the implementation of these regulatory requirements is the determination of readily measurable dose quantities. They also form the basis for the estimation of organ doses and of the effective dose for exposure and risk assessment. The aim of this paper is to describe the essential dosimetric concepts and methods used for the assessment of radiographic, fluoroscopic, and CT procedures. In addition, practical measures for reducing the radiation exposure of patients and personnel will be discussed.

Computed tomography in children: multicenter cohort study design for the evaluation of cancer risk

Exposure to ionizing radiation is a known risk factor for cancer. Cancer risk is highest after exposure in childhood. The computed tomography is the major contributor to the average, individual radiation exposure. Until now the association has been addressed only in statistical modeling. We present the first feasible study design on childhood cancer risk after exposure to computed tomography.

[Lung cancer -- CT screening for lung cancer dramatically improved survival after surgical resection]

Lung cancer is the leading cause of cancer deaths in Japan. Because the majority of patients with lung cancer have metastatic or locally advanced disease at presentation, early diagnosis and treatment are important in improving the currently low survival rate of lung cancer patients. Recent increase in frequency of detecting small-sized lung cancer can be attributed to the screening system, and surgery for early-stage lung cancer is performed more often. This tendency resulted in the recent improved survival after surgical resection seen in patients with lung cancer, which has led to renewed interest in screening program for lung cancer with the promise of detecting smaller and potentially more curable tumors. Several authors reported that the use of low-dose computed tomography screening in detecting lung cancer enabled better detection of small, low density nodules, which would lead to an excellent cure rate for the disease.

CT and MRI of early intrauterine pregnancy

OBJECTIVE

The objective of this article is to describe the CT and MRI findings of early intrauterine pregnancy.

CONCLUSION

Early pregnancy should be considered when CT or MRI shows a fluid-filled cystlike structure in the uterus of a woman of reproductive age especially if there is a coexistent ovarian corpus luteum cyst.

Bismuth breast and thyroid shield implementation for pediatric CT

Studies have indicated that infants and children are as much as ten times more susceptible to carcinogenesis from radiation than adults. Because data show bismuth breast and thyroid shields decrease radiation dose to sensitive areas without changes in image quality, Children's Healthcare of Atlanta implemented the use of bismuth shields in all patients undergoing CTexaminations. Staff education regarding the use of bismuth shielding was key to the success of this program.Their understanding of the benefits would ultimately assist in their support of shield use in the CT department. This program was made possible through a grant from the AHRA & Toshiba Putting Patients First Program. Otherwise, the cost of bismuth shielding would be supported by the operating budget of the organization and, with the decline in CT volume reported at many healthcare institutions,this cost may be too high for many hospitals.