Recent developments in CT: a review of the clinical applications and advantages of multidetector computed tomography

Assessing and coping with the financial burden of computed tomography utilization in Limbe, Cameroon: a sequential explanatory mixed-methods study

BACKGROUND

There has been a significant increase in computed tomography (CT) utilization over the past two decades with the major challenges being a high exposure to ionizing radiation and rising cost. In this study we assess the risk of financial hardship after CT utilization and elaborate on how users adapt and cope in a sub-Saharan context with user fee for services and no national health insurance policy.

METHODS

We carried out a sequential explanatory mixed methods study with a quantitative hospital-based survey of CT users followed by in-depth interviews of some purposively selected participants who reported risk of financial hardship after CT utilization. Data was summarized using frequencies, percentages and 95% confidence intervals. Logistic regression was used in multivariable analysis to determine predictors of risk of financial hardship. Identified themes from in-depth interviews were categorized. Quantitative and qualitative findings were integrated.

RESULTS

A total of 372 participants were surveyed with a male to female sex ratio of 1:1.2. The mean age (standard deviation) was 52(17) years. CT scans of the head and facial bones accounted for 63% (95%CI: 59-68%) and the top three indications were suspected stroke (27% [95%CI: 22-32%]), trauma (14% [95%CI: 10-18%]) and persistent headaches (14% [95%CI: 10-18%]). Seventy-two percent (95%CI: 67-76%) of the respondents reported being at risk of financial hardship after CT utilization and predictors in the multivariable analysis were a low socioeconomic status (aOR: 0.19 [95%CI: 0.10-0.38]; p < 0.001), being unemployed or retired (aOR: 11.75 [95%CI: 2.59-53.18]; p = 0.001) and not having any form of health insurance (aOR: 3.59 [95%CI: 1.31-9.85]; p = 0.013). Coping strategies included getting financial support from family and friends, borrowing money and obtaining discounts from the hospital administration and staff.

CONCLUSION

No health insurance ownership, being unemployed or retired and a low socioeconomic status are associated with financial hardship after CT utilization. Diverse coping strategies are utilized to lessen the financial burden, some with negative consequences. Minimizing out-of-pocket payments and/or the direct cost of CT can reduce this financial burden and improve CT access.

Diagnostic performance of 64-MDCT in detecting ERCP-proven periampullary duodenal diverticula

AIM

To determine the diagnostic performance of 64-slice multidetector computed tomography (64-MDCT) in detecting periampullary duodenal diverticula.

MATERIALS AND METHODS

Medical profiles of 120 endoscopic retrograde cholangiopancreatography (ERCP)-proven patients with (n = 100) and without (n = 20) periampullary duodenal diverticula who had undergone 64-MDCT were retrospectively reviewed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 64-MDCT in detecting periampullary duodenal diverticula were calculated. Potential factors that might influence the diagnostic performance of 64-MDCT in such patients were also examined.

RESULTS

Patients were 60 males and 60 females with the mean age of 68.8 ± 12.7 (27-93) years. Indications of ERCP were common bile duct stricture (n = 62) or stone (n = 41), biliary cholestasis (n = 16) and acute cholangitis (n = 1). The sensitivity, specificity, PPV, and NPV of 64-MDCT in detecting periampullary duodenal diverticula were 76%, 100%, 100%, and 45.5%, respectively. The size of diverticula was the only predictor of 64-MDCT performance, with better results observed in larger (> 20 mm) diverticula.

CONCLUSION

64-MDCT is a highly specific imaging modality in detecting periampullary duodenal diverticula. The diagnostic performance of 64-MDCT increases for larger diverticula.

Analysis of effective and organ dose estimation in CT when using mA modulation: A single scanner pilot study

INTRODUCTION

Effective dose (ED) estimation in CT examinations can be obtained by combining dose length product (DLP) with published ED per DLP coefficients or performed using software. These methods do not account for tube current (mA) modulation which is influenced by patient size. The aim of the work was to compare different methods of organ and ED estimation to measured values when using mA modulation in CT chest, abdomen and pelvis examinations.

METHOD

Organ doses from CT of the chest, abdomen and pelvis were measured using digital dosimeters and a dosimetry phantom. ED was calculated. Six methods of estimating ED accounting for mA modulation were performed using ImPACT CTDosimetry and Dose Length Product to ED coefficients. Corrections for the phantom mass were applied resulting in 12 estimation methods. Estimated organ doses from ImPACT CTDosimtery were compared to measured values.

RESULTS

Calculated EDs were; chest 12.35 mSv (±1.48 mSv); abdomen 8.74 mSv (±1.36 mSv) and pelvis 4.68 mSv (±0.75 mSv). There was over estimation in all three anatomical regions. Correcting for phantom mass improved agreement between measured and estimated ED. Organ doses showed overestimation of dose inside the scan range and underestimation outside the scan range.

CONCLUSION

Reasonable estimation of effective dose for CT of the chest and abdomen can be obtained using ImPACT CTDosimetry software or k-coefficients. Further work is required to improve the accuracy of ED estimation from CT of the pelvis. Accuracy of organ dose estimation has been shown to depend on the inclusion or exclusion of the organ from the scan range.