Image Quality Analysis of Head CTs Obtained on a New Portable Scanner Compared to Stationary CT

Background/Purpose: The use of mobile head CT scanning in the ICU setting has both clinical and economic advantages, particularly if able to provide image quality close or equal to fixed CT scanners. The purpose of the study is to evaluate the image quality of a new portable CT scanner, compared to a fixed CT platform. Materials/Methods: Inpatients (n=11), age> 60 requiring head CT evaluation were enrolled and consented to obtain an additional head CT on the portable CT, following their fixed exam. Nine patients were able to complete the study; seven patients received duplicate exams with matched imaging technique, and two patients received the portable head CT at a 20% reduced dose. Spatial resolution was evaluated with an ACR phantom. Relevant Hounsfield unit measurements were compared. Subjective image quality analysis was performed utilizing nine assessment categories. Results: Spatial resolution analysis demonstrated 7 lp/cm for the Standard CT, and 8 lp/cm for the portable CT. Hounsfield unit analysis demonstrated equivalent values for Air, Fat, Grey Matter, White Matter and Bone. For subjective image quality analysis, interreader agreement was high: on a Likert scale of 1-5, all assessment categories were rated 4 to 5 (satisfied to extremely satisfied), with an average score of 4.97, even at reduced dose exams. Individual reviewer comments identified difficulties with patient positioning on the portable CT scanner. Conclusion: Findings in a small number of patients suggest that, with proper patient positioning, the imaging quality of a prototype PHCT scanner is comparable to that of a current SOCCT scanner, even at 20% reduced dose.