Image Evaluation of Free-breathing Navigator Echo and Triggered Cardiac-gated Delayed Myocardial Enhancement Magnetic Resonance Imaging in Sedated Infants

We validated a navigator-echo-triggered sequence that drives magnetization before cardiac-gated inversion recovery T1 turbo field echo acquisition, in the sedated free-breathing pediatric population. Cardiac magnetic resonance imaging was performed on sedated infants with single ventricle. We calculated the signal-to-noise ratios and contrast-to-noise ratios of 2 groups of images obtained using respiratory triggering with and without navigator echo. All images were then visually assessed by 2 observers. The signal-to-noise ratio and the contrast-to-noise ratio were significantly higher with than without navigator echo (p<0.01; p<0.05). The visual assessment scores were also consistently better with than without navigator echo (p<0.01). Free-breathing navigator echo was found to have the advantage of decreasing the motion artifact caused by respiration. Cardiacgated inversion recovery T1 turbo field echo sequence for free-breathing navigator-echo-triggered respiration allows for the acquisition, in sedated infants, of diagnostic images whose quality exceeds that of the non-navigator-echo-triggered alternative

Robotic CT-guided out-of-plane needle insertion: comparison of angle accuracy with manual insertion in phantom and measurement of distance accuracy in animals

Objectives To evaluate the accuracy of robotic CT-guided out-of-plane needle insertion in phantom and animal experiments. Methods A robotic system (Zerobot), developed at our institution, was used for needle insertion. In the phantom experiment, 12 robotic needle insertions into a phantom at various angles in the XY and YZ planes were performed, and the same insertions were manually performed freehand, as well as guided by a smartphone application (SmartPuncture). Angle errors were compared between the robotic and smartphone-guided manual insertions using Student’s t test. In the animal experiment, 6 robotic out-of-plane needle insertions toward targets of 1.0 mm in diameter placed in the kidneys and hip muscles of swine were performed, each with and without adjustment of needle orientation based on reconstructed CT images during insertion. Distance accuracy was calculated as the distance between the needle tip and the target center. Results In the phantom experiment, the mean angle errors of the robotic, freehand manual, and smartphone-guided manual insertions were 0.4°, 7.0°, and 3.7° in the XY plane and 0.6°, 6.3°, and 0.6° in the YZ plane, respectively. Robotic insertions in the XY plane were significantly (p Conclusion Robotic CT-guided out-of-plane needle insertions were more accurate than smartphone-guided manual insertions in the phantom and were also accurate in the in vivo procedure, particularly with adjustment during insertion

A survey of nurses’ and physicians’ safety awareness in CT/MRI examinations

To perform computed tomography （CT）/magnetic resonance imaging （MRI） scans safely and reliably, adherence to a pre-scan checklist is crucial. However, physicians and nurses may differ in their recognition of the usefulness of this checklist. We conducted the present study to investigate possible differences between physicians’ and nurses’ awareness of CT/MRI scan safety in terms of their adherence to the pre-scan checklist.　We prepared an independently developed self-administered 23-item questionnaire about attributes of subjects, CT/ MRI scan safety recognition and current situation for CT/MRI examinations.　The survey was distributed to 468 participants who combined nurses and physicians at Okayama University Hospitalin Okayama, Japan. We analysis the responses of the 224 participants （117 nurses and 107 physicians）who returned the survey with on missing data （a 65.1% completion rate）. The overall safety recognition scores were significantly higher for the nurses than for the physicians （p＜0.001）. In addition, the physicians did not sufficiently know or implement the guidelines in the CT/MRI scan safety manual used at our hospital. Nurses and physicians demonstrated marked differences in their awareness and knowledge of safety regarding CT/MRI scans. Measures for improving safety recognition should thus be designed for individual healthcare occupations

Assessment of a New Elbow Joint Positioning Method Using Area Detector Computed Tomography

We propose a sitting position that achieves both high image quality and a reduced radiation dose in elbow joint imaging by area detector computed tomography (ADCT), and we compared it with the ‘superman’ and supine positions. The volumetric CT dose index (CTDIvol) for the sitting, superman, and supine positions were 2.7, 8.0, and 20.0 mGy and the dose length products (DLPs) were 43.4, 204.7, and 584.8 mGy • cm, respectively. In the task-based transfer function (TTF), the highest value was obtained for the sitting position in both bone and soft tissue images. The noise power spectrum (NPS) of bone images showed that the superman position had the lowest value up to approx. 1.1 cycles/mm or lower, whereas the sitting position had the lowest value when the NPS was greater than approx. 1.1 cycles/mm. The overall image quality in an observer study resulted in the following median Likert scores for Readers 1 and 2: 5.0 and 5.0 for the sitting position, 4.0 and 3.5 for the superman position, and 4.0 and 2.0 for the supine position. These results indicate that our proposed sitting position with ADCT of the elbow joint can provide superior image quality and allow lower radiation doses compared to the superman and supine positions