Dual fluoroscopy with live-image digital zooming significantly reduces patient and operating staff radiation during fenestrated-branched endovascular aortic aneurysm repair.

OBJECTIVE: Fenestrated-branched endovascular aneurysm repair (F/B-EVAR) is a complex procedure that generates high radiation doses. Magnification aids in vessel cannulation but increases radiation. The aim of the study was to compare radiation doses to patients and operating room staff from two fluoroscopy techniques, standard magnification vs dual fluoroscopy with live-image digital zooming during F/B-EVAR. METHODS: An observational, prospective, single-center study of F/B-EVAR procedures using Philips Allura XperFD20 equipment (Philips Healthcare, Amsterdam, The Netherlands) was performed during a 42-month period. Intravascular ultrasound, three-dimensional fusion, and extreme collimation were used in all procedures. Intraoperative live-image processing was performed with two imaging systems: standard magnification in 123 patients (81%) and dual fluoroscopy with live-image digital zooming in 28 patients (18%). In the latter, the live "processed" zoomed images are displayed on examination displays and live images are displayed on reference displays. The reference air kerma was collected for each case and represents patient dose. Operating staff personal dosimetry was collected using the DoseAware system (Philips Healthcare). Patient and staff radiation doses were compared using nonparametric tests. RESULTS: Mean age was 71.6 ± 11.4 years. The median body mass index was 27 kg/m2 (interquartile range [IQR], 24.4-30.6 kg/m2) and was the same for both groups. Procedures performed with dual fluoroscopy with digital zooming demonstrated significantly lower median patient (1382 mGy [IQR, 999-2045 mGy] vs 2458 mGy [IQR, 1706-3767 mGy]; P < .01) and primary operator radiation doses (101 µSv [IQR, 34-235 µSv] vs 266 µSv [IQR, 104-583 µSv]; P < .01) compared with standard magnification. Similar significantly reduced radiation doses were recorded for first assistant, scrub nurse, and anesthesia staff in procedures performed with dual fluoroscopy. According to device design, procedures performed with four-fenestration/branch devices generated higher operator radiation doses (262 µSv [IQR, 116.5-572 µSv] vs 171 µSv [IQR, 44-325 µSv]; P < .01) compared with procedures with three or fewer fenestration/branches. Among the most complex design (four-vessel), operator radiation dose was significantly lower with digital zooming compared with standard magnification (128.5 µSv [IQR, 70.5-296 µSv] vs 309 µSv [IQR, 150-611 µSv]; P = .01). CONCLUSIONS: Current radiation doses to patients and operating personnel are within acceptable limits; however, dual fluoroscopy with live-image digital zooming results in dramatically lower radiation doses compared with the standard image processing with dose-dependent magnification. Operator radiation doses were reduced in half during procedures performed with more complex device designs when digital zooming was used.

Improving the accuracy of digital templating: achieving success through stakeholder management.

The use of a marker ball in digital templating for hip arthroplasty is a well-established method of preoperative planning and is used to overcome the inherent magnification in plain film radiographs. Our hospital policy is to place a marker ball in all anteroposterior pelvic films taken in the emergency department (ED) which have been requested for suspected neck of femur fractures. We carried out a baseline measurement followed by three Plan-Do-Study-Act cycles for all pelvic films taken in ED during July 2016, November 2016, February 2017 and November 2017. Interventions between the baseline measurement and cycle 1 were to educate the lead radiographer and publish the results in the radiology newsletter, and between cycles 1 and 2 was to run a teaching session for radiographers, display posters in the X-ray department and place an electronic prompt on the X-ray machine to alert them of the need to place a marker ball in the X-ray field. Cycle 3 looked to see if improvements were sustained. 16/81 (20%) radiographs complied with the policy in our baseline measurement; 25/51 (46%, p=0.002) in cycle 1; 40/54 (74%, p=0.0056) in cycle 2; and 48/63 (76%) in cycle 3. Our quality improvement project led to large improvements in clinical practice through straightforward, small, but appropriately targeted interventions. Stakeholder management is key to successfully implementing change. The next step is to switch from the VoyantMark to the KingMark marker ball, as it has greater accuracy of templating and is also easier to place within the field of an X-ray.

The effect of changes in head position on enlargement of structures during panoramic radiography.

PURPOSE: Accuracy of panoramic radiographs is essential for distance measurements during implant planning, but it might be compromised by various factors. The aim of the present study was to evaluate the effect of vertical and horizontal head positioning on area-dependent enlargement ratios of digital panoramic radiography. MATERIALS AND METHODS: The mandible of a dry skull was marked with small steel globes. The skull was moved 1 to 4 degrees in 1-degree increments to the left and right and up and down. A series of 17 panoramic radiographs was obtained with the same digital radiographic device. For the rotated skull, horizontal and vertical distances, indicated by the steel globes, were compared to the distances with the ideal positioning of the skull. The results were analyzed statistically. RESULTS: Head positioning and angulation, anatomical site, and distance orientation influenced horizontal measurements. Enlargement ratios of horizontal distances of the right canine and first molar regions (skull rotation to the right 2 to 4 degrees) were significantly lower than those for the corresponding anatomical sites on the left side. Horizontal distance measurements of the different anatomical sites of the left and the right jaw did not differ significantly from each other when the skull was moved downward. When the skull was rotated upward, no significant differences were obtained for corresponding anatomical sites of the right and left arches. Enlargement ratios of vertical distances of different anatomical sites, as well as within the same anatomical site, were not significantly different from each other for the given skull rotations. CONCLUSIONS: Ideal head positioning for digital panoramic radiographs is mandatory to avoid improper enlargement ratios of horizontal distances, which can be important in implant dentistry.

Efficacy of panoramic radiographs in the preoperative planning of posterior mandibular implants: a prospective clinical study of 1527 consecutively treated patients.

OBJECTIVES: Various imaging techniques, including conventional radiography and computed tomography, are proposed to localize the mandibular canal prior to implant surgery. The aim of this study is to determine the incidence of altered mental nerve sensation after implant placement in the posterior segment of the mandible when a panoramic radiograph is the only preoperative imaging technique used. MATERIAL AND METHODS: The study included 1527 partially and totally edentulous patients who had consecutively received 2584 implants in the posterior segment of the mandible. Preoperative bone height was evaluated from the top of the alveolar crest to the superior border of the mandibular canal on a standard panoramic radiograph. A graduated implant scale from the implant manufacturer was used and 2 mm were subtracted as a safety margin to determine the length of the implant to be inserted. RESULTS: No permanent sensory disturbances of the inferior alveolar nerve were observed. There were two cases of postoperative paresthesia, representing 2/2584 (0.08%) of implants inserted in the posterior segment of the mandible or 2/1527 (0.13%) of patients. These sensory disturbances were minor, lasted for 3 and 6 weeks and resolved spontaneously. CONCLUSIONS: Panoramic examination can be considered a safe preoperative evaluation procedure for routine posterior mandibular implant placement. Panoramic radiography is a quick, simple, low-cost and low-dose presurgical diagnostic tool. When a safety margin of at least 2 mm above the mandibular canal is respected, panoramic radiography appears to be sufficient to evaluate available bone height prior to insertion of posterior mandibular implants; cross-sectional imaging techniques may not be necessary.