Potential risk assessment: a model for quality evaluation in fluoroscopy-guided interventional procedures.

This study presented a model applied for potential risk assessment in an interventional radiology setting. The model of potential risk assessment (MARP) consisted of the creation of a scale of indicators ranging from 0 to 5. The radiation levels were categorized according to gender, kind of procedure, value of kerma air product (Pka), and accumulated radiation dose (mGy). The MARP model was applied in 121 institutions over 8 y. A total of 201 656 patient radiation doses (Dose-area product and accumulated kerma) data were launched into the system over time, with an average of 22 406 doses per year. In the context of the workers (cardiologists, radiographers, and nurses) monitored during the MARP application, 8007 cases (with an average of 890 per year) of occupational radiation doses were recorded. This study showed a strategy for quality evaluation in fluoroscopy using a model with a compulsory information system for monitoring safety.

Phantom study of a self-shielded X-ray bone age assessment instrument against scattered radiation in children.

Hand-wrist radiography is the most common and accurate method for evaluating children's bone age. To reduce the scattered radiation of radiosensitive organs in bone age assessment, we designed a small X-ray instrument with radioprotection function by adding metal enclosure for X-ray shielding. We used a phantom operator to compare the scattered radiation doses received by sensitive organs under three different protection scenarios (proposed instrument, radiation personal protective equipment, no protection). The proposed instrument showed greater reduction in the mean dose of a single exposure compared with radiation personal protective equipment especially on the left side which was proximal to the X-ray machine (≥80.0% in eye and thyroid, ≥99.9% in breast and gonad). The proposed instrument provides a new pathway towards more convenient and efficient radioprotection.

Estimating of radiation output of X-RAY tube using mathematical model: Case of high-frequency machines.

PURPOSE: During any radiological procedure, it is important to know the dose to be-administered to the patient and this can be done by estimating the output of the X-ray tube either with a dosimeter or with a mathematical equation or Monte Carlo simulations. The aim of this work is to develop a new mathematical model equation (NMME) for estimating the output of high-frequency X-ray tubes. METHODS: To achieve this, data collected from ten machines in many regions of Cameroon were used (for nine machines) to build an initial model that does not take into account the anode angle and the tenth machine was used to test the model. Using the SpekCalc software, some simulations were carried out to evaluate the influence of the anode angle. This allowed the NMME to be proposed. RESULTS: The deviations frequencies between 0.65% and 19.61% were obtained by comparing the output values obtained using initial model with the measured values. The statistical hypothesis test showed that the estimated values using initial model and NMME are in agreement with those measured unlike the Kothan and Tungjai model. For the tenth machine, the percentage difference between estimated and measured values is less than 8 %. CONCLUSION: These results show that the proposed model performed better than the previous models. In the absence of a dosimeter, the NMME could be used to estimate the output of high frequency X-ray machines and therefore the radiation doses received by patients during diagnostic X-ray examinations.

Patient and physician radiation exposure during minimally invasive lumbar decompression: A prospective assessment of X-ray exposure risks.

INTRODUCTION: Minimally invasive lumbar decompression (mild®) is becoming a popular procedure for treating lumbar spinal stenosis (LSS) secondary to hypertrophic ligamentum flavum (LF). The mild® procedure is commonly performed under live fluoroscopic guidance and carries a risk of radiation exposure to the patient and healthcare. METHODS: One physician performed mild® on 41 patients at the Cleveland Clinic Department of Pain Management from October 2019 to December 2021, while wearing a radiation exposure monitor (Mirion Technologies). Mean fluoroscopy time, mean exposure per case, and mean exposure per unilateral level decompressed were the primary outcomes measured. The secondary outcome was to provide a comparison of radiation exposure during similar fluoroscopically guided procedures. RESULTS: Mean patient fluoroscopy exposure time was 2.1 min ±0.9 (range: 1.1-5.6) fluoroscopy time per unilateral level decompressed. The mean patient radiation skin exposure from mild® was 1.1 ± 0.9 mGym2, and the mean total dose was 142.3 ± 108.6 mGy per procedure. On average, the physician was exposed to an average deep tissue exposure of 4.1 ± 3.2 mRem, 2.9 ± 2.2 mRem estimated eye exposure, and 14.7 ± 11.0 mRem shallow tissue exposure per unilateral level decompressed. An individual physician would exceed the annual exposure limit of 5 Rem after approximately 610 mild® procedures per year. CONCLUSIONS: This study is an attempt to quantify the radiation exposure to the physician and patient during the mild® procedure. Compared with other fluoroscopically guided pain management procedures, patient and physician radiation exposure during mild® was low.

Proof-of-concept for a thin conical X-ray target optimized for intensity and directionality for use in a carbon nanotube-based compact X-ray tube.

BACKGROUND: Carbon nanotube-based cold cathode technology has revolutionized the miniaturization of X-ray tubes. However, current applications of these devices required optimization for large, uniform fields with low intensity. PURPOSE: This work investigated the feasibility and radiological characteristics of a novel conical X-ray target optimized for high intensity and high directionality to be used in a compact X-ray tube. METHODS: The proposed device uses an ultrathin, conical tungsten-diamond target that exhibits significant heat loading while maintaining a small focal spot size and promoting forward-directedness of the X-ray field through preferential attenuation of oblique-angled photons. The electrostatic and thermal properties of the theoretical tube were calculated and analyzed using COMSOL Multiphysics software. The production, transport, and calculation of radiological properties associated with the resultant X-ray field were performed using the Geant4 toolkit via its wrapper, TOPAS. RESULTS: Heat transfer analysis of this X-ray tube demonstrated the feasibility of a 200-kV electron beam bombarding the proposed target at a maximum current of 100 mA using a 1-ms symmetric duty cycle. The cathode of the X-ray tube was designed to be segmented into nine switchable electrical segments for modulation of the focal spot size from 0.4- to 10.8-mm. After importing the COMSOL-derived electron beam into TOPAS for X-ray production simulations, radiological analysis of the resultant field demonstrated high levels of intrinsic beam collimation while maintaining high intensity. A maximum dose rate of 17,887 cGy/min was calculated for 1-mm depth in water at 7-cm distance. CONCLUSIONS: The proposed X-ray tube design can create highly directional X-ray fields with superior fluence compared to that of current commercial X-ray tubes of comparable size.

Assessment of organ doses, peak skin doses and effective doses in patients undergoing anterior cervical discectomy and fusion utilising VirtualDose-IR software.

In this study, the effect of patient- and procedure-related parameters on organ doses (ODs), peak skin dose (PSD) and effective dose (E) during anterior cervical discectomy and fusion (ACDF) was evaluated. Patient- and procedure-related parameters, as well as fluoroscopy time, kerma-area product (KAP), cumulative air-kerma (Kair) and incident Kair, were analysed for 50 ACDF procedures performed with a mobile C-arm. These parameters were inserted in VirtualDose-IR software implementing sex-specific and body mass index (BMI)-adjustable anthropomorphic phantoms to calculate OD, PSD and E. The BMI, gender and type of implants did not significantly affect KAP, incident Kair, PSD and E. However, the type of fusion significantly affected the E. The single fusions in C5/C6 resulted in significantly higher KAP, incident Kair and E than C4/C5 levels, while those performed in C6/C7 resulted in significantly higher E and PSD than C4/C5 levels. The thyroid, oesophagus and salivary glands received the largest doses in all groups studied. The BMI did not significantly affect ODs. The salivary glands absorbed significantly higher doses in males than females, while the extrathoracic region's dose significantly increased for multi- than single-level fusions. The fusions in C6/C7 resulted in significantly higher oesophagus and thyroid doses than C3/C4 and C4/C5 levels, as well as fusions performed in C5/C6 compared with C4/C5 levels. The data presented here could be used by the neurosurgeons as a comparator for future studies in optimising radiation protection during ACDF procedures in the operating theatre by keeping the ODs, PSD and E as low as reasonably practicable.

Assessment of Radiation Exposure with Mandatory Two Fluoroscopic Views for Epidural Procedures.

BACKGROUND: Various regulations and practice patterns develop on the basis of Local Coverage Determination (LCD), which are variably perceived as guidelines and/or mandated polices/ regulations. LCDs developed in 2021 and effective since December 2021 mandated a minimum of 2 views for final needle placement with contrast injection which includes both anteroposterior (AP) and lateral or oblique view. Radiation safety has been a major concern for pain physicians and multiple tools have been developed to reduce radiation dose, along with improvement in technologies to limit radiation exposure while performing fluoroscopically guided interventional procedures, with implementation of principles of As Low As Reasonably Achievable (ALARA). The mandated 2 views of epidural injections have caused concern among some physicians, because of the potential of increased exposure to ionizing radiation, despite application of various principles to minimize radiation exposure. Others, including policymakers are of the opinion that it reduces potential abuse and improves safety. OBJECTIVE: To assess variations in the performance of epidural procedures prior to the implementation of the new LCD compared with after the implementation of the new LCD by comparing time and dosage for all types of epidural procedures. STUDY DESIGN: A retrospective, case controlled, comparative evaluation of radiation exposure during epidural procedures in interventional pain management. SETTING: An interventional pain management practice and a specialty referral center in a private practice setting in the United States. METHODS: The study was performed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria. The main outcome measure was radiation exposure time measured in seconds and dose measured in mGy-kG2 (milligray to kilogray squared per procedure). RESULTS: Changes in exposure and dose varied by procedural type and location. Exposure time in seconds increased overall by 21%, whereas radiation dose mGy-kG increased 133%. Fluoroscopy time increased most for lumbar interlaminar epidural injections of 43%, followed by 29% for cervical interlaminar epidural injections, 20% for caudal epidural injections, and 14% for lumbar transforaminal epidural injections. In contrast, highest increases were observed in the radiation dose mGy of 191% for caudal epidural injections, followed by 173% for lumbar interlaminar epidural injections, 113% for lumbar transforaminal epidural injections, and the lowest being cervical interlaminar epidural injections of 94%. This study also shows lesser increases for cervical interlaminar epidural injections because an oblique view is utilized rather than a lateral view resulting in a radiation dosage increase of 94% compared to overall increase of 133%, whereas the duration of time of 29% was higher than the overall combined duration of all procedures which only increased by 21%. LIMITATIONS: A retrospective evaluation utilizing the experience of a single physician. CONCLUSION: The results of this study showed significant increases in radiation exposure time and dosage; however, increase of dosage was overall 21% median Interquartile Range (IQR) compared to 133% of radiation dose median IQR. In addition, the results also showed variations for procedure, overall showing highest increases for lumbar interlaminar epidural injections for time (43%) and caudal epidural injections for dosage (191%).

Assessment of patient and occupational exposure and radiation risk from cath-lab procedure.

Due to the extended localized fluoroscopy, many radiographic exposures, and multiple procedures that might result in tissue reaction, patients and personnel received a significant radiation dose during interventional cardiology (IR) procedures. This study aims to calculate the radiation risk and assess patient and staff effective doses during IC procedures. Thirty-two patients underwent a Cath lab treatment in total. Ten Cath lab personnel, including six nurses, two cardiologists, and two X-ray technologists. Optical stimulating-luminescent dosimeters (OSL) (Al2O3:C) calibrated for this purpose were used to monitor both occupational and ambient doses. Using an automated OSL reader, these badges were scanned. The Air Kerma (mGy) and Kerma Area Products (KAP, mGy.cm2) have a mean and standard deviation (SD) of 371 ± 132 and 26052, respectively. The average personal dose equivalent (mSv) and its range for cardiologists, nurses and X ray technologists were 1.11 ± 0.21 (0.96-1.26), 0.84 ± 0.11 (0.68-1.16), and 0.68 ± 0.014 (0.12-0.13), respectively. The current study findings showed that the annual effective dose for cardiologists, nurses, and X-ray technologists was lesser than the yearly occupational dose limit of 20 mSv recommended by national and international guidelines. The patients' doses are comparable with some previously published studies and below the tissue reaction limits.

Intraoperative fluoroscopic safety assessment of femoral head implants with 3-dimensional risk parameters to minimize cut-out.

OBJECTIVE: This study aimed to introduce a method to extract the 3-dimensional spatial position of the femoral head implant from 2-dimensional fluoroscopic projections, allowing surgeons to assess fixation much more accurately and prevent cut-out complications in proximal femoral nailing. METHODS: To define a safety region for the tip in the femoral head, a novel 3-dimensional distance-based risk parameter called TSD3D was introduced. An intersection algorithm was developed that solely takes the fluoroscopic anteroposterior and lateral distances to reveal the 3-dimensional location of the screw or Kirschner wire tip, enabling the utilization of the 3-dimensional parameter. Orthogonal per- spectives of 6 femur proximal bone substitutes with randomly inserted Kirschner wires were imaged under fluoroscopy. The developed algorithm was used to calculate the implant tip location in 3-dimensional from 2-dimensional images for each case. Algorithm accuracy was validated with the computed tomography-obtained 3-dimensional models of the same femur substitutes. RESULTS: The newly introduced risk parameter successfully visualizes 3-dimensional safety regions. Utilizing the 2-dimensional fluoro- scopic distances as inputs to the algorithm, the 3-dimensional position of the implanted Kirschner wire tip is calculated with a maximum of 9.8% error for a single Cartesian-coordinate measurement comparison. CONCLUSION: By incorporating the newly introduced 3-dimensional risk parameter, surgeons can more precisely evaluate the position of the implant and avoid cut-out complications, instead of relying solely on misleading 2-dimensional fluoroscopic projections of the femoral head.

Comparison of organ dose from chest radiography with varying beam quality and constant exposure index.

The optimum X-ray tube voltage for chest radiographic examinations remains unclear; hence, the tube voltage varies between medical facilities. An exposure index (EI) was proposed to standardize the parameters for radiographic examinations. However, even if identical EI values are used to examine the same person, organ doses may vary due to differences in tube voltages. In this study, the variation in organ doses between different beam qualities under identical EI values for chest radiographic examinations was investigated using Monte Carlo simulations. A focused anti-scatter grid as well as standard and larger physique-type medical internal radiation dose (MIRD) phantoms were studied under tube voltages of 90, 100, 110, and 120 kVp. The organ doses in the MIRD phantom increased as the X-ray tube voltage decreased, even with identical EI values. The absorbed doses in the lungs of standard and large-sized MIRD phantoms at 90 kVp were 23% and 35% higher than those at 120 kVp, respectively. The doses to organs other than the lung at 90 kVp were also higher than those at 120 kVp. From the perspective of reducing radiation doses, a tube voltage of 120 kVp is considered better for chest examinations compared with a tube voltage of 90 kVp under identical EI values.

Angulation error assessment for the trajectory in the anteroposterior and lateral fluoroscopic views during percutaneous endoscopic transforaminal lumbar discectomy.

BACKGROUND: Anteroposterior (AP) and lateral fluoroscopies are often used to evaluate the intraoperative location and angulation of the trajectory in percutaneous endoscopic transforaminal lumbar discectomy (PETLD). Although the location of the trajectory shown in fluoroscopy is absolutely accurate, the angulation is not always reliable. This study aimed to evaluate the accuracy of the angle shown in the AP and lateral fluoroscopic views. METHODS: A technical study was performed to assess the angulation errors of PETLD trajectories shown in AP and lateral fluoroscopic views. After reconstructing a lumbar CT image, a virtual trajectory was placed into the intervertebral foramen with gradient-changing coronal angulations of the cephalad angle plane (CACAP). For each angulation, virtual AP and lateral fluoroscopies were taken, and the cephalad angles (CA) of the trajectory shown in the AP and lateral fluoroscopic views, which indicated the coronal CA and the sagittal CA, respectively, were measured. The angular relationships among the real CA, CACAP, coronal CA, and sagittal CA were further demonstrated with formulae. RESULTS: In PETLD, the coronal CA is approximately equal to the real CA, with a small angle difference and percentage error, whereas the sagittal CA shows a rather large angle difference and percentage error. CONCLUSION: The AP view is more reliable than the lateral view in determining the CA of the PETLD trajectory.

Attention to Detail: The Effect of Fluoroscopic Parallax on Limb Alignment Assessment During Corrective Osteotomy.

BACKGROUND: The accuracy of a corrective osteotomy is dependent on many factors. One error rarely considered is using noncentered fluoroscopic imaging to assess intraoperative alignment. This study quantified the coronal alignment error produced by visual parallax per interval changes in vertical and horizontal positioning of the C-arm and alignment rod during intraoperative evaluation. METHODS: Unilateral hip, ankle, and knee fluoroscopic images were obtained from a single intact cadaveric specimen. A center-center fluoroscopic image was obtained by moving the C-arm appeared in the center square of the nine-box grid. With the base of the C-arm stationary, the radiograph generator/intensifier portion of the C-arm was translated medially until the target bone appeared on the edge of the fluoroscopic image. RESULTS: One hundred eight images were obtained. Measurement error increased by an average of 14% per 10 mm of horizontal C-arm offset. Minimal effect was seen if the obtained image was within 5 mm of the true center; however, once 55 mm of offset was reached, all experimental conditions resulted in at least 10 mm of parallax error. CONCLUSION: Our results demonstrate that small variations in C-arm positioning can create statistically significant inaccuracies when assessing limb alignment using intraoperative fluoroscopy.

Alterations of posterior pharyngeal wall movement during swallowing in postoperative tongue cancer patients: assessment with a videofluoroscopic swallowing study.

This study aimed to determine the association between the progressive contraction of the posterior pharyngeal wall and dysphagia in postoperative patients with tongue cancer. A videofluoroscopic swallowing study (VFSS) was performed in 34 patients after tongue cancer surgery. Images were analyzed using a two-dimensional video measurement software. Cases in which the processes on the posterior pharyngeal wall moved downward from the 2nd to 4th vertebral regions were defined as "normal type", other cases were defined as "abnormal type". Twenty-four patients showed normal movement of the posterior pharyngeal wall, whereas 10 patients showed the abnormal type. The results showed that there was a significant difference in dysphagia scores between the postoperative swallowing type and swallowing dysfunction score. This implies that dysphagia is related to the movement of the posterior pharyngeal wall after tongue cancer surgery. Furthermore, the extent of resection and stage were significantly different between the normal and abnormal groups in the posterior pharyngeal wall movement. There was also a significant difference between the two groups in terms of the following: whether the tongue base was included in the excision range (p < 0.01), whether neck dissection was performed (p < 0.01), or whether reconstruction was not performed (p < 0.01). VFSS results showed that posterior pharyngeal wall movement was altered after surgery in patients with tongue cancer who had severe dysphagia.

Diagnostic Accuracy of the Eating Assessment Tool-10 (EAT-10) in Screening Dysphagia: A Systematic Review and Meta-Analysis.

The Eating Assessment Tool-10 (EAT-10) is used worldwide to screen people quickly and easily at high risk for swallowing disorders. However, the best EAT-10 cutoff value is still controversial. In this systematic review and meta-analysis, we estimated and compared the diagnostic accuracy of EAT-10 cutoff values of 2 and 3 for screening dysphagia. We searched the PubMed, Web of Science, EMBASE, Cochrane Library, CNKI, WANFANG, and VIP databases from May 2008 to March 2022. The meta-analysis included 7 studies involving 1064 subjects from 7 different countries. Two studies were classified as high quality and five studies as medium quality. With an EAT-10 cutoff value of 2, using flexible endoscopic evaluation of swallowing or video fluoroscopic swallowing study as the gold standard, the pooled sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio were 0.89 (95% confidence interval [CI] 0.82-0.93), 0.59 (95% CI 0.39-0.77), 2.17 (95% CI 1.38-3.42), 0.19 (95% CI 0.13-0.29), and 11.49 (95% CI 5.86-22.53), respectively. When a cutoff of 3 was used, these values were 0.85 (95% CI 0.68-0.94), 0.82 (95% CI 0.65-0.92), 4.84 (95% CI 1.72-13.50), 0.18 (95% CI 0.07-0.46), and 26.24 (95% CI 5.06-135.95), respectively. Using EAT-10 cutoff values of 2 and 3, the areas under the curve were 0.873 (95% CI 0.82-0.93) and 0.903 (95% CI 0.88-0.93), respectively, showing good diagnostic performance. EAT-10 can be used as a preliminary screening tool for dysphagia. However, a cutoff of 3 is recommended for EAT-10 due to better diagnostic accuracy.

CT-guided vs. fluoroscopically guided transforaminal epidural steroid injections for lumbar radiculopathy: a comparison of efficacy, safety and cost.

INTRODUCTION: There are no formal guidelines for whether CT-guided or fluoroscopy-guided TFESI should be undertaken for patients with symptoms of lumbar nerve root irritation and corresponding nerve impingement. Here, we sought to compare the efficacy, safety and cost of computer tomography (CT)-guided and fluoroscopically guided transforaminal epidural steroid injection (TFESI). MATERIALS AND METHODS: All patients who underwent lumbar TFESI at our institution between June 2016 and June 2018 were identified. Six-week follow-up outcomes were categorised. The radiation doses and associated cost was retrieved from our institution's costing system. RESULTS: One hundred and sixteen patients were included (CT-50; fluoroscopy-56). There were no complications. More patients were discharged 6 weeks after CT-guided lumbar TFESI when compared with fluoroscopically guided TFESI (CT-23, fluoroscopy-14 (P = 0.027)). There was no difference in the number of patients who were referred to surgery (P = 0.18), for further pain management (P = 0.45), or for further TFESI (P = 0.43). The effective radiation dose was significantly higher for CT-guided TFESI (CT-5.73 mSv (3.87 to 7.76); fluoroscopy-0.55 mSv (0.11 to 1.4) (P < 0.01)). The total cost for CT-guided lumbar TFESI was £237.50 (£235 to £337), over £800 less than under fluoroscopic guidance (£1052 (£892.80 to £1298.00), P < 0.01)). Removing cost associated with staff and theatre use (staffing, theatre, medical indemnity and overheads) revealed CT-guided lumbar TFESI to be less expensive than if the procedure was fluoroscopy-guided-CT-guided: £132.6 (130.8 to 197.5); fluoroscopy: £237.4 (£209.2 to £271.9) (P = 0.019). CONCLUSIONS: CT-guided TFESI was associated with a higher discharge rate, a lower cost, but a ten times higher radiation dose when compared with fluoroscopically guided TFESI. Prospective studies are required to compare the efficacy of these procedures and to investigate how the radiation dose of CT-guided TFESI can be reduced without jeopardising efficacy or safety.

Assessment of Intraoperative Rotational Alignment of Closed Locked Intramedullary Nailing for Humerus Fractures.

Intramedullary nailing of humerus fractures has evolved over the past half century and has grown in popularity especially for the polytraumatized patient. The importance of restoring appropriate rotational alignment is equivalent to that of restoring sagittal and coronal alignment to decrease the risk of shoulder degenerative changes and limit range of motion discrepancy from the contralateral limb. This technique is designed to introduce an intraoperative fluoroscopic method to obtain adequate rotational alignment of humeral shaft fractures treated with closed antegrade humeral locked nailing.

A quantitative accuracy assessment of the use of a rigid robotic arm in navigated placement of 726 pedicle screws.

BACKGROUND: Traditional minimally invasive fluoroscopy-based techniques for pedicle screw placement utilize guidance, which may require fluoroscopic shots. Computerized tomography (CT) navigation results in more accurate screw placement. Robotic surgery seeks to establish access and trajectory with greater accuracy. OBJECTIVE: This study evaluated the screw placement accuracy of a robotic platform. METHODS: Demographic data, preoperative/postoperative CT scans, and complication rates of 127 patients who underwent lumbosacral pedicle screw placement with minimally invasive navigated robotic guidance using preoperative CT were analyzed. RESULTS: On the GRS scale, 97.9% (711/726) of screws were graded A or B, 1.7% (12/726) of screws graded C, 0.4% (3/726) of screws graded D, and 0% graded E. Average offset from preoperative plan to final screw placement was 1.9 ± 1.5 mm from tip, 2.2 ± 1.4 mm from tail and 2.9 ± 2.3° of angulation. CONCLUSIONS: Robotic-assisted surgery utilizing preoperative CT workflow with intraoperative fluoroscopy-based registration improves pedicle screw placement accuracy within a patient's pedicles.

National inventory of authorized diagnostic imaging equipment in Ghana: data as of September 2020.

Introduction: to address the challenge of inadequate and non-equitable distribution of diagnostic imaging equipment, countries are encouraged to evaluate the distribution of installed systems and undertake adequate monitoring to ensure equitability. Ghana´s medical imaging resources have been analyzed in this study and evaluated against the status in other countries. Methods: data on registered medical imaging equipment were retrieved from the database of the Nuclear Regulatory Authority and analyzed. The equipment/population ratio was mapped out graphically for the 16 regions of Ghana. Comparison of the equipment/population ratio was made with the situation in other countries. Results: six hundred and seventy-four diagnostic imaging equipment units from 266 medical imaging facilities (2.5 units/facility), comprising computed tomography (CT), general X-ray, dental X-ray, single-photon emission computed tomography (SPECT) gamma camera, fluoroscopy, mammography and magnetic resonance imaging (MRI) were surveyed nationally. None of the imaging systems measured above the Organization for Economic Co-operation and Development (OECD) average imaging units per million populations (u/mp). The overall equipment/population ratio estimated nationally was 21.4 u/mp. Majority of the imaging systems were general X-ray, installed in the Greater Accra and Ashanti regions. The regional estimates of equipment/population ratios were Greater Accra (49.6 u/mp), Ashanti (22.4 u/mp), Western (21.4 u/mp), Eastern (20.6 u/mp), Bono East (20.0 u/mp), Bono (19.2 u/mp), Volta (17.9 u/mp), Upper West (16.7 u/mp), Oti (12.5 u/mp), Central (11.9 u/mp), Northern (8.9 u/mp), Ahafo (8.9 u/mp), Upper East (6.9 u/mp), Western North (6.7 u/mp), Savannah (5.5 u/mp) and North-East (1.7 u/mp). Conclusion: medical imaging equipment shortfall exist across all imaging modalities in Ghana. A wide inter-regional disparity in the distribution of medical imaging equipment exists contrary to WHO´s recommendation for equitable distribution. A concerted national plan will be needed to address the disparity.

Assessment of Newer Radiation Dose Reduction Techniques During Coronary Angiography.

Aims To evaluate the impact of Allura Clarity technology on radiation exposure in patients undergoing diagnostic coronary angiography. Methods A retrospective analysis was undertaken of invasive coronary angiograms performed by a single experienced operator in Cork University Hospital (CUH) (Allura Xper FD10 angiography system). In order to reduce operator variability, we also analysed cases performed by the same operator in the Bon Secours Hospital Cork (BSHC) (Allura Clarity FD10 angiography system). Cases were selected consecutively, having excluded those involving percutaneous coronary intervention, graft studies, aortography, ventriculography, right heart studies or fractional flow reserve studies. Results A total of 178 patients were included, equally distributed between the CUH arm (n=89) and the BSHC arm (n=89). Cohorts were very well matched in terms of age, gender, Body Mass Index, and procedural approach. The median radiation dose in CUH was a Dose Area Product (DAP) of 10,460 mGy.cm2 vs. median DAP of 12,795 mGy.cm2 in BSHC (p=0.148). The median fluoroscopy time in CUH was 2.25mins vs. median fluoroscopy time of 2.17mins in BSHC (p=0.675). Conclusion The use of the Allura Clarity system for diagnostic coronary angiography did not result in a significant difference in radiation dose or fluoroscopy time when compared to the reference Allura Xper system. Further research is needed to investigate the benefit of this new image noise reduction technology in diagnostic coronary angiography.