Cost-effectiveness of screening and valacyclovir-based treatment strategies for first-trimester cytomegalovirus primary infection in pregnant women in France.

OBJECTIVE: To assess the effectiveness, cost and cost-effectiveness of four screening strategies for first-trimester (T1) cytomegalovirus (CMV) primary infection (PI) in pregnant women in France. METHODS: In a simulated pregnant population of 800 000 (approximate number of pregnancies each year in France), using costs based on the year 2022, we compared four CMV maternal screening strategies: Strategy S1, no systematic screening (current public health recommendations in France); Strategy S2, screening of 25-50% of the pregnant population (current screening practice in France); Strategy S3, universal screening (current medical recommendations in France); Strategy S4, universal screening (as in Strategy S3) in conjunction with valacyclovir in case of T1 PI. Outcomes were total cost, effectiveness (number of congenital infections, number of diagnosed infections) and incremental cost-effectiveness ratio (ICER). Two ICERs were calculated, comparing Strategies S1, S2 and S3 in terms of euros (€) per additional diagnosis, and comparing Strategies S1 and S4 in € per avoided congenital infection. RESULTS: Compared with Strategy S1, Strategy S3 enabled diagnosis of 536 more infected fetuses and Strategy S4 prevented 375 congenital infections. Strategy S1 was the least expensive strategy (€98.3m total lifetime cost), followed by Strategy S4 (€98.6m), Strategy S2 (€106.0m) and Strategy S3 (€118.9m). In the first analysis, Strategy S2 was dominated and Strategy S3 led to an additional €38 552 per additional in-utero diagnosis, compared with Strategy S1. In the second analysis, Strategy S4 led to an additional €893 per avoided congenital infection compared with Strategy S1, and was cost-saving compared with Strategy S2. CONCLUSIONS: In France, current screening practice for CMV PI during pregnancy is no longer acceptable in terms of cost-effectiveness because this strategy was dominated by universal screening. Moreover, universal screening in conjunction with valacyclovir treatment would be cost-effective compared with current recommendations and is cost-saving compared with current practice. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Automatic segmentation of kidneys in computed tomography images using U-Net.

PURPOSE: Accurate segmentation of target volumes and organs at risk from computed tomography (CT) images is essential for treatment planning in radiation therapy. The segmentation task is often done manually making it time-consuming. Besides, it is biased to the clinician experience and subject to inter-observer variability. Therefore, and due to the development of artificial intelligence tools and particularly deep learning (DL) algorithms, automatic segmentation has been proposed as an alternative. The purpose of this work is to use a DL-based method to segment the kidneys on CT images for radiotherapy treatment planning. MATERIALS AND METHODS: In this contribution, we used the CT scans of 20 patients. Segmentation of the kidneys was performed using the U-Net model. The Dice similarity coefficient (DSC), the Matthews correlation coefficient (MCC), the Hausdorff distance (HD), the sensitivity and the specificity were used to quantitatively evaluate this delineation. RESULTS: This model was able to segment the organs with a good accuracy. The obtained values of the used metrics for the kidneys segmentation, were presented. Our results were also compared to those obtained recently by other authors. CONCLUSION: Fully automated DL-based segmentation of CT images has the potential to improve both the speed and the accuracy of radiotherapy organs contouring.

Automatic segmentation of thoracic CT images using three deep learning models.

PURPOSE: Deep learning (DL) techniques are widely used in medical imaging and in particular for segmentation. Indeed, manual segmentation of organs at risk (OARs) is time-consuming and suffers from inter- and intra-observer segmentation variability. Image segmentation using DL has given very promising results. In this work, we present and compare the results of segmentation of OARs and a clinical target volume (CTV) in thoracic CT images using three DL models. MATERIALS AND METHODS: We used CT images of 52 patients with breast cancer from a public dataset. Automatic segmentation of the lungs, the heart and a CTV was performed using three models based on the U-Net architecture. Three metrics were used to quantify and compare the segmentation results obtained with these models: the Dice similarity coefficient (DSC), the Jaccard coefficient (J) and the Hausdorff distance (HD). RESULTS: The obtained values of DSC, J and HD were presented for each segmented organ and for the three models. Examples of automatic segmentation were presented and compared to the corresponding ground truth delineations. Our values were also compared to recent results obtained by other authors. CONCLUSION: The performance of three DL models was evaluated for the delineation of the lungs, the heart and a CTV. This study showed clearly that these 2D models based on the U-Net architecture can be used to delineate organs in CT images with a good performance compared to other models. Generally, the three models present similar performances. Using a dataset with more CT images, the three models should give better results.

SU-E-E-04: Building and Strengthening the First Master's Program in Medical Physics in The Gulf Region.

PURPOSE: The first medical physics Master's program in the Arabian Gulf region was started in 2002 at King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, Saudi Arabia. METHODS: After consulting with national and international representatives from the AAPM, IOMP, the University of Wisconsin-Madison and King Faisal Specialist Hospital and Research Center (KFSHRC) we constructed a versatile and rigorous curriculum. The program requires the completion of 7 core courses, 7 required labs, a minimum of 3 elective courses, a research project, a four-month clinical rotation and passing and a comprehensive examination. The success of the program required very close collaboration with national hospitals such as King Fahad Specialist Hospital in Dammam (KFSH-D), KFSHRC, and Riyadh Military Hospital. We cemented the collaboration with a formal agreement between KFUPM and KFSH-D, whereby the clinical medical physicists are actively involved in teaching lectures and labs, evaluating students' performance and co-supervising their clinical rotation and research projects. In order to prepare our graduates for their medical physics careers, we emphasize innovative learning methods such as students centered learning, execution of course projects, experiential learning and acquiring research skills and tools such as Monte Carlo simulations. RESULTS: Our graduates have succeeded in securing clinical positions in some of the best hospitals in the region and achieved high employer satisfaction. Some students have gone to pursue their PhD's in North America and Europe. Many of our students succeeded in publishing their projects in international journals and international conferences. One of our students was instrumental in obtaining a US patent (US Patent # 785298) for an innovative x-ray tube design. CONCLUSIONS: We have achieved national recognition through the excellence of our graduates. In order to maintain high education quality standards and achieve international recognition, we are presently working to acquire IAEA approval and CAMPEP accreditation.

Dose calculation from a D-D-reaction-based BSA for boron neutron capture synovectomy.

Monte Carlo simulations were carried out to calculate dose in a knee phantom from a D-D-reaction-based Beam Shaping Assembly (BSA) for Boron Neutron Capture Synovectomy (BNCS). The BSA consists of a D(d,n)-reaction-based neutron source enclosed inside a polyethylene moderator and graphite reflector. The polyethylene moderator and graphite reflector sizes were optimized to deliver the highest ratio of thermal to fast neutron yield at the knee phantom. Then neutron dose was calculated at various depths in a knee phantom loaded with boron and therapeutic ratios of synovium dose/skin dose and synovium dose/bone dose were determined. Normalized to same boron loading in synovium, the values of the therapeutic ratios obtained in the present study are 12-30 times higher than the published values.

Scatter dose calculation for anti-scatter linear grids in mammography.

Monte Carlo simulations were used to optimize the geometry of a mammography anti-scatter linear grid to achieve minimum scatter-to-primary ratio (SPR) for different X-ray tube voltages. A single optimum design of the grid with 0.9mm septa height, 12microm septa thickness and 100microm interspace thickness was found for breast phantom thicknesses between 30 and 80mm. The optimal grid has 0.153-0.330 scatter-to-primary ratio, a Bucky factor (BF) less than 2.5 and a contrast improvement factor (CIF) of 1.3.

Doxycycline for the treatment of cutaneous leishmaniasis.

The incidence of cutaneous leishmaniasis has shown a resurgence in recent years in Tunisia. Because of the toxicity and high cost of pentavalent antimonials we have sought alternative medications. In a study of 14 patients with cutaneous leishmaniasis, ten patients achieved complete clinical regression of the lesions with oral administration of doxycycline, 200mg per day, for 15-30 days.

[Adverse effects of intralesional Glucantime in the treatment of cutaneous leishmaniosis]. / Les effets indésirables du Glucantime en intralésionnel dans le traitement de la leishmaniose cutanée.

OBJECTIVE: The treatment of cutaneous leishmaniasis used in Tunisia is Glucantime. The aim of this retrospective study was to determine the adverse effects of intralesional Glucantime and to calculate the risk/benefit rate of this treatment. RESULTS: Adverse effects were observed in 14 cases (5%). For facial lesions, we observed facial staphylococci in 2 cases, stibio-intolerance in 1 case, and a palpebral subcutaneous nodule in 1 case. In limb lesions the complications were: sporotrichoid nodules in 5 cases, vagal malaise (1 case), pyodermitis (1 case), erysipelas (1 case), necrosis (1 case), and urticaria (1 case). COMMENTARY: The adverse effects of intralesional Glucantime are mostly infections, mainly observed in cephalic localization, and stibio-intolerance. For this reason, intralesional injection of Glucantime must be avoided in the cephalic region.

[Glucantime injection: benefit versus toxicity]. / Glucantime par voie parentérale: bénéfice versus toxicité

UNLABELLED: Glucantime is the most common stibied derivative used to treat cutaneous leishmaniasis (CL) in Tunisia; however adverse effects have been reported. OBJECTIVES: This retrospective study deals with the various adverse of intramuscular glucantime used for CL. RESULTS: Nineteen patients (21%) receiving intramuscular Glucantime developed adverse effects. 8 male and 11 female patients, mean age 45, ranging from 8 to 84 years were affected. adverse effects were: fever (3), arthralgia and myalgia (4), nausea and vomiting (2), erythema nodosum (1), acute renal failure (3 including 1 lethal case), hepatic cytolysis (1), skin rash (4), and inflammation of the injection site (1). CONCLUSION: Adverse effects of intramuscular Glucantime were relatively frequent in our series. Arthralgia, myalgia, and skin rash were not severe and disappeared when the treatment was stopped. Stibiointoxication cases, mainly acute renal failure, were serious.

The potent platelet inhibitory effects of S-nitrosated albumin coating of artificial surfaces.

OBJECTIVES: We studied the antithrombotic effect of coating glass, collagen and metal stent surfaces with bovine serum albumin (BSA) covalently modified to carry S-NO functional groups denoted (pS-NO-BSA). METHODS: Video-enhanced light microscopy was used to visualize canine blood platelet adhesion and aggregation in a parallel plate glass chamber. Platelet adhesion was observed for 60 min on glass, glass coated with BSA, glass coated with pS-NO-BSA, collagen I (CO) surface, CO coated with BSA and CO coated with pS-NO-BSA. We also coated Palmaz-Shatz (P-S) stents with pS-NO-BSA. Coated and uncoated stents were then immersed in porcine platelet-rich plasma for two min and the platelet cyclic GMP level was measured. In six anesthetized pigs, coated and uncoated stents were placed in the carotid arteries and [111In]-labeled platelets were circulated for 2 h. The stented arteries were then removed and placed in a gamma well counter. RESULTS: There was significantly less platelet attachment, adhesion and aggregation on the pS-NO-BSA coated surfaces compared with the BSA coated and uncoated surfaces. The pS-NO-BSA coating increased the platelet cGMP levels to 5.9+/-0.7 pmoles/10(8) platelets compared with 2.7+/-0.9 pmoles/10(8) platelets for control (p < 0.01). The average gamma ray count from [111In]-labeled platelets that attached to the coated stents was 90,000+/-42,000/min and 435,000+/-290,000/min for the uncoated stents (p < 0.01). CONCLUSIONS: The pS-NO-BSA coating of thrombogenic surfaces reduces platelet adhesion and aggregation, possibly by increasing the platelet cGMP. This inhibitory effect appears to be a consequence of the direct antiplatelet actions of NO combined with the antiadhesive properties of albumin.

Grape juice but not orange or grapefruit juice inhibits platelet activity in dogs and monkeys.

Platelet aggregation (PA) contributes to both the development of atherosclerosis and acute platelet thrombus formation (APTF) followed by embolization producing cyclic flow reductions (CFR) in stenosed and damaged dog and human coronary arteries. In seven anesthetized dogs with coronary stenosis and medial damage, CFR occurred at 7 +/- 3/30 min and were abolished 127 +/- 18 min after gastric administration of 10 mL of purple grape juice/kg. Collagen-induced ex vivo whole blood PA decreased by 49 +/- 9% after the abolishment of CFR with grape juice. Ten mL of orange juice/kg (n = 5) and 10 mL of grapefruit juice/kg (n = 5) had no significant effect on the frequency of the CFR or on ex vivo PA. In vitro studies have suggested that flavonoids bind to platelet cell membranes and thus may have an accumulative or tissue-loading effect over time. To test this we fed 5 mL of grape juice/kg to 5 cynomologous monkeys for 7 d. Collagen-induced ex vivo PA decreased by 41 +/- 17% compared to control (pre-reatment) after 7 d of feeding. In the same 5 monkeys, neither 5 mL of orange juice/kg nor 5 mL of grapefruit juice/kg given orally for 7 d produced any significant change in PA. Grape juice contains the flavonoids quercetin, kaempferol and myricetin, which are known inhibitors of PA in vitro. Orange juice and grapefruit juice, while containing less quercetin than grape juice, primarily contain the flavonoids naringin, luteolin and apigenin glucoside. The flavonoids in grapes were shown in vitro to be good inhibitors of PA, whereas the flavonoids in oranges and grapefruit to be poor inhibitors of PA. The consumption of grape juice, containing these inhibitors of PA, may have some of the protection offered by red wine against the development of coronary artery disease (CAD) and acute occlusive thrombosis, whereas orange juice or grapefruit juice may be ineffective. Thus, grape juice may be a useful alternative dietary supplement to red wine without the concomitant alcohol intake.

Coronary flow and flow reserve in canines using MR phase difference and complex difference processing.

Coronary artery disease continues to be the leading cause of death for adults in the United States. Magnetic resonance imaging (MR) has the potential to dramatically impact the diagnosis of heart disease by noninvasively providing a wide range of anatomic and physiologic information. Previous research has shown that coronary flow, one component of a complete examination, can be accurately measured in the left anterior descending artery in vivo. The current work validates MR flow measurements in canine circumflex arteries using transit time ultrasound as a standard. The circumflex artery experiences greater in-plane motion and is a more stringent test for flow measurement accuracy. This work also compares two methods of processing MR velocity data, phase difference and complex difference techniques, and examines the sources of error present in the animal validation model. Phase difference processing with a 30% magnitude threshold best matched the mean ultrasound flow values (30% PD = 1.04 x US + 1.49, r = 0.94), but it was very sensitive to vessel boundary identification. The complex difference process was less sensitive to vessel boundary identification and correlated well with the transit time ultrasound despite systematic underestimations. The reasons for the discrepancies are shown to stem from a number of possible sources including variability of the ultrasound standard, low signal-to-noise ratios in the MR images, sensitivity of the MR technique to vessel boundary identification, and motion artifacts in the images.

Effect of Shear Stress on Acute Platelet Thrombus Formation in Canine Stenosed Carotid Arteries: An In Vivo Quantitative Study.

We investigated the in vivo effect of percent stenosis, trans-stenotic pressure, and shear stress (SS) on platelet accumulation (PA) in canine mechanically injured and stenosed carotid arteries. In 10 dogs, intimal damage and controlled variations in stenosis were produced on the carotid artery. Blood flow through the stenosis, trans-stenotic pressure, and stenosis geometry were measured. A NaI gamma detector was collimated and placed over the stenosis to detect gamma rays emitted by autologous radiolabeled platelets as they accumulated inside the stenosis. The SS was obtained from the finite difference solution of the Navier-Stokes equations. As the flow declined during thrombus formation, the radioactive count accumulated in an inverse fashion. The rate of flow decline directly correlated with the rate of PA during thrombus formation (r(2) > 0.9). Compared with the undamaged and unstenosed artery, the PA increased by 52 +/- 34% due to mild stenosis (40-60%). PA increased by 94 +/- 66% due to severe stenosis (60-70%) and by 145 +/- 56% due to critical stenosis (70-80%; P > 0.01). The platelet accumulation produced totally occlusive thrombus formation at levels of stenosis higher than 70 +/- 5% (diameter narrowing), and for trans-stenotic pressure gradients higher than 50 +/- 5 mmHg producing SS greater than 100 +/- 10 Pa. The PA was maximum at the stenotic portion of the vessel where the level of SS is the highest (P < 0.001). In vivo platelet-mediated thrombosis increases with SS and occurs at the stenotic portion of the stenosis where the SS is the highest. Severe stenoses produce critical levels of SS that potentiate thrombosis and lead to life-threatening arterial occlusion.

Increased shear stress overcomes the antithrombotic platelet inhibitory effect of aspirin in stenosed dog coronary arteries.

BACKGROUND: Shear stress is one of the known platelet activating mechanisms that leads to thrombosis. Increased shear stress has also been postulated to reverse the antithrombotic effect of some drugs such as aspirin (ASA). METHODS AND RESULTS: Experiments were conducted in five dogs to determine the minimal shear stress levels that produce acute platelet thrombus formation in mechanically stenosed arteries and the increase in shear required to reverse the antithrombotic effect of ASA. After intimal and medial damage, stenosis was produced in the circumflex coronary artery. We used the finite-difference numerical solution of the Navier-Stokes equation to determine the wall shear stresses in the area of stenosis. At 70+/-6% coronary diameter reduction, cyclic flow reductions (CFRs) caused by acute platelet thrombus formation were observed in the stenosed lumen. At this level of stenosis, the shear stress was 144+/-15 Pa. ASA given at a dose of 5 mg/kg IV inhibited in vivo acute platelet-mediated thrombus formation and abolished CFRs in all dogs. However, increasing the stenosis level to 80+/-5% caused the CFRs to return. The shear stress increased with the increased level of stenosis to 226+/-22 Pa. Thus, an average 10% increase in diameter narrowing caused a 56+/-20% increase in shear stress (P<.005) and renewed platelet activation and thrombus formation despite ASA pretreatment. CONCLUSIONS: Individuals who take ASA daily to prevent coronary artery thrombus formation may not be well protected when a change in hemodynamics, such as an acute hypertensive episode, or an increase in stenosis severity due a ruptured atherosclerotic plaque causes an increase in shear stress.

An umbilical data-acquisition system for measuring pressures between the foot and shoe.

We have developed an umbilical data-acquisition system for measuring pressures between the foot and shoe during walking. It consists of pressure sensors in the insoles of shoes, amplifier circuits, umbilical cables, an analog-to-digital converter, and a graphics display card in an IBM PC for real-time data collection and display. The applied pressure on a sensor decreases its resistance, which causes the output voltage of the amplifier circuit to increase. We attach seven sensors to the surface of each insole of a pair of extra-depth shoes and calibrate all the sensors in the insole before and after each test using a load cell as a reference. The IBM PC samples the outputs from the sensor and the load cell and stores a piecewise linear lookup table for use in compensation for the nonlinearity of the sensor. On the PC's graphics display, two programs provide displays of foot pressures as real-time bar graphs or as analog pressure versus time curves.