Potential Benefits of Photon-Counting CT in Dental Imaging: A Narrative Review.

Background/Objectives: Advancements in oral imaging technology are continually shaping the landscape of dental diagnosis and treatment planning. Among these, photon-counting computed tomography (PCCT), introduced in 2021, has emerged as a promising, high-quality oral technology. Dental imaging typically requires a resolution beyond the standard CT systems achievable with the specialized cone-beam CT. PCCT can offer up to 100 µm resolution, improve soft-tissue contrast, and provide faster scanning times, which are crucial for detailed dental diagnosis and treatment planning. Using semiconductor detectors, PCCT produces sharper images and can potentially reduce the number of scans required, thereby decreasing patient radiation exposure. This review aimed to explore the potential benefits of PCCT in dental imaging. Methods: This review analyzed the literature on PCCT in dental imaging from January 2010 to February 2024, sourced from PubMed, Scopus, and Web of Science databases, focusing on high-resolution, patient safety, and diagnostic efficiency in dental structure assessment. We included English-language articles, case studies, letters, observational studies, and randomized controlled trials while excluding duplicates and studies unrelated to PCCT's application in dental imaging. Results: Studies have highlighted the superiority of PCCT in reducing artifacts, which are often problematic, compared to conventional CBCT and traditional CT scans, due to metallic dental implants, particularly when used with virtual monoenergetic imaging and iterative metal artifact reduction, thereby improving implant imaging. This review acknowledges limitations, such as the potential for overlooking other advanced imaging technologies, a narrow study timeframe, the lack of real-world clinical application data in this field, and costs. Conclusions: PCCT represents a promising advancement in dental imaging, offering high-resolution visuals, enhanced contrast, and rapid scanning with reduced radiation exposure.

Radiation Overuse in Intensive Care Units.

Radiological imaging is essential for acute patient management in Intensive Care Units (ICUs); however, it introduces the risk of exposure to ionizing radiation. This review synthesizes research on radiation exposure in ICU settings, highlighting its rise during the COVID-19 pandemic and the rise in repetitive imaging. Our analysis extends to radiation safety thresholds, revealing that some ICU patients exceed the diagnostic reference level, emphasizing the need to balance diagnostic utility against potential long-term risks, such as cancer. Prospective studies have demonstrated an increase in the median cumulative effective dose in patients with trauma over time, prompting calls for improved awareness and monitoring. Moreover, innovative dose-reduction strategies and optimized protocols, especially in neuro-ICUs, promise to mitigate these risks. This review highlights the essential but risky role of radiological imaging in critical care. It advocates for rigorous radiation management protocols to safeguard patient health while ensuring the continuity of high-quality medical care.

Advantages of Photon-Counting Detector CT in Aortic Imaging.

Photon-counting Computed Tomography (PCCT) is a promising imaging technique. Using detectors that count the number and energy of photons in multiple bins, PCCT offers several advantages over conventional CT, including a higher image quality, reduced contrast agent volume, radiation doses, and artifacts. Although PCCT is well established for cardiac imaging in assessing coronary artery disease, its application in aortic imaging remains limited. This review summarizes the available literature and provides an overview of the current use of PCCT for the diagnosis of aortic imaging, focusing mainly on endoleaks detection and characterization after endovascular aneurysm repair (EVAR), contrast dose volume, and radiation exposure reduction, particularly in patients with chronic kidney disease and in those requiring follow-up CT.

Surveillance on Healthcare Workers During the First Wave of SARS-CoV-2 Pandemic in Italy: The Experience of a Tertiary Care Pediatric Hospital.

Healthcare workers (HCWs) play a central role in handling the ongoing coronavirus disease 2019 (COVID-19) pandemic. Monitoring HCWs, both symptomatic and asymptomatic, through screening programs, are critical to avoid the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the hospital environment to rapidly identify and isolate infected individuals and to allow their prompt return to work as soon as necessary. We aim to describe our healthcare surveillance experience (April 2-May 6, 2020) based on a combined screening consisting of real-time PCR (RT-PCR) on nasopharyngeal (NP) swabs and rapid serologic tests (RST) for SARS-CoV-2 in all HCWs of Meyer Children's University Hospital in Florence. Among the analyzed workers, 13/1690 (0.8%), all of them without clinical manifestations, was found positive for SARS-CoV-2 by using RT-PCR on NP swab: 8/1472 (0.5%) were found positive during the screening, 1/188 (0.5%) during contact with a positive individual (p > 0.05 vs. screening group), while 4/30 (13.3%) were found positive on the day of re-admission at work after an influenza-like-illness (p < 0.05). Concerning working areas, the majority of RT-PCR positivity (12/13) and serologic positivity (34/42) was found in non-COVID-19 dedicated areas (p > 0.05 vs. COVID-19 dedicated areas). No cases were registered among non-patients-facing workers (p = 0.04 vs. patient-facing group). Nurses and residents represented, respectively, the working role with the highest and lowest percentage of RT-PCR positivity. In conclusion, accurate surveillance is essential to reduce virus spread among HCWs, patients, and the community and to limit the shortage of skilled professionals. The implementation of the surveillance system through an efficient screening program was offered to all professionals, regardless of the presence of clinical manifestations and the level of working exposure risk, maybe wise and relevant.

Need to take special care of non-responders to hepatitis B vaccination among health-care workers, students and chronic patients.

Both our research and that published by Sticchi et al. on immunological memory against hepatitis B virus (HBV) in health-care workers (HCWs) vaccinated as infants or adolescents confirm that in those testing negative after the primary course, one additional (fourth) booster dose is able to elicit an anti-HBs response in >85% subjects. The fifth and the sixth doses further contribute substantially to a high overall response rate. The rate of subjects showing an anamnestic response after the booster dose was almost six-fold higher in HCWs compared to chronic patients. Since universal vaccination in Italy resulted in a significant decrease in HBV infections, special attention and testing should be addressed to those affected by chronic diseases.

High chance to overcome the non-responder status to hepatitis B vaccine after a further full vaccination course: results from the extended study on healthcare students and workers in Florence, Italy.

Healthcare workers (HCWs) are considered high-risk subjects for Hepatitis B Virus (HBV) infection due to occupational exposure to blood and body fluids. Vaccination represents the core strategy for HBV infection prevention. Following our previous publication on this topic, we aimed to assess the effectiveness of booster vaccine doses in eliciting the immunological response in seronegative (<10 mIU/mL) HCWs and students of Careggi Teaching Hospital, Florence (Italy). All subjects received primary vaccination course, and they were tested for serum anti-HBs antibodies. In seronegative subjects, a challenge dose of vaccine was administered and the test was repeated 1 month later. Six hundred and ninety-eight (87.8%) of 795 HCWs and students tested responded to the challenge dose. After this challenge dose, males more often had negative anti-HBs titer compared with females (15.9% vs 10.2%; p < .05). The completion of the second vaccination course was offered to subjects with persistently negative anti-HBs titer. 76.2% (32) of those who accepted the fifth dose, and 3 of the 5 who accepted the sixth dose seroconverted. This report shows the importance to convey a strong message to negative subjects at the initial anti-HBs dosage: accepting all the three additional vaccine doses allows the vast majority of them to obtain protection.

Is hepatitis B vaccination performed at infant and adolescent age able to provide long-term immunological memory? An observational study on healthcare students and workers in Florence, Italy.

Universal vaccination programmes against Hepatitis B Virus (HBV) have significantly reduced the burden of the disease; nevertheless, HBV infection remains a relevant issue for high-risk subjects, such as healthcare workers (HCWs), who may potentially be exposed to blood or body fluids. Our study evaluates the long-term duration of the immunological memory of HBV vaccination 11-23 years after primary immunization by examining the response to booster doses in HCWs and students of health disciplines at Careggi Teaching Hospital in Florence (Italy). All participants (n = 2,203) had received a complete HBV immunization course in infancy or adolescence. Blood samples were collected to measure antibody levels against the HBV surface antigen (anti-HBs); an anti-HBs titre <10 mIU/mL was considered as negative. The administration of the vaccination course during infancy induced lower long-term anti-HBs titres compared to those in case of vaccination performed during adolescence (titre <10 mIU/mL: 51.1% and 12.2% respectively; p < 0.001), also considering that an equal number of years has elapsed since vaccination. A booster dose administered to subjects vaccinated in infancy is able to induce anamnestic immunological response in a higher percentage of vaccinated people (p < 0.001). Few subjects (n. = 4) accepted a fifth dose of vaccine in the case of persistent anti-HBs negative titres; this aspect requires further investigation. The total absence of acute hepatitis B among vaccinated subjects suggests that the long incubation period of the disease allows the activation of immunologic memory mechanisms, which is also true in case of low anti-HBs level. In conclusion HCWs still represent a high-risk category; it is therefore, necessary to increase efforts to protect and vaccinate these subjects.

First deliveries after estrus induction using deslorelin and endoscopic transcervical insemination in the queen.

The present study consists of two distinct parts, experiment 1 and experiment 2. In experiment 1, 13 anestrous queens were treated with a 4.7-mg deslorelin subcutaneous implant to assess its effectiveness in inducing estrus in the domestic cat. Deslorelin is currently used for the reversible suppression of ovarian and testicular activity in dogs and cats and for estrus induction in the bitch. Estrus induction is also reported in the queen but never reported with a targeted study. All the queens showed a positive response to the induction protocol, and estrus was detected within an average of 5.0 ± 2.2 days after the implant placement in 13 out of 13 subjects (100%). Seven of 13 queens exhibited behavioral manifestations of estrus, and the mean number of follicles detected at ultrasound examination was 4.8 ± 1.6 per subject. In experiment 2, three of the queens previously treated with deslorelin for estrus induction were submitted to artificial insemination through endoscopic transcervical catheterization, a new nonsurgical technique for intrauterine sperm deposition. All of them (100%) were pregnant after insemination and they gave birth to healthy litters. The study, as a whole, proves the effectiveness of the 4.7-mg deslorelin subcutaneous implants in inducing estrus in the domestic cat and is, to our knowledge, the first study assessing fertility of the induced estruses. Moreover, it shows the effectiveness of endoscopic transcervical catheterization for artificial insemination in the queen.