Generation of Customized Bone Implants from CT Scans Using FEA and AM.

Additive manufacturing (AM) allows the creation of customized designs for various medical devices, such as implants, casts, and splints. Amongst other AM technologies, fused filament fabrication (FFF) facilitates the production of intricate geometries that are often unattainable through conventional methods like subtractive manufacturing. This study aimed to develop a methodology for substituting a pathological talus bone with a personalized one created using additive manufacturing. The process involved generating a numerical parametric solid model of the specific anatomical region using computed tomography (CT) scans of the corresponding healthy organ from the patient. The healthy talus served as a mirrored template to replace the defective one. Structural simulation of the model through finite element analysis (FEA) helped compare and select different materials to identify the most suitable one for the replacement bone. The implant was then produced using FFF technology. The developed procedure yielded commendable results. The models maintained high geometric accuracy, while significantly reducing the computational time. PEEK emerged as the optimal material for bone replacement among the considered options and several specimens of talus were successfully printed.

Recently developed radiopharmaceuticals for bacterial infection imaging.

BACKGROUND: Infection remains a major cause of morbidity and mortality, regardless of advances in antimicrobial therapy and improved knowledge of microorganisms. With the major global threat posed by antimicrobial resistance, fast and accurate diagnosis of infections, and the reliable identification of intractable infection, are becoming more crucial for effective treatment and the application of antibiotic stewardship. Molecular imaging with the use of nuclear medicine allows early detection and localisation of infection and inflammatory processes, as well as accurate monitoring of treatment response. There has been a continuous search for more specific radiopharmaceuticals to be utilised for infection imaging. This review summarises the most prominent discoveries in specifically bacterial infection imaging agents over the last five years, since 2019. MAIN BODY: Some promising new radiopharmaceuticals evaluated in patient studies are reported here, including radiolabelled bacterial siderophores like [68Ga]Ga-DFO-B, radiolabelled antimicrobial peptide/peptide fragments like [68Ga]Ga-NOTA-UBI29-41, and agents that target bacterial synthesis pathways (folic acid and peptidoglycan) like [11C]para-aminobenzoic acid and D-methyl-[11C]-methionine, with clinical trials underway for [18F]fluorodeoxy-sorbitol, as well as for 11C- and 18F-labelled trimethoprim. CONCLUSION: It is evident that a great deal of effort has gone into the development of new radiopharmaceuticals for infection imaging over the last few years, with remarkable progress in preclinical investigations. However, translation to clinical trials, and eventually clinical Nuclear Medicine practice, is apparently slow. It is the authors' opinion that a more structured and harmonised preclinical setting and well-designed clinical investigations are the key to reliably evaluate the true potential of the newly proposed infection imaging agents.

The effectiveness of radionuclide scintigraphy in confirming testicular torsion at delayed presentation.

Background: Testicular torsion (TT) is a urological emergency that needs early diagnosis and intervention to prevent testicular death and necrosis. This study aimed to determine the efficacy of testicular scintigraphy (TS) in confirming the clinical diagnosis of TT and how this imaging method correlates with the surgical findings. Methods: A retrospective cohort review of clinical data was performed for 68 patients referred for TS from January 2016 to December 2021 to rule out possible TT. The final diagnosis was confirmed at surgery for all those with TS positive for TT. Results: The median age of the patients was 18.5 years, interquartile range of 15-31 years. Commonly presenting symptoms were pain (99%) and swelling (68%). Only 6% had history of trauma. TT was diagnosed by technetium-99m (99mTc)-pertechnetate in 35 (51%) patients all of whom underwent surgical exploration. Of this group, 7 (20%) had manual detorsion intraoperatively (intermittent torsion), in 20 (57%) missed (complete) torsion was confirmed and 8 (23%) had a necrotic testis. Of the remaining 33 patients with results negative for torsion, 10 were normal and 23 were diagnosed with either epididymitis 13/23 (57%), orchitis 3/23 (13%) or 7/23 (30%) with epididymo-orchitis. TT was more common in patients under 15 and 15-19 years (P<0.05). The mean presentation time was 5 days with a range of 1-30 days. Conclusions: The 99mTc-pertechnetate scan remains an effective investigation in the diagnosis of TT and may serve as a gate-keeper for surgery even in patients who present late for treatment.