Mid-term outcomes of mastoid obliteration with biological hydroxyapatite versus bioglass: a radiological and clinical study.

PURPOSE: Radiological assessment of osseointegration of mastoid grafts: biological hydroxyapatite (Bio-Oss®) (BHA) versus bioglass S53P4 (Bonalive®) (BG). METHODS: Retrospective (10 ± 4 months post-surgery) monocentric high resolution computed tomography (CT) scan assessment (November 2018 and October 2020) by two independent radiologists (R1, R2), blinded to patient allocation. All patients who had undergone a total mastoid obliteration were eligible. Excluded: complications namely otological acute or chronic infections, unbalanced metabolic disease, long-term cortico-steroid therapy, auto-immune disease, history of allergy to grafting materials and post-surgery CT scan in other centers (n = 8). PRIMARY OUTCOMES: the ratio between two regions of interests (ROI) (graft to otic capsule). SECONDARY OUTCOMES: resorption of mastoid grafts and assessment of clinical tolerance. RESULTS: Included 21 patients (mean age: 29 ± 21 years; 5 females, 16 males). Significantly higher osseointegration for BHA vs. BG (R1 p = 0.043; R2 p = 0.004); almost perfect inter-reader agreement k = 0.922). The ROI ratios for BHA and BG to that of the otic capsule were 0.57 ± 0.11 (R1) and 0.59 ± 0.14 (R2); 0.43 ± 0.11 (R1) and 0.43 ± 0.08 (R2), respectively. Density increased significantly by 399 ± 261 Hounsfield units (HU) (p = 0.008) and decreased by 464 ± 161 HU (p < 0.001) for BHA vs. BG. Resorption rates were 24.1 ± 21.0% and 66.7 ± 15.1% (p = 0.076), respectively. No significant difference in clinical tolerance was observed. CONCLUSION: Post-operative CT scan of mastoid obliteration seems reliable in assessment of biomaterial graft's mid-term feasibility and stability: BHA seems to provide a more optimal osseointegration versus BG with no significant differences in graft resorption and clinical tolerance.

Feasibility of use of medical dual energy scanner for forensic detection and characterization of explosives, a phantom study.

OBJECTIVE: Detection of explosives is a challenge due to the use of improvised and concealed bombs. Post-bomb strike bodies are handled by emergency and forensic teams. We aimed to determine whether medical dual-energy computed tomography (DECT) algorithm and prediction model can readily detect and distinguish a range of explosives on the human body during disaster victim identification (DVI) processes of bombings. MATERIALS AND METHODS: A medical DECT of 8 explosives (Semtex, Pastex, Hexamethylene triperoxide diamine, Acetone peroxide, Nitrocellulose, Pentrite, Ammonium Nitrate, and classified explosive) was conducted ex-vivo and on an anthropomorphic phantom. Hounsfield unit (HU), electron density (ED), effective atomic number (Zeff), and dual energy index (DEI),were compared by Wilcoxon signed rank test. Intra-class (ICC) and Pearson correlation coefficients (r) were computed. Explosives classification was performed through a prediction model with test-retest samples. RESULTS: Except for DEI (p = 0.036), means of HU, ED, and Zeff were not statistically different (p > 0.05) between explosives ex-vivo and on the phantom (r > 0.80). Intra- and inter-reader ICC were good to excellent: 0.806 to 0.997 and 0.890, respectively. Except for the phantom DEI, all measurements from each individual explosive differed significantly. HU, ED, Zeff, and DEI differed depending on the type of explosive. Our decision tree provided Zeff and ED for explosives classification with high accuracy (83.7%) and excellent reliability (100%). CONCLUSION: Our medical DECT algorithm and prediction model can readily detect and distinguish our range of explosives on the human body. This would avoid possible endangering of DVI staff.

Post-mortem X-ray computed tomography (PMCT) identification using ante-mortem CT-scan of the sphenoid sinus.

PURPOSE: To evaluate forensic identification of individuals through visual comparison of sphenoid sinus anatomical configuration using ante- and post-mortem CT-scans. METHOD AND MATERIALS: Ante- and post-mortem head CT-scan of 33 individuals were retrospectively collected. Ten head CT-scans were randomly selected from various neurological contexts and added to the ante-mortem group. Ten other head CT-scans were randomly selected from our post-mortem PACS and added to the post-mortem group. These CT-scans were assigned into 2 groups for analysis: an ante-mortem group (33 + 10) and a post-mortem group (33 + 10). For ethics and to avoid identification bias, CT-scans were anonymized - not showing any head structure but only sphenoid sinuses. An anatomical based classification system using the sphenoid sinuses anatomical variations was created according to anatomical and surgical literature. This classification was used by readers to identify in two different steps a maximum of matched and then unmatched scans. RESULTS: The first reader had a sensitivity of 100% [CI: 89.4%-100%] and a specificity of 100% [CI: 99.8%-100%]. Sensitivity and specificity were respectively 93.9% [CI: 79.8%-99.3%] and 99.9% [CI: 99.6%-100%] for the second reader. Positive and negative predictive values were respectively 100% [CI: 89.4%-100%] and 100% [CI: 99.8%-100%] for the first reader. Positive and negative values were respectively 96.9% [CI: 83.8%-99.9%] and 99.9% [CI: 99.7%-100%] for the second reader. Inter-reader variability was estimated by Cohen's kappa and an excellent agreement was found. CONCLUSION: We reported an excellent validity and reliability of subjective visual comparison of ante- and post-mortem CT-data using an anatomical based classification of the sphenoid sinus.

Central nervous system MRI and cardiac implantable electronic devices.

As the population ages and indications for MRI increase, it is estimated that 50 to 75% of patients with a cardiac implantable electronic device (CIED) - pacemaker (PM) or implanted cardiac defibrillator (ICD) - will need an MRI during their CIED's lifetime. Three categories of materials are defined: MRI compatible, MRI non-compatible, and MRI conditional. MRI compatible CIEDs without electrodes have been developed, but do not allow battery changes, so that they are exclusively indicated for patients whose life expectancy is less than that of the battery (6-7years). For MRI conditional CIEDs, all manufacturers publish restrictions. These restrictions can relate to the patient (size, position in the MRI, body temperature), the MRI parameters (magnetic field), or the examination in itself (gradients, specific absorption rate, duration, isocenter). The neuroradiologist can expect to be confronted with the issue of MRI in patients with a CIED. The purpose of this review is to provide them with updated information on MRI and CIEDs.

Ultrasound-guided hookwire localization of non palpable cervical lymphadenopathy: A case-control study of operative time.

OBJECTIVE: We aimed at evaluating the impact of ultrasound-guided (US) hookwire localization of nonpalpable cervical lymphadenopathy on operating time. DESIGN AND METHODS: Retrospective case control study (January 2017 and May 2021) of 26 patients with lateral nonpalpable cervical lymphadenopathy undergoing surgery with (H+) and without (H-) per operative US-guided hook-wire localization. Operative time (general anesthesiology onset, hookwire placement, end of surgery) and surgery-related adverse events data were collected. RESULTS: Mean operative time was significantly shorter in H+ group versus H- group (26 ± 16 min vs. 43 ± 22 min) (p = 0.02). Histopathological diagnosis accuracy was 100% versus 94% (H+ vs. H-, p = 0.1). No significant between group difference in surgery-related adverse events was reported (wound healing, p = 0.162; hematomas, p = 0.498; neoplasms removal failure, p = 1). CONCLUSION: US-guided hookwire localization of lateral nonpalpable cervical lymphadenopathy allowed a significant reduction in operative time, comparable histopathological diagnosis accuracy and adverse events compared with H-.