Search

Purpose: Numerous studies have already reported on the anatomy of the superficial temporal artery (STA) on dissection or imaging, and more specifically on CT angiography. However, few studies have reported on the possible variations that exist between readers in the assessment of certain anatomical parameters. The aim of this study was to investigate the reproducibility of different anatomical measurements of the superficial temporal artery with CT angiography. Methods: Forty cranial iodine contrast-enhanced CT scans were searched in a retrospective monocentric study. Various anatomical categorical and quantitative measurements (more or less automatic) of the superficial temporal artery were assessed. To evaluate the inter-observer reproducibility of various anatomical measurements of the superficial temporal artery obtained through CT angiography, descriptive statistics, kappa statistics and intraclass correlation coefficients (ICC) were employed. Results: Eighty STAs were analyzed independently by two readers. The kappa coefficient for determining the mode of STA termination was substantial (kappa = 0.782). The number of loops was mean 0.22 vs. 0.25 (p = 0.981; ICC = 0.701) and the number of kinks was mean 5.68vs5.64 (p = 0.876; ICC = 0.860). No significant difference was found between readers for the determination of the distance of the STA termination to different superficial landmark lines. No significant difference in the orientation angles of the STA and the frontal and parietal branches was found. Semi-automatic measurements of the length of the STA appeared (ICC > 0.7) reproducible whereas semi-automatic measurements (surface, perimeter, short diameter, large diameter) appeared statistically less reproducible (ICC < 0.5). These results must also be interpreted in the light of the spatial resolutions inherent in the CT angiography technique. Conclusion: The present study provides information concerning the reproducibility of certain anatomical measurements of the superficial temporal artery in CT angiography. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the current practices in anatomy teaching at French universities in 2023. Methods: On January 10, 2023, a questionnaire was sent to all members of the official list of the French Medical College of Professors of Anatomy. Each Anatomy centre was asked to complete this online form only once. The questionnaire covered several key themes, including broad questions, dissections practices, "virtual" dissections, teaching methods and teaching staff. Results: The questionnaire was completed by 26/28 anatomy centres. Access to body donor dissection is reported to be mandatory in 15 of the 26 centers (58%), optional in 10 centers (38%), and "tolerated" in one center (4%). Fifteen of 26 centers (58%) reported having a virtual dissection table for teaching anatomy. Concerning the teaching of anatomy via live ultrasound, 10 out of 26 centers (38%) reported providing it. Regarding the teaching methods used for medical students, chalk and board lectures are the most common method, although the intensity of use varies. Most lectures are given with chalk and board in 42% (11/26) of the centers. In about 73% (19/26) of the centers, tablet lectures are used. Regarding anatomy teachers, it was reported that in 24/26 anatomy centres (92%), more than 50% of the courses for medical students are taught by professors holding the chair of anatomy (21/26 professors (81%), 3/26 associate professors (12%)). Conclusion: The present study endeavors to contribute to the existing body of knowledge on anatomy education by offering insights into the current practices in French universities. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this work was to assess, in a quantitative and qualitative way, the teaching of cervical and abdominal anatomy via ultrasound for medical students. Methods: For several years, tutorials on the study of anatomy through use of ultrasound on the living organism have been given at the Medical School of Brest. These sessions have focused on cervical anatomy and abdominal anatomy. Students were invited to quantitatively assess these lessons by taking two tests containing questions on both cervical and abdominal anatomy and ultrasound technique: a pre-test administered at the beginning of the year and a post-test at the end of the year. In addition, a qualitative assessment was carried out at the end of the year. Ten statements were presented, and students were asked to indicate their agreement or disagreement to a four-point Likert scale. Results: One hundred and twelve students answered all the questions on the pre-test with an average of 13.4 correct answers out of 20. Forty-eight students answered all the questions on the post-test with an average of 14.6/20. Twenty-six students who benefited from the courses gave positive feedback about the workshops on the qualitative assessment at the end of the year (median scores > = 3/4). Conclusion: The results of this work suggest that the use of ultrasound makes a positive contribution to the teaching of anatomy. The students interviewed think this type of tutorial should be an integral part of the anatomy curriculum at our university. In addition, this type of instruction can serve to introduce the use of ultrasound itself in a practical learning setting. [ABSTRACT FROM AUTHOR]

Simple Summary: For the treatment of high-grade gliomas, radiolabeled amino acid PET/CT could allow for a better tumor delineation for radiotherapy planning and to target aggressive tumor areas for radiotherapy dose escalation guiding. The aim of this ancillary study from the IMAGG prospective trial is to demonstrate a spatial similarity between the areas of high uptake on 18F-FET PET/CT before radio-chemotherapy (MTV), the residual tumor on post-therapy NADIR MRI (GTV 2), and the area of recurrence on MRI (GTV 3). These results on 23 patients showed modest similarity indices between MTV, GTV 2, and GTV 3. Nevertheless, their similarities improved in patients who underwent only biopsy or partial surgery. Delineation methods based on TBR ≥ 1.6 and 80–90% SUVmax showing a good agreement in the hotspot concept for targeting standard dose and radiation boost. The standard therapy strategy for high-grade glioma (HGG) is based on the maximal surgery followed by radio-chemotherapy (RT-CT) with insufficient control of the disease. Recurrences are mainly localized in the radiation field, suggesting an interest in radiotherapy dose escalation to better control the disease locally. We aimed to identify a similarity between the areas of high uptake on O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) positron emission tomography/computed tomography (PET) before RT-CT, the residual tumor on post-therapy NADIR magnetic resonance imaging (MRI) and the area of recurrence on MRI. This is an ancillary study from the IMAGG prospective trial assessing the interest of FET PET imaging in RT target volume definition of HGG. We included patients with diagnoses of HGG obtained by biopsy or tumor resection. These patients underwent FET PET and brain MRIs, both after diagnosis and before RT-CT. The follow-up consisted of sequential brain MRIs performed every 3 months until recurrence. Tumor delineation on the initial MRI 1 (GTV 1), post-RT-CT NADIR MRI 2 (GTV 2), and progression MRI 3 (GTV 3) were performed semi-automatically and manually adjusted by a neuroradiologist specialist in neuro-oncology. GTV 2 and GTV 3 were then co-registered on FET PET data. Tumor volumes on FET PET (MTV) were delineated using a tumor to background ratio (TBR) ≥ 1.6 and different % SUVmax PET thresholds. Spatial similarity between different volumes was performed using the dice (DICE), Jaccard (JSC), and overlap fraction (OV) indices and compared together in the biopsy or partial surgery group (G1) and the total or subtotal surgery group (G2). Another overlap index (OV') was calculated to determine the threshold with the highest probability of being included in the residual volume after RT-CT on MRI 2 and in MRI 3 (called "hotspot"). A total of 23 patients were included, of whom 22% (n = 5) did not have a NADIR MRI 2 due to a disease progression diagnosed on the first post-RT-CT MRI evaluation. Among the 18 patients who underwent a NADIR MRI 2, the average residual tumor was approximately 71.6% of the GTV 1. A total of 22% of patients (5/23) showed an increase in GTV 2 without diagnosis of true progression by the multidisciplinary team (MDT). Spatial similarity between MTV and GTV 2 and between MTV and GTV 3 were higher using a TBR ≥ 1.6 threshold. These indices were significantly better in the G1 group than the G2 group. In the FET hotspot analysis, the best similarity (good agreement) with GTV 2 was found in the G1 group using a 90% SUVmax delineation method and showed a trend of statistical difference with those (poor agreement) in the G2 group (OV' = 0.67 vs. 0.38, respectively, p = 0.068); whereas the best similarity (good agreement) with GTV 3 was found in the G1 group using a 80% SUVmax delineation method and was significantly higher than those (poor agreement) in the G2 group (OV'= 0.72 vs. 0.35, respectively, p = 0.014). These results showed modest spatial similarity indices between MTV, GTV 2, and GTV 3 of HGG. Nevertheless, the results were significantly improved in patients who underwent only biopsy or partial surgery. TBR ≥ 1.6 and 80–90% SUVmax FET delineation methods showing a good agreement in the hotspot concept for targeting standard dose and radiation boost. These findings need to be tested in a larger randomized prospective study. [ABSTRACT FROM AUTHOR]

• First prospective study comparing spatial differences between multiparametric perfusion MRI and FET PET • Multiparametric perfusion MRI volumes are highly correlated with CE T1 gadolinium volumes. • FET PET suggests that the metabolically tumor is underestimated by contrast enhanced MRI. • rCBV hot spot could be used to identify subvolume with increased neoangiogenesis. The aim of this study was to prospectively investigate tumor volume delineation by amino acid PET and multiparametric perfusion magnetic resonance imaging (MRI) in patients with newly diagnosed, untreated high grade glioma (HGG). Thirty patients with histologically confirmed HGG underwent O-(2-[18F]-fluoroethyl)- l -tyrosine (18F-FET) positron emission tomography (PET), conventional Magnetic Resonance Imaging (MRI) as contrast-enhanced (CE) and fluid-attenuated inversion recovery (FLAIR) and multiparametric MRI as relative cerebral blood volume (rCBV) and permeability estimation map (K2). Areas of MRI volumes were semi-automatically segmented. The percentage overlap volumes, Dice and Jaccard spatial similarity coefficients (OV, DSC, JSC) were calculated. The 18F-FET tumor volume was significantly larger than the CE volume (median 43.5 mL (2.5–124.9) vs. 23.8 mL (1.4–80.3), p = 0.005). The OV between 18F-FET uptake and CE volume was low (median OV 0.59 (0.10–1)), as well as spatial similarity (median DSC 0.52 (0.07–0.78); median JSC 0.35 (0.03–0.64)). Twenty-five patients demonstrated both rCBV and CE on MRI: The median rCBV tumor volume was significantly smaller than the median CE volume (p < 0.001). The OV was high (median 0.83 (0.54–1)), but the spatial similarity was low (median DSC 0.45 (0.04–0.83); median JSC 0.29 (0.07–0.71)). Twenty-eight patients demonstrated both K2 and CE on MRI. The median K2 tumor volume was not significantly larger than the median CE volume. The OV was high (median OV 0.90 (0.61–1)), and the spatial similarity was moderate (median DSC 0.75 (0.01–0.83); median JSC 0.60 (0.11–0.89)). We demonstrated that multiparametric perfusion MRI volumes (rCBV, K2) were highly correlated with CE T1 gadolinium volumes whereas 18F-FET PET provided complementary information, suggesting that the metabolically active tumor volume in patients with newly diagnosed untreated HGG is critically underestimated by contrast enhanced MRI. 18F-FET PET imaging may help to improve target volume delineation accuracy for radiotherapy planning. [ABSTRACT FROM AUTHOR]

Objective: To assess the diagnostic accuracy of iodine map computed tomography pulmonary angiography (CTPA), for segment-based evaluation of lung perfusion in patients with acute pulmonary embolism (PE), using perfusion single-photon emission CT (SPECT) imaging as a reference standard.Methods: Thirty participants who have been diagnosed with acute pulmonary embolism on CTPA underwent perfusion SPECT/CT within 24 h. Perfusion SPECT and iodine map were independently interpreted by 2 nuclear medicine physicians and 2 radiologists. For both modalities, each segment was classified as normoperfused or hypoperfused, as defined by a perfusion defect of more than 25% of a segment. The primary end point was the diagnostic accuracy (sensitivity and specificity) of iodine map for segment-based evaluation of lung perfusion, using perfusion SPECT imaging as a reference standard. Following blinded interpretation, a retrospective explanatory analysis was performed to determine potential causes of misinterpretation.Results: The median time between CTPA with iodine maps and perfusion SPECT was 14 h (range 2-23 h). A total of 597 segments were analyzed. Sensitivity and specificity of iodine maps with CTPA for the detection of segmental perfusion defects were 231/284 = 81.3% (95% CI 76.4 to 85.4%) and 247/313 = 78.9% (95% CI 74.1 to 83.1%), respectively. In retrospect, false results were explained in 48.7%.Conclusion: Iodine map CTPA showed promising results for the assessment of pulmonary perfusion in patients with acute PE, with sensitivity of 81.3% and specificity of 78.9%, respectively. Recognition of typical pitfalls such as atelectasis, fissures, or beam-hardening artifacts may further improve the accuracy of the test.Key Points: • Sensitivity and specificity of iodine subtraction maps for the detection of segmental perfusion defects were 81.3% (95% CI 76.4 to 85.4%) and 78.9% (95% CI 74.1 to 83.1%), respectively. • Recognition of typical pitfalls such as atelectasis, fissures, or beam-hardening artifacts may further improve the diagnostic accuracy of the test. [ABSTRACT FROM AUTHOR]

This technical note describes a novel CT scan protocol that includes a non-enhanced CT, dynamic CTA, and perfusion of the whole brain and CTA of the carotid arteries using a 320-row area detector CT scanner, with a unique contrast injection and acceptable radiation exposure dose in patients presenting with acute ischemic stroke. The acquisition parameters and reconstruction parameters will be discussed including the use of model-based iterative reconstruction (MBIR), time summing (tMIP), and subtraction techniques to optimize the results of this protocol.Key Points• Scanning on a 320-row area detector CT can achieve both brain perfusion with dynamic angiography and reconstructed arterial and venous CTA, and supra aortic trunk angiography, in a single acquisition. • It provides, in a single exam, a full diagnostic workup, i.e., all the acquisitions that are needed to make a quick decision, with reasonable exposure to ionizing radiation and reduced amount of medium contrast, in case of acute ischemic stroke presentation. [ABSTRACT FROM AUTHOR]