Automatic segmentation of femoral tumors by nnU-net.

BACKGROUND: Metastatic femoral tumors may lead to pathological fractures during daily activities. A CT-based finite element analysis of a patient's femurs was shown to assist orthopedic surgeons in making informed decisions about the risk of fracture and the need for a prophylactic fixation. Improving the accuracy of such analyses ruqires an automatic and accurate segmentation of the tumors and their automatic inclusion in the finite element model. We present herein a deep learning algorithm (nnU-Net) to automatically segment lytic tumors within the femur. METHOD: A dataset consisting of fifty CT scans of patients with manually annotated femoral tumors was created. Forty of them, chosen randomly, were used for training the nnU-Net, while the remaining ten CT scans were used for testing. The deep learning model's performance was compared to two experienced radiologists. FINDINGS: The proposed algorithm outperformed the current state-of-the-art solutions, achieving dice similarity scores of 0.67 and 0.68 on the test data when compared to two experienced radiologists, while the dice similarity score for inter-individual variability between the radiologists was 0.73. INTERPRETATION: The automatic algorithm may segment lytic femoral tumors in CT scans as accurately as experienced radiologists with similar dice similarity scores. The influence of the realistic tumors inclusion in an autonomous finite element algorithm is presented in (Rachmil et al., "The Influence of Femoral Lytic Tumors Segmentation on Autonomous Finite Element Analyses", Clinical Biomechanics, 112, paper 106192, (2024)).

The walls of the femoral neck as an auxiliary tool for femoral stem positioning.

BACKGROUND: Femoral anteversion is a major contributor to functionality of the hip joint and is implicated in many joint pathologies. Accurate determination of component version intraoperatively is a technically challenging process that relies on the visual estimation of the surgeon. The following study aimed to examine whether the walls of the femoral neck can be used as appropriate landmarks to ensure appropriate femoral prosthesis version intraoperatively. METHODS: We conducted a retrospective study based on 32 patients (64 hips) admitted to our centre between July and September 2020 who had undergone a CT scan of their lower limbs. Through radiological imaging analysis, the following measurements were performed bilaterally for each patient: anterior wall version, posterior wall version, and mid-neck femoral version. Anterior and posterior wall version were compared and evaluated relative to mid-neck version, which represented the true version value. RESULTS: Mean anterior wall anteversion was 20° (95% CI, 17.6-22.8°) and mean posterior wall anteversion was -12° (95% CI, -15 to -9.7°). The anterior walls of the femoral neck had a constant of -7 and a coefficient of 0.9 (95% CI, -9.8 to -4.2; p < 0.0001; R2 0.77).The posterior walls of the femoral neck had a constant of 20 and a coefficient of 0.7 (95% CI, 17.8-22.5; p < 0.0001; R2 0.60). CONCLUSIONS: Surgeons can accurately obtain femoral anteversion by subtracting 7° from the angle taken between the anterior wall and the posterior femoral condyles or by adding 20° to the angle taken between the posterior wall and the posterior femoral condyles.

Ultrasound, magnetic resonance imaging and radiography of the finger joints in psoriatic arthritis patients.

OBJECTIVES: To report the discrepancies and agreements between US, MRI and radiography of the hand in PsA, and to compare the sensitivity and specificity of US and radiography to MRI as the gold standard imaging study in PsA. METHODS: All of the 100 prospectively recruited consecutive PsA patients underwent clinical assessment and concomitant radiographic, US and MRI studies of the MCP, PIP and DIP joints of one hand. Synovitis, flexor tenosynovitis, extensor paratenonitis, erosions and bone proliferations were identified and scored. All readers were blinded to clinical data, and agreement was calculated based on prevalence-adjusted bias-adjusted kappa (PABAK). RESULTS: The prevalence of synovitis, flexor tenosynovitis, extensor paratenonitis and erosions was similar for US and MRI, while that of bone proliferation was significantly increased in US and radiography compared with MRI (P < 0.001). The absolute agreement between US and MRI was good-to-very good for synovitis (85-96%, PABAK = 0.70-0.92), flexor tenosynovitis (93-98%, PABAK = 0.87-0.96) and extensor paratenonitis (95-98%, PABAK = 0.90-0.97). Agreement between US, MRI and radiography was 96-98% (PABAK = 0.92-0.97) for erosions and 71-93% (PABAK = 0.47-0.87) for bone proliferations. Sensitivity of US with MRI as gold standard was higher for synovitis (0.5-0.86) and extensor paratenonitis (0.63-0.85) than for flexor tenosynovitis (0.1-0.75), while the specificity was high for each pathology (0.89-0.98). CONCLUSION: There is very good agreement between US and MRI for the detection of inflammatory changes in finger joints in PsA. US, radiography and MRI have a good-to-very good agreement for destructive changes.

High Prevalence of Right Ventricular/Left Ventricular Ratio ≥1 Among Patients Undergoing Computed Tomography Pulmonary Angiography.

AIM: Increased ratio between the right and left ventricular (RV/LV) diameters ≥1 is considered an important imaging marker for risk stratification among patients diagnosed with acute pulmonary embolism (PE). Our goal was to assess the prevalence of RV/LV≥1 among consecutive patients undergoing computed tomography pulmonary angiography, and to compare the prevalence of RV/LV≥1 between patients with and without PE. METHODS: Retrospective analysis of consecutive patients who underwent computed tomography pulmonary angiography due to clinical suspicion of PE between January 1, 2014 and December 31, 2014. The axial RV/LV diameters were measured. The prevalence of RV/LV ≥1 was compared between patients with and without PE and among PE patients, between those with central versus peripheral PE. RESULTS: The final cohort included 862 patients. A total of 142 (16.5%) had PE. RV/LV ≥1 was found in 553 (64.1%) of all patients, of them in 453 (63%) patients without PE and in 100 (70.4%) patients with PE (P=0.117). On multivariate analysis, PE was not significantly associated with RV/LV ≥1 (odds ratio [OR]: 1.4; 95% confidence interval [CI]: 0.9-2.1; P=0.102). There was no significant difference in the prevalence of RV/LV ≥1 among patients with central versus peripheral PE distribution (79.5% vs. 67%, P=0.101). Older age (OR: 1.03; 95% CI: 1.02-1.04; P<0.001) and male gender (OR: 1.51; 95% CI: 1.11-2.03; P=0.008), among all patients, were significantly associated with RV/LV diameter ≥1. CONCLUSION: As RV/LV ≥1 is highly prevalent (64.1%), without a significant difference between those with and without PE, an RV/LV ≥1 might not represent the cardiac response to the acute PE event, but rather the patient's baseline condition.

Left Atrial Volume as a Biomarker of Target Organ Damage in Cardionephrology: A Study in a Wide Range of Renal Function.

BACKGROUND: Cardiac chamber size was previously studied by echocardiography, among patients with progressive kidney disease only. We aimed to explore the relations between all heart chamber volumes as assessed by CT pulmonary angiography and renal function, throughout all ranges. METHODS: Using a novel technology for automatic four-chamber volumetric analysis, we analyzed CT pulmonary angiography results for 748 consecutive patients (between January 1 and December 31, 2014) without pulmonary embolism, and correlated the chamber volumes, indexed to body surface area, with the estimated glomerular filtration rates (eGFRs). RESULTS: After adjustment for age, all cardiac chamber volumes aside from that of the left ventricle inversely correlated with the eGFR. For every 10-unit decrease in eGFR, the volume indices of the left atrium, right atrium, and right ventricle were larger by 3.1%, 2.3%, and 1.5% (P < .001, P = .003, P = .007), respectively. There was a significant correlation between left atrial volume index and eGFR (r = -0.43; P < .001). In a categorical comparison, patients with even minimal renal dysfunction (eGFR, 60 to 90 mL/min/1.73 m2) had a 10.3% larger left atrial volume index (95% CI, 3.1-17.9; P = .004) compared to patients with an eGFR > 90 mL/min/1.73 m2. CONCLUSIONS: A simple concomitant volumetric analysis of all four cardiac chambers by CT pulmonary angiography demonstrated that differences in volume correlate with renal function even within the normal range spectrum. The difference was most evident in the left atrium. This finding may be the first clue to evolving cardiorenal syndrome and may serve as a target for early therapeutic interventions. TRIAL REGISTRY: ClinicalTrials.gov; Clinical Trials registration number (Helsinki Committee): 0603-15-TLV; URL: www.clinicaltrials.gov.

Head circumference in untreated and IGF-I treated patients with Laron syndrome: comparison with untreated and hGH-treated children with isolated growth hormone deficiency.

BACKGROUND: Head circumference (HC) is a simple and practical measure of brain size, development and longitudinal measurements of the HC in childhood are an index of brain growth. OBJECTIVE: To determine the effects of long IGF-I deficiency and treatment on HC in patients with Laron syndrome (LS). PATIENTS: 20 untreated adult LS patients, aged 48.4±11.2 years and 13 LS patients treated between ages of 5.6±4 to 11.3±3 years were studied. 15 patients with congenital IGHD treated between age 6.1±4 and 13±4 by hGH served as controls. METHODS: HC was expressed as standard deviation (SD) and Ht as SDS. HC was measured and plotted on Nellhaus charts. Linear height (Ht) was measured by a Harpenden Stadiometer. CONCLUSIONS: The mean HC deficit of the adult untreated LS males was -2.9±0.6 SD compared to a Ht deficit of -7.0±1.7 SDS. The HC of the LS adult females was -3.6±1 SD compared to a Ht SDS of -6.9±1.5 (p<0.001). IGF-I treatment (150-200 µg/kg once daily) increased the HC from -3.3±0.9 (m±SD) to normal values (0.87±1.8 SD) (p<0.001) in 11/13 children. The Ht SDS deficit decreased only by 1.5 SDS. hGH treatment of cIGHD children increased the HC from -2.0±1.8 to 0.3±1.2 SD and the Ht SDS from -4.8±1.6 to 1.6±1.0.