Weakly-supervised learning-based pathology detection and localization in 3D chest CT scans.

BACKGROUND: Recent advancements in anomaly detection have paved the way for novel radiological reading assistance tools that support the identification of findings, aimed at saving time. The clinical adoption of such applications requires a low rate of false positives while maintaining high sensitivity. PURPOSE: In light of recent interest and development in multi pathology identification, we present a novel method, based on a recent contrastive self-supervised approach, for multiple chest-related abnormality identification including low lung density area ("LLDA"), consolidation ("CONS"), nodules ("NOD") and interstitial pattern ("IP"). Our approach alerts radiologists about abnormal regions within a computed tomography (CT) scan by providing 3D localization. METHODS: We introduce a new method for the classification and localization of multiple chest pathologies in 3D Chest CT scans. Our goal is to distinguish four common chest-related abnormalities: "LLDA", "CONS", "NOD", "IP" and "NORMAL". This method is based on a 3D patch-based classifier with a Resnet backbone encoder pretrained leveraging recent contrastive self supervised approach and a fine-tuned classification head. We leverage the SimCLR contrastive framework for pretraining on an unannotated dataset of randomly selected patches and we then fine-tune it on a labeled dataset. During inference, this classifier generates probability maps for each abnormality across the CT volume, which are aggregated to produce a multi-label patient-level prediction. We compare different training strategies, including random initialization, ImageNet weight initialization, frozen SimCLR pretrained weights and fine-tuned SimCLR pretrained weights. Each training strategy is evaluated on a validation set for hyperparameter selection and tested on a test set. Additionally, we explore the fine-tuned SimCLR pretrained classifier for 3D pathology localization and conduct qualitative evaluation. RESULTS: Validated on 111 chest scans for hyperparameter selection and subsequently tested on 251 chest scans with multi-abnormalities, our method achieves an AUROC of 0.931 (95% confidence interval [CI]: [0.9034, 0.9557], p $ p$ -value < 0.001) and 0.963 (95% CI: [0.952, 0.976], p $ p$ -value < 0.001) in the multi-label and binary (i.e., normal versus abnormal) settings, respectively. Notably, our method surpasses the area under the receiver operating characteristic (AUROC) threshold of 0.9 for two abnormalities: IP (0.974) and LLDA (0.952), while achieving values of 0.853 and 0.791 for NOD and CONS, respectively. Furthermore, our results highlight the superiority of incorporating contrastive pretraining within the patch classifier, outperforming Imagenet pretraining weights and non-pretrained counterparts with uninitialized weights (F1 score = 0.943, 0.792, and 0.677 respectively). Qualitatively, the method achieved a satisfactory 88.8% completeness rate in localization and maintained an 88.3% accuracy rate against false positives. CONCLUSIONS: The proposed method integrates self-supervised learning algorithms for pretraining, utilizes a patch-based approach for 3D pathology localization and develops an aggregation method for multi-label prediction at patient-level. It shows promise in efficiently detecting and localizing multiple anomalies within a single scan.

Access to phage therapy at Hospices Civils de Lyon in 2022: Implementation of the PHAGEinLYON Clinic program.

OBJECTIVES: To describe the set-up in 2022 of the PHAGEinLYON Clinic program dedicated to improve access to phage therapy in France using pharmaceutical-grade phages. METHODS: We described the process, prospectively collected all phage therapy requests received during 2022 and reviewed them retrospectively to analyze the decision and also the patient care pathway (NCT05883995). RESULTS: Among 143 phage therapy requests, the indication was confirmed by multidisciplinary team meetings for 57 (40%) of them, and 44 were infected with bacteria that could be easily targeted by phages in France. Finally, 33 patients were treated, including 26 at our institution as compassionate use or in a clinical trial. Main indications were complex bone and joint infections, endovascular infections and lung infections. To manage these patients, 172 pharmaceutic phage cocktails targeting S. aureus and/or P. aeruginosa were prepared; 57 were dedicated to local, and 99 to intravenous injections. During the follow-up, 18 (69%) patients had a favorable clinical evolution, 6 (23%) required subsequent phage therapy, with the same phages with a greater phage exposition, or with different phages from elsewhere. CONCLUSIONS: The implementation of the PHAGEinLYON Clinic program in 2022 was associated with a groundbreaking access of phage therapy in France.

[Role of whole-body ultrasound in severe pre-eclampsia and post-partum hemorrhage]. / Pré-éclampsie sévère et hémorragie post-partum: apport de l'échographie « corps entier ¼

PURPOSE: Management of severe pre-eclamptic patients is a challenge for the staff on obstetrical wards. We demonstrate that ultrasound applied to several organs performed at a patient's bedside gave the information required for the patient's management, without the need to transfer her to the radiology department or to call external consultants. CLINICAL FEATURES: A 29-yr-old severely pre-eclamptic patient with HELLP syndrome (hemolysis, cytolysis, thrombopenia) presented, in the post-partum period, with an occult uterine hemorrhage diagnosed with bedside abdominal/pelvic ultrasound. Ultrasound was also used to insert a central venous catheter. After undergoing a hysterectomy to control hemorrhage and receiving activated factor VII, the patient recovered uneventfully. Hemodynamic management was optimized non-invasively using pulmonary and cardiac ultrasound, when the patient developed hemorrhagic shock followed by pulmonary edema. Volume replacement was guided by cardiac ultrasound findings, and we were able to detect incipient interstitial pulmonary edema and follow its course using pulmonary ultrasound. CONCLUSION: Practitioners must be aware of the role of whole-body ultrasound in the diagnosis and treatment of complex, multi-organ conditions such as pre-eclampsia. Moreover, ultrasound helps in the management of global hemodynamics. The training of anesthesiologists in a variety of ultrasound techniques should be encouraged.

Occult pulmonary embolism in intensive care unit patients undergoing chest computed tomography scan: incidence and effect on outcomes.

OBJECTIVE: To determine the incidence of occult pulmonary embolism (PE) and the associated morbidity in an intensive care unit (ICU). DESIGN: Retrospective study. SETTING: Fifteen-bed ICU of a university hospital. PARTICIPANTS: Two hundred patients who underwent chest computed tomography (CT) scans with administration of contrast. INTERVENTIONS: The patients were classified into 3 groups: (1) Occult PE if the chest CT scan was not taken, specifically for elucidating the diagnosis of PE, but it confirmed this diagnosis; (2) non-occult PE if the chest CT scan was taken to elucidate a suspected diagnosis of PE and confirmed this diagnosis; and (3) the chest CT scan did not confirm this diagnosis. The analysis was conducted to identify the effect of a diagnosis of occult PE on the outcomes of patients. MEASUREMENTS AND MAIN RESULTS: Among the 200 patients who underwent chest CT scan, 27 (13%) patients had PE, in whom 18 (9%) were classified as occult PE and 9 (4.5%) as non-occult PE. The duration of ICU stay was increased in patients with PE, as compared with the controls (23 [18-48] days v 17 [10-20] days v 14 [7-29] days; p = 0.02 for occult PE, non-occult PE, and controls, respectively). No difference was observed in mortality rate among the 3 groups. CONCLUSION: Occult PE was found in 9% of the cohort. This emphasized the need for developing diagnostic strategies in high-risk patients. Future studies should aim at assessing interventions for preventing this event.

Seventeen Cases of Daptomycin-Induced Eosinophilic Pneumonia in a Cohort of Patients Treated for Bone and Joint Infections: Proposal for a New Algorithm.

Background: Daptomycin is increasingly used in the treatment of bone and joint infections (BJIs) and may be responsible for daptomycin-induced eosinophilic pneumonia (DIEP), a potentially severe adverse drug reaction. The aim of this study was to describe DIEP in patients treated at a referral center for the management of BJI, and to revisit current definitions of this disease. Methods: Patients treated from 1 January 2012 to 31 March 2021 were included in a prospective cohort (NCT02817711), in which all potential serious adverse events are prospectively recorded. Patients diagnosed with DIEP were retrospectively analyzed using different definitions. Results: In a total of 4664 patients included in the cohort during the study period, 1021 patients (21.9%) received daptomycin, of whom 17 (1.7%) were diagnosed with DIEP. Most patients were male (n = 11 [64.7%]), and periprosthetic joint infection was the commonest BJI (n = 12 [70.6%]). Only 1 patient had bronchoalveolar lavage (BAL) eosinophil count ≥25%, while most patients had peripheral blood eosinophilia (n = 15 [88.2%]). Chest computed tomography (CT) was compatible with eosinophilic pneumonia in 13 of 14 cases (92.9%). All patients recovered upon discontinuation of daptomycin. Using the different definitions available, only a minority of cases fulfilled existing criteria for DIEP. We propose a new algorithm that includes specific CT scan signs, and systemic instead of BAL eosinophilia. Conclusions: DIEP is a rare event that requires prompt discontinuation of the causative antibiotic. Current criteria to diagnose definite DIEP are too restrictive and not easily applicable in clinical practice. A new algorithm is proposed here (Lyon algorithm) to facilitate the early identification of DIEP.

Osteocutaneous-flap-related osteomyelitis following mandibular reconstruction: a cohort study of an emerging and complex bone infection.

Osteocutaneous flap (OCF) mandible reconstruction is at high risk for surgical site infection. This study aimed to describe diagnosis, management, and outcome of OCF-related osteomyelitis. All patients managed at our institution for an OCF-related osteomyelitis following mandible reconstruction were included in a retrospective cohort study (2012-2019). Microbiology was described according to gold-standard surgical samples, considering all virulent pathogens, and potential contaminants if present on at least two samples. Determinants of treatment failure were assessed by logistic regression and Kaplan-Meier curve analysis. The 48 included patients (median age 60.5 (IQR, 52.4-66.6) years) benefited from OCF mandible reconstruction mostly for carcinoma ( n = 27 / 48 ; 56.3 %) or osteoradionecrosis ( n = 12 / 48 ; 25.0 %). OCF-related osteomyelitis was mostly early ( ≤ 3 months post-surgery; n = 43 / 48 ; 89.6 %), presenting with local inflammation ( n = 28 / 47 ; 59.6 %), nonunion (wound dehiscence) or sinus tract ( n = 28 / 47 ; 59.6 %), and/or bone or device exposure ( n = 21 / 47 ; 44.7 %). Main implicated pathogens were Enterobacteriaceae ( n = 25 / 41 ; 61.0 %), streptococci ( n = 22 / 41 ; 53.7 %), Staphylococcus aureus ( n = 10 / 41 ; 24.4 %), enterococci ( n = 9 / 41 ; 22.0 %), non-fermenting Gram-negative bacilli ( n = 8 / 41 ; 19.5 %), and anaerobes ( n = 8 / 41 ; 19.5 %). Thirty-nine patients (81.3 %) benefited from surgery, consisting of debridement with implant retention (DAIR) in 25 / 39 (64.1 %) cases, associated with 93 (IQR, 64-128) days of antimicrobial therapy. After a follow-up of 18 (IQR, 11-31) months, 24 / 48 (50.0 %) treatment failures were observed. Determinants of treatment outcomes were DAIR (OR, 3.333; 95 % CI, 1.020-10.898) and an early infectious disease specialist referral (OR, 0.236 if ≤ 2  weeks; 95 % CI, 0.062-0.933). OCF-related osteomyelitis following mandibular reconstruction represents difficult-to-treat infections. Our results advocate for a multidisciplinary management, including an early infectious-disease-specialist referral to manage the antimicrobial therapy driven by complex microbiological documentation.

Lumbar septic arthritis and psoas abscess due to Aggregatibacter aphrophilus.

Invasive infections due to Aggregatibacter aphrophilus mainly include negative blood culture endocarditis and osteoarticular infections. The authors present herein a rare case of posterior septic arthritis related to A aphrophilus involving lumbar spine with contiguous abscesses of psoas and paravertebral muscles. The infection likely originated from oral cavity. A good outcome was observed after a prolonged and targeted antibiotherapy.