Diagnosis of multiple sclerosis using optical coherence tomography supported by explainable artificial intelligence

BACKGROUND/OBJECTIVES

Study of retinal structure based on optical coherence tomography (OCT) data can facilitate early diagnosis of relapsing-remitting multiple sclerosis (RRMS). Although artificial intelligence can provide highly reliable diagnoses, the results obtained must be explainable.

SUBJECTS/METHODS

The study included 79 recently diagnosed RRMS patients and 69 age matched healthy control subjects. Thickness (Avg) and inter-eye difference (Diff) features are obtained in 4 retinal layers using the posterior pole protocol. Each layer is divided into six analysis zones. The Support Vector Machine plus Recursive Feature Elimination with Leave-One-Out Cross Validation (SVM-RFE-LOOCV) approach is used to find the subset of features that reduces dimensionality and optimises the performance of the classifier.

RESULTS

SVM-RFE-LOOCV was used to identify OCT features with greatest capacity for early diagnosis, determining the area of the papillomacular bundle to be the most influential. A correlation was observed between loss of layer thickness and increase in functional disability. There was also greater functional deterioration in patients with greater asymmetry between left and right eyes. The classifier based on the top-ranked features obtained sensitivity = 0.86 and specificity = 0.90.

CONCLUSIONS

There was consistency between the features identified as relevant by the SVM-RFE-LOOCV approach and the retinotopic distribution of the retinal nerve fibres and the optic nerve head. This simple method contributes to implementation of an assisted diagnosis system and its accuracy exceeds that achieved with magnetic resonance imaging of the central nervous system, the current gold standard. This paper provides novel insights into RRMS affectation of the neuroretina.

Is the Mnr locus of Triticeae species the same as the Ndh and Dia loci?

The menadione reductase (MNR), the nicotinamide adenine dinucleotide dehydrogenase (NDH) and diaphorase (DIA) isozymes were studied in the allohexaploid Triticum aestivum cv "Chinese Spring" and in five diploid Triticeae species. The Mnr1, Ndh3and Dia1 loci were located on the chromosome arms 3AL, 3BL and 3DL of T. aestivum, respectively. These loci were also located on the 3H chromosome of Hordeum vulgare cv "Betzes", the 3L chromosome of Aegilops longissima and the 6RL chromosome arm of Secale cereale cv "Imperial". The chromosomal location results together with the segregation studies support a tetrameric behaviour of the MNR1, NDH3 and DIA1 isozymes. The Ndh1 and Dia3 loci were located on homoeologous group 4 showing a monomeric behaviour. The chromosomal locations and linkage data of the Mnr, Ndh and Dia loci suggest that Mnr1=Ndh3=Dia1; Ndh1=Dia3 and Ndh2=Dia2.

[HELLP syndrome: case report and review of the literature]

The case of a 32-years-old primipara in her thirty-second week of pregnancy who presented acute epigastric pain, citopenia, elevation in hepatic enzymes and analytical signs of hemolysis is presented. Ultrasonography demonstrated multiple hyperechogenic nodular images in the liver leading to a wide differential diagnosis. Liver biopsy findings, together with the mentioned clinico-biological alterations were indicative of the HELLP syndrome. Following caesarean, the patient presented rapid and total, symptomatic and analytical, improvement. Based on this case, a review of this entity in the literature and its prognostic implications and possible therapeutic approaches are reported.

[Endobronchial lipomas. Apropos of 4 cases]

We present 4 cases of endobronchial lipomas observed in our department over the last fifteen years. Histological diagnosis was obtained in all cases after endobronchoscopy and biopsy. Endobronchial exeresis was possible in one patient, lobectomy was required in a second. For the other two patients, surgery was not performed due to the patient's age and the small size of the tumor. Radiography, bronchoscopy and computed tomography findings suggested the diagnosis which was confirmed at pathology examination of the biopsy or surgical specimen. Treatment for endobronchial lipoma should be as conservative as possible either by endobronchial or laser resection. Thoracotomy should only be used when bronchial or pulmonary alterations are irreversible.

[Combined therapy using ranitidine and sucralfate in duodenal ulcer resistant to cimetidine]

122 patients with duodenal ulcus have been treated with a cimetidine's single night dose of 800 mg over 6 or 12 weeks. After this period of time, 18 patients still had their wounds without complete healing. This group of patients had been afterwards treated with a combination of ranitidine and sulfacrate over a six weeks period. Only 3 of them achieved a complete ulcus reepitelization, although all of them were clinically asymptomatic. These 3 patients moved to a nightly maintenance treatment guideline of 150 mg of ranitidine, but they quickly presented relapses. A significantly higher consumption of tobacco and alcohol was observed among the patients who did not heal after 12 weeks of treatment with cimetidine. On the other hand the rest of the general facts and ulcus endoscopic characteristics have been similar both in patients resistant to cimetidine and in those who had a favorable evolution.