Discrimination between non-functioning pituitary adenomas and hypophysitis using machine learning methods based on magnetic resonance imaging‑derived texture features

Purpose

Hypophysitis is a heterogeneous condition that includes inflammation of the pituitary gland and infundibulum, and it can cause symptoms related to mass effects and hormonal deficiencies. We aimed to evaluate the potential role of machine learning methods in differentiating hypophysitis from non-functioning pituitary adenomas.

Methods

The radiomic parameters obtained from T1A-C images were used. Among the radiomic parameters, parameters capable of distinguishing between hypophysitis and non-functioning pituitary adenomas were selected. In order to avoid the effects of confounding factors and to improve the performance of the classifiers, parameters with high correlation with each other were eliminated. Machine learning algorithms were performed with the combination of gray-level run-length matrix-low gray level run emphasis, gray-level co-occurrence matrix-correlation, and gray-level co-occurrence entropy.

Results

A total of 34 patients were included, 17 of whom had hypophysitis and 17 had non-functioning pituitary adenomas. Among the 38 radiomics parameters obtained from post-contrast T1-weighted images, 10 tissue features that could differentiate the lesions were selected. Machine learning algorithms were performed using three selected parameters; gray level run length matrix-low gray level run emphasis, gray-level co-occurrence matrix-correlation, and gray level co-occurrence entropy. Error matrices were calculated by using the machine learning algorithm and it was seen that support vector machines showed the best performance in distinguishing the two lesion types.

Conclusions

Our analysis reported that support vector machines showed the best performance in distinguishing hypophysitis from non-functioning pituitary adenomas, emphasizing the importance of machine learning in differentiating the two lesions.

     

Tear in mitral anterior leaflet as a complication of Manouguian's procedure in a woman with an aortic valve prosthesis

Complications of valve replacement are diverse. In addition to morbidity due to the prosthetic valve itself (e.g. endocarditis, thrombosis), complications due to operative technique may occur in complex cases, as in aortic valve replacement with annular enlargement. Postoperative echocardiography is a simple, non-invasive method to evaluate patients with prosthetic valves. Detailed knowledge of the surgical technique employed and of probable complications is necessary to make an accurate diagnosis. The case is reported of a woman with aortic valve replacement and annular enlargement who had mitral regurgitation due to a tear in the anterior mitral leaflet as a complication of Manouguian's annulus enlargement.     

Pulsed Doppler tissue imaging can help to identify patients with right ventricular infarction

This study was planned to assess whether tissue Doppler imaging is a useful method for the detection of the right ventricular myocardial infarction. Forty-eight patients with acute inferior myocardial infarction and 24 age- and sex-matched healthy controls were included in this study. Twenty-four patients had electrocardiographic signs of inferior myocardial infarction without right ventricular infarction (group I), and the other 24 patients had electrocardiographic signs of inferior myocardial infarction with right ventricular infarction (group II). From the echocardiographic apical four-chamber view, peak systolic, early diastolic, and late diastolic velocities of the tricuspid annulus at the right ventricular free wall were recorded with the use of pulsed-wave Doppler tissue imaging. The tricuspid annular peak tissue Doppler imaging systolic velocity was significantly lower in group I (14.03 ± 2.57cm/s, P 0.005) and in group II (8.50 ± 0.84cm/s, P 0.005) than in controls (16.63 ± 2.31cm/s). The tricuspid annular peak systolic (8.50 ± 0.84cm/s vs 16.63 ± 2.31cm/s) and peak early diastolic (10.99 ± 3.28cm/s vs 19.39 ± 4.3cm/s) velocities were significantly lower in group II than in group I, as compared with controls (P 0.001). Peak early diastolic velocity of tricuspid annulus (10.99 ± 3.28cm/s vs 19.39 ± 4.3cm/s) was significantly lower in group I than in controls (P 0.001); however, late diastolic velocity was significantly lower in group II (15.98 ± 5.08cm/s, P 0.05) than in group I (18.21 ± 2.63cm/s, P 0.05) and in controls (19.02 ± 5.29cm/s). The results of this study indicate that tricuspid annular peak systolic and early diastolic velocities are reduced in patients with right ventricular infarction. The velocity of the tricuspid annulus by tissue Doppler imaging is simple and can be used to distinguish whether patients with inferior myocardial infarction have right ventricular infarction.This study was presented at the XXIII. Congress of the European Society of Cardiology, Stockholm, Sweden, 1–5 September 2001     

Effectiveness of gemcitabine as second-line chemotherapy in non-small cell lung cancer

The role of a second-line chemotherapy after an initial treatment with a platinum-based regimen remains largely undefined. In this retrospective clinical effectiveness study, gemcitabine as monotherapy was evaluated in the second-line chemotherapy in 34 non-small cell lung cancer (NSCLC) cases that had been previously received chemotherapy and did not respond to the treatment or presented with relapses. Gemcitabine was given intravenous at a dose of 1250 mg/m2 on days one, eight every three weeks. Median age was 50 years and squamous cell carcinoma was the most common malignancy (44.1%). No patient had a complete response, 7 (20.6%) patients had a partial response. The median survival was 29 weeks. The 1-year survival probability was estimated at 26.5%. Median time to disease progression was 13 weeks. Gemcitabine was well tolerated in this patient population. Among totally 119 chemotherapy cycles, we observed grade 3 and 4 toxicities only in 2.5% of cycles. As a result of the study, single agent gemcitabine is found to be tolerable and to have moderate effectiveness in the second-line chemotherapy in NSCLC. It should be placed among treatment options.     

Comparison of the Effects of Desflurane and Propofol Anesthesia on the Inflammatory Response and S100β Protein During Coronary Artery Bypass Grafting

Cardiopulmonary bypass (CPB) contributes to the secretion of anti-inflammatory cytokines that mediate the inflammatory response observed during open heart surgery. In addition to many factors, type of anesthesia management affects immune response and central nervous system in cardiac surgery. The aim of this study was to assess the effect of propofol versus desflurane anesthesia on systemic immune modulation and central nervous system on patients undergoing coronary artery bypass grafting. Forty patients undergoing elective coronary artery bypass graft surgery with CPB were included in this prospective randomized study. Patients were allocated to receive propofol (n?=?20) or desflurane (n?=?20) for maintenance of anesthesia. The blood samples for IL-6, IL-8, TNF-α, and S100β were drawn just prior to the operation before the induction of anesthesia, second before cardiopulmonary bypass, third after CPB, fourth 4 h postoperatively at the ICU. Major finding in our study is that S100β levels were lower in propofol group when compared to desflurane anesthesia. And also immune reaction was less in patients exposed to desflurane anesthesia when compared to propofol anesthesia as indicated by lower plasma concentrations of IL-8 and IL-6. Propofol is more preferable in terms of S100β for anesthetic management for CABG.