Analysis and compensation for errors in electrical impedance tomography images and ventilation-­related measures due to serial data collection

Electrical impedance tomography (EIT) is increasingly being used as a bedside tool for monitoring regional lung ventilation. However, most clinical systems use serial data collection which, if uncorrected, results in image distortion, particularly at high breathing rates. The objective of this study was to determine the extent to which this affects derived parameters. Raw EIT data were acquired with the GOE­MF II EIT device (CareFusion, Höchberg, Germany) at a scan rate of 13 images/s during both spontaneous breathing and mechanical ventilation. Boundary data for periods of undisturbed tidal breathing were corrected for serial data collection errors using a Fourier based algorithm. Images were reconstructed for both the corrected and original data using the GREIT algorithm, and parameters describing the filling characteristics of the right and left lung derived on a breath by breath basis. Values from the original and corrected data were compared using paired t­ tests. Of the 33 data sets, 23 showed significant differences in filling index for at least one region, 11 had significant differences in calculated tidal impedance change and 12 had significantly different filling fractions (p = 0.05). We conclude that serial collection errors should be corrected before image reconstruction to avoid clinically misleading results

Headache in patients with pituitary adenoma: Clinical and paraclinical findings

Aim: The aim of this article is to generate hypotheses for the mechanism of pituitary adenoma headache. Patients and methods: Fifty-eight patients with pituitary adenoma were prospectively analysed for prevalence and manifestation of tumour headache. Intrapersonal and neoplasm-associated risk factors were assessed. Results: Twenty-four patients (41%) had tumour-attributed headache, seven had migraine-like, 11 tension-type headache-like headache, and three both. Cluster headache-like headache was found once, and two headaches remained unclassified. Tumour-attributed headache was associated with a positive history of headache (p = 0.03; OR 3.4), nicotine abuse (p3% (p = 0.02; OR 11.0). For patients with migraine-like tumour-attributed headache, risk factors were younger age (p = 0.02), nicotine abuse (p3% (p = 0.03; OR 14.1). For tension-type headache-like headache, the main risk factor was a positive history of tension-type headache (p = 0.045; OR 5.6). Conclusion: Headache predisposition and local tumour effects might be important for the pathophysiology of pituitary adenoma headache and tumour headache in general