Разработка и исследование конструкции привода управляемого задерживающего устройства шароструйно-эжекторного бурового снаряда

В работе рассмотрены принципы шароструйного бурения, а так же устройство шаростуйно-эжекторного снаряда. Предложены варианты модернизации данного снаряда.In this paper, the principles of pellet impact drilling, as well as the construction of a pellet-ejector projectile, are considered. Variants of modernization of this projectile are offered

Examples of paired T1 mapping and corresponding T2* map.

<p>Panel A: T1 mapping, with colour scale bar on top. Panel B: T2* map, with colour scale bar below. In both panels, from left to right, data from a normal volunteer, a patient with mild iron overload, a patient with moderate iron overload and a patient with severe iron overload, are separately shown. Colour scale for T1 map is on top, for T2* map is at the bottom of the picture. Low T1, corresponding to iron, is represented in blue in the T1 maps, and low T2* is represented in pink-to-blue.</p

Examples of paired T2*-T1 non-concordance.

<p>Panel A: T2* and T1 map in a healthy volunteer. Panel B: T1 map and T2* map of two patients with normal T2* but low T1. Colour scale for T1 map is on top, for T2* map is at the bottom of the picture. Please note the blue shift of the myocardium in the T1 maps represented in panel B, compared to the healthy volunteer. Similarly, some pink areas may be spotted in the corresponding T2* maps, absent in the healthy volunteer. Nevertheless, dark blood T2* analysis performed with CMR Tools Thalassemia plug in gave normal results in both patients.</p

Baseline patient characteristics.

<p>Baseline patient characteristics.</p

Myocardial T2*—T1 mapping relationship in Thalassemia major.

<p>(B): log-log linear regression lines for T2*—T1 (here Dark Blood T2*—MOLLI) in three different T2* intervals (T2* <20ms, T2* = 20-30ms and T2* >30ms)<b>–</b>for >30ms, the regression line is not drawn as the p value is 0.38 (weak relationship). (A): On the Y-axis are represented the r2 values of the relationship between T2* and T1 (both after log transformation). Data are obtained for a 30 samples moving window, with steps of 1 sample at a time, smoothed by a low-pass filter of order 3. Afterward, a new equispaced series was generated by linear interpolation. The point, corresponding to T2* = 28.7ms, was the local maximum found by setting the first derivative equal to 0, immediately before a large variation of the determination coefficient. A rounded value of T2* = 30ms has then been used to delimit a T2* range of 20-30ms, with suspect mild iron accumulation.</p

T2* vs T1 in Thalassemia major patients.

<p>The dashed lines highlight the cut off points for T2* (here Dark Blood, conventionally 20ms) and T1 (MOLLI, 916ms, as calculated from the healthy volunteer cohort). Dots localised in the grey quadrants represents discordance. All subjects with a discordant classification (n = 62, 38% of the cohort) fall into the lower right panel, i.e. they are characterized by normal T2*(iron not present), low T1 (iron present). Thus, apparently, T2* fails to identify 2 out of every 3 patients with cardiac iron overload.</p