41 research outputs found
Successful endovascular repair of an iliac AV fistula in a 49-year-old woman with progressive dyspnea, right leg pain and edematous swelling of the extremity.
<p><b>A</b>) Volume reconstruction (VR) with AV fistula between the right common iliac artery and vein (arrow); note the massive enlargement of the inferior cava vein. <b>B</b>) Angiographic correlation of the finding. <b>C</b>) The control angiogram after stent graft placement reveals a type 1A endoleak with persistent AV fistula (arrow). <b>D</b>) VR 12 months after implantation of a second stent graft (arrows) shows complete occlusion of the AV fistula.</p
Endovascular Repair of Arterial Iliac Vessel Wall Lesions with a Self-Expandable Nitinol Stent Graft System - Table 1
<p>CIA = common iliac artery, IIA = internal iliac artery, EIA = external iliac artery, d = diameter, l = length.</p><p>* = reperfused IIA aneurysm 3 days (patient no. 6) resp. 5 days (patient no. 15) after infrarenal endovascular aneurysm repair.</p
Successful stent graft placement of a ruptured IIA aneurysm in a 77-year-old man with acute abdominal pain in the left lower quadrant.
<p><b>A</b>) Volume reconstruction (VR) shows a large left IIA aneurysm with the irregular boundaries (arrows) indicating a rupture. <b>B</b>) On axial CT scan the true size of the aneurysm is depicted with active bleeding within the thrombosed part and blood surrounding the aneurysm (arrows). <b>C</b>) Selective angiography shows a strong IIA aneurysm (arrow) with major side branches. <b>D</b>) Angiogram after stent graft placement and coiling of aneurysm shows complete exclusion of the aneurysm from blood flow.</p
PRFS-Based MR Thermometry Versus an Alternative T1 Magnitude Method – Comparative Performance Predicting Thermally Induced Necrosis in Hepatic Tumor Ablation
<div><p>Objective</p><p>To compare the accuracy of a semi-quantitative proton resonance frequency shift (PRFS) thermal mapping interface and an alternative qualitative T1 thermometry model in predicting tissue necrosis in an established routine setting of MRI-guided laser ablation in the human liver.</p> <p>Materials and Methods</p><p>34 cases of PRFS-guided (GRE) laser ablation were retrospectively matched with 34 cases from an earlier patient population of 73 individuals being monitored through T1 magnitude image evaluation (FLASH 2D). The model-specific real-time estimation of necrotizing thermal impact (above 54 °C zone and T1 signal loss, respectively) was correlated in size with the resulting necrosis as shown by lack of enhancement on the first-day contrast exam (T1). Matched groups were compared using the Mann-Whitney test.</p> <p>Results</p><p>Online PRFS guidance was available in 33 of 34 cases. Positive size correlation between calculated impact zone and contrast defect at first day was evident in both groups (p < 0.0004). The predictive error estimating necrosis was median 21 % (range 1 % - 52 %) in the PRFS group and 61 % (range 22 - 84 %) in the T1 magnitude group. Differences in estimating lethal impact were significant (p = 0.004), whereas the real extent of therapy-induced necrosis showed no significant difference (p > 0.28) between the two groups.</p> <p>Conclusion</p><p>PRFS thermometry is feasible in a clinical setting of thermal hepatic tumor ablation. As an interference-free MR-tool for online therapy monitoring its accuracy to predict tissue necrosis is superior to a competing model of thermally induced alteration of the T1 magnitude signal.</p> </div
Risk of pneumothorax according to the stage of pulmonary emphysema.
<p>Multinomial logistic regression shows linear correlation of increasing emphysema percentage and a heightened risk of the incidence of pneumothorax after CT-guided PTPB.</p
Exemplary images of CT-guided percutaneous transthoracic pulmonary biopsies with and without lung emphysema.
<p>Pulmonary nodule in otherwise normal lung parenchyma before (A) and after PTPB (B). No post-interventional complication was detected. Pictures (C) and (D) show a patient with pulmonary emphysema. After PTBP (D) CT examination revealed pneumothorax and parenchyma hematoma.</p
Means and standard deviations of analyzed parameters.
<p>Means and standard deviations of analyzed parameters.</p
T1 magnitude thermal imaging in a dual applicator ablation of hepatic colorectal carcinoma metastasis.
<p>Preablation T1 (A), mandrin placement (B), peak temperature with T1 signal loss (T1 FLASH 2D: TE 4,8 ms, TR 100 ms, BW 260 Hz/pixel, flip angle 70°, slice thickness 5 mm, fat saturation) (C), necrotic contrast defect on 24 h CEMR (D).</p
Box blot analysis of predictive errors for PRFS and T1 magnitude thermal monitoring.
<p>Values (parts per hundred) of over- and underestimation were evaluated in the PRFS group (range 1 % - 52 %), of underestimation alone in the T1 magnitude group (range 22 % - 84 %). The predictive error is almost threefold the amount with the older T1 magnitude method (median 61 % as compared with 21 %). </p
MR-guided therapy control.
<p>Example case (A) of an initially T1-hypointense recurrent tumor (arrowheads) at the margin of an older inhomogeneously hyperintense ablation zone. Phase difference image derived from subtracting a non-heating reference image (B) and thermal map with color-coded pixels in a quadrate ROI at peak temperature as being displayed on screen during the procedure (C), fast GRE sequences at 1.5 T Magnetom Avanto, Siemens Healthcare, Erlangen, Germany; TE 12 ms, TR 970 ms, BW 260 Hz/pixel, flip angle 65°, field of view (FOV) 320 mm, matrix size 128x128, slice thickness of 3 mm, fat suppression. Color-codes of phase image and online ROI are unequal. The last picture (D) shows the ablation-induced necrosis (arrowheads) demarcated as a lack of extracellular contrast uptake at portal venous phase on 24 h CEMR.</p