Objective
Assessing the feasibility and efficiency of interventions using ultrasound (US) volume navigation (V Nav) with real time needle tracking and image fusion with contrast enhanced (ce) CT, MRI or US.
Methods
First an
in vitro
study on a liver phantom with CT data image fusion was performed, involving the puncture of a 10 mm lesion in a depth of 5 cm performed by 15 examiners with US guided freehand technique vs. V Nav for the purpose of time optimization. Then 23 patients underwent ultrasound-navigated biopsies or interventions using V Nav image fusion of live ultrasound with ceCT, ceMRI or CEUS, which were acquired before the intervention. A CEUS data set was acquired in all patients. Image fusion was established for CEUS and CT or CEUS and MRI using anatomical landmarks in the area of the targeted lesion. The definition of a virtual biopsy line with navigational axes targeting the lesion was achieved by the usage of sterile trocar with a magnetic sensor embedded in its distal tip employing a dedicated navigation software for real time needle tracking.
Results
The
in vitro
study showed significantly less time needed for the simulated interventions in all examiners when V Nav was used (p<0.05). In the study involving patients, in all 10 biopsies of suspect lesions of the liver a histological confirmation was achieved. We also used V Nav for a breast biopsy (intraductal carcinoma), for a biopsy of the abdominal wall (metastasis of ovarial carcinoma) and for radiofrequency ablations (4 ablations). In 8 cases of inflammatory abdominal lesions 9 percutaneous drainages were successfully inserted.
Conclusion
Percutaneous biopsies and drainages, even of small lesions involving complex access pathways, can be accomplished with a high success rate by using 3D real time image fusion together with real time needle tracking.
IntroductionTo prospectively evaluate quantitative assessment of fluorescence optical imaging (FOI) for differentiation of synovitic from non-synovitic joints in patients suffering from rheumatoid arthritis (RA).MethodsFOI of the hands was performed in patients with active RA, and a stratified quantitative fluorescence readout (FLRO) of 3 phases (1-120 s; 121-240 s; 241-360 s) was generated for 5 individual joints of the clinical predominant hand (carpal joint, metacarpophalangeal and proximal interphalangeal joints of digits II & III). To dissect the effect of the overall perfusion of the hand from the perfusion due to synovitis, a fluorescence ratio (FLRA) was additionally calculated, dividing each FLRO by the readout of the eponychium of digit II. The mean FLRO and FLRA were compared between joints with absent vs. present synovitis determined by clinical examination, grayscale, color Doppler ultrasonography, or magnetic resonance imaging (MRI).ResultsThe analysis for 90 individual joints from 18 patients yielded FLRO ranging from 4.4 to 49.0 × 103, and FLRAs ranging from 0.37 to 2.27. Overall, the analyses based on the FLRA revealed a higher discrimination than the analyses related to the FLRO, demonstrating most significant differences in phases 2 and 3. A sensitivity of 26/39 (67%) and a specificity of 31/40 (77%) were calculated for FLRA of phase 3 using a cut-off value of more than 1.2 to detect MRI-confirmed synovitis with FOI.ConclusionsFOI has a potential for visualizing synovitis in subjects with RA. For adequate FOI interpretation, quantitative analysis should be based on the novel FLRA calculated for phases 2 and 3.
Despite heparin coating and systemic anticoagulation, thrombotic clot formation is a serious complication in extracorporeal membrane oxygenation (ECMO). We describe our first results of visualization of thrombotic deposits in ECMO devices using advanced multidetector computed tomography (MDCT). A bioline-coated polymethylpentene membrane oxygenator (MO) after 8 days of ECMO treatment (device 1) and a factory-sealed MO serving as an internal quality control (device 2) were analyzed with three-dimensional (3D) visualization volume rendering technique (VRT) using a 0.6 mm3 voxel isotropic MDCT dataset. After the computed tomography (CT) scan, device 1 was anatomically dissected for direct visualization of potential deposits and further analyzed by scanning electron microscopy (SEM). The VRT 3D model based on the MDCT dataset of device 1 showed red-coded areas within the gas exchange surface of the device consistent with fibrous and cellular deposits. These deposits could be confirmed by anatomical dissection of the device and by SEM. Device 2 showed no signs of clot formation in MDCT using the same VRT settings. It was demonstrated that MDCT with VRT is able to detect thrombotic deposits in ECMO devices under ex vivo conditions. MDCT allows direct visualization of the actual thrombus load of a used ECMO device as well as the quantification of the thrombus volume and could, therefore, play a significant role in better understanding the oxygenator thrombosis in modern ECMO treatment.
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