[Show abstract][Hide abstract] ABSTRACT: The purpose of this study is to describe our initial experience with embolization of pulmonary arteriovenous malformations (PAVMs) using hydrogel microcoils. The technical and radiological outcomes were retrospectively reviewed in seven patients with nine simple-type PAVMs (median feeder size 4 mm, range 3-6 mm) who underwent embolization. Hydrogel microcoils were mainly used, and detachable bare microcoils were combined as needed to occlude the terminal feeding artery just before the sac. Of a total of 43 microcoils, 30 (69.8%) hydrogel microcoils were deployed in eight PAVMs with the median number 3.5 (range 2 to 6) per lesion. All hydrogel microcoils were successfully deployed without microcatheter stuck or malposition. In the remaining one small PAVM, only soft bare microcoils were used, however, resulting in recanalization requiring additional coils in the second session. The venous sac was substantially shrunk in all lesions treated with hydrogel microcoils with the median size reduction rate 95.0% (range 81.8% to 99.0%) during the median follow-up period 10 months (range 6 to 18 months). In conclusion, hydrogel microcoils were safely and effectively applied for occluding PAVMs with relatively small feeders.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
Cone-beam CT (CBCT) guided targeting system or XperGuide (Philips Medical Systems) is a real-time 3D needle navigation system on live fluoroscopy overlapped with CBCT image as a practical tool. The purpose of this study was to evaluate the accuracy and procedure time of this system compared to conventional CT guidance technique using a phantom model.
METHOD AND MATERIALS
A phantom was made of corn flour and clay that contained multiple 1cm kneaded erasers as targets. The target can be recognized at CBCT and CT images, but invisible under X-ray fluoroscopy. The needle path reaching the target was planned on CBCT or CT images of the phantom on 3D-workstation. Four interventional radiologists inserted a 19G 20cm needle to aim at separately five targets in different set angles under XperGuide or conventional CT guidance in one session. Each interventional radiologist performs needle interventions totally in two sessions under XperGuide and in two sessions under conventional CT guidance. To verify the accuracy of the puncture, the gap or distance between the needle tip and the center of the target was measured on CBCT or CT images obtained after each puncture. Procedure time was also measured.
All targets were successfully targeted with the first needle pass in all sessions using both techniques by four interventional radiologists. Mean distance from the surface puncture point to the target was 104±13 mm and 101±17 mm (p=0.54), mean gap was 1.88±0.83 and 4.06±1.22 mm (p<0.01) and mean procedure time was 192±64 seconds and 318±110 seconds (p<0.01) under XperGuide and conventional CT guidance, respectively.
CBCT guided targeting system or XperGuide allows more accurate lesion targeting and quicker needle interventions in a phantom model compared to conventional CT guidance.
CBCT guided targeting system or XperGuide allows accurate lesion targeting and quick needle interventions. This system will improve needle interventions.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the correlation between packing density and the incidence of coil compaction or recanalization of visceral artery aneurysms (VAAs) after coil packing.
Between July 2004 and April 2012, coil packing was performed for 46 true visceral aneurysms (16 splenic, 11 pancreaticoduodenal, eight renal, six hepatic, three superior mesenteric, one right gastric, and one gastroepiploic) in 42 patients. The size and volume of the aneurysm, packing density, and the incidences of compaction and recanalization were evaluated retrospectively.
The mean follow-up period was 37 months ± 8 (range, 11-80 mo). The mean packing density was 19% ± 8 (range, 5%-42%), mean aneurysm size was 19 mm ± 8 (range, 5-40 mm), and mean volume was 4,108 mm(3) ± 5,435 (range, 72-26,235 mm(3)). Compaction and recanalization occurred in two (4%) and 12 aneurysms (26%), respectively. The mean packing density was significantly lower in aneurysms with compaction or recanalization than in unaffected aneurysms (12% vs 22%; P = .00014). There was a significant difference in mean packing density between small (< 20 mm; 22%) and large (≥ 20 mm) aneurysms (15%; P = .0045). The mean size and volume were significantly larger for coil-compacted or recanalized aneurysms than for unaffected aneurysms (P < .05). In aneurysms with a packing density of at least 24%, no compaction or recanalization occurred.
Coil compaction or recanalization after coil packing for VAAs more often occurs after insufficient embolization with low packing density and in patients with large aneurysms.
No preview · Article · Jun 2013 · Journal of vascular and interventional radiology: JVIR
[Show abstract][Hide abstract] ABSTRACT: Gelatin sponge and polyvinyl alcohol particles have been the most popular particulate embolic agents for transarterial chemoembolization (TACE) of liver tumors. Over the last decade, calibrated microspheres have been introduced and increasingly used in liver tumor embolization in Western countries. In addition, drug-eluting beads (DEB) have been introduced for sustained local drug release. Such long-awaited spherical embolic agents will be introduced in Japan in the near future. The advantages of these microspheres are that particles are uniform in size and shape, and easy to inject through a microcatheter. They can travel distally to vessels corresponding to the particle size; in other words, the occlusion level can be predicted according to the particle size chosen. Thus, new bland microspheres and DEB may bring a significant advancement to embolization for primary liver tumors as well as hepatic metastases from various cancers. However, at this point, the published data suggests that both conventional TACE and DEB-TACE are equally effective for treatment of unresectable hepatocellular carcinoma, when patients are carefully selected. Therefore, indication, patient selection, and embolization techniques will be essential in order to individually adapt newer embolic agents based on oncological, anatomical and technical considerations.
No preview · Article · Jul 2012 · International Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Most studies of computer-aided detection (CAD) for pulmonary nodules have focused on solid nodule detection. The aim of this study was to evaluate the performance of a commercially available CAD system in the detection of pulmonary nodules with or without ground-glass opacity (GGO) using 64-detector-row computed tomography compared to visual interpretation.
Computed tomographic examinations were performed on 48 patients with existing or suspicious pulmonary nodules on chest radiography. Three radiologists independently reported the location and pattern (GGO, solid, or part solid) of each nodule candidate on computed tomographic scans, assigned each a confidence score, and then analyzed all scans using the CAD system. A reference standard was established by a consensus panel of different radiologists, who found 229 noncalcified nodules with diameters > or = 4 mm. True-positive and false-positive results and confidence levels were used to generate jackknife alternative free-response receiver-operating characteristic plots.
The sensitivity of GGO for 3 radiologists (60%-80%) was significantly higher than that for the CAD system (21%) (McNemar's test, P < .0001). For overall and solid nodules, the figure-of-merit values without and with the CAD system were significantly different (P = .005-.04) on jackknife alternative free-response receiver-operating characteristic analysis. For GGO and part-solid nodules, the figure-of-merit values with the CAD system were greater than those without the CAD system, indicating no significant differences.
Radiologists are significantly superior to this CAD system in the detection of GGO, but the CAD system can still play a complementary role in detecting nodules with or without GGO.
No preview · Article · Apr 2009 · Academic radiology