Computed tomography-guided lung biopsy: Association between biopsy needle angle and pneumothorax development.

Computed tomography (CT)-guided lung biopsy is a well-established diagnostic method for pulmonary lesions. However, the use of this technique often results in pneumothorax development. The aim of the present study was to evaluate the association between biopsy needle angle and pneumothorax development associated with computed tomography-guided lung biopsy. We retrospectively analyzed the results of CT-guided lung biopsies for 325 cases to investigate physical risk factors for pneumothorax development. Biopsy needle angle and patient positioning were included in the analysis. Pneumothorax occurred in 160 of 325 procedures (49.2%). Discontinuation of the procedure as a result of pneumothorax occurred in 18 of 160 procedures (11.2%). Upper lung lobe pneumothorax occurred in 40.8% (58/142), middle lobe in 17.6% (25/142), and lower lobe pneumothorax occurred in 41.5% (59/142) of these procedures. Discontinuation of the procedure occurred in 2.5% of the upper lobe (4/160), 0.6% of the middle lobe (1/160), and 8.1% of the lower lobe (13/160) biopsies. Mild pneumothorax occurred in 59.4% (95/160), moderate in 25.0% (40/160), and severe in 7.5% (12/160) of the affected cases, and biopsy was discontinued in 11.2% (18/160) of the affected cases. When the needle angle was <90°, 40.3% (131/325) of the patients experienced no pneumothorax development, 40.0% (130/325) developed pneumothorax, and 4.3% (14/325) of the procedures were discontinued. The results showed that use of CT-guided lung biopsy can reduce the rate of pneumothorax development that occurs when other procedures are used. The access route is simple and easy to puncture, and proper use of breath holding reduces diaphragmatic movement.

Optimal dilution of contrast medium for quantitating parenchymal blood volume using a flat-panel detector.

Objective Similar to perfusion studies after acute ischemic stroke, measuring cerebral blood volume (CBV) via C-arm computed tomography before and after therapeutic interventions may help gauge subsequent revascularization. We tested serial dilutions of intra-arterial injectable contrast medium (CM) to determine the optimal CM concentration for quantifying parenchymal blood volume by flat-panel detector imaging (FD-PBV). Methods CM was diluted via saline power injector, instituting time delays for FD-PBV studies. A red/green/blue (RGB) color scale was employed to quantify/compare FD-PBV and magnetic resonance-derived CBV (MRCBV). Results Contrast values of right and left common carotid arteries did not differ significantly at CM dilutions of ≥20%. RGB analysis of FD-PBV imaging (relative to MR-CVB), showed CM dilution altered the colors (by 16%), increasing red and decreasing blue ratios. Conclusion Diluting CM to 20% resulted in no laterality differential of FD-PBV imaging, with left/right quantitative ratios approaching 1.1 (optimal for clinical use).

Dose reduction in cone-beam CT scanning for intracranial stent deployment before coil embolization of intracranial wide-neck aneurysms.

PURPOSE: Flat panel detector (FD)-equipped angiography machines are increasingly used for neuro-angiographic imaging. During intracranial stent-assisted coil embolization procedures, it is very important to clearly and quickly visualize stent shape after deployment in the vessel. It is necessary to quickly visualize stents by cone-beam computed tomography (CBCT). The aim of this study was to compare CBCTs at 10 and 20 s, and to confirm that this method is useful for neuro-endovascular treatment procedures. MATERIALS AND METHODS: We treated 30 patients with wide-necked intracranial aneurysms with a flexible, self-expanding neurovascular stent and subsequent aneurysm embolization with platinum micro-coils. We performed the CBCT after stent deployment. We compared the 10 s and 20 s CBCTs, using the full width one-half maximum (FWHM) visualization. RESULTS: Accurate stent placement with subsequent coil occlusion of the aneurysms was feasible in all patients. Stent struts were clearly visualized on both 10 s and 20 s CBCTs. Importantly, 10 s CBCT can reduce the radiation dose by about 42%, compared with 20 s CBCT. Performing 10 s CBCT with a 14% dilution of the contrast medium may significantly improve image acquisition during stent-assisted coil embolization. CONCLUSIONS: Reduced-dose, 10 s CBCT can visualize stents in clinical cases, while significantly reducing radiation exposure.

[Examination of factors useful for choosing a method to assist coil embolization of unruptured cerebral aneurysm].

BACKGROUND: In coil embolization of neurovascular aneurysms, we have noted that few wide-necked unruptured aneurysms are successfully embolized. This prompted us to search for useful factors to assist the choice of methods of coil embolization. METHOD: We first measured aneurysm size and volume using auto measurement (NVvol) and VER (NVver). Second, we calculated the volume (NVapp) and VER (NVapp) using approximation expressions. Third, we measured the end-on view neck angle using a 3 dimensional digital subtraction angiography (3D-DSA) image. RESULTS: NVvol and NVapp were correlated (y=0.87x). NVvol VER and NVapp VER approached 24% in 41 clinical cases. The dome/neck ratio averaged 1.15. Length of neck and the end-on view neck angle were significantly different between the stent-assisted group and the balloon-assisted group. NVvol and NVapp showed a good correlation with basic examination results in 41 clinical cases. CONCLUSION: The end-on view neck angle is significantly different. This boundary neck angle was 100° for the two groups. The end on-view neck angle is thus a useful factor for deciding medical treatment strategy.

[Importance of three dimensional-fusion image after stent-assisted coil embolization of unruptured aneurysm].

PURPOSE: We made the fusion image of both stent and platinum coil after embolization of an unruptured aneurysm. METHOD: After scanning with cone beam computed tomography, we made three dimensional (3D) images of stent and coil and fused them. CONCLUSION: We can evaluate unruptured aneurysm after embolization by using a fusion image. 3D-fusion image is useful on clinical cases.

[Importance of an automatic measurement base on the first coil diameter in regard to coil embolization of a cerebral aneurysm].

We compared the accuracy in evaluating an unrapture aneurysm between NV and 3D-DSA. In vitro, we evaluated the accuracy in calculating the volume of the Aneurysm model. We compared the diameter of the first coil and estimated the diameter of the Aneurysm. The Aneurysm size calculated by NV resembled the first coil more than the size measured by 3D-DSA. In clinical cases, the measurement of NV is objective; the measurement of 3D-DSA, however, is subjective by person. NV has an automatic measurement that is useful for clinical cases.