Three-dimensional printed 316L stainless steel cardiovascular stent's electrolytic polishing and its mechanical properties / 生物医学工程学杂志

The interventional therapy of vascular stent implantation is a popular treatment method for cardiovascular stenosis and blockage. However, traditional stent manufacturing methods such as laser cutting are complex and cannot easily manufacture complex structures such as bifurcated stents, while three-dimensional (3D) printing technology provides a new method for manufacturing stents with complex structure and personalized designs. In this paper, a cardiovascular stent was designed, and printed using selective laser melting technology and 316L stainless steel powder of 0-10 µm size. Electrolytic polishing was performed to improve the surface quality of the printed vascular stent, and the expansion behavior of the polished stent was assessed by balloon inflation. The results showed that the newly designed cardiovascular stent could be manufactured by 3D printing technology. Electrolytic polishing removed the attached powder and reduced the surface roughness Ra from 1.36 µm to 0.82 µm. The axial shortening rate of the polished bracket was 4.23% when the outside diameter was expanded from 2.42 mm to 3.63 mm under the pressure of the balloon, and the radial rebound rate was 2.48% after unloading. The radial force of polished stent was 8.32 N. The 3D printed vascular stent can remove the surface powder through electrolytic polishing to improve the surface quality, and show good dilatation performance and radial support performance, which provides a reference for the practical application of 3D printed vascular stent.

Workstation scheme and implementation for a medical imaging information system / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To discuss the scheme and implementation of workstation configuration for medical imaging information systems suitable to the practical situation in China.</p><p><b>METHODS</b>The workstations were logically divided into picture archiving and communication system (PACS) workstations and radiology information system (RIS) workstations. The former applied to three kinds of diagnostic practice: the small matrix images, large matrix images and high resolution grayscale display applications. The latter consisted many different models defined by the usage and function processes.</p><p><b>RESULTS</b>A dual-screen configuration for image interpretation workstations integrated the image-viewing and reporting procedures physically. Small matrix images as CT or MR were operated on 17 inch (1 inch = 2.54 cm) color monitors, while conventional X-ray interpretation was performed on 21 inch color monitors or portrait format grayscale 2 k by 2.5 k monitors. All other RIS workstations not involved in imaging process were set up with a common PC configuration.</p><p><b>CONCLUSION</b>Workstation schemes for medical imaging information systems should satisfy the basic requirements of medical imaging and investment budget.</p>

CT features and anatomic distribution of pleural dissemination in lung cancer / 中国肺癌杂志

<p><b>BACKGROUND</b>To study the CT appearance of lung cancer combined with pleural dissemination and its anatomic characteristics.</p><p><b>METHODS</b>CT findings of 32 cases of lung cancer with pleural dissemination proved by surgery and pathology were analyzed.</p><p><b>RESULTS</b>The main CT manifestations were pleural effusion (24 cases), visceral pleural dissemination with nodules (10 cases), parietal pleural dissemination with nodules (16 cases), and pleural thickening (31 cases). Out of the cases with visceral pleural disseminations, nodules distributed on the lung surface in 9 sites, while on the interlobular pleura in 10 sites. Parietal pleural dissemination with nodules were found in 45 sites which located on the diaphragmatic pleura, the costal pleura, the mediastinal pleura, and the pulmonary ligament. The diameters of the small nodules ranged from 2 to 5 mm, and the large nodules from 5 to 10 mm. There were direct invasion with tumor induced pleural thickening in 10 cases, while indirect invasion in 21 cases. In the later cases, 9 cases had parietal pleural thickening less than 10 mm, 4 circumferential pleural thickening, 5 mediastinal pleural involvement thickening, and 3 pulmonary ligament thickening.</p><p><b>CONCLUSIONS</b>Pleural effusion is the main manifestation of lung cancer combined with pleural dissemination. The CT features of lung cancer with pleural dissemination are the parietal and visceral pleural nodules, as well as the pleural thickening. The nodules are likely to distribute on parietal pleura of the diaphragmatic and the costal pleura, and they may transfer to the pulmonary ligament.The early small disseminating nodules are miliary in size, and only can be detected on the pulmonary window of chest CT scan.</p>

A preliminary application of MR dynamic time-resolved subtracted perfusion imaging to qualitative and partial quantitative evaluation of the blood supply by pulmonary artery in peripheral type lung cancer / 中国肺癌杂志

<p><b>BACKGROUND</b>To explore the application of MR time-resolved subtracted perfusion imaging to qualitatively and partially quantitatively evaluate blood supply by pulmonary artery in patients with peripheral type lung cancer.</p><p><b>METHODS</b>Twenty-three patients with peripheral type lung cancer proved cytologically or/and histologically underwent MR perfusion study. The time-resolved subtracted imaging which provided the perfusion images in different phases were performed. First-pass time-signal intensity curves of pulmonary artery, descending aorta, lung mass were obtained respectively, and start-time and peak-time of them were compared. The signal enhanced ratio of the masses in pulmonary artery and aorta perfusion phases were calculated respectively.</p><p><b>RESULTS</b>Fourteen masses began to enhance during pulmonary circulation phase and reached peak value during systematic-circulation phase, and the average signal change ratio during pulmonary circulation phase was much smaller than that during systematic-circulation phase, indicating their blood supply came both from pulmonary and systematic blood circulation, but mainly from the latter. Seven masses began to enhance and reached peak value during systematic-circulation phase, indicating their blood supply came mainly from systematic blood circulation. Two masses began to enhance and reached peak value during pulmonary-circulation phase, indicating their blood supply came mainly from pulmonary blood circulation.</p><p><b>CONCLUSIONS</b>MR dynamic time-resolved subtracted perfusion imaging is feasible to qualitatively and relatively quantitatively evaluate blood supply of pulmonary artery for peripheral type lung cancer.</p>

The value of MR dynamic time-resolved subtracted imaging in evaluating the blood supply by systemic artery in patients with lung cancer / 中国肺癌杂志

<p><b>BACKGROUND</b>To explore the application value of MR dynamic time-resolved subtracted imaging in qualitative and quantitative assessment of blood supply by systemic artery in patients with lung cancer.</p><p><b>METHODS</b>A prospective study using MR FSPGR pulse sequence dynamic scan after contrast enhancement was undertaken in fifty-one patients with lung cancer which were proved by cytology or/and histology. The time-resolved subtracted imaging were acquired using the pre- and post-enhanced images in different phases of pulmonary circulation during the first-pass period (FPP) of contrast agent. The time-signal curves of FPP at four ROI placed on pulmonary artery (PA), descending aorta (DA), mass (M) and contralateral pulmonary parenchyma (PP), and the ST (start-time) and PT (peak-time) of those four ROI were measured. The enhancement ratio of the signals of M/PP at PA/DA peak time (E MP , E MA , E PP , E PA ) were calculated.</p><p><b>RESULTS</b>According to the time-resolved subtracted imaging during PA phase, intensity of the signal was low in 7 cases, medium in 2, but not enhanced in other 42 cases. All the 51 cancer masses were remarkably enhanced during DA phase. During FPP, the ST [(5.90±0.51)s] and PT [(12.75±0.67)s] of PP were slightly later than the ST [(4.19±0.43)s] and PT [(10.59±0.66)s] of PA, while the ST [(11.03±0.80)s] and PT [(33.62±3.06)s] of cancer masses were later than ST [(9.43±0.59)s] and PT [(19.81±4.14)s] of DA. E MA was significantly higher than E MP (91.47%±18.83% vs 15.38%±11.03%, P < 0.001), while E PP were remarkably higher than E PA (273.83%±48.60% vs 140.65%±24.40%, P < 0.001).</p><p><b>CONCLUSIONS</b>MR dynamic time-resolved subtracted imaging is feasible to be a non-invasive technique in qualitative and relatively quantitative assessment of blood supply by systemic artery in patients with lung cancer.</p>

CT and MRI findings of cancerous invasion of the main pulmonary artery in lung cancer: the correlation with pathologic features and the value in making surgical plan / 中国肺癌杂志

<p><b>BACKGROUND</b>To study the correlation between CT/MRI features and surgical and pathological findings of cancerous invasion of the main pulmonary artery (CIMPA) in lung cancer and to evaluate the role of CT and MRI in making surgical plan.</p><p><b>METHODS</b>CT findings in 15 cases and MRI findings in 13 cases were observed and blindly compared with surgical and pathological findings in this prospective study of 23 cases of central type lung cancer.</p><p><b>RESULTS</b>The CT and MRI features showed as follows: the wall thickening sign in 73.7% of CT and 84.6% of MRI; lumen narrowing sign in 55.3% of CT and 69.2% of MRI; peri-vascular fat sign in 100.0% of both CT and MRI. Two types of CIMPA were visualized: contacted type (10 cases in CT and 7 cases in MRI) and encased type (5 cases in CT and 6 cases in MRI). Surgically, contacted type was found in 10 cases who all underwent lobectomy with sleeve-angioplasty. Encased type was found in 13 cases, among whom unresectable in 2, pneumonectomy in 7, and lobectomy with angioplasty in 4. Of the 21 resected specimen, the cancerous infiltration was demonstrated 100.0% (21/21) in adventitia, 66.7% (14/21) in media and 4.8% (1/21) in intima. There was no significant difference in the deepness of the cancer infiltration between the two types (P>0.05). Acute or chronic inflammatory infiltration which enhanced the thickening of the wall were shown on all specimens. CT and MRI findings were well corresponding to surgical and pathological appearance (Kappa value = 0.61 in CT and 0.84 in MRI).</p><p><b>CONCLUSIONS</b>In our study of CIMPA, CT and MRI features characterized by wall thickening and lumen narrowing without occlusion are closely correlated with pathological findings that cancerous invasion prominently limited adventitia and media with remarkable proliferation of connective tissue, and classifying two types is valuable in making surgical plan.</p>

Design and optimizing factors of PACS network architecture / 中华放射学杂志

Objective Exploring the design and optimizing factors of picture archiving and communication system (PACS) network architecture. Methods Based on the PACS of shanghai first hospital to performed the measurements and tests on the requirements of network bandwidth and transmitting rate for different PACS functions and procedures respectively in static and dynamic network traffic situation, utilizing the network monitoring tools which built in workstations and provided by Windows NT. Results No obvious difference between switch equipment and HUB when measurements and tests implemented in static situation except router which slow down the rate markedly. In dynamic environment Switch is able to provide higher bandwidth utilizing than HUB and local system scope communication achieved faster transmitting rate than global system. Conclusion The primary optimizing factors of PACS network architecture design include concise network topology and disassemble tremendous global traffic to multiple distributed local scope network communication to reduce the traffic of network backbone. The most important issue is guarantee essential bandwidth for diagnosis procedure of medical imaging.

Benign and Malignant Meningiomas: Differentiation by Using DSC MR Perfusion Imaging / 实用放射学杂志

Objective To evaluate the value of dynamic susceptibility-contrast (DSC) MR perfusion imaging in differentiating benign and malignant meningiomas on the basis of differences in their vascularity in both tumor parenchyma and peritumoral region. Methods 33 patients with pre-operation meningiomas(25 benign and 8 malignant) underwent conventional and DSC MR perfusion imaging. Maximum relative cerebral blood volume (rCBV) and corresponding relative mean transit time (rMTT) values of the same part in both tumor parenchyma and peritumoral region were calculated (compared with contralateral normal white matter). The peritumoral region was defined as the area immediately adjacent (0.05) in parenchyma part and both were statistically significant (t test, ?

The management and realizing of image data flow in PACS / 中华放射学杂志

Objective To explore the management model and realizing of PACS image data flow. Methods Based on the implementing environment and management model of PACS image data flow after full digital reengineering for radiology department in Shanghai First Hospital was completed, analysis on image data flow types, procedure, and achieving pattern were conducted. Results Two kinds of image data flow management were set up for the PACS of Shanghai First Hospital, which included image archiving procedure and image forward procedure. The former was implemented with central management model while the latter was achieved with a program that functionally acted as workflow management running on the central server. Conclusion The image data flow management pattern, as a key factor for PACS, has to be designed and implemented functionally and effectively depending on the performance environment, the tasks and requirements specified to particular user.

The scheme and implementing of workstation configuration for medical imaging information system / 中华放射学杂志

Objective To discuss the scheme and implementing for workstation configuration of medical imaging information system which would be adapted to the practice situation of China. Methods The workstations were logically divided into PACS workstations and RIS workstations, the former applied to three kinds of diagnostic practice: the small matrix images, large matrix images, and high resolution grayscale display application, and the latter consisted of many different models which depended upon the usage and function process. Results A dual screen configuration for image diagnostic workstation integrated the image viewing and reporting procedure physically, while the small matrix images as CT or MR were operated on 17 in (1 in =2.54 cm) color monitors, the conventional X ray diagnostic procedure was implemented based on 21 in color monitors or portrait format grayscale 2 K by 2.5 K monitors. All other RIS workstations not involved in image process were set up with a common PC configuration. Conclusion The essential principle for designing a workstation scheme of medical imaging information system should satisfy the basic requirements of medical image diagnosis and fit into the available investment situation.