Objective To evaluate the value of 3-D reconstruction in multi-detector spiral CT urography (MDCTU) for diagnosing upper urinary tract diseases (UUTDs) by means of both diagnostic sensitivity and ROC curve. Methods A total of 41 patients with UUTD were collected. All of them took MDCTU as well as reconstructions including MPR, MIP and VR. Compared with golden standards, the diagnostic value of MDCTU, MPR, MIP and VR were evaluated using both diagnostic sensitivity and ROC curve. Results a) A total of 49 upper urinary tract lesions were detected in those 41 patients; b) For UUTD, the localization diagnostic sensitivities of MPR, MIP, and VR were 48/49 (98.0%), 27/49 (53.2%), and 19/49 (38.8%), respectively; while their qualitative diagnostic sensitivities were 47/49 (95.9%), 17/49 (34.7%), and 13/49 (26.5%), respectively; the differences between MPR and the others were significantly (Plt;0.05); c) For distinguishing benign from malignant lesions, the Az value (area under ROC curve) of MPR, MIP, and VR were 0.998, 0.736 and 0.669, respectively; the differences between MPR and the others were significant (Plt;0.05); and d) MPR was completely the same as MDCTU in both diagnostic sensitivity and Az value. Conclusion The common 3-D reconstructions in MDCTU were different in value. MPR is highest in the diagnostic efficiency, which is similar to MDCTU, and is regarded as the basis of diagnosis; while MIP and VR are more stereo and intuitive. So it shows that the comprehensive application of CTU 3-D reconstructions has important value for diagnosing UUTD and distinguishing benign from malignant.
Objective To study the clinical significance of multi-slice spiral CT in portal vein imaging. Methods One hundred and thirty seven cases underwent enhanced scan with GE Light SpeedQX/i4 CT scanner were collected, including 41 cases of liver cancer, 20 cases of hepatic cirrhosis, 21 cases of cavernous hemangioma of liver, 9 cases of hepatic abscess, 6 cases of carcinoma of gallbladder, 14 cases of cholangiocarcinoma, 16 cases of pancreatic carcinoma, and 5 cases in normal. The results of portal vein images were reconstructed with three-dimensional software and analyzed. Results In 109 cases, portal vein, cranial mesenteric vein, and splenic vein were demonstrated successfully in the stage of portal vein: volume rendering images were clear in 84 cases, and maximum intensity projection images and multiplanar reconstruction images were clear in 109 cases. Forty-five cases of portal hypertension, 18 cases of opened collateral circulation, 15 cases of portal vein tumor thrombus, 1 case of splenic vein tumor thrombus, and 6 cases of large cavernous hemangioma were demonstrated successfully. Conclusion The portal vein imaging with multi-slice spiral CT can show the dissection and lesions of portal vein and its branches clearly, and can provide the clinical evidence for clinicians to formulate a treatment plan correctly.
Objective To evaluate the application value of spiral CT virtual endoscopy and three dimensional imaging in fiberoptic bronchoscopic balloon dilation in patients with benign tracheobronchial stenosis. Methods Thirty-three cases of benign tracheobronchial stenosis from June 2004 to November 2008 were checked by spiral CT with airway tracheobronchial reconstruction. For the patients with indications, balloon dilatation was performed under fiberoptic bronchoscope. The three-dimensional reconstruction images were compared with the findings under bronchoscopy. And the preoperative and postoperative three-dimensional reconstruction images were compared for airway diameter. Results Three cases were found stenosis of middle lobe by CT virtual endoscopy and did not undergo balloon dilatation. The remaining 30 cases were confirmed by bronchoscopy findings similar to the images by tracheobronchial reconstruction with CT, with consistent rate of 100% . Immediate postoperative three-dimensional CTreconstruction of tracheal bronchus revealed that diameter of stenotic bronchus increased from ( 2. 7 ±1. 3) mm to ( 6. 9 ±1. 6) mmafter operation. Conclusion Multislice spiral CT virtual endoscopy is helpful in fiberoptic bronchoscopic balloon dilation in patients with benign tracheobronchial stenosis and postoperative follow-up.
Objective To investigate the feasibility of establishing the visualization models of intraneural microvessels of sciatic nerves in Sprague Dawley (SD) rats by systemic infusion of Evan’s blue (EB) or lead oxide and to compare the advantages and disadvantages. Methods Fifteen healthy adult SD rats of either gender, weighing 200-250 g, were randomly divided into traditional group (group A, n=5), fluorescence group (group B, n=5), and radiography group (group C, n=5). Ink, EB, and lead oxide, all mixed with gelatin solution, were injected in groups A, B, and C, respectively. After 2 hours of cryopreservation under 4°C, all sciatic nerves were harvested and observed through stereomicroscope to make sure the filling condition. The two-dimentional (2D) images were then collected via reflexion fluorescent microscope in group B and via micro-CT scan in group C. All images were imported into computer to establish three-dimentional (3D) reconstruction models by Mimics 15.0. Results All groups could show the outline of intraneural microvessels of sciatic nerves under stereomicroscope. Diameters of them were measured under fluorescent microscope, ranging from 10 µm to 30 µm. Both groups B and C could establish 3D reconstruction models from 2D images. These models could clearly reproduce the structure of microvessels. Conclusion Both EB and lead oxide can be used to establish 3D reconstruction models to observe structure of the intraneural vessels. However, EB has some disadvantages, such as predisposition to infiltration, grainy 2D images and time-consuming procedure; it is not suitable for researches of large specimen. Though 2D pictures from lead oxide have lower resolution than EB, it is easier to be manipulated and appropriate for experiments of large specimen.
【Abstract】 Objective To evaluate the feasibility and effectiveness of reconstruction of mandibular bone defects using three-dimensional skull model and individualized titanium prosthetics from computer assisted design. Methods Between July 2002 and November 2009, 9 patients with mandibular defects accepted restorative operation using individualized bone prosthetics. Among 9 cases, 4 were male and 5 were female, aged 19-55 years. The causes of mandibulectomy were benign lesions in 8 patients and carcinoma of gingival in 1 patient. Mandibular defects exceeded midline in 2 cases, involved condylar in 4 cases, and was limited in one side without involvement of temporo-mandibular joint in 3 cases. The range of bone defects was 9.0 cm × 2.5 cm-17.0 cm × 2.5 cm. The preoperative spiral CT scan was performed and three-diamensional skull model was obtained. Titanium prosthetics of mandibular defects were designed and fabricated through multi-step procedure of reverse engineering and rapid prototyping. Titanium prosthetics were used for one-stage repair of mandibular bone defects, then two-stage implant denture was performed after 6 months. Results The individualized titanium prosthetics were inserted smoothly with one-stage operative time of 10-23 minutes. All the cases achieved incision healing by first intention and the oblique mandibular movement was corrected. They all got satisfactory face, had satisfactory contour and good occlusion. In two-stage operation, no loosening of the implants was observed and the abutments were in good position with corresponding teeth which were designed ideally before operation. All cases got satisfactory results after 1-9 years of follow-up. At last follow-up, X-ray examinations showed no loosening of implants with symmetry contour. Conclusion Computer assisted design and three-dimensional skull model techniques could accomplish the design and manufacture of individualized prosthetic for the repair of mandibular bone defects.
【Abstract】 Objective To observe the distribution feature of nerve bundles in C7 nerve anterior and posterior division end. Methods The brachial plexus specimen was harvested from 1 fresh adult cadaver. After C7 nerve was confirmed, the distal end of anterior and posterior division was dissected and embedded by OCT. Then the samples were serially horizontally sliced with each 10 μm deep. After acetylcholinesterase (AChE) histochemical staining, the stain characteristics of different nerve fiber bundles were observed and amount of the nerve fiber bundles were counted under optic-microscope. At last, the imaging which were collected were three-dimensional (3-D) reconstructed by using Amira 4.1 software. Results There was no obvious difference in the stain between the anterior and posterior divisions. The running of the nerve fiber bundles were dispersive from proximal end of nerve to distal end of nerve. Nerve fiber bundles of anterior division were mainly sensor nerve fiber bundles, which located in medial side. Nerve fiber bundles of posterior division were mainly moter nerve fiber bundles, having no regularity in the distribution of nerve fiber bundles. The total number of nerve fiber bundles in distal end of anterior division was 7.85 ± 1.04, the number of motor nerve fiber bundles was 2.85 ± 0.36, and the number of sensor nerve fiber bundles was 5.13 ± 1.01. The total number of nerve fiber bundles in distal end of posterior division was 9.79 ± 1.53, the number of motor nerve fiber bundles was 6.00 ± 0.69, and the number of sensor nerve fiber bundles was 3.78 ± 0.94. There were significant differences in the numbers of motor and sensor nerve fiber bundles between anterior and posterior divisions (P lt; 0.05). The microstructure 3-D model was reconstructed based on serial slice through Amira 4.1. The intercross and recombination process of nerves bundles could be observed obviously. The nerve bundle distribution showed cross and combination. Conclusion Nerve fiber bundles of anterior division are mainly sensor nerve fiber bundles and locate in medial side. Nerve fiber bundles of posterior division are mainly motor nerve fiber bundles, which has no regularity in the distribution of nerve fiber bundles. The 3-D reconstruction can display the internal structure feature of the C7 division end.
Objective To study the feasibility of virtual intercondylar notchplasty by applying MRI two-dimensional (2D) images to reconstruct three-dimensional (3D) images and measure the size of intercondylar notch. Methods Thirty healthy volunteers who had no knee joint disease and surgery history were selected. There were 15 females and 15 males with an age range of 20-30 years, weight range of 45-74 kg, and height range of 150-185 cm. They were divided into male group and female group, and the knees of each group were divided into 2 subgroups (the left group and right group). MRI scan of the left and right knees was performed, and the 2D images of MRI were imported into Mimics10.01 medical image control system for 3D reconstruction. The related anatomical data as follows were measured from the 3D digital model and analyzed by statistical software: notch width (NW), condylar width (CW), and notch width index (NWI). Then the 3D knee images of patients with anterior cruciate ligament (ACL) injury were collected between January and March 2010, and 4 patients with narrow intercondylar notch (NWI≤0.2) were selected for reconstructing the 3D model of the knee and simulating the intercondylar notch plasty. Then, the volume of osteotomy in 3D model was calculated and applied in the ACL reconstruction surgery, and whether the graft had impingement with intercondylar notch or not was evaluated. Results There were significant differences in NW and CW between male group and female group (P≤lt;≤0.05), but no significant difference was found in the NWI (P≤gt;≤0.05). And there was no significant difference in NW, CW, and NWI between the left and right knees both in male group and female group (P≤gt;≤0.05). After ACL reconstruction and intercondylar notchplasty, the shape of intercondylar notch became normal (NWI≤gt;≤0.22), no impingement occurred between the graft and intercondylar notch under arthroscopy within 3-month follow-up. Conclusion The shape of intercondylar notch of 3D model based on MRI 2D images is similar to the real intercondylar notch. NWI is one of important indexes which can reflect the narrow level of intercondylar notch. The virtual intercondylar notchplasty may provide preoperative plan and guidence for ACL reconstruction operation to avoid the impingement between graft and intercondylar notch after surgery.
Objective To study digitize design of custom-made radial head prosthesis and to verify its matching precision by the surgery of preoperative three-dimensional (3-D) virtual replacement. Methods Six healthy adult volunteers (3 males and 3 females, aged 25-55 years with an average of 33 years) received slice scan of bilateral elbow by Speed Light 16-slice spiral CT. The CT Dicom data were imported into Mimics 10.0 software individually for 3-D reconstruction image, and the left proximal radial 3-D image was extracted, the mirror of the image was generated and it was split into 2 pieces: the head and the neck. The internal diameter and the length of the radial neck were obtained by Mimics 10.0 software measurement tools. In Geomagic Studio 12 software, the radial head was simulated to cover the cartilage surface (1 mm thickness) and generated to an entity. In UG NX 8.0 software, the stem of prosthesis was designed according to the parameters above and assembled head entity. Each custom-made prosthesis was performed and verified its matching precision by the surgery of preoperative 3-D virtual replacement. Results Comparing the morphology of 6 digitize custom-made prostheses with ipsilateral radial heads by the 3-D virtual surgery, the error was less than 1 mm. The radial head prosthesis design on basis of the contralateral anatomy was verified excellent matching. Conclusion The 3-D virtual surgery test and the digitized custom-made radial head prosthesis will be available for clinical accurate replacement.
Objective To explore the histochemical staining for distinguishing and local izing nerve fibers and fascicles at histological level in three-dimensional reconstruction of peri pheral nerves. Methods The right median nerve was harvested from one fresh cadaver and embedded in OCT compound. The sample was serially horizontally sl iced with 6 μm thickness. All sections were stained with Karnovsky-Roots method (group A, n=30) firstly and then stained with toluidine blue (group B, =28) and Ponceau 2R (group C, n=21) in proper sequence. The results of each step were taken photos (× 100). After successfully stitching, the two-dimensional panorama images were compared, including texture feature, the number and aver gray level of area showing acetylchol inesterase (AchE) activity, and result of auto microscopic medical image segmentation. Results In groups A, B, and C, the number of AchE-positive area was (21.63 ± 4.06)× 102, (20.64 ± 3.51)× 102, and (20.54 ± 5.71)× 102, respectively, showing no significant difference among 3 groups (F=0.64, P=0.54); the mean gray level was (1.41 ± 0.06)× 102, (1.10 ± 0.05)× 102, and (1.14 ± 0.07)× 102, respectively, showing significant differences between group A and groups B and C (P lt; 0.001). In the image of group A, only AchE-positive area was stained; in the image of group B, myelin sheath was obscure; and in the image of group C, axons and myelin sheath could be indentified, the character of nerve fibers could be distinguished clearly and accurately, and the image segmentation of fascicles could be achieved easier than other 2 images. Conclusion The image of Karnovsky-Roots-toluidine blue-Ponceau 2R staining has no effect on the AchE-positive area in the image of Karnovsky-Roots staining and shows better texture feature. This improved histochemical process may provide ideal image for the three-dimensional reconstruction of peri pheral nerves.
Objective To discuss the authenticity of reconstructing the anterior cruciate l igament (ACL) threedimensional digital model of normal adult knee joint by use of MRI. Methods The double knee joint specimens were selected from 20 fresh normal adult corpses and double knee joint of 20 normal adult volunteers, and were scanned with MRI; continuous image data of level thick 1.0 mm were acquired, and then these data were imported into Mimics 10.01 software for three-dimensional reconstruction; and full three-dimensional digital models were built, including the corpse specimens (corpsemodel group) and normal adult (normal model group). The relevance anatomy index of ACL were measured with easuring tool of Mimics 10.01 software, and double knee joint specimens of 20 fresh normal adult corpses were dissected, and the relevance data were measured (corpse specimens group). Results There was no significant difference in all indexes between corpse model group and corpse specimen group (P gt; 0.05), and between corpse model group and normal model group (P gt; 0.05). Conclusion The image data gathered by MRI could reconstruct the ACL three-dimensional digital model of normal adult knee joint, which has authenticity.