Objective To explore the characteristics of changes in temperature and stiffness within the microwave-induced ablation region.Methods A type of Thy-ablation microwave antenna was used upon a design of various combination of ablation duration and power to induce heated region in samples of fresh porcine liver.Three special sites were set to assess the corresponding temperature and stiffness in each heated region.The temperature was continuously measured by using electronic thermometer with microwave on going,while stiffness was determined 5min after the ending of ablation by using real-time ultrasonic elastography,strain ratio,a quantitative indicator.Results The SR values and temperature determinations decreased progressively from the central to the peripheral area of the heated region.There was a linear regression between the temperatures (X) and SRs (Y),with Y =0.666 X-37.17.A significant correlation exists between X and Y,with the correlation coefficient being 0.956(P ＜0.001).The stiffness and temperature at the central sites are variable with the changes of both ablation time and power,but little changed at the peripheral sites of heated-region,which we name a phenomenon due to the ending effect of microwave propagation.Conclusions Temperature and stiffness increase considerably following microwave radiation but they are heterogeneously distributed within the ablated region in porcine liver.The characteristic gradient changes are confirmed of both temperature and the elasticity.It is presumable that good recognition and understanding and full utilization of these characteristics are conducive to reasonable control of tumor microwave ablation therapy.

Objective To make a comparative assessment on both the therapeutic effects and side effects between percutaenous lauromacrogol injection therapy(PLIT) and percutaenous ethanol injection therapy(PEIT) for simple hepatic or renal cyst.Methods In group A,55 patients with simple hepatic or renal cysts underwent ultrasound-guided aspiration and successive PLIT.The intra-operative side effects were investigated and the therapeutic effects assessment by using ultrasonography was conducted 3 months after the treatment.In group B,60 patients with simple hepatic or renal cysts had received ultrasound-guided aspiration and PEIT sometime before.The intra-operative side effects and therapeutic effects on the thirdmonth ultrasonography were independently reviewed according to their case records.Results In group A,3 patients(5.5 ％) expressed slight discomfort but not pain while receiving lauromacrogol injection.Follow-up ultrasound examination at the end of third month demonstrated the cysts in 43 patients completely regressed,while cysts in rest 12 patients shrank over 50 ％ in size,showing the overall response rate(ORR) and completely cure rate(CCR) were 100％ (55/55) and 78.2％ (43/55) for PLIT respectively.In group B,12 patients(20％) suffered from slight to moderate irritating pain or drunk performance.The third-month ultrasound examination disclosed that cysts in 47 patients completely vanished,and cysts in the other 13patients shrank more than a half,indicating the ORR and CCR were 100％ (60/60) and 78.3 ％ (47/60) for PEIT respectively.Conclusions Although their therapeutic efficacy are perfectly similar,PLIT is much more superior to PEIT in term of less and minor side effects.

Objective To evaluate the clinical,neuroimaging and electrophysiology features of 62 patients with multiple system atrophy(MSA).Methods Sixty-two cases with diagnosis of probable MSA were recruited in a retrospective studied.Clinical,neuroimage and external anal sphincter electromyography (EAS-EMG)data was retrospectively analyzed.Results In 62 cases(44 male and 18 female),the onset age was between 37 and 76.Among them,29 cases(46.8 % )were MSA-A,with orthostatie hypotension as the main clinical manifestation;24 cases(38.7 % )were MSA-C,with cerebellar ataxia ag the main chnical manifestation;9 cases(14.5 % )were MSA-P,with extrapyramidal symptoms as the main clinical manifestation.MRI showed that main lesion of MSA-A was in the cerebellum:that of MSA-C was in the cerebellum,pons and medulla;and that of MSA-P was in the putamen.Fifty-one cases did EAS-EMG and 46 cases showed neurogenie impairments.Nineteen cases were initially misdiagnosed with other diseases.Conclusions MSA is easy to be omitted or misdiagnosed at early stage.The diagnostie rate of MSA can be increased by the combination of clinical expressions,neuroimage,EAS-EMG and other necessary examinations.

Objective To investigate the elasticity reduction of liver tissue due to microwave ablation and the relevance to the histographic damages. Methods An experimental study using fresh porcine liver was designed. Elasto-ultrasonography scanning both in color display and strain ratio calculations was conducted before and 5 min after microwave ablation ( 2450 MHz) in manner of antenna insertion under ultrasound guidance to determine the alterations of the liver elasticity, in correspondence with the histopathologic assessment of each ROI. Results Elasto-ultrasonography showed a significant elasticity reduction and hardness augment of the targeted liver tissue and the corresponding histopathology revealed increases in the amount of massive coagulative necrosis and coking of liver cells after microwave irradiation,in proportional to the applied field power and working time. Conclusions Elasto-ultrasonography helps to demonstrate microwave-induced lesion in porcine liver got rapidly hardened. It is possible to estimate the tissue necrosis to the changing of tissue hardening.

Objective To investigate the ultrasonic and pathological features of porcine striped muscle injury from thermal and chemical factors respectively, and to analyze the limitation of ultrasound diagnosis given by doctors with different skill levels. Methods An experimental study using fresh porcine striped muscle in vitro was designed, where the injury were caused by microwave ablation (2 450 MHz) and Anhydrous acetic acid (99.8%) injection separately. Blind to pathologic results, the two-dimensiona sonograms taken from each model were analyzed by sonographers with different skill levels independently. Finally, the diagnoses were evaluated and compared among them. Results Two-dimensional sonograms showed distinct changes of the textures in both injury models, which was characterized as the disappearance of regular tissue structure. However, the corresponding histopathology revealed obvious differences between the two interventions on ultrasonograms. There was no statistical difference between chief physician and attending doctor (both of them had over 5-year experiences on skeletal muscle ultrasound ) in identifying the ultrasonic features of boundary, shape and muscle texture (Kappa=0.933, 0.845, 0.789;Kappa=0.790, 0.935, 0.865, all P<0.05). Compared with residents′diagnosis, there were signiifcant differences in identifying the ultrasonic features of echo level and muscle texture in both injury models:Echo level in thermal injury group:chief physician vs residents, Kappa=0.323;attending doctor vs residents, Kappa=0.297. Texture feature in thermal injury group:chief physician vs residents, Kappa=0.259;attending doctor vs residents, Kappa=0.112. Texture feature in chemical injury group:chief physician vsresidents, Kappa=0.253;attending doctor vs residents, Kappa=0.070. Conclusions Microwave ablation and Anhydrous acetic acid can cause different histopathologic changes in correspondence with various features on two-dimensional sonograms. But ultrasonographers with different skill levels leads to signiifcant variations in identiifcation and qualitative diagnosis, which is impossible to be quantitatively analyzed. Chief physician and attending doctor can draw a consistent conclusion and demonstrate the ultrasounic characteristics in porcine striped muscle injury model from thermal or chemical factors.

Objective To analyze the clinical,imaging and pathological features of cortical vein thrombosis (CoVT). Methods Ten patients with CoVT (4 patients with CoVT alone and 6 patients with CoVT and venous sinus thrombosis)treated at Navy General Hospital from January 2006 to Jun 2013 were collected retrospectively.Its etiology,imaging,and pathological features of brain tissue in 3 patients were analyzed. Results Of the 10 patients with CoVT,3 were female and 7 were male.Their mean age was 31 ± 15 years old.(1)Brain CT scan and MRI showed hemorrhagic cerebral infarction,and contrast-enhanced MRI showed scattered heterogeneous enhancement within lesions. DSA could find CoVT at different parts.(2)3 patients underwent brain biopsy because they were initially diagnosed as brain tumor. Pathological examination showed glial cell,endothelial proliferation and phagocytic reaction.Scattered spotty bleeding was observed,and significant expansion of small veins,A few of them had blood stasis and thrombosis. Conclusion CoVT is one kind of intracranial venous thrombosis. It is more common occurred in young and middle aged adults,and most of them were venous sinus thrombosis.It is caused by retrograde thrombosis and spread to cortical veins.CoVT is easily to be misdiagnosed as brain tumor.Combination of clinical and imaging findings is needed for accurate diagnosis.

Objective To increase the awareness of autoimmune pancreatitis (AIP) and correct diagnosis rate of AIP by investigating radiologic characteristic of AIP and small pancreatic cancers.Methods The clinical data and radiologic imaging of 24 AIP patients who met the Asia diagnostic criteria of AIP in 2008 and 25 cases of pathologically condirmed small pancreatic cancer were retrospectively reviewed.All imaging findings were reviewed,especially on the shape,enhancement patterns of mass,pancreatic ducts,peripancreatic and extra-pancreatic manifestations. Chi-square test and Fisher test were used for statistical analysis.ResultsThe imaging signs,including location of masses,distal pancreatic atrophy,enhancing mass during portal phase,truncated duct sign of pancreatic duct,capsule-like rim and renal involvement,was significantly different between AIP and small pancreatic cancer ( x2 =9.010,10.506,15.488,8.688,6.292 and 4.966 respectively,P ＜0.05 ).But only two signs,distal pancreatic atrophy and enhancing mass during arterial and portal phase,were statistically different between local AIP and small pancreatic cancer (P ＜0.05).ConclusionsThe typical imaging features of diffuse AIP is distinct and helpful for the differential diagnosis of AIP from small pancreatic carcinoma,but there is limited value in the differential diagnosis between local AIP and small pancreatic cancer.

Objective To explore the value of brain CT scanning for distinguishing tumor-like inflammatory demyelinating diseases (TIDD) from glioma or primary central nervous system lymphoma.Methods The brain CT features in 20 patients with TIDD(10 female,10 male;mean age (35.6±14.0)years;range,6-51 years)and 32 gliomas(16 female,16 male;mean age(42.0±19.8)years;range,12-75 years)and 6 lymphomas(3 female,3 male;mean age(53.8±11.8)years;range,32-68 years)were retrospectively reviewed and compared between brain tumors and TIDD.Results (1)Among the 38 primary brain tumors,there were 19 cases(50%,14 gliomas,5 lymphomas)with hyperdense lesions,10 cases(26.3%,9 gliomas,1 lymphomas)with isodense lesions,and 9 glionms (23.7%)with hypodense lesions.In contrast,the brain unenhanced CT manifestation of 20 TIDD all showed with hypodense lesions.(2)On unenhanced CT the lesions of 6 lymphomas all were hyperdense or isodense,like 90% of 20 high grade gliomas(WHO grade Ⅲ and Ⅳ),but this rate for grade Ⅱ was only 41.7%.(3)According to the shape of hyperdense lesions of the 19 primary brain tumors with,7 cages(6 gliomas,1 lymphomas)manifested with asymmetric hyperdense small-patches,4 cases(1 gliomas,3 lymphomas)with symmetric hyperdense large-patches,4 cases(3 gliomas,1 lymphomas)with diffused hyperdensed lesions,and 4 cases(4 gliomas)with ring-shaped hyperdensed lesions.Furthermore,4 primary brain tumors(4 lymphomas)underwent CT enhanced scanning and all the cases showed strong enhancement(3 cases with hyperdense lesions and 1 with isodense lesions on unenhanced CT),but only 3 cases of 7 TIDD showed mild enhancement in contrast.(4)By Spearman's relevant analysis,hyperdense and isodense on unenhanced CT was proved to have significant positive correlation between the grade of gliomas(r=0.435,P=0.013).Therefore,the frequency of hyperdense and isodense lesions in lymphomas and WHO grade Ⅲ and Ⅳ astrocytoma was higher in contrast with low grade astrocytoma.Conclusions Brain CT as a simple,economical and practical examination method has significant meaning for differentiating TIDD from glioma or PCNSL and could be used as an adjuvant method for MRI and magnetic resonance spectroscopy.Patients with hyperdense or isodense on unenhanced CT or strong enhancement could be excluded from TIDD.

Objective To summarize the clinical features, neuroimaging findings and pathological characteristics of 26 patients with tumor-like inflammatory demyelinating diseases (TIDD) confirmed by histopathology for better diagnosis and differential diagnosis. Methods The clinical features, neuroimaging findings and pathological characteristics of 26 patients (14 male, 12 female) with pathologically proven TIDD(24 brain-type and 2 spinal cord-type ) were retrospectively analysed. Results The mean onset age was 6-69 (36.7±13.8) years. Twenty-one patients had good prognosis with a median followed-up duration of 51.0 months. Two patients were died of post-operative complication and pulmonary infection respectively and the remaining 3 patients were lost to followed up. The TIDD patients almost showed monophasic clinical setting. Headache, indifference accompanied with hypomnesis were the commonest initial symptoms. The positive or abnormol rates of cerebrospinal fluid oligoclonal bands (OCB) and myelin basic protein (MBP)in TIDD patients were high. The involvements of bilateral and multi-lesions were commonest in TIDD (61.5%, 65.4% respectively). Twenty-two patients with CT unenhanced scanning showed hypodense lesions. Long T1 and long T2 signal intensity was showed on MRI and most cases apeared round-like lesion in shape. Acccording to the shape of enhancement of the 23 patients performed with contrast agents, 11 were shown with open-ring enhancement, 4 cases (including 2 accompanied with open-ring enhancement) with complete ring enhancement, 3 with asymmetrical dotted enhancement, 2 with diffused even enhancement,and no enhancement was seen in the other 6. Furthermore, 14 cases with DWI and 12 with FLAIR all appeared hyperdensity. The typical pathological changes were demyelinating, perivascular inflammatory cells infiltration and reactive gliosis. Occationally, the Creutzfeuldt cells were also found in brain tissue of some patients. Conclusions TIDD is a distinct demyelinating disease entity. In spite of being apt to be confused with the neoplasm in brain and spinal cord. TIDD has its own-features, for example, OCB is frequently positive in patients with TIDD and the level of MBP may be significantly increased. Furthermore, the involvements of bilateral and multi-lesions are the common in TIDD, and most cases showed open-ring enhancement or complete rim enhancement on MRI. In addition, all cases present hypodense lesions on unenhanced CT and patients with hyperdense seemed not to be considered as TIDD.

BACKGROUND: Recently, trans-pedicle screw internal fixation has markedly improved the rigidity of spinal fixation and hence the fusion rate. But when placed incorrectly, the pedicle screw can injure the spinal cord and/or nerve roots, resulting in serious complications.OBJECTIVE: To evaluate the application value of preoperative CT scans-based navigation technique in the spinal pedicle screw internal fixation surgery.DESIGN, TINE AND SETTING: A prospective, randomized, and controlled observation was performed at the Department of Orthopedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences between January 2006 and December 2008.PARTICIPANTS: A total of 95 patients who underwent pedicle screw internal fixation due to spine diseases were randomly assigned to a navigation group (n = 45) and a conventional group (n = 50).METHODS: In the navigation group, patients were subjected to pedicle screw insertion with the assistance of computer navigation technique and while in the conventional group, patients underwent pedicle screw insertion using the conventional anatomic landmark combined with fluoroscopy.MAIN OUTCOME MEASURES: Screw channel preparation time, excellent and good rate of screw position, and postoperative complications.RESULTS: In the navigation group, totally 206 pedicle screws were inserted under navigation guidance, with an excellent and good rate of 96.1%; and navigation could not be continued in 9 patients for a three-dimensional registration error. In the conventional group, altogether 285 pedicle screws were inserted, and the excellent and good rate was 100%. No significant difference was found between the two groups (P > 0.05). The navigation group exhibited longer screw channel preparation time than the conventional group [(360±22) seconds vs. (56+8) seconds, P < 0.01]. No postoperative complications were found in each group.CONCLUSION: The preoperative CT scans-based navigation technique produces similar accuracy of pedicle screw insertion, but markedly prolonged operation time, compared with the conventional anatomic landmarks, exhibiting limited application value in the spinal pedicle screw internal fixation.