Objective To study the effects of gantry rotation time on image quality in 64-slice spiral CT. Methods Using the same CT technique and body mode as those used for 64-slice spiral CT, delta phantom was firstly layed on the isocenter, then scanned and reconstructed with SOMATOM Sensation 64-slice spiral CT. Slice sensitivity profile(SSP) was measured from which modulation transfer function (MTF) were got by Fourier transfer. The Catphan500 phantom was layed on the table, then scanned and reconstructed with SOMATOM Sensation 64-slice spiral CT. The maximum linepair and minimum size of the targets visualized. Results The MTF curve was nearly overlapped on 0.5 s and 1.0 s gantry rotation time, the values of 5% MTF were 11.3 LP/cm and 11.9 LP/cm. Their spatial resolution and low contrast resolution were completely identical.Conclusion The image quality is no distinction on 0.5 s group and 1.0 s group of gantry rotation time. In order to shorten the scan time and eliminate the breath defect, we suggest that the 0.5 s gantry rotation time be used routinely at body spiral scan mode.

ObjectiveTostudy the value of color Doppler sonography in diagnosisof rhabdomyolysis.Methods The color Doppler sonography images of twenty-one patients with diagnosed rhabdomyolysis were retrospective analyzed.The pathological changes of the muscle were observed.Results The appearance of ultrasound was cloundness and rough-cast glass change in the diseased area of rhabdomyolysis.The diseased region can be found by ultrasound,and location and scope can be displayed clearly.There were major differences in the location of rhabdomyolysis because of etiological factor.The muscle volume and tension of rhabdomyolysis were increased for trauma,the individual patients will lead to the osteofascial compartment syndrome.There was no blood flow signal or little blood flow signal in the diseased area of rhabdomyolysis.Conclusions The color Doppler sonography is an efficient method for diagnosis of rhabdomyolysis.

Objective To study the value of high frequency sonography in diagnosis of peripheral nerve lipofibroma hamartoma.Methods The high frequency sonography images of seventeen patients with diagnosed peripheral nerve lipofibroma hamartoma were retrospective analyzed.The sonography features were compared with clinical surgery.Results The position and internal structure of nerve can be found by high frequency ultrasound,and which nerve fascicle,location and scope of lipofibroma hamartoma can be displayed clearly.The involved peripheral nerve was showed expansive growth.Because the hyperechoic fat tissue and hypoechoic nerve fibers alternated with one and another,the feature of high frequency sonography was lotus-like,there was no blood flow signal in nerve.Conclusions High frequency sonography is the preferred imaging method for diagnosis of lipofibroma hamartoma.

Objective To study the diagnosis value of giant cell temporal arteritis with high frequency ultrasonography and magnetic resonance imaging.Methods The total of 29 cases testified as giant cell temporal arteritis clinically were assessed by high frequency ultrasonography and magnetic resonance imaging.The 29 cases were assessed by high frequency ultrasonography,the 11 cases were assessed by magnetic resonance imaging,mural thickness and lumen diameter of temporal arteries were examined,and were compared with the biopsy specimens.Meanwhile 30 healthy volunteers were randomly selected as control group,the ultrasonography of normal temporal arteries were analyzed.Results All temporal arteries were diaplayed clearly.27 cases were diagnosed for giant cell temopral arteritis by high frequency ultrasonography in 29 cases,the diagnostic accuracy was 93.1％.The 11 cases were diagnosed by magnetic resonance imaging,the diagnostic accuracy was 100％.The imaging features were mural thickness,the lumen stenosis,and partial temporal arteries occluded,the mural was contrasted by Gd-DTPA.Conclusions High frequency ultrasonography and magnetic resonance imaging are noninvasive methods for giant cell temporal arteritis diagnosis,it is important clinical value for therapy.

Objective To study the clinical value of color Doppler ultrasonography in the persistent sciatic artery.Methods The ultrasonographic images of eleven patients with persistent sciatic artery diagnosed by CT angiography or digital subtraction angiography were retrospective analyzed,the ultrasonographic features were summarized.Results The sciatic artery showed the enlarged internal iliac artery,which continued into the thigh in a posterior location,the sciatic artery described a tortuous course toward the knee,slowly filling normal-appearing popliteal artery in 8 cases,there were no connection with popliteal artery in 1 cases.The common femoral artery and superficial femoral artery was dysplasia in 7 patients,which was thinner than the popliteal artery.Conclusions The ultrasonography is the effective imaging method for diagnosis of the persistent sciatic artery.

Objective To study the clinical value of high frequency ultrasonography in acute closed mallet finger.Methods The high frequency ultrasonographic images of thirty-six patients with diagnosed acute closed mallet finger were retrospective analyzed.The ultrasonographic features were analyzed.Results The position and internal structure of extensor tendon could be showed by high frequency ultrasound,the position and injury level of acute closed mallet finger were identified.In 36 patients of acute closed mallet finger,6 cases were complete tear combined avulsion fracture,the ultrasonography showed the disruption in the extensor tendon at the level of the distal interphalangeal joint,the hyperechoic fracture fragment were found in the distal end of extensor tendon.22 cases were complete tear and no avulsion fracture,the longitudinal imaging showed the disruption in the extensor tendon at the level of the distal interphalangeal joint and the retraction of the tendon end.8 cases were partial tear,the ultrasonography showed that extensor tendons were thickened and hypoechoic,the section of extensor tendons were still continuous.Conclusions High frequency ultrasonography is the preferred imaging method for diagnosis of acute closed mallet finger,it will be important value for clinical treatment method.

Objective To evaluate the value of ultrasonography in diagnosing tendon xanthoma.Methods The ultrasonographic images of 17 patients with tendon xanthomas confirmed by surgery and pathology were retrospectively analyzed.The ultrasonographic features were summarized.Results The ultrasonographic images showed the location,number,size,shape,boundary,internal echo,involvement and blood supply of tendon xanthomas clearly.Tendon xanthomas showed hypoechoic masses within the tendons,mostly located on the extensor aspect of the hands,feet or bilateral Achilles tendons,symmetric growth,irregular-shaped and inhomogeneous,with loss of the normal fibrillar pattern in longitudinal plane.The abundant blood flow inside the tendon can be detected by color Doppler examination.Conclusions High frequency sonography is the preferred imaging method for diagnosis of tendon xanthomas.

Objective To study the diagnosis value of high frequency sonography in nontraumatic upper limb nerve torsion.Methods High frequency sonography images of thirteen patients with diagnosed nontraumatic upper limb nerve torsion were retrospective analyzed.The sonography features were compared with the clinical surgery.Results The position and internal structure of nerve can be found by high frequency ultrasound,and which nerve fascicle,location and scope of nerve torsion can be displayed clearly.The features of high frequency sonography was single or multi-segmental hourglass-like change,the two sides of nerve with hourglass like change was thickened,the echo was low,and perineurium structures in upper limb nerve was blurry.Conclusions High frequency sonography is the preferred imaging method for diagnosis of nontraumatic upper limb nerve torsion.

Objective To explore the optimum voltage for digital chest radiography in adult. Methods PMMAs of Different thickness (7.2, 9.0, 10. 8 and 12. 6 cm) were used to simulate chest of different depth ( 17. 5, 22. 5, 27.0 and 32. 5 cm). The combinants of contrast-detail Cdrad 2.0 phantom and above PMMAs were exposed with automatic exposure control (AEC) and different tube voltages. The images of these combinants were obtained and the entrance surface dose (ESD) was recorded. The imaging quality factor (IQF) was calculated and the curves were drawn between the ESD,IQF and kV. The PMMAs of different thickness, on which a contrast object ( PMAA of 5 cm diameter and 1.8 cm thickness ) was placed, were exposed with the same condition used for above test. Their images were obtained and SNRs were calculated. Results The ESD, SNR and IQFinv of different chest depth decreased with increase of kV.When tube voltages of 70, 100 and 140 kV were used, for 17. 5 cm chest depth, the ESD was 0. 22, 0. 09 and 0. 06 mGy, the IQF was 43.3, 58. 8 and 72. 0, the SNR was 7.5, 6. 2 and 5.0; for 22. 5 cm chest depth, the ESD was 0.37, 0.12 and 0.06 mGy, the IQF was 56. 0, 61.4 and 65.3, the SNR was 6. 4, 5.2 and 3. 8; for 27. 0 cm chest depth, the ESD was 0. 52, 0. 20 and 0. 09 mGy, the IQF was 54. 2, 64. 3 and 91. 0, the SNR was 6. 0, 4. 8 and 3. 5; for 31.5 cm chest depth, the ESD was 0.53, 0.24 and 0. 10 mGy,the IQF was 53.2, 66. 8 and 95.3, the SNR was 5. 7, 4. 5 and 3. 0. Conclusion To balance ESD, SNR and IQF, proper tube voltage should be chosen for chest radiography according to thickness and constitution of patients.

Objective To investigate the morphology and relationships with the adjacent structures in the pineal region on the thin sections and to provide anatomic data for imaging diagnosis and surgical treatment of diseases in this region. Methods By CT and MRI examination, one normal head specimen was selected for this study. Using the computerized freezing milling technique, the specimen was sliced from anterior to posterior. The in vivo MR images were obtained from ten normal Chinese male adult volunteers using a 3.0 T GE scanner. The base lines of the sectioning and the MR scan were perpendicular to the AC-PC line. Then primary sections were contrasted with the corresponding MR images. Results By the appearance of the pineal peduncle and the disappearance of the pineal gland, the pineal region could be divided into three parts from anterior to posterior, and the shape changed from an inverted triangle to a trapezoid and a triangle gradually. The first interspace was getting wider in the anterior and middle parts of the pineal region, while in the posterior part of the pineal region, it was getting narrower and disappeared finally. From anterior to posterior, the bilateral internal cerebral veins were always in the midline of the pineal region and descended gradually.Conclusion By the computerized freezing milling technique, the anatomic details and adjacent relationships of the pineal region could be exhibited clearly in the thin serial sections, which could help the imaging diagnosis and surgical treatments for minute diseases in this region.