ABSTRACT
Objective ToexplorethevalueofMR DKIinevaluationofmicrostructuredamageincervicalspinalcordinjury(CSCI) Methods 32casesofCSCIpatientsconfirmedbyclinicalexaminationand20casesofhealthycontrolgroupwereinvestigatedbyconventional MRIandDKIexamination.AccordingtoT2WIsignal,theinjurygroupweredividedintoA,Bgroup,Agroupofhighsignalgroup(n＝14)andBgroupofnegativegroup (n＝18).A,BgroupsandcontrolgroupweremeasuredbyFA,meandiffusivity(MD)and mean kurtosis(MK)valuesatdifferenttimes (acute,4 weeksafterinjury,2to3 monthsafterinjury)andthedata wereanalyzedby SPSS17.0statisticalsoftware.TheROCcurvewasusedtoevaluatetheabilityofdifferentparametersindiagnosingCSCI.Results In A,BgroupsFAvaluesdecreasedearlyandincreasedgradually,butwerealwayslowerthanthecontrolgroup,andthedifferencewas statisticallysignificant(P＜0.001).InAgroup MDvalueincreasedearlyanddecreasedgradually,butwashigherthanthecontrol group (P＜0.001).InAgroup MKvaluedecreasedearlyandincreasedsignificantly(P＜0.001).InBgroup MDvalueincreasedand MKvaluedecreasedintheacutephase(P＜0.001),lateron MDand MKvaluesgraduallytendtothecontrolgroup,thedifference wasnotstatisticallysignificant(P＞0.05).Conclusion DKIcannoninvasivelyreflectthemicroGdamageofCSCI,whichcannotbedisplayed byconventionalMRIfortheearlydetectionofspinalcordabnormalities.TheFAvalueisofhighdiagnosticvalue.
ABSTRACT
Objective To evaluate the diagnostic value of diffusion tensor imaging(DTI)and diffusion kurtosis imaging(DKI)in marchiafava bignami disease(MBD)of chronic alcoholism.The ROC curve was used to analyze the diagnostic significance of each parameter (FA,ADC and MK values).Methods Sixty-eight patients with chronic alcoholism were enrolled in this study,sixty normal middle-aged people were selected as the control group.The ROC curves of differentparameters in the diagnosis of chronic alcoholism were drawn,after whichthe thresholds were determined to evaluate the clinical significance of FA,ADC and MK values in the diagnosis of the disease.Results The FA and MK values of patients with chronic alcoholism were found to be significantly lower than those of the normal control group(P<0.01).ROC curve analysis showed that the critical values for the FA,ADC and MK parameters were 0.274,5.55 and 0.874,respectively.Conclusion Compared with the ADC and MK parameters,FA parameter has a high clinical significance in the diagnosis of MBD.
ABSTRACT
Objective To explore the diagnostic value of MSCT in solitary fibrous tumor of the pleura(SFTP).Methods The clinical and CT data of 12 patients with SFTP confirmed by pathology were analyzed retrospectively.Results The main clinical symptom and CT findings of 12 patients with SFTP included:chest tightness(n=8),dyspnea(n=6),chest pain(n=5),cough(n=2);round (n=7),irregular(n=5);envelope(n= 6),lobulation(n= 5 );necrosis (n= 9),calcification (n= 3);the diameter was 3 - 22 cm, mean (11.3±2.4)cm;clear boundaries between lesions and lung tissue(n=9),an acute angle between lesions and chest wall(n=7);uneven obviously “map-like”enhancement after injecting contrast medium,which 7 cases of lesions can be seen in the circuitous vasculature and 3 cases was showed mild-moderate enhancement.Conclusion SFTPs have characteristic CT features,contrast enhanced CT play an unique advantage.
ABSTRACT
Objective To detect the atherosclerotic plaque by 64-slice CT angiography and study the correlation between vulnerable plaque and progressive stroke.Methods One hundred and one patients with cerebral ischemic stroke were divided into progressive stroke group (32 cases) and non-progressive stroke group (69 cases) according to the pathogenetic condition.The stenosis degree and vulnerability of artherosclerotic plaques was recorded and analyzed.Results The percentage of severe or occlusion carotid artery stenosis in progressive stroke group was 28.1％(9/32),which was significantly increased compared with that in non-progressive stroke group [8.7％(6/69)],and there was significant difference (P =0.011).The percentage of vulnerable plaque in progressive stroke group was 75.0％ (24/32),which was significantly increased compared with that in non-progressive stroke group [42.0％ (29/69)],and there was significant difference (P =0.002).There was significant difference in the ulcer plaque between two groups among the different type of vulnerable plaques (lipid core,surface irregularities,ulcers plaque) (P =0.016).Multivariate analysis showed that diabetes mellitus (OR =3.327,95％ CI:1.211-9.145) and vulnerable plaque (OR =3.699,95％ CI:1.292-10.589) was related with progressive stroke.Conclusions Vulnerable plaque and diabetes mellitus are the independent risk factors of progressive stroke.64-slice CT angiography can clear display carotid vulnerable plaque,which is important for clinical treatment.
ABSTRACT
BACKGROUND: An effective method to enhance the accuracy and sensitivity of magnetic resonance imaging (MRI) is to select a targeted contrast agent. OBJECTIVE: To prepare gadopentetic acid -polybutylcyanoacrylate nanoparticle (Gd-PBCA-NP) and to investigate its liver-targeted values in animal experiments.DESIGN, TIME AND SETTING: A comparative observation was performed at the Laboratory of Department of RadiologicelCenter, Nanfang Hospital between September 2004 and January 2005. MATERIALS: Gd-PBCA-NPs were prepared by anionic emulsion polymerization. METHODS: A total of 18 Wistar rats were randomly divided into 3 groups, with 6 rats per group: Gd-DTPA, PBCA-NP, and Gd-PBCA-NP. Following caudal venepuncture (catheter remained), rats received 0.1 mmol/kg Gd-DTPA, 10 mL/kg PBCA-NP, or 10 mL/kg Gd-PBCA-NP. MRI scans (coronal and transverse) were performed prior to and after different enhancement protocols using a head coil for transmission and reception of the signal. Immediately after contrast medium injection, dynamic data of each group were acquired at 5, 15, 30, 60, and 120 minutes using imaging parameters the same as for the pre-contrast images. MAIN OUTCOME MEASURES: The morphology of Gd-PBCA-NPs was observed using transmission electron microscope. The size and the index of size distribution were measured through the use of laser granulometer (Malvern-3000HS). The Gd ion concentration in the dialysate was determined by inductively coupled plasma atomic emission spectroscopy for calculation ofencapsulation efficiency and loading capacity of Gd-PBCA-NP. The enhanced rate of the liver at each time point was calculated. RESULTS: The morphology of Gd-PBCA-NPs was spherical shape with core-shell structure and without adherence between particles. The average size of Gd-PBCA-NPs was 65.7 nm, and the index of size distribution was 0.09 measured by dynamic light scattering. The average encapsulation efficiency and loading capacity of Gd-PBCA-NPs were 81.97% and 51.23%, respectively. After intravenous injection of Gd-DTPA, the enhanced rate of the liver was 35.2% and 48.6% at 5 and 15 minutes respectively and the kidney was obviously enhanced; at 30 minutes, the enhancement of the liver recovered to normal level. After intravenous injection of Gd-PBCA-NPs, the average enhanced rate of the liver was 3.4%, 22.7%, 36.1%, 56.4%, and 24.8% at 5, 15, 30, 60, and 120 minutes accordingly. After intravenous injection of PBCA-NP, the enhancement of the liver was not found. CONCLUSION: Gd-PBCA-NPs can be taken as liver-targeted MRI contrast agents and have potential application value in MRI.
ABSTRACT
BACKGROUND:Sensitivity of diagnoses differentiating smaller nodes of splenic metastasis (＜ 1 cm) from CT and MRI is poor. So whether superparamagnetic iron oxide can enhance magnetic resonance imaging (MRI) of splenic VX2 tumor in rats need to be further studied.OBJECTTVE: To establish splenic VX2 tumor models, investigate MRI scanning combining with superparamagnetic iron oxide of specific reticuloendothelial system, and study the diagnostic significance of superparamagnetic iron oxide-enhanced MR images on splenic metastases.DESIGN: Duplicated-measured animal study.SETTING: Medical Imaging Center, Nanfang Hospital of the Southern Medical University.MATERIALS: The experiment was carried out in the Medical Imaging Center (Military Key Laboratory), Nanfang Hospital of the Southern Medical University from May 2005 to March 2006. A total of 25 adult SD rats, of either gender, weighing 200-300 g, were selected in this study. The animal experiment had got confirmed consent from local ethic committee. All rats were randomly divided into tumor group (n =20) and blank control group (n =5).METHODS: Models of VX2 tumor in spleen were established successfully. The images obtained before and after administration of superparamagnetic iron oxide. T1-weighted image(T1WI) (450/12 ms) and T2-weighted image(T2WI)(4 000/128 ms) were used to scan sequences. The imaging parameters of various tissues were analyzed before and after superparamagnetic iron oxide-enhanced MRI scanning. Rats in the blank control group were not used to establish models and the sequences were scanned as the same as those in the experimental group.MAIN OUTCOME MEASURES: Signal characteristics of various tissues before and after before and after superparamagnetic iron oxide-enhanced MRI scanning.RESULTS: Eight out of 20 rats died in the tumor group and other 12 and 5 rats in the control group were involved in the final analysis. MR scanning indicated that 8 rats in the tumor group had splenic VX2 tumor. ① On plain MR scanning T1-weighted splenic VX2 tumor showed hypointensity or isointensity which approximated to the signal intensity (SI) of splenic parenchyma. All lesions had been not displayed well. ② On superparamagnetic iron oxide enhancement T2WI sequence the SI of splenic parachyma decreased obviously with percentage of signal intensity loss (PSIL) was 56.11%,But the SI of tumor was not evidently change with PSlL was 1.90%. Nevertheless the signal-to-noise ratio (SNR) of normal splenic parenchyma around the lesions had obviously difference (P ＜ 0.001) comparatively. So the contrast between tumor and spleen increased, and tumor displayed more clear. Moreover the contrast-to-noise (CNR) between VX2 tumor and splenic parenchyma had an evidently difference with before and after admininstration of superparamagnetic iron oxide (P ＜ 0.001 ).CONCLUSION: On superparamagnetic iron oxide enhancement T1WI sequence the contrast of tumor-to-spleen is poor.So it is not good to characterize the lesions in spleen. On superparamagnetic iron oxide enhanced T2WI the contrast degree of lesions increased obviously. Consequently, superparamagnetic iron oxide-enhanced T2WI MRI scanning can improve the rate of detection and characterization in lesions of spleen.