Acta Academiae Medicinae Sinica

Objective To compare the accuracy of whole body diffusion weighted magnetic resonance imaging (WB-DWI) with that of somatostatin receptor scintigraphy (SRS) in the detection and localization of the lesions in patients with oncogenic osteomalacia (OOM). Methods Totally 6 patients with clinically suspected oncogenic osteomalacia were enrolled. All of them underwent WB-DWI and SRS within 2 weeks to evaluate the possible presence of tumors that lead to osteomalacia. Surgical and pathological findings were considered as the gold standard. The sensitivity, specificity, and accuracy were calculated. Results Pathology confirmed the diagnosis of two soft tissue tumors (including 1 angiolipoma and 1 mensenchumal tumor) and one bone tumor of malignant neurofibroma. The sensitivity, specificity, and accuracy in the identification of lesions in patients with oncogenic osteomalacia were 33.33%, 100%, 66.67% for WB-DWI and 33.33%, 66.67%, 50% for SRS (P>0.05). Conclusion For adult patients with osteomalacia, WB-DWI and SRS can provide mutually supportive data and be used for identifying potential oncogenic osteomalacia.

Objective To summarize the value and limitations of magnetic resonance (MR) plaque imaging for intracranial arteries. Method The data of MR plaque imaging of intracranial arteries in 422 patients performed in Peking Union Medical College Hospital from December 2006 to September 2010 were analyzed retrospectively. Results The success rate for MR plaque imaging of intracranial arteries was 97%. MR plaque imaging clearly displayed the wall structure of the arteries trunk (M1 segment of middle cerebral arteries, M2-3 segment of anterior cerebral arteries, and basilar arteries). Good inter-observer (k=0.91, 95% CI=0.80-1.03) and intra-observer reproducibility (k=0.96,95% CI=0.88-1.03) was observed in the evaluation of middle cerebral arteries’ atherosclerosis. The wall features had significant difference between symptomatic and asymptomatic intracranial arteries’stenosis; compared with asymptomatic middle cerebral artery stenosis(35 cases), symptomatic middle cerebral artery stenosis(26 cases) had a significantly larger wall area (P=0.000), greater remodeling ratio (P=0.000), higher prevalence of expansive remodeling (outward expansion of the vessel wall) (P=0.003), and lower prevalence of constrictive remodeling (P=0.008). Arteritis of middle cerebral artery (3 cases) showed circular wall-thicking with apparent gadolinium-diethylene triamine pentaacetic acid-biotin enhancement. Conclusion The MR plaque imaging is helpful in the evaluation of intracranial arteries stenosis, although it still has the limitations such as short scan range and low resolution.

Objective To explore the transverse relaxation rate with gradient echo R2^* changes in patients with Parkinsonian variant of multiple system atrophy (MSA-P) with a voxel-based analysis of R2^* map. Methods Whole brain structural images and multi-echo T2^* weighted image were acquired in 27 patients with probable MSA-P and 24 healthy individuals. R2^* maps of the MSA-P were compared with the controls by voxel-based methods. Result Compared with the controls, MSA-P patients showed significant R2^* decrease bilaterally in brain stem, cerebellar hemispheres, insular lobe, temporal lobes, caudate nucleus, and corpus callosum (P<0.005). Conclusions R2^* can reveal the significant brain involvements of MSA-P. The introduction of gradient echo may increase the sensitivity, although the susceptible artifact may interfere the detection efficiency of R2^*.

Objective To investigate the value of magnetic resonance imaging (MRI) in the preoperative assessment of endometrial cancer. Methods Ninety-four patients with histopathologically confirmed endometrial carcinoma were retrospectively enrolled in this study. MRI findings were compared with the pathologic findings in all cases. The depth of myometrial invasion and lymph node metastasis were evaluated by T2 weighted imaging (T2WI) combined with contrast enhancement or diffusion weighted imaging (DWI). Results Among these 94 patients，62 had no or superficial myometrial involvement and 32 cases had deep myometrial involvement. Meanwhile, 24 groups of metastatic lymph nodes and 164 groups of non-metastatic lymph nodes were detected. The accuracy, specificity, sensitivity, negative predictive value, and positive predictive value of T2WI combined with contrast enhancement in discriminating no/superficial myometrial involvement from deep myometrial involvement were 88.3%, 90.3%, 84.4%, 91.8%, and 81.8%, whereas those of T2WI combined with DWI were 81.9%, 87.1%, 71.9%, 85.7%, and 74.2%, respectively. The accuracy, specifi- city, sensitivity, negative predictive value, and positive predictive value of T2WI combined with contrast enhancement in identifying metastatic lymph nodes were 89.4%, 96.8%, 54.5%, 90.9%, and 78.3%, whereas those of T2WI combined with DWI were 91.5%, 95.5%, 72.7%, 94.3%, and 77.4%, respectively. Conclusions T2WI combined with contrast enhancement is superior to T2WI combined with DWI in evaluation of the depth of myometrial invasion. However, DWI is more sensitive in identifying lymph node metastasis than T2WI combined with contrast enhancement.

Objective To evaluate the feasibility of high-field magnetic resonance in measuring the thickness and width of extraocular muscles, calculate the ratio of thickness to width, and summarize the characters of the diameters and its ratio in patients with Gaves’ ophthalmopathy (GO) with upper-lid retraction. Methods Sixteen GO patients with upper-lid retraction (GO group) and 14 healthy control group were enrolled in this study. All the patients underwent enhanced high-field magnetic resonance orbital scan. The thickness and width of extrocular muscles were measured on axial, coronal or oblique sagittal enhanced T1 weighted images. The ratio of thickness to width (R1) and width to thickness (R2) were calculated. The diameters or ratio was evaluated as enlarged when they were 2 standard deviation greater than mean values of extraocular muscle in healthy control. Results The thickness of levator palpebrae superioris, medial rectus, and inferior rectus muscles in GO group were significantly larger than those in the control group (P=0.000, P=0.017, P=0.032, respectively. The width of superior oblique muscles in GO group was significantly larger than that in control group (P=0.000). The R1 values of levator palpebrae superioris, inferior rectus, medial rectus, and lateral rectus muscles in GO group were significant larger than those in the control group (P=0000,P=0.037, P=0019,P=0.032, respectively. The R2 value of superior oblique muscles was significant larger than that in the control group (P=0.027). Aslo in GO group, 32 extraocular muscles showed an increased thickness 47% of thickened extraocular muscles had an increased R1. Conclusions Enhanced orbit imaging with high-field magnetic resonance is helpful in the quantitative assessment of the thickness and width of extraocular muscles. In GO patients, in addition to the levator palpebrae superioris muscles, some other extraocular muscles also becomes thicker. Moreover, the increased diameters of superior oblique muscles is mainly due to the increase of its width R1 and R2 values can reflect the thickness and width of extraocular muscles and their relationship.

Objective To explore the clinical and magnetic resonance imaging (MRI) findings of pituitary hyperplasia due to primary hypothyroidism. Method The clinical presentations, laboratory examinations, and MRI findings of 11 patients with pituitary hyperplasia secondary to primary hypothyroidism diagnosed at our hospitals from the beginning of 2008 to the end of 2011 were retrospectively reviewed. Results The clinical manifestations in 11 patients included growth arrest（7/8), mental retardation （6/8）, cold intolerance and fatigue（6/11）, slightly increased body weight (6/11), galactorrhea (3/11), paramenia (8/9), precocious puberty companying vaginal bleeding (2/2)，and blurry vision (3/11). Laboratory investigations revealed grossly increased thyroid stimulating hormone, decreased thyroxine, and slightly elevated prolactin levels in all cases. Thyroid antibody was positive in six cases. On MRI, pituitary mass were detected a large intrasellar with/without suprasellar extension in all patients，showing the characteristic of symmetric enlargement. Spherical shape was viewed in 5 cases，with the height of （12.22±3.12）mm. In the other 6 cases, the pituitary mass with the shape of calabash extended superiorly to suprasellar area, with a height of（18.95±2.23）mm. The signal of pituitary mass was isointense to grey matter both on T1 weighted imaging and T2 weighted imaging. Bright short T1 signal in posterior lobe of pituitary was visible. Pituitary stalk was detected only in 4 cases from MRI without dislocation, while the width of pituitary stalk was within the normal limit. Conclusions Pituitary hyperplasia should be considered when homogenous enlargement of the pituitary gland is found on MRI. The integration of MRI findings, clinical manifestations, and laboratory findings is helpful for the proper identification of the primary endocrine disease and thus avoid misdiagnosis.

Objective To investigate the feasibility of in vitro and in vivo magnetic resonance imaging (MRI) and fluorescence imaging tracking of transplanted bone mesenchymal stem cells (BMSCs) dual-labeled with ultrasmall superparamagnetic iron oxide (USPIO) and red fluorescence protein (RFP). Methods BMSCs were incubated with culture medium containing USPIO for 24 hours. The Prussian-blue staining, transmission electron microscopy and trypan-blue staining were used to study the efficacy and safety of labeling. F344 rat model of acute myocardial infarction was established by ligating the left anterior descending coronary artery. The dual-labeled BMSCs were injected into the margin of the infraction myocardium. Then MRI and fluorescence imaging were performed to trace the cells both in vitro and in vivo. Postmortal study was carried out to observe the distribution of transplanted cells in myocardium. Results The percentage of dual-labeled BMSCs reached 99% after co-incubating with USPIO for 24 hours. USPIO particles were mainly located in lysosomes. As demonstrated by trypan-blue staining, there was no significant deference in viability between labeled and unlabeled groups (P＞0.05). All dual-labeled transplanted BMSCs showed a significant decreasing signal on MRI, and the signal intensity changes had no significant difference over 4 weeks (P=0.66). In vitro cell tracing with fluorescence imaging of isolated heart from F344 rats was successful，while in vivo cell tracing with fluorescence imaging failed. Prussian blue staining showed that USPIO distributed near the infracted myocardium, corresponding with the fluorescence imaging. Conclusion MRI can be used to trace the dual-labeled BMSCs transplanted into F344 rat hearts in vivo, while fluorescence imaging and pathological fluorescence imaging can trace the transplanted cells in vitro.

Objective To assess the diagnostic value of magnetic resonance imaging (MRI) in the follow-up of patients with hepatocellular carcinomas treated with radiofrequency ablation (RFA) and to compare it with that of computed tomography (CT). Methods From December 2009 to September 2011, 40 patients (47 hepatocellular carcinomas) were treated with RFA after transcatheter arterial chemoembolization and underwent MRI and CT for follow-up. RFA margins were assessed on a five-point scale with receiver operating characteristic curve analysis. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were evaluated. Results The interobserver agreement rate for MRI was significantly higher (Kappa=0.935) than for CT (Kappa=0.714; P < 0.05). The scores of 1 and 5 points for MRI, which confirms the presence or absence of residual tumor, accounted for 89.4% (84/94), while for CT accounting for only 31.9% (30/94). The area under the receiver operating characteristic curve of MRI was significantly higher than that of CT (P < 0.05), as were the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of detection rate (mean, 100%, 96.4%, 76.9%, 100%, and 96.8% for MRI, respectively, vs. 30.0%, 57.1%, 10.3%, 87.7%, and 63.8% for CT). Conclusion MRI is superior to CT in assessing the RFA margins in terms of the diagnostic accuracy and detection rate .

Objective To assess the values of diffusion weighted imaging and contrast-enhanced magnetic resonance imaging (MRI) in the evaluation of early endometrial cancer. Methods We retrospectively analyzed the imaging data of 27 patients with pathologically confirmed stage Ⅰ-Ⅱ endometrial cancer. These patients received pelvic magnetic resonance imaging, diffusion weighted imaging with apparent diffusion coefficient-T2 weighted imaging fusion images(ADC-T2WI), and T1 weighted imaging (T1WI) of contrast-enhanced scan sequence. The accuracies of these image modes were analyzed and compared. Results The accuracy of routine pelvic MRI scan, diffusion weighted imaging with ADC-T2WI fusion images, and T1WI of contrast-enhanced scan for the early diagnosis of endometrial cancer was 66.7%, 85.2%, and 92.5%, respectively. The sensitivity, specificity and diagnostic accuracy of diffusion weighted imaging with ADC-T2WI fusion images in the diagnosis of lesions with a 1/2 depth of muscle were 82.3%, 75%, and 85.2%. Conclusions Routine pelvic MRI scan sequence has certain errors for the early diagnosis of endometrial cancer. On the contrary, the diffusion weighted imaging with ADC-T2WI image fusion has remarkably increased diagnostic accuracy. The T1WI of contrast-enhanced scan can clearly display most of the lesions by identifying the muscular infiltrations, and therefore can provide the most accurate information for the staging of early endometrial cancer.

Objective To evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of lesions in the sellar region. Methods The MRI data of 142 patients with surgically and pathologically proved lesions in the sellar region were retrospectively analyzed. Based on the MRI findings, the lesions were divided into pituitary adenoma and sellar region diseases except pituitary adenoma. According to the pathologic features, the sellar region diseases except pituitary adenoma were further divided into cystic lesions, parenchymatous lesions, and cystic and parenchymatous lesions. Results Of these 142 patients, pituitary adenoma was found in 30 cases, cystic lesions of sella region diseases except pituitary ademoma in 24. Further classification resulted in 66 cases of parenchymatous lesions and 22 cases of cystic and parenchymatous lesions.Conclusion MRI-based classification of lesions in the sellar region is useful for the diagnosis and differential diagnosis.

Objective To explore the changes of different brain metabolites during hepatolenticular degeneration using diffusion weighted magnetic resonance imaging (DWI) and magnetic resonance spectroscopy (MRS) in patients with hepatolenticular degeneration and study the correlation of apparent diffusion coefficient(ADC) values and MRS with the different pathological changes. Methods Totally 53 patients with hepatolenticular degeneration were enrolled in this study and divided into DWI high-signal group (n=31) and DWI low-signal group (n=22). Magnetic resonance scan, DWI, and spectroscopy were performed before treatment and 4 months after treatment. The changes of ADC value, N-acetyl aspartate (NAA)/creatine (Cr) ratio, and choline (Cho)/Cr ratio were recorded. Results Before treatment, the NAA/Cr ratio was significantly higher in the DWI high-signal group than in DWI low-signal group (P=0.002), whereas ADC value and NAA/Cr ratio were significantly lower (P=0.004, P=0.014, respectively). After treatment, the NAA/Cr ratio was still significantly higher in the DWI high-signal group (P=0.036), while the differences of ADC value and Cho/Cr ratio showed no statistical deference (P>0.05). In the DWI high-signal group, the ADC value and NAA/Cr ratio were significantly elevated after treatment (P=0.006, P=0.008), whereas the Cho/Cr ratio showed no significant change (P>0.05). In the DWI low signal group, NAA/Cr ratio was significantly increased after treatment (P=0.015), while the ADC value and Cho/Cr ratio showed no significant change (P>0.05). Conclusions DWI combined MRS imaging can be used to evaluate the microscopic structure and metabolic changes during copper deposition and thus, compared with the conventional magnetic resonance imaging provide more information on metabolism. Therefore, they can be useful tools in the early diagnosis and efficacy evaluation of hepatolenticular degeneration.

Objective To study the correlation between apparent diffusion coefficient (ADC) and Ki-67, a marker of tumor activity, in the diagnosis of gliomas. Methods Conventional magnetic resonance imaging (MRI), enhanced scanning, and diffusion-weighted imaging were performed in 76 patients with pathologically confirmed gliomas. The ADC values were measured at tumor parenchyma and the corresponding contralateral normal brain. The relatively ADC (rADC) values of the tumor parenchyma were calculated. The correlation of the ADC values with tumor grades was analyzed. The expression of Ki-67 was detected by immunohistochemical staining. The correlation between ADC value and Ki-67 in the diagnosis of gliomas was analyzed. Results The ADC values and rADC values of high-grade gliomas were significantly lower than those of low-grade gliomas. The ADC values of tumor parenchyma were inversely associated with the degree of malignancy of the gliomas(r=-0.898, r=-0.868; P<0.01). The expression of Ki-67 was significantly higher in high-grade gliomas than that in low-grade gliomas. The Ki-67 labeling index in grade Ⅲ and Ⅳ gliomas were (29.48±19.78)% and (31.21±17.50)%, respectively. Both of them were significantly higher than Ki-67 labeling index in low-grade (grade Ⅰ and Ⅱ) gliomas [(2.33±2.20)%] (P<0.01). Nevertheless, the Ki-67 labeling index showed no significant difference between grade Ⅲ and Ⅳ gliomas (P>0.05). The expression of Ki-67 was negatively correlated with the ADC values and rADC values in tumor parenchyma （r=-0.627, r=-0.607; P<0.01). Conclusion The ADC and rADC values of tumor parenchyma can indirectly reflect the proliferation and malignancy of gliomas and therefore can be useful for the grading of glioma.

Objective To investigate the association between the genetic variations of six transmembrance protein of prostate 2 (STAMP2) with type 2 diabetes mellitus (T2DM) in Xinjiang Uygur population. Methods A case-control study was conducted based on epidemiological investigation. A total of 1838 Uygur subjects were selected and divided into two groups: T2DM group (n=274) and control group (n=1564). All exons, flanking introns, and the promoter regions of STAMP2 gene were sequenced in 48 Uygur Xinjiang population with diabetes. Representative variations selected were genotyped by TaqMan-PCR method in all individuals. Results Ten noval and 6 known variations in the STAMP2 gene were identified. The distribution of genotype rs8122 significantly differed between T2DM group and control group (P=0.05), whereas the distribution of genotypes rs1981529 and rs34741656 showed no such difference. The fasting insulin in the total cohort and homeostasis model of assessment index in females showed significant difference between these two groups (P<0.05), while the adjusted P value showed no statistical significance (P>0.05). In the male population, the different genotypes of rs8122 variation of STAMP2 gene were not significantly different (P>0.05). Conclusion Three polymorphisms (rs8122, rs1981529 and rs34741656) of STAMP2 gene may be not related with T2DM in Xinjiang Uygur population.

Objective To explore the feasibility and safety of transtracheal assisted sublingual approach to totally endoscopic thyroidectomy by studying the anatomical approach and adjacent structures. Methods A total of 5 embalmed adult cadavers from Chengdu Medical College were dissected layer by layer in the cervical region, pharyngeal region, and mandible region, according to transtracheal assisted sublingual approach that was verified from the anatomical approach and planes. A total of 15 embalmed adult cadavers were dissected by arterial vascular casting technique, imaging scanning technique, and thin layer cryotomy. Then the vessel and anatomical structures of thyroid surgical region were analyzed qualitatively and quantitatively. Three-dimensional visualization of larynx artery was reconstructed by Autodesk 3ds Max 2010(32). Transtracheal assisted sublingual approach for totally endoscopic thyroidectomy was simulated on 5 embalmed adult cadavers.Results The sublingual observed access was located in the middle of sublingual region. The geniohyoid muscle, mylohyoid seam, and submental triangle were divided in turn in the middle to reach the plane under the plastyma muscles. Superficial cervical fascia, anterior body of hyoid bone, and infrahyoid muscles were passed in sequence to reach thyroid gland surgical region. The transtracheal operational access was placed from the cavitas oris propria, isthmus faucium, subepiglottic region, laryngeal pharynx, and intermediate laryngeal cavit, and then passed from the top down in order to reach pars cerviealis tracheae where a sagittal incision was made in the anterior wall of cartilagines tracheales to reach a ascertained surgical region. Conclusion Transtracheal assisted sublingual approach to totally endoscopic thyroidectomy is anatomically feasible and safe and can be useful in thyroid gland surgery.

Objective To explore the effects of different liquid therapies on the intracranial pressure, brain water content, and expressions of aquaporin-4 and N-methyl-D-aspartate-1 in the brain tissue. Methods Two intervention factors including the colloids (two levels: 4% gelofusine; 6% hydroxyethyl starch and sodium chloride injection) and the crystal/gel ratios (two levels: 0∶1; 1∶1) were set based on the results of the analysis of variance of factorial design. Thirty-two patient who had undergone epilepsy surgery were equally and randomly divided into four groups: group A (4% gelofusine, crystal/gel ratio 0∶1); group B (6% hydroxyethyl starch and sodium chloride injection, crystal/gel ratio 0∶1); group C (4% gelofusine, crystal/gel ratio 1∶1); and group D (6% hydroxyethyl starch and sodium chloride injection, crystal/gel ratio 1∶1). The intracranial pressure during operation was recorded. After the operation, the intracranial pressure and brain water content were measured and the expressions of aquaporin-4 and N-methyl-D-aspartate-1 in the brain tissue were determined with Western blot. Glasgow coma scores were obtained 2 hours after operation. Results The intracranial pressure (F=55.714, P=0.000; F=142.432, P=0.000) and the brain water content (F=31.477, P=0.000; F=84.896, P=0.000) significantly increased after the application of the 6% hydroxyethyl starch and sodium chloride injection and crystal/gel ratio 1∶1, and the expressions of aquaporin-4 (F=37.205, P=0.000; F=149.652, P=0.014) and N-methyl-D-aspartate-1(F=29.664, P=0.000; F=65.951, P=0.000) in the brain tissue significantly increased. There were additive effects between two of them (the intracranial pressure: F=11.056, P=0.002; the brain water content: F=8.007, P=0.008; the expression of aquaporin-4: F=9.845, P=0.004; and the expression of N-methyl-D-aspartate-1: F=5.020, P=0.033). However, the Glasgow coma score showed no significant difference after the administration (P>0.05). Conclusion The liquid therapy with 4% gelofusine and crystal/gel ratio 0∶1 can result in better control on the intracranial pressure, brain water content and expressions of aquaporin-4 and N-methyl-D-aspartate-1 in the brain tissue better than the liquid therapy with 6% hydroxyethyl starch and crystal/gel ratio 1∶1 during neurosurgery, although it may not improve the coma status.

With the capability of measuring the water molecular diffusion qualitatively and quantitatively, diffusion weighted imaging (DWI) is currently the optimal and the only magnetic resonance method to observe water molecular diffusion motion in living tissues. Along with the advances in magnetic resonance technology, particularly the development of fast imaging sequences, DWI has been widely used in the imaging of liver, pancreas, kidneys and other solid organs. In recent years, DWI has been applied in the stomach. This article summarizes recent research on the application of DWI for the diagnosis and treatment of gastric cancer.

Magnetic resonance imaging has became the major method for rectal cancer diagnosis. As a novel magnetic resonance functional imaging technique, diffusion-weighted imaging has improved the lesion detection sensitivity and provided more information on changes in body functions. The past two decades have witnessed the increasing application of this technique in clinical practices. This article summarizes the application of diffusion weighted imaging in rectal cancer diagnosis.