Value of 3T magnetic resonance dynamic contrast-enhanced and diffusion-weighted imaging in differential diagnosis of musculoskeletal tumors / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the value of magnetic resonance dynamic contrast-enhanced (MR-DCE) and magnetic resonance diffusion-weighted imaging (MR-DWI) in the differentiation of benign and malignant musculoskeletal tumors.</p><p><b>METHODS</b>Sixty-three patients with pathologically confirmed musculoskeletal tumors were examined with MR-DCE and MR-DWI. Using single shot spin echo planar imaging sequence and different b values of 400, 600, 800 and 1000 s/mm(2), we obtained the apparent diffusion coefficient (ADC) of the lesions. ADC values were measured before and after MR-DCE, with a b value of 600 s/mm(2). The 3D fast acquired multiple phase enhanced fast spoiled gradient recalled echo sequence was obtained for multi-slice of the entire lesion. The time-signal intensity curve (TIC), dynamic contrast-enhanced parameters, maximum slope of increase (MSI), positive enhancement integral, signal enhancement ratio, and time to peak (T(peak)) were also recorded.</p><p><b>RESULTS</b>ADC showed no significant difference between benign and malignant tumors when the b value was 400, 600, 800, or 1000 s/mm(2), and it was not significantly different between benign and malignant tumors in both pre-MR-DCE and post-MR-DCE with b value of 600 s/mm(2). TIC were classified into four types type1 showed rapid progression and gradual drainage; type2 showed rapid progression but had no or slight progression; type 3 showed gradual progression; and type 4 had no or slight progression. Most lesions of type1 or type2 were malignant, whereas most lesions of type 3 or type 4 were benign. When using type1 and type 2 as the standards of malignancy, the diagnostic sensitivity and specificity was 87.23% and 50.00%, respectively. The types of TIC showed significant difference between benign and malignant musculoskeletal tumors(χ(2)=17.009,P=0.001). When using MSI 366.62 ± 174.84 as the standard of malignancy, the diagnostic sensitivity and specificity was 86.78% and 78.67%, respectively. When using T(peak)≤70s as the standard of malignancy, the diagnostic sensitivity and specificity was 82.89%and 85.78%, respectively. Positive enhancement integral and signal enhancement ratio showed no significant difference between benign and malignant musculoskeletal tumors.</p><p><b>CONCLUSIONS</b>TIC, MSI and T(peak) of MR-DCE are valuable in differentiating benign from malignant musculoskeletal tumors. T(peak) has the highest diagnostic specificity, and TIC has the highest diagnostic sensitivity. The mean ADC value are no significant difference between benign and malignant tumors.</p>

Application value of 3T 1H-magnetic resonance spectroscopy in diagnosing tumors of bone and soft tissue / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study benign and malignant bone and soft tissue tumors with 1H-magnetic resonance spectroscopy (1H-MRS) at 3 Tesla MR scanner and assess the value of 1H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors. METHODS; Totally 49 patients with clinically and pathologically confirmed bone and soft tissue tumors were enrolled in this study. 1H-MRS was performed before treatment with point-resolved spectroscopy sequence. The imaging characteristics of 1H-MRS for bone and soft tissue tumors were observed and the possible differences between benign and malignant tumors was compared. Since spectra were directly found under single-voxel proton MRS brain examination, the peak height of choline containing compounds (Cho) opposite to the creatine (Cr) and the Cho peak were observed, and then the malignancies of the tumors were judged. Cho/Cr value was calculated and used to distinguishing benign tumors from malignancies.</p><p><b>RESULTS</b>1H-MRS spectra of bone and soft tissue tumors were different from those of the normal muscles, and such difference also existed between benign and malignant tumors. The Cho peak disappeared or was extremely low among benign tumors. The Cho/Cr values of malignant tumors and benign tumors were 3.13 +/- 0.9 and 1.34 +/- 1.02, respectively (P = 0.02). Using 1.79 as the threshold value, the Cho/Cr value had sensitivity, specificity, and accuracy of 94%, 80%, and 90%, respectively, in diagnosing malignancies.</p><p><b>CONCLUSIONS</b>The increased Cho level, as measured by 1H-MRS, is related with the bone and soft tissue malignant tumor. Cho/Cr value is useful in distinguishing benign tumors from malignancies. 1H-MRS can be an important supplement to the conventional magnetic resonance imaging.</p>

Angiogenesis and its maturation of hepatocellular carcinoma and its correlation with the deoxyhemoglobin parameters R2 * and T2 * values by using noninvasive magnetic resonance imaging / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the angiogenesis and its maturation of hepatocellular carcinoma (HCC) and its correlation with deoxyhemoglobin parameters R2 * and T2 * values and the lesion/muscle R2*, T2 * ratio by using noninvasive magnetic resonance imaging (MRI).</p><p><b>METHODS</b>T2 *, R2 * values and the lesion/muscle R2 *, T2 * ratio in tumor periphery and center were calculated via series T2 * images in a total of 31 patients with surgically and pathologically confirmed HCC. After surgery, all sections were obtained from the specimen periphery in accordance with the MR analyzed areas. Continuous slices of each lesion were stained with hematoxylin-eosin (HE), and immunohistochemical staining was performed in vascular endothelial growth factor (VEGF), Flk-1, proliferating cell nuclear antigen (PCNA), CD34, and alpha smooth muscle actin (SMA). The expressions of VEGF, Flk-1, and PCNA index (PI) were evaluated. According to CD34 and SMA, some vascular parameters, including number, mean vessel area, total vessel area, circumference, diameter, distance between adjacent vessels, and variety index of microvessel and mature vessel, were calculated with a computed analysis system. The amounts of arterioles and veinlets, mature vessel index, and mean perfused fraction (mPF) were also recorded. All vessel parameters were compared with the calculated values of MRI.</p><p><b>RESULTS</b>R2 * value or lesion/muscle R2 * ratio decreased and T2 * value or the lesion/muscle T2 * ratio increased in HCC when compared with hepatic parenchyma (P < 0.05); however, those values between lesion periphery and center and among different pathological grades were not significantly different (P > 0.05). T2 * value and the lesion/muscle T2 * ratio significantly decreased when the expression of VEGF was positive (P < 0.05). T2 * value was negatively correlated with microvessel amount (P = 0.047, r = - 0.639), while T2 * value and the lesion/muscle T2 * ratio were positively correlated with mPF (P = 0.040, r = 0.655; P = 0.048, r = 0.40, respectively). R2 * value was also positively correlated with mean area (P = 0.028, r = 0.688), total area (P = 0.021, r = 0.712) or circumference (P = 0.037, r = 0.663) of microvessel, and negatively correlated with mPF (P = 0.024, r = - 0.702). Meanwhile, the lesion/muscle R2 * ratio was positively correlated with mean area (P = 0.043, r = 0.647) and circumference (P = 0.026, r = 0.694) of microvessels.</p><p><b>CONCLUSION</b>R2 * or T2 * value may be influenced by the variation of deoxyhemoglobin caused by the heterogeneity of angiogenesis.</p>

Changes of 3-tesla 31P-MR spectroscopy of bone and soft tissue tumors / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the characteristic changes of 31P-MR spectroscopy of bone and soft tissue tumors.</p><p><b>METHODS</b>41 patients were examined by phosphorus surface coil of 3 tesla MR machine, including 18 benign tumor foci and 28 malignant foci, and adjacent normal muscles. The areas under the peaks of various metabolites in the spectra were measured, including phosphomonoester (PME), inorganic phosphours (Pi), phosphodiester (PDE), phosphocreatine (Pcr), adenosine triphosphate (ATP) gamma, alpha, beta. The ratios of the metabolites to beta-ATP, NTP and Pcr were calculated. Intracellular pH was calculated according to the chemical shift change of Pi relative to Pcr.</p><p><b>RESULTS</b>The ratios of Pcr/PME and PME/NTP in benign and malignant tumor groups were significantly different from those of the normal group (P<0.05). Between benign and malignant tumor groups, the ratios of PME/beta-ATP and PME/NTP were significantly different (P<0.05).</p><p><b>CONCLUSION</b>Pcr/PME and PME/NTP are potential diagnostic indexes of bone and soft tissue tumors. PME/beta-ATP and PME/NTP are potential indexes of differential diagnosis of bone and soft tissue tumors.</p>

Multi-slice CT angiography in the diagnosis of Takayasu's arteritis / 中华放射学杂志

Objective To evaluate the clinical value of multi-slice CT(MSCT)angiography in the diagnosis of Takayasu's arteritis.Methods Fourteen patients underwent MSCT angiography with use of 90 ml contrast media at a rate of 3.5 ml/s.Images were generated for vascular assessment with various reconstructional techniques,including multi-planar reformat(MPR),maximum intensity projection(MIP), volume rendering(VR),CT virtual endoscopy(CTVE)and advanced vessel analysis(AVA).Results MSCT angiography findings was consistent with the clinical changes of Takayasu's arteritis in all cases.The integrated information including reconstructional and transverse images clearly presented various luminal abnormalities,such as stenosis,occlusion and dilatation in the affected aorta,as well as its major branches and collateral circulation.Furthermore,it depicted mural abnormities,especially concentric arterial wall thickening.Steno-occlusive type(8/14)was more common than mixed type(6/14).According to Lupi- Herrea's classification,type Ⅰ in 5 cases,type Ⅱ in 2,type Ⅲ in 6 and type Ⅳ in 1 were recorded in the present study.Conclusion MSCT angiography is reliable imaging modality for the detection of Takayasu's arteritis.It is useful for early diagnosis because it allows evaluation of wall thickness rather than merely the luminal diameter,which is especially important for prognosis.It might be used as the first choice in the diagnosis of this disease as a simple,convenient and noninvasive method.