MRI-based radiomic features in histological grading of breast invasive ductal carcinoma / 医学研究生学报

Objective The histological grade of breast cancer is closely related with the treatment and prognosis of the malignancy, and radiomics plays a valuable role in the identification of its grade. This article aimed to investigate the values of the conventional parameters of breast MRI and breast MRI-based imaging features in the histological grading of breast invasive ductal carcinoma (IDC).Methods This retrospective study included 71 cases of breast cancer treated in our hospital from June 2015 to June 2016. We obtained the traditional quantitative parameters of MRI, including the apparent diffusion coefficient (ADC) and initial enhancement rate (IER), performed manual segmentation of the ADC and DCE maps, extracted the radiomic features and analyzed the differences in the radiomic signatures between low- and high-grade IDC. Using logistic regression analysis, we assessed the values of ADC and IER and the radiomic signatures of the ADC and DCE images in differentiating low-grade from high-grade IDC.Results The values of ADC, B_sum_variance, L_SRE and R_RP were significantly lower (P0.05). In differentiating high-grade from low-grade IDC, the ADC image-based radiomic signature model achieved a significantly higher AUC (0.858 [0.774-0.924]) than the ADC (0.709 [0.588-0.830]) and DCE model (0.691 [0.565-0.818]), and the former also manifested markedly higher accuracy, specificity, and rates of positive and negative prediction than the latter two.Conclusion ADC- and MRI-based radiomic features play a valuable role in differentiating high-grade from low-grade IDC, particularly the former, which could provide even more clinical information, while IER is of little value in this aspect.

Value of mamography, CT and DCE-MRI in detecting axillary lymph node metastasis of breast cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the diagnostic value of mammography, computed tomography (CT), and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for axillary lymph node staging in breast cancer patients.</p><p><b>METHODS</b>From February, 2014 to October, 2015, 109 women with breast cancer received examinations with preoperative mamography, CT, and DCE-MRI. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the 3 modalities were evaluated using histopathologic assessments as the gold standard.</p><p><b>RESULTS</b>In total, 39.4% (43/109) of the patients had axillary lymph node metastasis. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of mamography for determining lymph node metastasis were 14.0%, 84.8%, 56.9%, 37.5% and 60.0%, respectively; those of CT were 93.0%, 57.6%, 71.6%,58.8% and 92.7%, and those of DCE-MRI were 95.3%, 65.2%, 77.1%, 64.1% and 95.6%, respectively. Compared with the histopathologic result, the Kappa coefficients of mamography, CT, and DCE-MRI were -0.13, 0.459 and 0.558, respectively. The specificity of mamography was significantly higher (P<0.05), but its sensitivity, accuracy, positive predictive value, and negative predictive value were significantly lower than those of CT and DCE-MRI (P<0.05). Compared with CT, DCE-MRI had significantly higher sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for diagnosis of lymph node metastasis (P<0.05).</p><p><b>CONCLUSION</b>DCE-MRI has a greater diagnostic power than CT and mammography, and CT has a greater diagnostic power than mammography for axillary lymph node metastasis in breast cancer patients. Mamography alone should be used cautiously for the diagnosis of lymph node metastasis.</p>

Pleomorphic xanthoastrocytoma in the lateral ventricle with extensive subarachnoid dissemination: report of a case and review of the literature / 中华医学杂志(英文版)

Pleomorphic xanthoastrocytoma (PXA) is a rare benign tumor that is usually located in the superficial cerebral hemisphere. Most reports of PXAs have included only a single case or small series. Therefore, the data with respect to the natural history of this tumor are fragmentary. We report a case of a PXA in the unusual location of the right lateral ventricle with extensive subarachnoid dissemination. To our knowledge, this is a rare case of PXA in the lateral ventricle. In addition, extensive subarachnoid space dissemination of this distinctly benign type of glioma is exceedingly rare. In our case, there was meningeal dissemination and metastases to the bilateral trigeminal nerves and oculomotor nerves. The neuroradiographic features, tumor location, and dissemination were reviewed.

Experimental study on monitoring gene expression by noninvasive method in rabbit VX2 liver tumor model / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of monitoring therapeutic effect of adenovirus vector containing IL12-IRES-CKb gene on a rabbit VX2 liver tumor model by using phosphorous-31 magnetic resonance spectroscopy (31P MRS).</p><p><b>METHODS</b>A total of 18 healthy New Zealand White rabbits were used to generate animal models by implanting VX2 tumor chips into livers through laparotomy. Tumor-bearing animals were randomly divided into three groups and were injected with AdCMVIL12-IRES-CKb, AdCMV-Empty and saline respectively via ear veins. 31P MRS scan was performed after animals were fed with creatine solution for five days. Animals were euthanized thereafter and tumors were removed for pathological examination, immunohistochemistry (IHC) staining and protein analysis (Western blot).</p><p><b>RESULTS</b>The intrahepatic and seral expressions of creatine kinase (CKb) and IL-12 were detected only in AdCMVIL12-IRES-CKb group. Tumor diameters pre- and post- treatment in three groups were 1.63+/-0.04 vs 1.62+/-0.03 in AdCMVIL12-IRES-CKb group (P = 0.229), 1.59+/-0.05 vs 1.84+/-0.11 in AdCMV-Empty group (P = 0.003) and 1.60+/-0.02 vs 2.07+/-0.12 in saline group (P = 0.001), respectively. Pcr Changes between pre- and post- treatment among the three groups were compared (F = 6.235, P value is less than 0.05). PCr increased significantly in AdCMVIL12-IRES-CKb group as compared to AdCMV-Empty (P = 0.004) and saline group (P = 0.049), whereas no change found between AdCMV-Empty and saline group (P = 0.153).</p><p><b>CONCLUSION</b>31P MRS, an effective and non-invasive functional imaging method, can be used to monitor the therapeutic effect of adenovirus vector containing IL12-IRES-CKb gene on rabbit VX2 liver tumor model through detecting metabolic product of imaging reporter gene CKb (pCr).</p>

18F-FDG PET/CT in diagnosis of malignant pericardial lesions / 中华核医学杂志

Objective To assess the value of integrated 18 F-fluorodeoxyglucose (FDG) PET/CT in differentiation of malignant and benign pericardial effusion. Methods 18F-FDG PET/CT were performed in 23 patients with pericardial effusion. The detected soft tissue tumor or nodulous lession in pericardium or the thickened pericardium, with the maximum standardized uptake value( SUVmax ) ≥2.5, was defined as PET/CT-positive. The invaded lession in pericardium with SUVmax ≥2.5 was also as the positive. The difference of SUVmax of benign and malignant lesions was analyzed with two-independent-sample test of nonparametric tests. The final diagnosis was confirmed by biopsy or post-operative pathology. Results The diagnosis were confirmed with 14 malignant and 9 benign lesions. The median of SUVmax was 6.0 in malignancy group and 2.2 in benign group (z= -3. 279, P =0.001 ). According to the pathology results, there were one false negative case and two false positive cases with PET/CT imaging interpretation. The sensitivity, specificity,accuracy, positive predictive value ( PPV ) and negative predictive value ( NPV ) of 18 F-FDG PET/CT in diagnosis of benignity or malignance of pericardium effusion were 92.9% ( 13/14), 7/9, 87.0% (20/23),86.7% (13/15) and 7/8, respectively. Conclusion For the patients with pericardium effusion 18F-FDG PET/CT may be a helpful modality for malignancy differentiation

Computed tomography and magnetic resonance imaging features of desmoid-type fibromatosis: comparison with the pathological findings / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the computed tomography (CT) and magnetic resonance imaging (MRI) features of desmoid-type fibromatosis, and improve the diagnostic accuracy and understanding of the disease.</p><p><b>METHODS</b>The CT and MRI features of 18 cases of surgically and pathologically confirmed desmoid-type fibromatosis were reviewed retrospectively. Among the patients, 10 received CT pre- and post-contrast scanning, and 8 patients had MRI pre- and post-contrast scanning. The CT and MRI features were analyzed in comparison with the pathological findings.</p><p><b>RESULTS</b>In the extra abdominal cases, the tumors occurred in the head and neck in 3, in the dorsal part of the chest in 2, in the abdominal wall and groin area in 9, and in the peritoneal cavity in 4; concomitant Gardner syndrome was found in 1 case. In 4 cases the tumor occurred within 1 to 3 years after abdominal surgeries. Pathologically, the lesion was hard and composed of fusiform fibroblasts and myofibroblast. The cells showed no obvious heteromorphism with few karyokinesis, growing invasively and recurrent locally but without distant metastasis. Immunohistochemically, the fibroblasts and myofibroblasts expressed vimentin, and the myofibroblasts were positive for SMA. On CT and MRI, the lesion appeared benign with malignant growth pattern, and caused compression of the adjacent organs and vessels or encasement of the vessels; the border was unclear without encapsulation, and necrosis and calcification was scarce. The density and signal of the tumor were well distributed. Twelve patients displayed obvious enhancement and 5 showed uneven enhancement.</p><p><b>CONCLUSION</b>The CT and MRI features of desmoid-type fibromatosis are characteristic, and CT and MRI are valuable modalities for the diagnosis and differential diagnosis of the tumor.</p>

A comparative study of diffusion-weighted magnetic resonance imaging and pathological findings of liver fibrosis in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the alteration of apparent diffusion coefficient (ADC) in diffusion-weighted MR imaging (MR-DWI) of liver fibrosis and its pathological basis in rabbits.</p><p><b>METHODS</b>Five rabbits in the control group and 22 with experimental liver fibrosis induced by transperitoneal injection of carbon tetrachloride (CCl4) were examined with MR-DWI. Diffusion-weighted SE EPI sequence with a relatively high b factor (b=600 s/mm2) was used to measure the ADC. The mean values of ADC were compared among the rabbits in different stages of liver fibrosis and analyzed in relation to the pathological findings.</p><p><b>RESULTS</b>The mean ADC value decreased significantly with increased severity of liver fibrosis (P<0.05). Pathologically, the amount and extension of fibrotic matrix increased, and the hepatic necroinflammation worsened with the progression of the liver fibrosis.</p><p><b>CONCLUSION</b>The ADC value decreases with the progression of liver fibrosis possibly as the result of water diffusion limitation due to increased fibrous tissue in the liver and abnormal water diffusion within the intracellular and extracellular spaces.</p>

Detection and its clinical value of myocardial bridging with 64-slice spiral CT coronary angiography / 南方医科大学学报

<p><b>UNLABELLED</b>To evaluate the detection rate of myocardial bridging by 64-slice spiral CT coronary angiography.</p><p><b>METHODS</b>The data of 3011 patients with suspected coronary artery disease undergoing 64-slice spiral CT coronary angiography were collected and analyzed retrospectively.</p><p><b>RESULTS</b>A total of 174 cases (5.8%) with myocardial bridging were detected by 64-slice spiral CT coronary angiography, among which 168 (96.6%) had single foci of involvement and 6 (3.4%) had were multiple foci. Involvement of the left anterior descending coronary artery (LAD) was detected in 167 out of the 174 cases (96.0%). The length of the myocardial bridge varied between 5 and 120 mm (mean of 30.5 mm), and the depth of the tunneled artery ranged between 1.3 and 2.8 mm (mean 2.3 mm). Seventy-nine of the cases (45.4%) had uncomplicated myocardial bridging and 95 (54.6%) had myocardial bridging complicated by coronary atherosclerosis.</p><p><b>CONCLUSION</b>Multi-slice spiral CT coronary angiography is a reliable and noninvasive modality for diagnosis of myocardial bridging to allow direct measurement of the length and depth of the myocardial bridge and detection of concurrent coronary and cardiac lesions.</p>

In vivo magnetic resonance imaging tracking of transplanted adipose-derived stem cells labeled with superparamagnetic iron oxide in rat hearts / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the feasibility of in vivo magnetic resonance imaging (MRI) tracking of transplanted adipose-derived stem cells (ADSCs) labeled with superparamagnetic iron oxide (SPIO) in rat heart.</p><p><b>METHODS</b>ADSCs were labeled with poly-L-lysine (PLL)-SPIO complexes. Intracellular iron uptake was identified by Prussian blue stain and transmission electromicroscopy. Trypan blue staining was used to test the viability of the labeled cells. In vitro MRI of labeled cells was performed. SPIO-labeled ADSCs were transplanted into normal rat hearts and were in vivo imaged with MRI. Image findings on MRI were correlated with histological findings of the rat hearts.</p><p><b>RESULTS</b>The labeling efficacy of ADSCs with PLL-SPIO was nearly 100%. Light microscopy revealed the SPIO particles were located in the cytoplasm of the ADSCs by Prussian blue staining. Transmission electromicroscopy revealed that the SPIO particles were located in the endosomes in the cytoplasm. There was no significantly deference in viability between labeled and unlabeled groups demonstrated by Trypan blue test (P > 0.05). MRI showed signal loss in gel mixed with labeled cells as compared with the unlabeled cells group and blank group. Signal void on rat hearts were demonstrated on MRI and were well correlated with histological findings where Prussian-blue-stain positive cells presented.</p><p><b>CONCLUSION</b>MRI can be used to in vivo track the transplanted ADSCs labeled with SPIO into rat hearts and facilitate to understand the conditions of the labeled cells in the transplanted areas.</p>

Diagnostic value of 64-slice spiral CT coronary angiography for restenosis after bypass surgery / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the accuracy of 64-slice spiral CT in diagnosis of restenosis of coronary artery bypass grafts (CABG) and native coronary arteries in patients after bypass surgery.</p><p><b>METHODS</b>Fifty-eight patients receiving bypass surgery with totally 140 CABG (43 arterial and 97 venous grafts) were examined using 64-slice spiral CT. CABG and all native coronary arteries with a diameter of >1.5 mm were evaluated for the presence of significant stenoses (>50% diameter reduction) in comparison with the results by coronary angiography as the golden standard.</p><p><b>RESULTS</b>Of the 140 CABG examined, 38 were occluded and 104 remained patent, all of which were accurately identified by 64-slice spiral CT. The sensitivity of CT for restenosis detection in the patent graft was 100% (18/18) with a specificity of 95.2% (80/84). In the segmental evaluation of the native coronary arteries, the sensitivity of the CT in identifying significant stenosis in the evaluable segments (90%) was 84% (87/103) with a specificity of 74% (384/518). The accuracy of CT in detecting the presence of at least 1 stenosis in the CABG, distal runoff vessels or nongrafted arteries was 91% (53/58).</p><p><b>CONCLUSION</b>CT allows noninvasive angiographic evaluation of both the native coronary arteries and bypass grafts after bypass surgery.</p>

Grading of rabbit skeletal muscle trauma by diffusion tensor imaging and tractography on magnetic resonance imaging / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To distinguish the edema, injury, or rupture in the traumatic skeletal muscle fiber in vivo using diffusion tensor imaging (DTI) and tractography on magnetic resonance imaging (MRI).</p><p><b>METHODS</b>The skeletal muscle trauma models were made in 4 rabbits (eight hindlimbs) by iron discus (weight 1.0 kg, diameter 6 cm) falling down vertically from 45 cm height to rabbits' thighs. Conventional sequences and two-dimensional (2D) diffusion-weighted (DW) spin-echo (SE) echo planar imaging (EPI) sequence with fat suppression (b = 600 s/mm2) were performed on 1. 5T MRI scanner. The grading of edema, injury, and fiber rupture in the damaged muscle were made according to their histopathological views, which was consistent with the images. The mean apparent diffusion coefficient (ADC) values and fractional anisotropy (FA) values were measured from the region of interests (ROIs) of all groups on 2D DW images used for tractography. Analysis of variance test was performed to analyze all data.</p><p><b>RESULTS</b>ADC values of the areas in normal muscle, edema muscle, injury muscle, and ruptured muscle were (6.12 +/- 1.34) x 10(-3), (6.38 +/- 1.30) x 10(-3), (8.06 +/- 0.97) x 10(-3), and (9.57 +/- 0.93) x 10(-3) mm2/s, respectively. There was significant difference among groups (P < 0.001), but no difference between edema muscle and normal muscle group (P > 0.05). The FA values of normal muscle, edema muscle, injury muscle, and ruptured muscle were 0.42 +/- 0.12, 0.36 +/- 0.12, 0.26 +/- 0.09, 0.12 +/- 0.08, respectively, with a significant difference among groups (P < 0.001). In the edema muscle, the tracking cross-fiber could be seen but it decreased slightly. In the injury muscle, the tracking fiber decreased markedly. In the ruptured muscle, the transverse-orientation tracking fiber vanished, yet some interrupted longitudinal-orientation tracking fiber could be found.</p><p><b>CONCLUSION</b>The edema, injury, and rupture of muscle fiber in rabbit damaged skeletal muscle can be verified according to the ADC and the FA on DTI and tractography.</p>

Initial study of quantitative analysis of fatty liver by ~1H-MR spectroscopy imaging / 中华放射学杂志

Objective To investigate the feasibility of ~1H-MR spectroscopy(~1H-MRS)imaging to quantitatively detect fatty liver.Methods Twenty patients with fatty liver and 11 healthy volunteers underwent plain CT scan,conventional MR imaging and ~1H-MRS analysis.The blood lipid and liver function were tested on the same day as the MR examination.~1H-MRS sequence measured the peaks of H_2O and lipid,and the areas under the peaks.The relative contents of the lipid compound were calculated,and compared with the results of CT scan and liver function tests.Results The CT values of the normal group and the fatty liver group were(59?9)HU and(24?11)HU respectively.On ~1H-MRS a protruding high H_2O peak and a flat low lipid peak were observed in the normal group,while the protruding high H_2O peak and a high lipid peak appeared in the fatty liver group.The values of lipid peak in the normal group and the fatty liver group were(0.05?0.01)?10~5,(0.70?0.24)?10~5 respectively(t=4.32,P0.05),the areas under the lipid peak were(1.36?0.73)?10~9、(2.35?1.15)?10~9 respectively(t=5.21,P0.05).Conclusion ~1 H-MRS imaging is feasible to quantitatively detect liver fat and is a non-invasive method for detecting early fatty liver.

Multidetector CT of the coronary imaging:assessment of image quality and accuracy in detecting stenoses / 中华放射学杂志

Objective To evaluate the image quality of 64-multi detector computed tomography (MDCT)and the clinical accuracy in detecting coronary artery lesions.Methods One hundred and five patients were studied by MDCT.The results were compared with invasive coronary angiography(ICA). Patients were excluded for atrial fibrillation,but not for high heart rate,coronary calcification,or obesity. MDCT was analyzed with regard to image quality and presence of coronary artery lesions.Results The data evaluation of the image quality was based on a total of 1365 segments(13 coronary segments for each patient),of which 1144 segments were considered to have diagnostic image quality,but 221 segments (16.2%)could not be sufficiently evaluated because of severe calcifications(153 segments)and motion artifacts(68 segments).The median calcium score[Agatston score equivalent(ASE)]was 154(range 0—1983).87 of the 105 patients had an ASE of less than 1,000[median 105(range 0—994)],and 18 patients had an ASE greater than 1000[median 1477(range 1115—1983)].For detecting lesions with 50% or greater narrowing(without any exclusion criteria),the overall sensitivity,specificity,positive predictive value,and negative predictive value were 85.7%,97.9%,93.0%,and 95.5%,respectively. When limiting the number of patients to those with a calcium score of less than 1000 ASE,the threshold- corrected sensitivity for lesions with 50% or greater narrowing was 96.0%;specificity,98.9%;positive predictive value,95.3%;and negative predictive value,99.0%.Conclusion Our results indicate high quantitative and qualitative diagnostic accuracy of 64-slice MSCT in comparison to QCA in a broad spectrum of patients.