Value of Magnetic Resonance Imaging Texture Analysis in the Differential Diagnosis of Benign and Malignant Breast Tumors

Objective To investigate the difference in texture features on diffusion weighted imaging(DWI) images between breast benign and malignant tumors.Methods Patients including 56 with mass-like breast cancer, 16 with breast fibroadenoma, and 4 with intraductal papilloma of breast treated in the Hainan Hospital of Chinese PLA General Hospital were retrospectively enrolled in this study, and allocated to the benign group(20 patients) and the malignant group(56 patients) according to the post-surgically pathological results. Texture analysis was performed on axial DWI images, and five characteristic parameters including Angular Second Moment(ASM), Contrast, Correlation, Inverse Difference Moment(IDM), and Entropy were calculated. Independent sample t-test and Mann-Whitney U test were performed for intergroup comparison. Regression model was established by using Binary Logistic regression analysis, and receiver operating characteristic curve(ROC) analysis was carried out to evaluate the diagnostic efficiency. Results The texture features ASM, Contrast, Correlation and Entropy showed significant differences between the benign and malignant breast tumor groups(PASM= 0.014, Pcontrast= 0.019, Pcorrelation= 0.010, Pentropy= 0.007). The area under the ROC curve was 0.685, 0.681, 0.754, and 0.683 respectively for the positive texture variables mentioned above, and that for the combined variables(ASM, Contrast, and Entropy) was 0.802 in the model of Logistic regression. Binary Logistic regression analysis demonstrated that ASM, Contrast and Entropy were considered as thespecific imaging variables for the differential diagnosis of breast benign and malignant tumors.Conclusion The texture analysis of DWI may be a simple and effective tool in the differential diagnosis between breast benign and malignant tumors.

Nomogram prediction of vessels encapsulating tumor clusters in small hepatocellular carcinoma≤3 cm based on enhanced magnetic resonance imaging

BACKGROUND Vessels encapsulating tumor clusters(VETC)represent a recently discovered vascular pattern associated with novel metastasis mechanisms in hepatocellular carcinoma(HCC).However,it seems that no one have focused on predicting VETC status in small HCC(sHCC).This study aimed to develop a new nomogram for predicting VETC positivity using preoperative clinical data and image features in sHCC(≤3 cm)patients.AIM To construct a nomogram that combines preoperative clinical parameters and image features to predict patterns of VETC and evaluate the prognosis of sHCC patients.METHODS A total of 309 patients with sHCC,who underwent segmental resection and had their VETC status confirmed,were included in the study.These patients were recruited from three different hospitals:Hospital 1 contributed 177 patients for the training set,Hospital 2 provided 78 patients for the test set,and Hospital 3 provided 54 patients for the validation set.Independent predictors of VETC were identified through univariate and multivariate logistic analyses.These independent predictors were then used to construct a VETC prediction model for sHCC.The model’s performance was evaluated using the area under the curve(AUC),calibration curve,and clinical decision curve.Additionally,Kaplan-Meier survival analysis was performed to confirm whether the predicted VETC status by the model is associated with early recurrence,just as it is with the actual VETC status and early recurrence.RESULTS Alpha-fetoprotein_lg10,carbohydrate antigen 199,irregular shape,non-smooth margin,and arterial peritumoral enhancement were identified as independent predictors of VETC.The model incorporating these predictors demonstrated strong predictive performance.The AUC was 0.811 for the training set,0.800 for the test set,and 0.791 for the validation set.The calibration curve indicated that the predicted probability was consistent with the actual VETC status in all three sets.Furthermore,the decision curve analysis demonstrated the clinical benefits of our model for patients with sHCC.Finally,early recurrence was more likely to occur in the VETC-positive group compared to the VETC-negative group,regardless of whether considering the actual or predicted VETC status.CONCLUSION Our novel prediction model demonstrates strong performance in predicting VETC positivity in sHCC(≤3 cm)patients,and it holds potential for predicting early recurrence.This model equips clinicians with valuable information to make informed clinical treatment decisions.

Preoperative prediction of hepatocellular carcinoma microvascular invasion based on magnetic resonance imaging feature extraction artificial neural network

BACKGROUND Hepatocellular carcinoma(HCC)recurrence is highly correlated with increased mortality.Microvascular invasion(MVI)is indicative of aggressive tumor biology in HCC.AIM To construct an artificial neural network(ANN)capable of accurately predicting MVI presence in HCC using magnetic resonance imaging.METHODS This study included 255 patients with HCC with tumors<3 cm.Radiologists annotated the tumors on the T1-weighted plain MR images.Subsequently,a three-layer ANN was constructed using image features as inputs to predict MVI status in patients with HCC.Postoperative pathological examination is considered the gold standard for determining MVI.Receiver operating characteristic analysis was used to evaluate the effectiveness of the algorithm.RESULTS Using the bagging strategy to vote for 50 classifier classification results,a prediction model yielded an area under the curve(AUC)of 0.79.Moreover,correlation analysis revealed that alpha-fetoprotein values and tumor volume were not significantly correlated with the occurrence of MVI,whereas tumor sphericity was significantly correlated with MVI(P<0.01).CONCLUSION Analysis of variable correlations regarding MVI in tumors with diameters<3 cm should prioritize tumor sphericity.The ANN model demonstrated strong predictive MVI for patients with HCC(AUC=0.79).

Retrorectal tumors in adults:Magnetic resonance imaging findings

AIM:To retrospectively evaluate the magnetic resonance imaging (MRI) features of adult retrorectal tumors and compare with histopathologic findings.METHODS:MRI features of 21 patients with preoperative suspicion of retrorectal tumors were analyzed based on the histopathological and clinical data.RESULTS:Fourteen benign cystic lesions appeared hypointense on T1-weighted images,and hyperintense on T2-weighted images with regular peripheral rim.Epidermoid or dermoid cysts were unilocular,and tailgut cysts were multilocular.Presence of intracystic intermediate signal intensity was observed in one case of tailgut cyst with a component of adenocarcinoma.Six solid tumors were malignant lesions and showed heterogeneous intensity on MRI.Mucinous adenocarcinomas showed high signal intensity on T2-weighted and mesh-like enhancing areas on fat-suppressed T2-weighted images.There was a fistula between the mass and anus with an internal opening in mucinous adenocarcinomas arising from anal fistula.Gastrointestinal stromal tumors displayed low signal intensity on T1-weighted images,and intermediate to high signal intensity on T2-weighted images.Central necrosis could be seen as a high signal on T2-weighted images.CONCLUSION:MRI is a helpful technique to define the extent of the retrorectal tumor and its relationship to the surrounding structures,and also to demonstrate possible complications so as to choose the best surgical approach.

Linear endoscopic ultrasonography vs magnetic resonance imaging in ampullary tumors

AIM:To assess linear endoscopic ultrasound (L-EUS) and magnetic resonance imaging (MRI) in biliary tract dilation and suspect small ampullary tumor.METHODS:L-EUS and MRI data were compared in 24 patients with small ampullary tumors;all with subsequent histological confirmation.Data were collected prospectively and the accuracy of detection,histological characterization and N staging were assessed retrospectivelyusing the results of surgical or endoscopic treatment as a benchmark.RESULTS:A suspicion of ampullary tumor was present in 75% of MRI and all L-EUS examinations,with 80% agreement between EUS and histological findings at endoscopy.However,L-EUS and histological TN staging at surgery showed moderate agreement (κ=0.54).CONCLUSION:L-EUS could be a useful adjunct as a diagnostic tool in the evaluation of patients with sus-pected ampullary tumors.

DIFFERENTIATION BETWEEN MALIGNANT AND BENIGN OVARIAN TUMORS BY MAGNETIC RESONANCE IMAGING

Objective To determine the magnetic resonance （MR） imaging findings of an ovarian mass which are most predictive of malignancy and assess the value of intravenous gadolinium administration in the characterization of an ovarian mass. Methods Totally 74 consecutive patients with a clinically or sonographicaUy indeterminate adnexal mass underwent MR imaging, of whom 59 had subsequent surgical resection of 70 adnexal masses. These 59 patients formed the study population. MR imaging studies were prospectively and independently reviewed by a senior and a junior radiologist. The senior radiologist also reevaluated the studies in a blind fashion after a minimum 6 months interval. The sensitivity, specificity, positive predictive value, and negative predictive value of contrast-enhanced and unenhanced MR im- aging were evaluated Results The most predictive MR imaging findings for malignancy were presence of vegetations in a cystic lesinn and presence of necrosis in a solid lesion. The odds ratio was even higher when the ancillary finding of peritoneal metastasis or ascites was present. Contrast media contributed significantly to lesinn characterization. Total 70 ovarian masses were detected by contrast-enhanced MR imaging including 37 malignant ovarian masses and 33 benign ovarian masses with 87% （61/70）accuracy, 86% （32/37）sensitivity, 88% （29/33）specificity, 89% （32/36）positive predictive value, and 85% （29/34） negative predictive value, whereas 70 ovarian masses were detected by unenhanced MR imaging with 74% （52/70） accuracy, 73 % （27/37） sensitivity, 76 % （ 25/33 ） specificity, 77% （27/35） positive predictive value, and 71% （ 25/35 ） negative predictive value. There were significant differences in accuracy （ P 〈 0. 01 ）, sensitivity （ P 〈0. 01 ）, specificity （ P 〈0. 01 ） between contrast-enhanced and unenhanced MR imaging. Conclusion Contrast-enhanced MR imaging is highly accurate in detection and characterization of complex adnexal masses.

Prediction of radiosensitivity in primary central nervous system germ cell tumors using dynamic contrast-enhanced magnetic resonance imaging

Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） germ cell tumors（GCTs）.Methods： DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic（ROC） curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results： A significant elevation in transfer constant（K^trans） and extravascular extracellular space（Ve）（P=0.000）, as well as a significant reduction in rate constant（Kep）（P=0.000） was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value（PPV） of 95.8%, and negative predictive value（NPV） of 100%.Conclusions： Relative K^trans appeared promising in predicting tumor response to radiation therapy（RT）. It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.

Advanced magnetic resonance imaging findings in salivary gland tumors

Salivary gland tumors(SGTs)make up a small portion(approximately 5%)of all head and neck tumors.Most of them are located in the parotid glands,while they are less frequently located in the submandibular glands,minor salivary glands or sublingual gland.The incidence of malignant or benign tumors(BTs)in the salivary glands varies according to the salivary gland from which they originate.While most of those detected in the parotid gland tend to be benign,the incidence of malignancy increases in other glands.The use of magnetic resonance imaging(MRI)in the diagnosis of SGTs is increasing every day.While conventional sequences provide sufficient data on the presence,localization,extent and number of the tumor,they are insufficient for tumor specification.With the widespread use of advanced techniques such as diffusion-weighted imaging,semiquantitative and quantitative perfusion MRI,studies and data have been published on the differentiation of malignant or BTs and the specificity of their subtypes.With diffusion MRI,differentiation can be made by utilizing the cellularity and microstructural properties of tumors.For example,SGTs such as high cellular Warthin’s tumor(WT)or lymphoma on diffusion MRI have been reported to have significantly lower apparent diffusion values than other tumors.Contrast agent uptake and wash-out levels of tumors can be detected with semiquantitative perfusion MRI.For example,it is reported that almost all of the pleomorphic adenomas show an increasing enhancement time intensity curve and do not wash-out.On quantitative perfusion MRI studies using perfusion parameters such as Ktrans,Kep,and Ve,it is reported that WTs can show higher Kep and lower Ve values than other tumors.In this study,the contribution of advanced MRI to the diagnosis and differential diagnosis of SGTs will be reviewed.

Magnetic resonance imaging of soft-tissue tumors of the extremities: A practical approach

Diagnosis of extremity soft-tissue tumors can be challenging.Characteristics of tumor margins can help precisely identify locally aggressive or non-aggressive behavior for surgical planning,but cannot differentiate benign from malignant lesions.Most malignant tumors can have inhomogeneous signals on T2-weighted images.Although a uniform signal on T2-weighted images can be a reliable indication of a benign lesion,a well-defined mass with homogeneous internal signal intensity does not definitively identify a benign lesion.Some common and distinctive soft-tissue lesions can have specific clinical and imaging features allowing a diagnosis without biopsy.These are known as determinate lesions.This illustrative report presents a diagnostic guide for extremity soft-tissue tumors based on tissue signal and morphological characteristics on magnetic resonance images.It is important for clinicians to be familiar with the imaging characteristics of common determinate lesions.

Fetal brain tumors:Prenatal diagnosis by ultrasound and magnetic resonance imaging

Congenital central nervous system tumors diagnosed during pregnancy are rare, and often have a poor prognosis. The most frequent type is the teratoma. Use of ultrasound and magnetic resonance image allows the suspicion of brain tumors during pregnancy. However, the definitive diagnosis is only confirmed after birth by histology. The purpose of this mini-review article is to describe the general clinical aspects of intracranial tumors and describe the main fetal brain tumors.

Value of ultrasound and magnetic resonance imaging combined with tumor markers in the diagnosis of ovarian tumors

BACKGROUND Compare the diagnostic performance of ultrasound(US),magnetic resonance imaging(MRI),and serum tumor markers alone or in combination for detecting ovarian tumors.AIM To investigate the diagnostic value of US,MRI combined with tumor markers in ovarian tumors.METHODS The data of 110 patients with ovarian tumors,confirmed by surgery and pathology,were collected in our hospital from February 2018 to May 2023.The dataset included 60 cases of benign tumors and 50 cases of malignant tumors.Prior to surgery,all patients underwent preoperative US and MRI examinations,as well as serum tumor marker tests[carbohydrate antigen 125(CA125),human epididymis protein 4(HE4)].The aim of the study was to compare the diagnostic performance of these three methods individually and in combination for ovarian tumors.RESULTS This study found statistically significant differences in the ultrasonic imaging characteristics between benign and malignant tumors.These differences include echo characteristics,presence or absence of a capsule,blood flow resistance index,clear tumor shape,and blood flow signal display rate(P<0.05).The apparent diffusion coefficient values of the solid and cystic parts in benign tumors were found to be higher compared to malignant tumors(P<0.05).Additionally,the time-intensity curve image features of benign and malignant tumors showed significant statistical differences(P<0.05).The levels of serum CA125 and HE4 in benign tumors were lower than those in malignant tumors(P<0.05).The combined use of US,MRI,and tumor markers in the diagnosis of ovarian tumors demonstrates higher accuracy,sensitivity,and specificity compared to using each method individually(P<0.05).CONCLUSION US,MRI,and tumor markers each have their own advantages and disadvantages when it comes to diagnosing ovarian tumors.However,by combining these three methods,we can significantly enhance the accuracy of ovarian tumor diagnosis,enabling early detection and identification of the tumor’s nature,and providing valuable guidance for clinical treatment.

Prediction of the lymphatic,microvascular,and perineural invasion of pancreatic neuroendocrine tumors using preoperative magnetic resonance imaging

BACKGROUND Significant correlation between lymphatic,microvascular,and perineural invasion(LMPI)and the prognosis of pancreatic neuroendocrine tumors(PENTs)was confirmed by previous studies.There was no previous study reported the relationship between magnetic resonance imaging(MRI)parameters and LMPI.AIM To determine the feasibility of using preoperative MRI of the pancreas to predict LMPI in patients with non-functioning PENTs(NFPNETs).METHODS A total of 61 patients with NFPNETs who underwent MRI scans and lymphadenectomy from May 2011 to June 2018 were included in this retrospective study.The patients were divided into group 1(n=34,LMPI negative)and group 2(n=27,LMPI positive).The clinical characteristics and qualitative MRI features were collected.In order to predict LMPI status in NF-PNETs,a multivariate logistic regression model was constructed.Diagnostic performance was evaluated by calculating the receiver operator characteristic(ROC)curve with area under ROC,sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV)and accuracy.RESULTS There were significant differences in the lymph node metastasis stage,tumor grade,neuron-specific enolase levels,tumor margin,main pancreatic ductal dilatation,common bile duct dilatation,enhancement pattern,vascular and adjacent tissue involvement,synchronous liver metastases,the long axis of the largest lymph node,the short axis of the largest lymph node,number of the lymph nodes with short axis>5 or 10 mm,and tumor volume between two groups(P<0.05).Multivariate analysis showed that tumor margin(odds ratio=11.523,P<0.001)was a predictive factor for LMPI of NF-PNETs.The area under the receiver value for the predictive performance of combined predictive factors was 0.855.The sensitivity,specificity,PPV,NPV and accuracy of the model were 48.1%(14/27),97.1%(33/34),97.1%(13/14),70.2%(33/47)and 0.754,respectively.CONCLUSION Using preoperative MRI,ill-defined tumor margins can effectively predict LMPI in patients with NF-PNETs.

Magnetic Resonance Imaging for Diagnosis and Analysis of Bone Tumors and Bone Tuberculosis

The purpose of the study is to explore the diagnostic value of magnetic resonance imaging in bone tuberculosis and bone tumors.Firstly,148 patients with bone tumor and bone tuberculosis were selected,74 cases in each group.Perform magnetic resonance imaging(MRI)examinations on all patients,relevant parameters were set and the changes in the value of the dispersion system were recorded to obtain T1-weighted imaging and T2-weighted imaging.The results showed that among 74 patients,41 cases were bone damage,38 cases were joint swelling,27 cases were sparse bone,10 cases were bone hyperplasia and 5 cases were dead bone and calcification.The imaging manifestations of bone tumors were 45 cases of fractures,26 cases of surrounding soft tissue infiltration,10 cases of hip duct enlargement and 11 cases of sacral foramen enlargement.After MRI diagnosis,the accuracy of diagnosing 74 cases of bone tumor was 100%,and the accuracy of diagnosing 65 cases of bone tuberculosis was 87.84%.The difference between the two groups was statistically significant(P<0.05).The diffusion sensitivity coefficient of MRI weighted imaging was 150 s/mm2,and there was no significant difference in ADC values between the two groups(P>0.05).When the diffusion sensitivity coefficient is 300 s/mm2,and the difference between the two groups was statistically significant(P<0.05).Therefore,MRI had a certain diagnostic value for bone tuberculosis and bone tumors,and MRI had a higher diagnostic value and richer information for bone tumors.Corresponding treatment can be performed to improve the prognosis.

Gadoxetic acid-enhanced magnetic resonance imaging can predict the pathologic stage of solitary hepatocellular carcinoma

BACKGROUND Although important for determining long-term outcome, pathologic stage of hepatocellular carcinoma (HCC) is difficult to predict before surgery. Current state-of-the-art magnetic resonance imaging (MRI) using gadoxetic acid provides many imaging features that could potentially be used to classify single HCC as pT1 or pT2. AIM To determine which gadoxetic acid-enhanced MRI (EOB-MRI) findings predict pathologic stage T2 in patients with solitary HCC (cT1). METHODS Pre-operative EOB-MRI findings were reviewed in a retrospective cohort of patients with solitary HCC. The following imaging features were examined: Hyperintensity in unenhanced T2-weighted images, hypointensity in unenhanced T1-weighted images, arterial enhancement, corona enhancement, washout appearance, capsular appearance, hypointensity in the tumor tissue during the hepatobiliary (HB) phase, peritumoral hypointensity in the HB phase, hypointense rim in the HB phase, intratumoral fat, hyperintensity on diffusionweighted imaging, hypointensity on apparent diffusion coefficient map, mosaic appearance, nodule-in-nodule appearance, and the margin (smooth or irregular). Surgical pathology was used as the reference method for tumor staging. Univariate and multivariate analyses were performed to identify predictors of microvascular invasion or satellite nodules. RESULTS There were 39 (34.2%;39 of 114) and 75 (65.8%;75 of 114) pathological stage T2 and T1 HCCs, respectively. Large tumor size (≥ 2.3 cm) and two MRI findings, i.e., corona enhancement [odds ratio = 2.67;95% confidence interval: 1.101-6.480] and peritumoral hypointensity in HB phase images (odds ratio = 2.203;95% confidence interval: 0.961-5.049) were associated with high risk of pT2 HCC. The positive likelihood ratio was 6.25 (95% confidence interval: 1.788-21.845), and sensitivity of EOB-MRI for detecting pT2 HCC was 86.2% when two or three of these MRI features were present. Small tumor size and hypointense rim in the HB phase were regarded as benign features. Small HCCs with hypointense rim but not associated with aggressive features were mostly pT1 lesions (specificity, 100%). CONCLUSION Imaging features on EOB-MRI could potentially be used to predict the pathologic stage of solitary HCC (cT1) as pT1 or pT2.

Transrectal ultrasound and magnetic resonance imaging measurement of extramural tumor spread in rectal cancer

AIM： To evaluate the agreement between transrectal ultrasound （TRUS） and magnetic resonance imaging （MRI） in classification of ≥ T3 rectal tumors. METHODS： From January 2010 to January 2012, 86 consecutive patients with ≥ T3 tumors were included in this study. The mean age of the patients was 66.4 years （range： 26-91 years）. The tumors were all ≥ T3 on TRUS. The sub-classification was defined by the penetration of the rectal wall： a： 0 to 1 mm; b： 1-5 mm, c： 6-15; d： 〉 15 mm. Early tumors as ab （≤ 5 ram） and advanced tumors as cd （〉 5 mm）. All patients underwent TRUS using a 6.5 MHz transrectal transducer. The MRI was performed with a 1.5 T Phil- ips unit. The TRUS findings were blinded to the radiol- ogist performing the interpretation of the MRI images and measuring the depth of extramural tumor spread RESULTS： TRUS found 51 patients to have an early ≥ T3 tumors and 35 to have an advanced tumor, where- as MRI categorized 48 as early ≥ T3 tumors and 38 as advanced tumors. No patients with tumors classified as advanced by TRUS were found to be early on MRI. The kappa value in classifying early versus advanced T3 rectal tumors was 0.93 （95% CI： 0.85-1.00）. We found a kappa value of 0.74 （95% CI： 0.63-0.86） for the total sub-classification between the two methods. The mean maximal tumor outgrowth measured by TRUS, 5.5 mm ± 5.63 mm and on MRI, 6.3 mm ±6.18 mm, P = 0.004. In 19 of the 86 patients the following CT scan or surgery revealed distant metastases; of the 51 patients in the ultrasound ab group three （5.9%） had metastases, whereas 16 （45.7%） of 35 in the cd group harbored distant metastases, P = 0.00002. The odds ratio of having distant metastases in the ultra- sound cd group compared to the ab group was 13.5 （95% CI： 3.5-51.6）, P = 0.00002. The mean maximal ultrasound measured outgrowth was 4.3 mm （95% CI： 3.2-5.5 mm） in patients without distant metastases, while the mean maximal outgrowth was 9.5 mm （95% CI： 6.2-12.8 ram） in the patients with metastases, P = 0.00004. Using the MRI classification three （6.3%） of 48 in the MRI ab group had distant metastases, while 16 （42.1%） of the 38 in the MRI cd group, P = 0.00004. The MRI odds ratio was 10.9 （95% CI： 2.9-41.4）, P = 0.00008. The mean maximal MRI measured out- growth was 4.9 mm （95% CI： 3.7-6.1 turn） in patients without distant metastases, while the mean maximal outgrowth was 11.5 mm （95% CI： 7.8-15.2 mm） in the patients with metastases, P = 0.000006. CONCLUSION： There is good agreement between TRUS and MRI in the pretreatment sub-classification of ≥ T3 tumors. Distant metastases are more frequent in the advanced group.

Clinicopathological study of solid and pseudopapillary tumor of pancreas: Emphasis on magnetic resonance imaging findings

AIM: To report the clinicopathological features and magnetic resonance imaging (MRI) findings of solid and pseudopapillary tumor (SPT) of pancreas.METHODS: From 1981 to 2005, 26 surgically treated cases of SPT were retrospectively reviewed. MRI findings of the latest 11 consecutive SPT cases were investigated.RESULTS: There were 25 women and one man having SPT (median age: 23 year) with a median tumor size of 7.5 cm. Among them, nine patients developed solid pseudopapillary carcinoma. During the median follow-up period of 66 mo, the 5-year survival rate of the 26 SPT patients was 96.2%. Three MRI features were proposed including Type 1 image, displaying SPT with completely solid part. All SPT patients with type 1 image were detected incidentally. Type 2 image displays of SPT with solid mass hemorrhage and type 3 image with massive hemorrhage. All the eight SPT patients with type 2 and 3 images suffered abdominal pain due to hemorrhage from SPT.CONCLUSION: SPT had a favorable survival rate irrespective of surgical procedures, malignancy, and MRI findings, however, MRI could reliably correlate with its clinicopathological features.

Pancreatic neuroendocrine neoplasms: Magnetic resonance imaging features according to grade and stage

AIMTo describe magnetic resonance (MR) imaging features of pancreatic neuroendocrine neoplasms (PanNENs) according to their grade and tumor-nodes-metastases stage by comparing them to histopathology and to determine the accuracy of MR imaging features in predicting their biological behavior.METHODSThis study was approved by our institutional review board; requirement for informed patient consent was waived due to the retrospective nature of the study. Preoperative MR examinations of 55 PanNEN patients (29 men, 26 women; mean age of 57.6 years, range 21-83 years) performed between June 2013 and December 2015 were reviewed. Qualitative and quantitative features were compared between tumor grades and stages determined by histopathological analysis.RESULTSIll defined margins were more common in G2-3 and stage III-IV PanNENs than in G1 and low-stage tumors (P < 0.001); this feature had high specificity in the identification of G2-3 and stage III-IV tumors (90.3% and 96%, 95%CI: 73.1-97.5 and 77.7-99.8). The mean apparent diffusion coefficient value was significantly lower in G2-3 and stage III-IV lesions compared to well differentiated and low-stage tumors (1.09 × 10-3 mm2/s vs 1.45 × 10-3 mm2/s and 1.10 × 10-3 mm2/s vs 1.53 × 10-3 mm2/s, P = 0.003 and 0.001). Receiving operator characteristic analysis determined optimal cut-offs of 1.21 and 1.28 × 10-3 mm2/s for the identification of G2-3 and stage III-IV tumors, with sensitivity and specificity values of 70.8/80.7% and 64.5/64% (95%CI: 48.7-86.6/60-92.7 and 45.4-80.2/42.6-81.3).CONCLUSIONMR features of PanNENs vary according to their grade of differentiation and their stage at diagnosis and could predict the biological behavior of these tumors.

Magnetic resonance diffusion tensor imaging and fibertracking diffusion tensor tractography in the management of spinal astrocytomas

Some specially imaging of magnetic resonance imaging,the diffusion-weighted imaging(DWI),the diffusion tensor imaging and fractional anisotropy(FA),are useful to described,detect,and map the extent of spinal cord lesions.FA measurements may are used to predicting the outcome of patients who have spinal cord lesions.Fiber tracking enable to visualizing the integrity of white matter tracts surrounding some lesions,and this information could be used to formulating a differential diagnosis and planning biopsies or resection.In this article,we will describe the current uses for DWI and fiber tracking and speculate on others in which we believe these techniques will be useful in the future.

Texture analysis on parametric maps derived from dynamic contrast-enhanced magnetic resonance imaging in head and neck cancer

AIM: To investigate the merits of texture analysis on parametric maps derived from pharmacokinetic modeling with dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) as imaging biomarkers for the prediction of treatment response in patients with head and neck squamous cell carcinoma(HNSCC). METHODS: In this retrospective study,19 HNSCC patients underwent pre- and intra-treatment DCEMRI scans at a 1.5T MRI scanner. All patients had chemo-radiation treatment. Pharmacokinetic modeling was performed on the acquired DCE-MRI images,generating maps of volume transfer rate(Ktrans) and volume fraction of the extravascular extracellular space(ve). Image texture analysis was then employed on maps of Ktrans and ve,generating two texture measures: Energy(E) and homogeneity.RESULTS: No significant changes were found for the mean and standard deviation for Ktrans and ve between pre- and intra-treatment(P > 0.09). Texture analysis revealed that the imaging biomarker E of ve was significantly higher in intra-treatment scans,relative to pretreatment scans(P < 0.04). CONCLUSION: Chemo-radiation treatment in HNSCC significantly reduces the heterogeneity of tumors.

Clinical Value of Whole-body Magnetic Resonance Diffusion Weighted Imaging on Detection of Malignant Metastases

Objective To evaluate the value of whole-body diffusion weighted imaging （WB-DWI） on detection of malignant metastasis. Methods Forty-six patients with malignant tumors underwent WB-DWI examinations between April 2007 and August 2007 in our hospital. Before WB-DWI examination, the primary cancers of all the patients were confirmed by pathology, and the TNM-stage was assessed with conventional magnetic resonance imaging （MRI） or computed tomography （CT）. WB-DWI was performed using short TI inversion recovery echo-planar imaging （STIR-EPI） sequence. Abnormal high signal intensities on WB-DWI were considered as metastases. The results of WB-DWI were compared with other imaging modalities. For the assessment of the diagnostic capability of WB-DWI, WB-DWI were compared with CT for demonstrating mediastinal lymph node metastases and lung metastases, and with conventional MRI for demonstrating metastases in other locations. Results WB-DWI demonstrated 143 focuses, 14 routine imaging. The number of bone metastases depicted of which were diagnosed to be benign lesions in on WB-DWI and routine imaging was 85 and 86; lymph node metastases was 17 and 18; liver metastases was 14 and 14; lung metastases was 4 and 8; and brain metastases was 6 and 8, respectively. WB-DWI failed to detect 12 metastatic lesions including 3 osteoplastic bone metastases, 4 lung metastases, 3 mediastinal lymph node metastases, and 2 brain metastases Four metastatic lesions including 2 deltopectoral lymph nodes and 2 rib metastases were detected with WB-DWI alone, all of which evolved greatly during clinical follow-up for more than 6 months. WB-DWI had higher detection rates for metastatic lesions in liver, bone, and lymph nodes than those in lung and brain （ X^2=30, P〈0.001）. Conclusions WB-DWI could detect most of metastatic lesions that were diagnosed with conventional MRI and CT. The limitations of WB-DWI might be had high false-positive rate and low efficiency in detecting mecliastinal lymph node, brain, and lung metastases.