Predicting anaplastic lymphoma kinase rearrangement status in patients with non-small cell lung cancer using a machine learning algorithm that combines clinical features and CT images.

Purpose: To develop an appropriate machine learning model for predicting anaplastic lymphoma kinase (ALK) rearrangement status in non-small cell lung cancer (NSCLC) patients using computed tomography (CT) images and clinical features. Method and materials: This study included 193 patients with NSCLC (154 in the training cohort, 39 in the validation cohort), 68 of whom tested positive for ALK rearrangements and 125 of whom tested negative. From the nonenhanced CT scans, 157 radiomic characteristics were extracted, and 8 clinical features were collected. Five machine learning (ML) models were assessed to find the best classification model for predicting ALK rearrangement status. A radiomic signature was developed using the least absolute shrinkage and selection operator (LASSO) algorithm. The predictive performance of the models based on radiomic features, clinical features, and their combination was assessed by receiver operating characteristic (ROC) curves. Results: The support vector machine (SVM) model had the highest AUC of 0.914 for classification. The clinical features model had an AUC=0.805 (95% CI 0.731-0.877) and an AUC=0.735 (95% CI 0.566-0.863) in the training and validation cohorts, respectively. The CT image-based ML model had an AUC=0.953 (95% CI 0.913-1.0) in the training cohort and an AUC=0.890 (95% CI 0.778-0.971) in the validation cohort. For predicting ALK rearrangement status, the ML model based on CT images and clinical features performed better than the model based on only clinical information or CT images, with an AUC of 0.965 (95% CI 0.826-0.882) in the primary cohort and an AUC of 0.914 (95% CI 0.804-0.893) in the validation cohort. Conclusion: Our findings revealed that ALK rearrangement status could be accurately predicted using an ML-based classification model based on CT images and clinical data.

Use of intravoxel incoherent motion MRI to assess placental perfusion in normal and Fetal Growth Restricted pregnancies on their third trimester.

INTRODUCTION: Intravoxel Incoherent Motion (IVIM) MRI is a non-invasive, in vivo techniques which can assess placental perfusion quantitatively, and be useful for evaluating placental microcirculation. Our primary aim was to investigate whether fetal growth restriction (FGR) pregnancies have different placental perfusion and diffusion compared with normal pregnancies using IVIM. A secondary aim was to investigate correlations between placental IVIM parameters and gestational age in normal pregnancy. METHODS: This study population included 17 FGR pregnancies and 36 normal pregnancies between 28 + 3 to 38 + 0 weeks. All women underwent a MRI examination including an IVIM sequence with 9 b-values on a 3.0 T MRI system. The standard diffusion coefficeint (D), pseudodiffusion (D*) and perfusion fraction (f) were calculated. RESULTS: Placental f was significantly lower in the FGR group than that in the normal group (33.96 ± 2.62(%) vs 38.48 ± 5.31(%), p = 0.002). Placental D and D* in two groups showed no statistical significance (P > 0.05). Placental f moderately increased with increasing gestational age in normal pregnancies (r = 0.411, p = 0.013), and there existed a negative correlation between D values and gestational age (r = -0.390, p = 0.019). DISCUSSION: The f values are able to distinguish FGR from normal pregnancies. It can be uses as a feasible index to evaluate placenta perfusion. Gestational age-associated changes in placental IVIM parameters likely reveal trajectories of microvascular perfusion fraction and diffusion characteristics in the normal developing placenta.

Conventional MRI Features of Central Nervous System Embryonal Tumor, Not Otherwise Specified in Adults: Comparison with Glioblastoma.

RATIONALE AND OBJECTIVES: The purpose of this study was to explore conventional MRI features that can accurately differentiate central nervous system embryonal tumor, not otherwise specified (CNS ETNOS) from glioblastoma (GBM) in adults. MATERIALS AND METHODS: Preoperative conventional MRI images of 30 CNS ETNOS and 98 GBMs were analyzed by neuroradiologists retrospectively to identify valuable MRI features. Five blinded neuroradiologists independently reviewed all these MRI images, and scored MRI features on a five-point scale. Kendall's coefficient of concordance was used to measure inter-rater agreement. Diagnostic value was assessed by the area under the curve (AUC) of receiver operating curve, and sensitivity and specificity were also calculated. RESULTS: Seven MRI features, including isointensity on T1WI, T2WI, and FLAIR, ill-defined margin, severe peritumoral edema, ring enhancement, and broad-based attachment sign, were helpful for the differential diagnosis of these two entities. Among these features, ring enhancement showed the highest inter-rater concordance (0.80). Ring enhancement showed the highest AUC value (0.79), followed by severe peritumoral edema (0.67). The combination of seven features showed the highest AUC value (0.86), followed by that of three features (ill-defined margin, severe peritumoral edema, and ring enhancement) (0.83). CONCLUSION: Enhancement pattern, peritumoral edema, and margin are valuable for the discrimination between CNS ETNOS and GBM in adults.

An Optimized Integrin α6-Targeted Magnetic Resonance Probe for Molecular Imaging of Hepatocellular Carcinoma in Mice.

INTRODUCTION: Integrin α6 is an attractive diagnostic biomarker for molecular imaging of hepatocellular carcinoma (HCC) as it has an extremely high positive rate (approximately 94%) in clinical early-stage HCC. In this study, based on our previously identified integrin α6-targeted peptide, we developed an optimized integrin α6-targeted magnetic resonance (MR) probe dubbed DOTA(Gd)-ANADYWR for MR imaging of HCC in mice. MATERIALS AND METHODS: The longitudinal (R1) relaxivity of DOTA(Gd)-ANADYWR was measured on a 3.0 T MR system . The specific tumor enhancement of the agent was investigated in four distinct mouse models, including subcutaneous, orthotopic, genetically engineered and chemically induced HCC mice. RESULTS: The R1 relaxivity value of DOTA(Gd)-ANADYWR is 5.11 mM-1s-1 at 3.0 T, which is similar to that of the nonspecific clinical agent Gadoteridol. DOTA(Gd)-ANADYWR generated superior enhanced MR signal in HCC lesions and provided complementary enhancement MR signals to the clinically available hepatobiliary MR contrast agent gadoxetate disodium (Gd-EOB-DTPA). Importantly, DOTA(Gd)-ANADYWR could efficiently visualize small HCC lesion (approximately 1 mm) which was hardly detected by the clinical Gd-EOB-DTPA. CONCLUSION: These findings suggest the potential application of this integrin α6-targeted MR probe for the detection of HCC, particularly for small HCC.

Multiple mathematical models of diffusion-weighted magnetic resonance imaging combined with prognostic factors for assessing the response to neoadjuvant chemotherapy and radiation therapy in locally advanced rectal cancer.

PURPOSE: To investigate whether the apparent diffusion coefficient (ADC), intravoxel incoherent motion (IVIM), and stretched exponential model (SEM) based on histogram analyses derived from the whole-tumor volume combined with prognostic factors can be used to assess the response to chemotherapy and radiation therapy (CRT) in locally advanced rectal cancer (LARC). MATERIALS AND METHODS: This study included 60 patients with LARC who underwent diffusion-weighted imaging with 9b values (0-1000s/mm2) before CRT. Histograms derived from the whole-tumor volume were used to obtain the ADC, IVIM (Dslow, Dfast, and f), and SEM parameters (distributed diffusion coefficient (DDC) and α). The histogram metrics and prognostic factors before CRT were compared between pathological complete response (pCR) and non-pCR patients. The receiver operating characteristic (ROC) and the area under the ROC curve (AUC) were generated to analyze the histogram metrics and prognostic factors. RESULTS: A significant difference was only found in the tumor volume between the pCR and non-pCR groups (p = 0.033, AUC = 0.740). The ADC mean, DDC median, and most of the histogram metrics were significantly lower in the pCR group than the non-pCR group (p = 0.000-0.025), and AUC was highest for the ADC mean (0.890). Only the Dslow median differed significantly between the two groups (p = 0.023, AUC = 0.721). However, the Dfast, f, and α histogram metrics did not differ significantly between the pCR and non-pCR groups. The AUC for the ADC mean combined with the tumor volume was 0.908, with a sensitivity of 100% and specificity of 81%. The inter-observer agreements were good or excellent for the ADC and SEM histogram parameters but generally fair for IVIM. CONCLUSION: The whole-tumor ADC mean combined with the tumor volume was highly accurate for predicting pCR. The IVIM models were inferior to ADC and SEM at predicting pCR.

Diffusion-weighted MR imaging of locally advanced breast carcinoma: the optimal time window of predicting the early response to neoadjuvant chemotherapy.

BACKGROUND: It is very difficult to predict the early response to NAC only on the basis of change in tumor size. ADC value derived from DWI promises to be a valuable parameter for evaluating the early response to treatment. This study aims to establish the optimal time window of predicting the early response to neoadjuvant chemotherapy (NAC) for different subtypes of locally advanced breast carcinoma using diffusion-weighted imaging (DWI). METHODS: We conducted an institutional review board-approved prospective clinical study of 142 patients with locally advanced breast carcinoma. All patients underwent conventional MR and DW examinations prior to treatment and after first, second, third, fourth, sixth and eighth cycle of NAC. The response to NAC was classified into a pathologic complete response (pCR) and a non-pCR group. DWI parameters were compared between two groups, and the optimal time window for predicting tumor response was established for each chemotherapy regimen. RESULTS: For all the genomic subtypes, there were significant differences in baseline ADC value between pCR and non-pCR group (p < 0.05). The time point prior to treatment could be considered as the ideal time point regardless of genomic subtype. In the group that started with taxanes or anthracyclines, for Luminal A or Luminal B subtype, postT1 could be used as the ideal time point during chemotherapy; for Basal-like or HER2-enriched subtype, postT2 as the ideal time point during chemotherapy. In the group that started with taxanes and anthracyclines, for HER2-enriched, Luminal B or Basal-like subtype, postT1 could be used as the ideal time point during chemotherapy; for Luminal A subtype, postT2 as the ideal time point during chemotherapy. CONCLUSIONS: The time point prior to treatment can be considered as the optimal time point regardless of genomic subtype. For each chemotherapy regimen, the optimal time point during chemotherapy varies across different genomic subtypes.

Study on the cephalopelvic relationship with cephalic presentation in nulliparous full-term Chinese pregnant women by MRI with three-dimensional reconstruction.

PURPOSE: To analyze the relationship between fetal head size and maternal pelvis size using magnetic resonance imaging (MRI) with a 3-D reconstruction technique. METHODS: A total of 301 nulliparous full-term Chinese pregnant women with cephalic presentation were enrolled and received MRI examinations before labor onset. Data were collected and imported into Mimics software to reconstruct the maternal pelvis and fetus. RESULTS: Of 301 pregnant women, 212 underwent vaginal delivery and 32 received cesarean section. The body mass index (BMI) was significantly different between the vaginal delivery group and the suspected cephalopelvic disproportion (CPD) group; the larger the BMI, the higher was the risk of CPD. The transverse diameter of the pelvic inlet and the posterior sagittal diameter of the midpelvis were significantly larger in the vaginal delivery group, compared with the suspected CPD group. Fetal weight > 3.5 kg could be used as a diagnostic indicator for CPD. CONCLUSIONS: BMI is a risk factor for CPD, and fetal weight < 3.5 kg is an important diagnostic indicator for natural delivery in Chinese pregnant women.

Solid pseudopapillary tumor of the pancreas: clinical features and imaging findings.

This study aimed to report clinical features and CT, MRI, PET/CT findings of solid pseudopapillary tumor (SPT) of the pancreas. Thirty-four patients with pathologically proven SPT were retrospectively reviewed. Most patients were asymptomatic. SPTs in male patients mainly appeared as solid and near solid tumors. Mixed tumors and cystic tumors had larger size than solid and near solid tumors. Solid tumors and solid part of mixed tumors were T2 hyperintense and T1 hypointense and had progressive enhancement. Four tumors (80%) showed markedly even or uneven 18F-FDG uptake. These characteristic features can help differentiate SPT from other pancreatic neoplasms.

Multifunctional superparamagnetic nanoparticles conjugated with fluorescein-labeled designed ankyrin repeat protein as an efficient HER2-targeted probe in breast cancer.

Based on the discordance of human epidermal growth factor receptor-2 (HER2) expression between primary and metastatic/recurrent breast cancer, HER2 molecular imaging, which had potential to systemically assess and dynamically monitor HER2 expression, might improve the selection of patients for anti-HER2 therapy. In this study, designed ankyrin repeat protein (DARPin) G3, a novel binding protein with picomolar affinity for HER2, was used and multifunctional superparamagnetic nanoparticles modified with fluorescein-5-maleimide-labeled DARPin G3 (SPIO-G3-5MF) were developed for HER2 imaging. Our results showed that SPIO-G3-5MF nanoparticles, which possessed uniform size of about 100 nm, favorable dispersity and low cytotoxicity, could selectively bind to HER2-positive breast cancer cells even in the presence of trastuzumab. Biodistribution assay demonstrated that abundant accumulation and long retention of SPIO-G3-5MF were observed in HER2-positive transplantation breast tumors although a portion of SPIO-G3-5MF nanoparticles were unavoidably captured by liver and spleen. Further MR imaging revealed that SPIO-G3-5MF could selectively image HER2-positive transplantation breast tumors, yielding remarkable T2 signal reduction (50.33 ± 2.90% at 6 h and 47.29 ± 9.36% at 24 h). Our study suggested that SPIO-G3-5MF might be a promising MR molecular probe for diagnosing and monitoring HER2 expression state of breast cancer in the future.

The relationship between fractional anisotropy value and tumor microarchitecture in late-stage rat glioma.

OBJECTIVE: To explore the magnetic resonance diffusion tensor imaging (MR-DTI) features of in the late stage of Wistar rat C6 brain glioma, and the relationship between fractional anisotropy value and tumor microarchitecture. METHODS: The concentration of more than 1.0 × 106/10 µL glioma cells and complete medium were injected stereotactically into the right caudate nucleus of the experimental group (n = 35) and control group (n = 10), respectively. Conventional MRI, DTI, and enhanced T1WI scans were Performed using the GE Signa HD × 3.0T MRI scanner about 3-4 weeks after implantation for the rats. Postprocessing was done using the DTI specific software Function Tool to gain FA image. Many ROIs were drawn avoiding hemorrhage, necrosis areas in tumor parenchyma, the value of FA was recorded. Each surviving rat brain was examined histologically using HE and immunohistochemical staining for VEGF and CD34. Pearson correlation analysis was used to determine the relationships between FA values and VEGF, MVD, cell density, respectively. RESULTS: A total of 35 tumor-bearing rats were confirmed the tumor formation by the subsequent MRI and pathological examination. The mean FA values of the tumor and the contralateral brain tissue were 0.17 ± 0.03 and 0.31 ± 0.05 respectively, and the difference was statistically significant (t = 12.80, P < 0.05). The mean FA value of grade III glioma (n = 12) was 0.16 ± 0.03, and the average FA value of grade IV glioma (n = 23) was about 0.18 ± 0.04. There was no significant difference between the two groups (t = 1.92, P > 0.05). FA value in the late stage of Wistar rat C6 brain glioma has significant positive correlation to VEGF, MVD, cell density. The correlation coefficients between FA and VEGF, MVD, and cell density were 0.67, 0.65 and 0.71 (P < 0.05), respectively. CONCLUSIONS: The FA value of rat glioma tumor in the late stage can preoperatively provide an accurate, reliable and noninvasive imaging monitoring method to evaluate the microstructure of glioma (cell density, the extent of angiogenesis, fiber bundle integrity and tumor cell infiltration and so on), predict the biological behavior of the tumor and make out surgical plan.

[Clinical analysis of 939 patients with adrenal lesions detected by abdominal computed tomography].

OBJECTIVE: To investigate the prevalence, etiology and clinical characteristics of adrenal lesions detected by abdominal computed tomography (CT). METHODS: This retrospective study was conducted in patients with adrenal lesions detected by abdominal CT examinations in Nanfang Hospital between July, 2014 and June, 2015. The clinical data of the patients were collected for analysis of the demographics, comorbidities, imaging characteristics, biochemical profiles, clinical diagnosis and intervention. RESULTS: A total of 939 patients with adrenal lesions were identified from 19 004 patients undergoing abdominal CT scan over the defined period. The mean age of the patients was 53.2 years and 560 of the patients were male. Among the total cases with adrenal lesions, the percentages of cases with adrenal masses tended to increase progressively with age. Endocrine studies were done in 270 of the total patients, which identified non-functioning masses in 38.9%, primary aldosteronism in 16.3%, Cushing's syndrome in 4.1%, subclinical Cushing's syndrome in 7.0%, and pheochromocytomas in 7.0% of the cases. Adrenal incidentalomas was detected in 191 patients, with a detection rate of 1.0% among the overall patients undergoing abdominal CT scans. Imaging study detected adenomas (70.3%), cortical carcinomas (2.4%), and metastases (0.5%). Of 191 patients with adrenal incidentalomas, only 76 (39.8%) underwent endocrine evaluation, including 34 with nonfunctioning adrenal masses, 17 with pheochromocytoma, 7 with primary aldosteronism, and 5 with subclinical Cushing's syndrome. CONCLUSION: s The overall detection rates of adrenal lesions and adrenal incidentalomas by abdominal CT were 4.9% and 1.0%, respectively, in our cohort of patients undergoing the examination over the defined period. Although most of the lesions were benign and nonfunctioning, malignant and functional lesions were also detected. As many as 60% of the patients with adrenal incidentalomas did not have hormonal testing. Clinicians need to have greater awareness of adrenal incidentalomas and standard protocol for its management should be established.

[Value of PI-RADS v2 scores combined with prostate specific antigen in diagnosis of peripheral zone prostate cancer: a logistic regression analysis].

OBJECTIVE: To assess the value of Prostate Imaging and Reporting and Data System: Version 2 (PI-RADS v2) combined with prostate specific antigen (PSA) in the diagnosis of peripheral zone (PZ) prostate cancer (PCa). METHODS: The preoperative magnetic resonance imaging and PSA data were ananlyzed for 69 patients with pathologically confirmed PCa and 109 non-PCa patients. PI-RADS v2 scores (1-5) was used to evaluate the risk of PZ PCa. The total PSA (tPSA) level, free to total PSA ratio (f/t PSA), PSA density (PSAD), PZ-PSAD and PI-RADS v2 scores were compared between the PCa and non-PCa patients. Logistic regression models were established with parameters that differed significantly the two groups. The receiver opearting characteristics (ROC) curve was constructed based on the P values derived from the logical regression models and PI-RADS scores to assess the diagnostic efficiency. RESULTS: PI-RADS v2 score, tPSA, f/t PSA, PSAD and PZ-PSAD differed significantly between the two groups (P<0.01). Four predictive multivariate models were established: Logit P=-6.825+1.024PI-RADS v2+ 0.223tPSA (A), Logit P=-4.354+1.586PI-RADS v2-12.7841f/tPSA (B), Logit P=-8.993+1.630PI-RADS v2+17.091PSAD (C), and Logit P=-9.434+1.596PI-RADS v2+10.494PZ-PSAD (D), whose area under the ROC curves was 0.908, 0.891, 0.944, and 0.961, respectively, all significantly greater than that of PI-RADS v2 score (P<0.05). CONCLUSION: Compared with PI-RADS v2 score alone, the combination of PI-RADS v2 score and PSA in the logistic regression model can improve the diagnostic efficiency of PZ PCa and offers better confidence in the decision of biopsy in suspected cases.

[Analysis of normal pelvis morphometry of modern Chinese southern Han female and its correlation with age].

OBJECTIVE: To analyze the normal pelvis morphometry of Chinese southern Han female and its correlation with age. METHODS: From August 2009 to September 2011, 289 Han nationality females who received pelvis CT scan at Nanfang Hospital of Southern Medical University were eligible for the study. Their mean age was 43.5 years, with normal body development and no pelvic abnormality. The patients were divided into 3 age groups: 25 to 40 (n = 109), 41 to 50 (n = 115), and >50 years (n = 65). After constructing a three-dimensional digital model of the pelvis, the following parameters were measured, including transverse inlet diameter, posterior sagittal diameter of pelvic inlet, sagittal inlet, diagonal conjugate, biischial diameter, posterior sagittal diameter of midpelvis, sagittal midpelvic diameter, intertuberous distance, posterior sagittal diameter of outlet, angle of pubic arch, sagittal outlet, penal height, sacrum length and sacrum curvature. The relationship between all parameters and age was analyzed. RESULTS: (1) The posterior sagittal diameters of pelvic inlet of the 25 to 40 age group, 41 to 50 age group, >50 years age group were (53 ± 8), (51 ± 7), (48 ± 6) mm. The sagittal inlet of the three groups were (122 ± 8), (120 ± 9), (114 ± 8) mm. And the diagonal conjugate of the three groups were (135 ± 10), (132 ± 9), (127 ± 9) mm. All had significant differences among the three groups (P < 0.01) . (2) The posterior sagittal diameter of midpelvis of the three groups were (43 ± 6), (44 ± 6), (43 ± 7) mm, and the sagittal midpelvic diameter of the three groups were (119 ± 8), (120 ± 8), (119 ± 7) mm, with no significant difference among the three groups (P > 0.05). (3) The intertuberous distance of the three groups were (122 ± 11), (121 ± 10), (117 ± 11) mm, and the posterior sagittal diameter of outlet of the three groups were (56 ± 9), (58 ± 8), (57 ± 9) mm. There was no significant difference among the three groups (P > 0.05) .(4) Penal height of three groups were (31 ± 3), (33 ± 3), (34 ± 3) mm, there was with significant differences (P < 0.01) .(5) Pearson correlation analysis showed that penal height was positively correlated with age (r = 0.331, P < 0.05), while sagittal inlet, posterior sagittal diameter of inlet, diagonal conjugate, intertuberous distance, angle of pubic arch, sacrum length and sacrum curvature were negatively correlated with age (r = -0.120 to -0.343, P < 0.05). CONCLUSIONS: The shape of the pelvic inlet of Chinese southern Han female changed from sagittal elliptic into transverse elliptic form, and the posterior part of pelvic inlet became larger.Sacral concavity was increased and the pelvis became deeper. Mid pelvis and the pelvic outlet was almost unchanged, and showed no correlation with age.

Primary malignant fibrous histiocytoma of the abdominal cavity: CT findings and pathological correlation.

AIM: To study computed tomography (CT) features of abdominal malignant fibrous histiocytoma (MFH) in various rare locations. METHODS: We retroprospectively identified cases of MFH involving the abdominal cavity. Particular attention was paid to details regarding imaging features and histological types. RESULTS: The study population consisted of seven men and one woman, with a mean age of 52.5 years. Seven patients had some physical symptoms, while one was incidentally detected. The sites of origin were liver (n = 3), greater omentum (n = 1), superior mesentery (n = 1), ileum (n = 1), right psoas muscle (n = 1) and right kidney (n = 1). With the exception of the ileum lesion, all were of huge size. The contour of the lesions was more or less clear. Foci of necrosis were present in six lesions (n = 6). On plain CT scan, all lesions were hypo to iso dense. The lesion in the greater omentum was cystic. One lesion (n = 1) showed significant enhancement and the cystic lesion showed mild peripheral enhancement. An abundance of blood vessels surrounding the mass was seen in two lesions (n = 2) and both were of the inflammatory variety. Pathological examination revealed storiform-pleomorphic variety (n = 4), inflammatory variety (n = 3) and myxoid variety (n = 1). Two of the patients with inflammatory MFH had a clinical presentation of fever and one was afebrile, however, blood investigations in all three showed leukocytosis. CONCLUSION: Primary MFHs of the abdominal viscera and gastrointestinal tract are generally huge soft tissue masses containing areas of low attenuation and mild to moderate contrast enhancement.

Intracranial extramedullary hematopoiesis in beta-thalassemia.

Extramedullary hematopoiesis (EMH) represents tumor-like proliferation of hemopoietic tissue which complicates chronic hemoglobinopathy. Intracranial EMH is an extremely rare occurrence. Magnetic resonance imaging (MRI) offers a precise diagnosis. It is essential to distinguish EMH from other extradural central nervous system tumors, because treatment and prognosis are totally different. Herein, we report the imaging findings of beta-thalassemia in a 13-year-old boy complaining of weakness of left side of the body and gait disturbance; CT and MRI revealed an extradural mass in the right temporoparietal region.

¹¹C-methionine and ¹8F-fluorodeoxyglucose positron emission tomography/CT in the evaluation of patients with suspected primary and residual/recurrent gliomas.

BACKGROUND: (18)F-fluorodeoxyglucose (FDG) is the most widely used radiotracer in tumor imaging, but its use for brain gliomas and recurrence is limited by the high (18)F-FDG uptake in normal brain tissue. (11)C-methionine (MET) has low uptake in the normal brain tissue, providing potential advantages over (18)F-FDG. The aim of the study was to investigate the diagnostic value of (11)C-MET compared to (18)F-FDG positron emission tomography and computed tomography (PET/CT) in patients with suspected primary and residual/recurrent gliomas. METHODS: Eighty paired PET/CT scans using (11)C-MET and (18)F-FDG were performed on 44 newly diagnosed patients with suspected gliomas and 36 post-operative patients with suspected residual/recurrent tumors. PET/CT results were evaluated by visual and semiquantitative analysis. The sensitivity, specificity and accuracy for detection of gliomas and residual/recurrent tumors were calculated using visual analysis. Tumor to contralateral normal gray matter (T/G) ratio was calculated for semiquantitative analysis. RESULTS: Final pathology of the 44 newly diagnosed patients included 26 gliomas (14 high-grade and 12 low-grade tumors) and 18 non-glioma benign lesions. Residual/recurrent gliomas were verified in 28 patients and excluded in 8/36 post-operative patients by subsequent histopathologic examination and/or clinical follow-up for more than six months. The sensitivity, specificity and accuracy of (11)C-MET PET/CT were 88.5%, 83.3% and 86.4% for gliomas and 96.4%, 87.5% and 94.4% for residual/recurrent gliomas, respectively. The sensitivity, specificity and accuracy of (18)F-FDG PET/CT were 50.0%, 88.9% and 65.9% for gliomas and 46.4%, 100.0% and 58.3% for residual/recurrent gliomas, respectively. (11)C-MET had a higher sensitivity than (18)F-FDG (83.3% vs. 33.3%, P = 0.031) in low-grade gliomas, but had no significant difference in sensitivity from (18)F-FDG for high-grade gliomas (92.9% vs. 64.3%, P = 0.219). (11)C-MET T/G uptake ratios in high-grade gliomas, low-grade gliomas and benign lesions were 1.94 ± 0.53, 1.78 ± 0.61 and 1.06 ± 0.34, respectively. (18)F-FDG T/G uptake ratios in high-grade gliomas, low-grade gliomas and benign lesions were 1.05 ± 0.37, 0.66 ± 0.14 and 0.63 ± 0.17, respectively. CONCLUSIONS: (11)C-MET PET/CT is superior to (18)F-FDG PET/CT in detecting and delineating gliomas and residual/recurrent tumors, especially low-grade gliomas and residual/recurrent lesions present in gray matter, but its role in non-invasive grading of the tumors is limited.

Intracranial Extramedullary Hematopoiesis in Beta-Thalassemia

Extramedullary hematopoiesis (EMH) represents tumor-like proliferation of hemopoietic tissue which complicates chronic hemoglobinopathy. Intracranial EMH is an extremely rare occurrence. Magnetic resonance imaging (MRI) offers a precise diagnosis. It is essential to distinguish EMH from other extradural central nervous system tumors, because treatment and prognosis are totally different. Herein, we report the imaging findings of beta-thalassemia in a 13-year-old boy complaining of weakness of left side of the body and gait disturbance; CT and MRI revealed an extradural mass in the right temporoparietal region.

[Mammography and magnetic resonance imaging for diagnosis of the intraductal papilloma of the breast].

OBJECTIVE: To investigate the features of intraductal papilloma of the breast in mammography and magnetic resonance imaging (MRI) and assess the diagnostic values of the two imaging modalities. METHODS: Fifteen patients with intraductal papilloma of the breast confirmed surgically and pathologically underwent X-ray examination of the breast, and 11 of them also received enhanced MRI. The imaging findings by mammography and MRI were compared. RESULTS: Enhanced MRI clearly displayed the location and morphology of the intraductal papilloma, and 7 patients showed smooth tumor margins and 2 showed irregular margins. On T(1)WI, the lesions were isointense or slightly hypointense, and appeared isointense or slightly hyperintense on T(2)WI. Some of the intraductal papillomas were seen encapsulated in the dilated ductal. The varying enhancement features of the lesions increased the difficulty in distinguishing from carcinoma. Mammography identified intraductal papillomas only in 2 of the 15 cases (13%) with lesion feature similar to that found by MRI. Fine cluster calcification was found in 1 case. CONCLUSION: MRI can more accurately define the location of the lesion than X-ray. In spite of some resemblance in the MRI findings between intraductal papillomas and breast carcinoma, MRI still serves as a useful diagnostic modality for intraductal papilloma that shows some characteristic findings.