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.

Machine Learning-Based Multiparametric Magnetic Resonance Imaging Radiomic Model for Discrimination of Pathological Subtypes of Craniopharyngioma.

BACKGROUND: Preoperative, noninvasive discrimination of the craniopharyngioma subtypes is important because it influences the treatment strategy. PURPOSE: To develop a radiomic model based on multiparametric magnetic resonance imaging for noninvasive discrimination of pathological subtypes of craniopharyngioma. STUDY TYPE: Retrospective. POPULATION: A total of 164 patients from two medical centers were enrolled in this study. Patients from the first medical center were divided into a training cohort (N = 99) and an internal validation cohort (N = 33). Patients from the second medical center were used as the external independent validation cohort (N = 32). FIELD STRENGTH/SEQUENCE: Axial T1 -weighted (T1 -w), T2 -weighted (T2 -w), contrast-enhanced T1 -weighted (CET1 -w) on 3.0 T or 1.5 T magnetic resonance scanners. ASSESSMENT: Pathological subtypes (squamous papillary craniopharyngioma and adamantinomatous craniopharyngioma) were confirmed by surgery and hematoxylin and eosin staining. Optimal radiomic feature selection was performed by SelectKBest, the least absolute shrinkage and selection operator algorithm, and support vector machine (SVM) with a recursive feature elimination algorithm. Models based on each sequence or combinations of sequences were built using a SVM classifier and used to differentiate pathological subtypes of craniopharyngioma in the training cohort, internal validation, and external validation cohorts. STATISTICAL TESTS: The area under the receiver operating characteristic curve (AUC) was used to assess the diagnostic performance of the radiomic models. RESULTS: Seven texture features, three from T1 -w, two from T2 -w, and two from CET1 -w, were selected and used to construct the radiomic model. The AUC values of the radiomic model were 0.899, 0.810, and 0.920 in the training cohort, internal and external validation cohorts, respectively. The AUC values of the clinicoradiological model were 0.677, 0.655, and 0.671 in the training cohort, internal and external validation cohorts, respectively. DATA CONCLUSION: The model based on radiomic features from T1 -w, T2 -w, and CET1 -w has a high discriminatory ability for pathological subtypes of craniopharyngioma. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: 2.

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.

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.

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.

Esthesioneuroblastoma methods of intracranial extension: CT and MR imaging findings.

INTRODUCTION: Esthesioneuroblastoma (ENB) is an aggressive neuroectodermal malignancy in the upper nasal cavity with local infiltration and lymphatic or hematogenous metastasis. The purpose of this paper is to document three types of direct intracranial extensions by ENB using computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: Eleven patients with pathologically confirmed ENB were admitted in our hospital between December 2002 and December 2008. Their magnetic resonance (MR; n = 10) and CT (n = 8) images were retrospectively reviewed, and particular attention was paid to tumor location and extension, enhancement pattern, cervical lymph node metastasis, and Kadish stage. RESULTS: The majority of patients were male (8/11) with Kadish stage C tumor (10/11). Three types of direct intracranial extension by ENBs were put forward according to their MR and CT findings. The primary tumors were well-defined soft-tissue masses centered in the roof of the nasal cavity eroding into the paranasal sinuses (11/11), the contralateral nasal cavity (4/11), the cranial cavity (5/11), and the fossa orbitalis (3/11). The tumor parenchyma were hypointensity on T1-weighted images, heterogeneous hyperintensity on T2-weighted images, and isodensity or slight hyperdensity on CT images with scattered necroses (4/11) and marginal cysts(4/11). Their enhancements were significant and inhomogeneous. Cervical lymph nodes metastases were observed in four patients (4/11), but no pathologically proved distant metastasis was observed. CONCLUSION: Three types of direct intracranial extensions by ENB can be found on CT and MRI: cranio-orbital-nasal-communicating ENB, cranio-nasal-communicating ENB, and orbital-nasal-communicating ENB.

[A comparative study of Gd-DTPA and HSA-Gd-DTPA in magnetic resonance lymphography].

OBJECTIVE: To compare the effects of two contrast agents, Gd-DTPA and HSA-Gd-DTPA, in magnetic resonance (MR) lymphography. METHODS: Twelve New-Zealand rabbits were randomized into Gd-DTPA and HSA-Gd-DTPA groups with subcutaneous (interdigital skin fold) injection of the two contrast agents (0.2 ml of 0.5 mmol/L Gd(3+)) for MR lymphography of the popliteal lymph nodes examined in the axial and sagital orientation. T(1)-weighted, T1-weighted fat suppressed, and T(2)-weighted spin-echo (SE) images of the lymph nodes were obtained in plain scans. The post-contrast scanning started at 30 min, 1 h and 3 h after Gd-DTPA administration and at 10 min, 30 min and 60 min after HSA-Gd-DTPA injection to obtain T(1)-weighted images with identical imaging parameters. The signal intensity of popliteal lymph node was measured and the enhancement rate calculated. RESULTS: After subcutaneous injection, Gd-DTPA quickly entered blood circulation to result in obvious enhancement of the anterior-tibial vein and the urine and also in heterogeneous enhancement of the popliteal lymph nodes. HSA-Gd-DTPA did not enter the blood, causing obvious homogeneous enhancement of the lymphatic vessels and lymph nodes. HSA-Gd-DTPA resulted in higher enhancement rate than Gd-DTPA, and the enhancement rate in Gd-DTPA group decreased with time as opposed to that of the HSA-Gd-DTPA group. CONCLUSION: HSA-Gd-DTPA has better performance than Gd-DTPA in MR lymphography after subcutaneous administration.

[Magnetic resonance imaging enhanced by superparamagnetic iron oxide particles in detecting lymph node metastasis of tumors: an experimental study].

OBJECTIVE: To investigate the value of superparamagnetic iron oxide particles (SPIO) in magnetic resonance (MR) imaging for detecting lymph node metastasis of tumors. METHODS: Twelve New Zealand rabbits were used in this study, 6 of which received unilateral intra-muscular inoculation of VX2 carcinoma cells to induce lymph node metastasis of the tumor, and the other 6 served as normal control group. MR images of the lymph nodes of the rabbits were obtained before and 12 h after subcutaneous injection of SPIO, followed by image analysis in correlation with pathological examinations. RESULTS: On plain MR images, normal and metastatic lymph nodes showed similar signal characteristics. After administration of SPIO, the signal intensity of both normal lymph nodes and metastatic ones remained unchanged in spin echo (SE) T1-weighted images. On SE T2-weighted images, the signal intensity of normal lymph nodes significantly decreased heterogeneously, while that of all metastatic lymph nodes remained unchanged. In gradient recalled echo (GRE) T2-weighted images, the signal intensity of normal lymph nodes decreased significantly and homogeneously, while that of 4 rabbits in metastasis group remained unchanged, with the signal intensity in the other 2 rabbits decreased heterogeneously. CONCLUSION: SPIO-enhanced MR imaging can be applied to detect lymph node metastasis of the tumors.

[Superparamagnetic iron oxide-enhanced magnetic resonance imaging of hepatocellular carcinoma in rats].

OBJECTIVE: To evaluate the value of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the diagnoses of focal liver lesions. METHODS: Twenty rat models of hepatocellular carcinoma were induced by feeding the rats with N-nitrosodiethylamine. Before and after SPIO injection into the rats, MR imaging was performed including the sequences of spin-echo (SE) T1WI (390 ms/14 ms), TSE T2WI (4 100 ms/99 ms), SE Dual-echoes (1 800 ms/20 ms/70 ms), GRE FLASH T2*WI (600 ms/15 ms/15 ), and GRE FLASH T1WI (150 ms/14 ms/70 ). Another 5 normal rats were selected as negative control, which also received SPIO and MR imaging in the same manner as described above. The characteristics of SPIO-enhanced MRI of different liver lesions were analyzed. RESULTS: After SPIO enhancement, the signal intensity of normal liver and cirrhotic liver both decreased, especially on GRE T2*WI. The signal intensity of hepatocellular carcinoma (HCC), regenerative nodules (RN), and focal nodule hyperplasia (FNH) all increased on T1WI images. On T2WI and T2*-weighted images, the signal intensity of HCC remained high, while significant signal loss occurred in RN and FNH. After SPIO administration, the contrast-to-noise (CNR) of HCC on GRE T2*-weighted images was greater than that of other sequences. CONCLUSION: SPIO has not only considerable T2-negative effect but also slightly T1-shortening effect, which is of great value in the differential diagnosis of focal liver lesions.