Sclerosing Angiomatoid Nodular Transformation of the Spleen: Radiological Findings and Radiological-pathological Correlation

Introduction: The objective of this study was to describe the CT and MRI features of sclerosing angiomatoid nodular transformation (SANT) of the spleen with pathologic correlation. Materials and Methods: Ten patients with surgically resected and pathologically confirmed SANTs were included. Clinical history was reviewed, and gross pathologic, histologic, and immunohistochemical findings were recorded. CT and MRI examinations were evaluated by two radiologists. Results: Patients included seven men and three women, with a mean age of 42.9±16.7 years. Pathologic features of SANTs involved multiple angiomatous nodules in a radiating pattern with a central stellate fibrous scar and evidence of hemosiderin deposition. 9 cases showed a lobulated demarcated margin, 8 cases a slight hypoattenuating, 1 isoattenuating, and 1 case with two lesions demonstrated a slight hyperattenuating margin, respectively. Multiple scattered punctate calcifications were involved in 2 cases. 5 cases manifested hypointensity on in-phase imaging, 1 iso-intensity, and 4 iso-hypointensity on out-of-phase imaging. Progressive and centripetal enhancement were exhibited in 10 cases, spoke-wheel pattern in 3 cases, and nodular enhancement in 4 cases, respectively. The central fibrous scar was identified in 8 cases during delayed enhancement. Conclusion: Characteristics of SANTs on CT/MRI reflected the underlying pathology. Hypointensity on DWI and T2WI, and change of signal on T1 chemicalshift imaging were found to be due to hemosiderin deposition and fibrous tissue. Typical feature was a solitary, round, lobulated mass with a fibrous scar. Progressive and centripetal enhancement, spoke-wheel pattern, nodular enhancement, and delayed enhancement of central fibrous scar were observed.

Diagnostic performance of MRI, SPECT, and PET in detecting renal cell carcinoma: a systematic review and meta-analysis.

BACKGROUND: Renal cell carcinoma (RCC) is one of the most common malignancies worldwide. Noninvasive imaging techniques, such as magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET), have been involved in increasing evolution to detect RCC. This meta-analysis aims to compare to compare the performance of MRI, SPECT, and PET in the detection of RCC in humans, and to provide evidence for decision-making in terms of further research and clinical settings. METHODS: Electronic databases including PubMed, Web of Science, Embase, and Cochrane Library were systemically searched. The keywords such as "magnetic resonance imaging", "MRI", "single-photon emission computed tomography", "SPECT", "positron emission tomography", "PET", "renal cell carcinoma" were used for the search. Studies concerning MRI, SPECT, and PET for the detection of RCC were included. Pooled sensitivity, specificity, and the area under the summary receiver operating characteristic (SROC) curve (AUC), etc. were calculated. RESULTS: A total of 44 articles were finally detected for inclusion in this study. The pooled sensitivities of MRI, 18F-FDG PET and 18F-FDG PET/CT were 0.80, 0.83, and 0.89, respectively. Their respective overall specificities were 0.90, 0.86, and 0.88. The pooled sensitivity and specificity of MRI studies at 1.5 T were 0.86 and 0.94, respectively. With respect to prospective PET studies, the pooled sensitivity, specificity and AUC were 0.90, 0.93 and 0.97, respectively. In the detection of primary RCC, PET studies manifested a pooled sensitivity, specificity, and AUC of 0.77, 0.80, and 0.84, respectively. The pooled sensitivity, specificity, and AUC of PET/CT studies in detecting primary RCC were 0.80, 0.85, and 0.89. CONCLUSION: Our study manifests that MRI and PET/CT present better diagnostic value for the detection of RCC in comparison with PET. MRI is superior in the diagnosis of primary RCC.

Risk Factors and Outcomes of Stroke-Associated Pneumonia in Patients with Stroke and Acute Large Artery Occlusion Treated with Endovascular Thrombectomy.

BACKGROUND AND PURPOSE: Stroke-associated pneumonia (SAP) often increases high hospital mortality, prolongs length of hospital stay, and has considerable economic impact on healthcare costs. We aimed to explore independent predictors of SAP in acute anterior large artery occlusion patients who treated with endovascular treatment (EVT). METHODS: Consecutive patients with acute anterior large artery occlusion stroke who underwent EVT from the Nanjing Stroke Registry from January 2019 to January 2020 were identified retrospectively. Patients were divided into SAP group and Non-SAP group. In the univariate analysis, variables including demographics, clinical factors, labs, and EVT features were compared between the two groups. Then a multivariable logistic regression analysis was conducted to determine independent predictors of SAP. RESULTS: One hundred and twelve patients were enrolled. Patients with SAP, compared to those without SAP, had lower modified treatment in cerebral infarction (mTICI) score 2b-3 rate (54.8% vs 85.2%; P = 0.001), higher asymptomatic intracerebral hemorrhage rate (48.4% vs 28.4%; P = 0.046), lower modified Rankin Scale (mRS) score 0-2 rate at 90days rate (9.7% vs 60.5%; P < 0.001), and higher mortality at 90days (38.7% vs 11.1%; P = 0.001). The independent predictors of SAP were dysphagia (Unadjusted Odds ratio[OR] 6.49, 95% Confidence interval[CI] 2.49-16.92; P = 0.02; Adjusted OR 3.59, 95% CI 1.19-10.83; P = 0.02), neutrophil-lymphocyte ratio (Unadjusted OR 1.19, 95% CI 1.1-1.3; P = 0.001; Adjusted OR 1.15, 95% CI 1.06-1.25; P = 0.001), and mTICI 2b-3 (Unadjusted OR 0.21, 95% CI 0.08-0.54; P = 0.001; Adjusted OR 0.3, 95% CI 0.1-0.92; P = 0.04). CONCLUSION: Dysphagia, higher neutrophil-lymphocyte ratio, and failed recanalization were associated with SAP in acute ischemic stroke patients underwent endovascular therapy. Identification and prevention of SAP was necessary and important.

Diagnostic evaluation of diffusion kurtosis imaging for prostate cancer: Detection in a biopsy population.

PURPOSE: To prospectively assess the feasibility of diffusional kurtosis (DK) imaging for distinguishing prostate cancer(PCa) from benign prostate hyperplasia (BPH) in comparison with standard diffusion-weighted (DW) imaging, as well as low-from high-grade malignant regions. MATERIALS AND METHODS: 147 consecutive patients with suspected PCa underwent multi-parametric 1.5-TMR. Diffusion kurtosis imaging was acquired with with 5 b values (0,600,800,1600,and 2400sec/mm2).Region of interest (ROI)-based measurements were performed on ADC, D, and K map by two radiologists. Data were analyzed by using mixed-model analysis of variance and receiver operating characteristic curves. Correlations among the three parameters (ADC,D and K) in all patients, and correlations between three parameters with the tumor Gleason score (GS) in PCa group were analyzed using Pearson's correlation coefficient in peripheral zone(PZ) and transiton zone(TZ). RESULTS: 58 patients were proved with PCa (9 GS 3 + 3[PZ/TZ = 4/5], 49 GS ≥ 7 [PZ/TZ = 26/23]), and 89 patients were with BPH. ADC,D and K were able to distinguish benignance from tumor tissue both in PZ and TZ(P＜0.01), but performed poorly in neither differentiating low-(GS 3 + 3) from high-grade (GS≥3 + 4) disease, nor GS(3 + 4) from GS(4 + 3).There was a weak correlation between the GS and ADC, D (PZ:ADC r=-0.113, D r=-0.139; TZ:ADC r=-0.104,D r=-0.103), while a moderate correlation between the GS and K(PZ:K r = 0.492; TZ:K r = 0.433, P＜0.01).K had significantly greater area under the curve for differentiating PCa from BHP than ADC both in PZ and TZ. CONCLUSION: DK model may add value in PCa detection and diagnosis, but none can differentiate low-from high-grade PCas (including GS=3+4 from GS=4+3).

Differentiation between intraspinal schwannoma and meningioma by MR characteristics and clinic features.

OBJECTIVES: To retrospectively review the MRI characteristics and clinic features and evaluate the effectiveness of MR imaging in differentiating intraspinal schwannomas and meningiomas, with the excised histopathologic findings as the reference standard. MATERIALS AND METHODS: One hundred and four schwannomas (M/F, 57:47) and 53 meningiomas (M/F, 13:40) underwent MR examinations before surgical treatment. Simple clinic data and imaging findings were considered:(a) location (craniocaudal and axial), (b) size, (c) morphology, (d) dural contact, (e) signal characteristics, (f) enhancement degree and patterns. The usefulness of the algorithm for differential diagnosis was examined between the two tumors. RESULTS: Interobserver agreement was good (κ = 0.7-0.9). Ten cases meningiomas demonstrated multiple lesions. There was a female predominance in the meningiomas (P < 0.001). Meningiomas predominantly were located in the ventral or anterolateral areas of thoracic regions, while schwannomas in the posterolateral areas of the thoracic and the lumbar regions (P < 0.001). Mean size of the lesions was 1.47 ± 0.36 cm for meningioma, and 2.02 ± 1.13 cm for schwannoma (P < 0.001). A dumbbell shape with intervertebral foramen widening could detect schwannomas, while the "dural tail sign" did meningiomas (P < 0.001). Hypointense and miscellaneous signal implied meningioma on T1WIs (P < 0.001). Isointense was more frequently observed in the meningiomas, while the fluid signal intensity and miscellaneous signal in the schwannomas on T2WIs (P < 0.001). Schwannomas usually manifested rim enhancement, while meningiomas diffuse enhancement (P = 0.005). There were six variables including the logistic equation (age, size, dural tail sign, morphology, T2WI, and axial location). The accuracy of the algorithm in diagnosis of schwannomas was 87.1%. CONCLUSIONS: Combination of clinic data and MRI performs significantly for differentiating between intraspinal meningiomas and schwannomas.

Atorvastatin protects BV­2 mouse microglia and hippocampal neurons against oxygen­glucose deprivation­induced neuronal inflammatory injury by suppressing the TLR4/TRAF6/NF­κB pathway.

Atorvastatin is a member of the statin class of drugs, which competitively inhibit the activity of 5­hydroxy­3­methylglutaryl­coenzyme A reductase. The aim of the present study was to assess whether atorvastatin may protect BV­2 microglia and hippocampal neurons against oxygen­glucose deprivation (OGD)­induced neuronal inflammatory injury and to determine the underlying mechanisms by which its effects are produced. Cell viability and apoptotic ability were assessed using an MTT assay and annexin V­fluorescein isothiocyanate/propidium iodide double staining followed by flow cytometry, respectively. The expression of inflammation and apoptosis­associated mRNAs and proteins were assessed using reverse transcription­quantitative polymerase chain reaction and western blotting, and the expression of inflammatory factors was determined using ELISA. The results of the current study revealed that atorvastatin treatment suppressed the viability of OGD BV­2 microglia and hippocampal neurons. Furthermore, atorvastatin treatment reduced the expression of proinflammatory factors in OGD BV­2 microglia. Additionally, it was demonstrated to downregulate the toll­like receptor 4 (TLR4)/tumor necrosis factor receptor­associated factor 6 (TRAF6)/nuclear factor­κB (NF­κB) pathway in OGD BV­2 microglia. Atorvastatin also inhibited the apoptosis of OGD hippocampal neurons by regulating the expression of apoptosis­associated proteins. It was concluded that atorvastatin treatment may protect BV­2 microglia and hippocampal neurons from OGD­induced neuronal inflammatory injury by suppressing the TLR4/TRAF6/NF­κB pathway. This may provide a potential strategy for the treatment of neuronal injury.

Pancreatic ductal adenocarcinoma and chronic mass-forming pancreatitis: Differentiation with dual-energy MDCT in spectral imaging mode.

OBJECTIVE: To investigate the value of dual-energy MDCT in spectral imaging in the differential diagnosis of chronic mass-forming chronic pancreatitis (CMFP) and pancreatic ductal adenocarcinoma (PDAC) during the arterial phase (AP) and the pancreatic parenchymal phase (PP). MATERIALS AND METHODS: Thirty five consecutive patients with CMFP (n=15) or PDAC (n=20) underwent dual-energy MDCT in spectral imaging during AP and PP. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in iodine concentration between the AP and PP, contrast-to-noise ratio (CNR) and the slope K of the spectrum curve were calculated. RESULTS: Normalized iodine concentrations (NICs) in patients with CMFP differed significantly from those in patients with PDAC during two double phases (mean NIC, 0.26±0.04 mg/mL vs. 0.53±0.02 mg/mL, p=0.0001; 0.07±0.02 mg/mL vs. 0.28±0.04 mg/mL, p=0.0002, respectively). There were significant differences in the value of the slope K of the spectrum curve in two groups during AP and PP (K(CMFP)=3.27±0.70 vs. K(PDAC)=1.35±0.41, P=0.001, and K(CMFP)=3.70±0.17 vs. K(PDAC)=2.16±0.70, p=0.003, respectively). CNRs at low energy levels (40-70 keV) were higher than those at high energy levels (80-40 keV). CONCLUSION: Individual patient CNR-optimized energy level images and the NIC can be used to improve the sensitivity and the specificity for differentiating CMFP from PDAC by use of dual-energy MDCT in spectral imaging with fast tube voltage switching.

Disrupted Structural Brain Network in AD and aMCI: A Finding of Long Fiber Degeneration.

Although recent evidence has emerged that Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) patients show both regional brain abnormalities and topological degeneration in brain networks, our understanding of the effects of white matter fiber aberrations on brain network topology in AD and aMCI is still rudimentary. In this study, we investigated the regional volumetric aberrations and the global topological abnormalities in AD and aMCI patients. The results showed a widely distributed atrophy in both gray and white matters in the AD and aMCI groups. In particular, AD patients had weaker connectivity with long fiber length than aMCI and normal control (NC) groups, as assessed by fractional anisotropy (FA). Furthermore, the brain networks of all three groups exhibited prominent economical small-world properties. Interestingly, the topological characteristics estimated from binary brain networks showed no significant group effect, indicating a tendency of preserving an optimal topological architecture in AD and aMCI during degeneration. However, significantly longer characteristic path length was observed in the FA weighted brain networks of AD and aMCI patients, suggesting dysfunctional global integration. Moreover, the abnormality of the characteristic path length was negatively correlated with the clinical ratings of cognitive impairment. Thus, the results therefore suggested that the topological alterations in weighted brain networks of AD are induced by the loss of connectivity with long fiber lengths. Our findings provide new insights into the alterations of the brain network in AD and may indicate the predictive value of the network metrics as biomarkers of disease development.

Disrupted functional brain connectivity and its association to structural connectivity in amnestic mild cognitive impairment and Alzheimer's disease.

Although anomalies in the topological architecture of whole-brain connectivity have been found to be associated with Alzheimer's disease (AD), our understanding about the progression of AD in a functional connectivity (FC) perspective is still rudimentary and few study has explored the function-structure relations in brain networks of AD patients. By using resting-state functional MRI (fMRI), this study firstly investigated organizational alternations in FC networks in 12 AD patients, 15 amnestic mild cognitive impairment (aMCI) patients, and 14 age-matched healthy aging subjects and found that all three groups exhibit economical small-world network properties. Nonetheless, we found a decline of the optimal architecture in the progression of AD, represented by a more localized modular organization with less efficient local information transfer. Our results also show that aMCI forms a boundary between normal aging and AD and represents a functional continuum between healthy aging and the earliest signs of dementia. Moreover, we revealed a dissociated relationship between the overall FC and structural connectivity (SC) in AD patients. In this study, diffusion tensor imaging tractography was used to map the structural network of the same individuals. The decreased FC-SC coupling may be indicative of more stringent and less dynamic brain function in AD patients. Our findings provided insightful implications for understanding the pathophysiological mechanisms of brain dysfunctions in aMCI and AD patients and demonstrated that functional disorders can be characterized by multimodal neuroimaging-based metrics.

Differentiation of Crohn's disease from intestinal tuberculosis by clinical and CT enterographic models.

BACKGROUND: Crohn's disease (CD) and intestinal tuberculosis (ITB) have similar clinical, radiological, and endoscopic features. The objective of our study was to investigate the values of clinical features and computed tomographic (CT) enterographic manifestations in the differential diagnosis between CD and ITB. METHODS: Clinical features and CT enterographic manifestations in a cohort of 141 patients with CD and 47 patients with ITB were reviewed retrospectively. Parameters were screened by logistic regression analysis. Furthermore, the diagnostic efficacy of screened parameters was analyzed by regression equation (mathematical model) and receiver operating characteristic curve. RESULTS: The clinical features indicative of CD were hematochezia and perianal disease; features indicative of ITB include positive purified protein derivative skin test, occurrence of ascites, pulmonary tuberculosis, and night sweats. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of regression mathematical model established by clinical features were 94.3, 80.4, 91.0, 93.7, and 82.6%, respectively. CT enterographic manifestations indicative of CD were the involvement of the left colon, asymmetric pattern of involvement and abscess, comb sign; manifestations indicative ITB were the distribution of the lymph nodes along the right colic artery, contracture of ileocecal valve, fixed patulous ileocecal valve and lymph nodes with central necrosis The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of regression mathematical model established by CT enterographic parameters were 96.5, 93.6, 95.7, 97.8, and 89.8%, respectively. CONCLUSIONS: The accuracy of CT enterographic model suggests the possibility of using CT enterography as an alternative to endoscopy in the differentiation between CD and ITB.

Noninvasive assessment of response to neoadjuvant chemotherapy in osteosarcoma of long bones with diffusion-weighted imaging: an initial in vivo study.

OBJECTIVES: The purpose of our study is to investigate whether diffusion-weighted imaging (DWI) is useful for monitoring the therapeutic response after neoadjuvant chemotherapy in osteosarcoma of long bones. MATERIALS AND METHODS: Conventional magnetic resonance imaging (MRI) and DWI were obtained from 35 patients with histologically proven osteosarcomas. MR examinations were performed in all patients before and after 4 courses of preoperative neoadjuvant chemotherapy. Apparent diffusion coefficients (ADC) were measured. The degree of tumor necrosis was assessed macroscopically and histologically by two experienced pathologists after operation. Student's t test was performed for testing changes in ADC value. Pearson's correlation coefficient was used to estimate the correlation between necrosis rate and post- neoadjuvant chemotherapy ADC values. P<0.05 was considered to denote a significant difference. RESULTS: The difference of the whole osteosarcoma between pre- neoadjuvant chemotherapy ADC value (1.24±0.17×10(-3) mm(2)/s) and post- (1.93±0.39×10(-3) mm(2)/s) was significant difference (P<0.01). Regarding in patients with good response, the post- neoadjuvant chemotherapy values were significantly higher than the pre- neoadjuvant chemotherapy values (P<0.01). The post- neoadjuvant chemotherapy ADC value in patients with good response was higher than that of poor response (t = 8.995, P<0.01). The differences in post- neoadjuvant chemotherapy ADC between viable (1.03±0.17×10(-3) mm(2)/s) and necrotic (2.38±0.25×10(-3) mm(2)/s) tumor was highly significant (t = 23.905, P<0.01). A positive correlation between necrosis rates and the whole tumor ADC values (r = 0.769, P<0.01) was noted, but necrosis rates were not correlated with the ADC values of necrotic (r = -0.191, P = 0.272) and viable tumor areas (r = 0.292, P = 0.089). CONCLUSIONS: DWI can identify residual viable tumor tissues and tumor necrosis induced by neoadjuvant chemotherapy in osteosarcoma. The ADC value can directly reflect the degree of tumor necrosis, and it is useful to evaluate the preoperative neoadjuvant chemotherapy response in patients with osteosarcoma.

Synchronous portal-superior mesenteric vein or adjacent organ resection for solid pseudopapillary neoplasms of the pancreas: a single-institution experience.

Solid pseudopapillary neoplasms of the pancreas (SPN) have been reported increasingly; however, series focusing on portal-superior mesenteric vein (PV/SMV) or adjacent organ resection are limited in the literature. The aim of this study was to present our experience in treating patients with SPN who underwent this extensive resection. Ten eligible patients were retrospectively reviewed and analyzed. Eight females and two males with a median age of 23 years (range, 11 to 58 years) and a median tumor diameter of 12 cm (range, 4 to 20 cm) were observed. All patients had imaging signs of vascular and/or adjacent organ involvement. Resection with curative intent was performed in all patients; eight underwent synchronous PV/SMV resection and two underwent synchronous left nephrectomy. Malignant SPN was confirmed in seven patients. Postoperative mortality was nil and morbidity occurred in five patients. At a median follow-up of 67.5 months (range, 12 to 110 months), nine patients were alive with no evidence of disease and one died of liver metastases. In conclusion, malignant SPN are low-grade tumors with good prognosis. More aggressive attitude should be adopted when PV/SMV or adjacent organ involvement is indicated on preoperative imaging. En bloc synchronous PV/SMV or adjacent organ resection should be applied, when necessary, to achieve complete resection.

Giant cell-rich osteosarcoma in long bones: clinical, radiological and pathological features.

PURPOSE: The purpose of this study was to review the clinical presentation, imaging, pathology and outcome of patients with giant cell-rich osteosarcoma (GCRO) of long bones. MATERIALS AND METHODS: Radiography (n=9), magnetic resonance imaging (MRI) (n=6), computed tomography (CT) (n=3) and clinical course of nine patients (five males and four females; mean age, 26 years) with pathologically confirmed GCRO were retrospectively reviewed. Specific imaging findings, including size, eccentricity, ossification, lysis, cystic change, expansile growth, periosteal reaction, cortical destruction, soft tissue extension and joint involvement were documented. RESULTS: Presenting symptoms were pain in six patients and pain and palpable mass in three. An ill-defined margin surrounding a predominantly osteolytic lesion was detected at the proximal tibia (n=7) or femur (n=2) on imaging studies. Seven cases showed limited ossification. Three cases had tumours in the metaphysis and six in the metaepiphysis. The average maximum tumour dimension was 4.7 cm×5.2 cm×7.8 cm. Microscopically, tumours were composed of atypical cells with scanty osteoid formation and multinucleated giant cells. All patients received chemotherapy, and surgery was performed in eight patients. Three patients were dead and six were alive at the last follow-up. CONCLUSIONS: GCRO is a rarer variant that has very close resemblance to giant cell tumour. Patients usually present nonspecific symptoms of pain and palpable mass. It usually shows an osteolytic lesion with locally spared new bone formation in the metaphysis and/or metaepiphysis on imaging. Histologically, the atypical tumour cells with osteoid formation and multinucleated giant cells are the key factor in the diagnosis and differential diagnosis.

Adenosquamous carcinoma of the pancreas: multidetector-row computed tomographic manifestations and tumor characteristics.

OBJECTIVE: The purpose of this article was to present the adenosquamous carcinoma (ASqC) of the pancreas: multidetector-row computed tomographic (CT) features and tumor characteristics. MATERIALS AND METHODS: The clinical data and CT studies of 12 patients with pathologically proven ASqC of the pancreas between the dates February 2001 and February 2010 were retrospectively analyzed. RESULTS: The presenting symptoms of ASqC of the pancreas were nonspecific. Elevated serum levels of carbohydrate antigen 19-9, carbohydrate antigen 12-5, and carcinoembryonic antigen were noted. The tumor was most commonly involved in the pancreatic head in 6 patients, with the dilation of the common bile duct and the upstream main pancreatic duct. All ASqCs exhibited invasive growth. No calcification and intratumoral hemorrhage were noted in ASqCs. Ten tumors showed enhancement in the early arterial phase and persistent enhancement in the portal vein phase. CONCLUSION: The typical CT appearance of ASqC was solitary oval or round without any capsule and a defined margin. The dilation of the main pancreatic duct and/or the common bile duct was always discovered. The huge infiltrative lesion outside the pancreas was detected in the tail and/or the body of the pancreas. Not only the elevation of carbohydrate antigen 19-9 is common, but also Ca12-5 and CEA, whereas human alpha fetoprotein elevation is not observed. The enhancement pattern of tumor showed persistence in the portal vein phase.

Primary diaphyseal osteosarcoma in long bones: imaging features and tumor characteristics.

OBJECTIVE: This study aims to assess retrospectively the imaging features of diaphyseal osteosarcoma and compare its characteristics with that of metaphyseal osteosarcoma. MATERIALS AND METHODS: Eighteen pathologically confirmed diaphyseal osteosarcomas were reviewed. Images of X-ray (n=18), CT (n=12) and MRI (n=15) were evaluated by two radiologists. Differences among common radiologic findings of X-ray, CT and MRI, and between diaphyseal osteosarcomas and metaphyseal osteosarcomas in terms of tumor characteristics were compared. RESULTS: The common imaging features of diaphyseal osteosarcoma were bone destruction, lamellar periosteal reaction with/without Codman triangle, massive soft tissue mass/swelling, neoplastic bone and/or calcification. CT and MRI had a higher detection rate in detecting bone destruction (P=0.001) as compared with that of X-ray. X-ray and CT resulted in a higher percentage in detecting periosteal reaction (P=0.018) and neoplastic bone and/or calcification (P=0.043) as compared with that of MRI. There was no difference (P=0.179) in detecting soft tissue mass among three imaging modalities. When comparing metaphyseal osteosarcoma to diaphyseal osteosarcoma, the latter had the following characteristics: a higher age of onset (P=0.022), a larger extent of tumor (P=0.018), a more osteolytic radiographic pattern (P=0.043). CONCLUSION: As compared with metaphyseal osteosarcoma, diaphysial osteosarcoma is a special location of osteosarcoma with a lower incidence, a higher age of onset, a larger extent of tumor, a more osteolytic radiographic pattern. The osteoblastic and mixed types are diagnosed easily, but the osteolytic lesion should be differentiated from Ewing sarcoma. X-ray, CT and MRI can show imaging features from different aspects with different detection rates.

Differentiation between benign and malignant solid pseudopapillary tumor of the pancreas by MDCT.

PURPOSE: The purpose of this study was to determine if characteristic features on computed tomographic and (or) magnetic resonance imaging can differentiate benign and malignant solid pseudopapillary neoplasms (SPN). MATERIALS AND METHODS: A total of 82 pathologically diagnosed SPN patients were included. CT and MRI were reviewed by 3 radiologists. Each tumor was analyzed through the clinical and imaging features. RESULTS: The highest occurrence of malignant SPN was observed in the group of patients (11-19 years old) followed by the group of patients (50-65 years old). When the tumor was located in the tail and the size was equal or larger than 6.0 cm, the positive and predictive value, the predictive value, sensitivity and specificity for a malignant SPN were 61.5%, 100%, 100% and 78.6%, respectively. Presence of complete encapsulation was more frequent in benign SPNs, but focal discontinuity in the malignant SPNs. Amorphous or scattered calcifications, all near-solid tumors and presence of upstream pancreatic ductal was found in the benign SPNs. CONCLUSION: A focal discontinuity of the capsule, large tumor size (>6.0 cm) and a pancreatic tail location may suggest malignancy of SPN. In contrast, tumors with amorphous or scattered calcifications, and all near-solid tumors may be indicative of benignancy. Age (less than 20 or more than 50 years old) is a possible risk factor of SPN. In comparison to other pancreatic neoplasms, such as ductal adenocarcinoma, a complete/incomplete pseudo-capsule, without upstream pancreatic duct dilatation and lymph nodes metastasis, and the presence of internal calcification and hemorrhage are more likely SPN.