Rust Prevention Property of a New Organic Inhibitor under Different Conditions.

The corrosion resistance properties of a new type of environmentally-friendly organic inhibitor containing amino ketone molecules are presented in this paper. To evaluate the prevention effect of the inhibitor on corrosion of reinforcement, the electrochemical characteristics of steels in the simulated concrete pore solution (SPS) were investigated under varied conditions of the relevant parameters, including concentrations of the inhibitor and NaCl, pH value, and temperature. The inhibition efficiency of the material was characterized through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and the weight loss of steels. The results reveal a significant improvement in the corrosion resistance of steels with the inhibitor. A maximum resistance value of 89.07% was achieved at an inhibitor concentration of 4%. Moreover, the new organic inhibitor exhibited good corrosion protection capability for steels under different NaCl concentrations. Its inhibition efficiency was determined to be 65.62, 80.06, and 66.30% at NaCl concentrations of 2, 3.5 and 5%, respectively. On the other hand, it was found that an alkaline environment was favorable for an enhanced corrosion prevention effect, and an optimal pH value of 11.3 was observed in this work. Besides, the inhibition efficiencies at different temperatures showed a trend of 25 > 35 > 40 > 20 > 30 °C, with a maximum value of 81.32% at 25 °C. The above results suggest that the new organic material has high potential to be used as an eco-friendly and long-term durable inhibitor for steel corrosion prevention under complex conditions.

Hydrophobically Associating Polymers Dissolved in Seawater for Enhanced Oil Recovery of Bohai Offshore Oilfields.

As compared to China's overall oil reserves, the reserve share of offshore oilfields is rather significant. However, offshore oilfield circumstances for enhanced oil recovery (EOR) include not just severe temperatures and salinity, but also restricted space on offshore platforms. This harsh oil production environment requires polymers with relatively strong salt resistance, solubility, thickening ability, rapid, superior injection capabilities, and anti-shearing ability. As a result, research into polymers with high viscosity and quick solubility is recognized as critical to meeting the criteria of polymer flooding in offshore oil reservoirs. For the above purposes, a novel hydrophobically associating polymer (HAP) was prepared to be used for polymer flooding of Bohai offshore oilfields. The synthetic procedure was free radical polymerization in aqueous solutions starting at 0 °C, using acrylamide (AM), acrylic acid (AA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), and poly(ethylene glycol) octadecyl methacrylate (POM) as comonomers. It was discovered that under ideal conditions, the molecular weight of HAP exceeds 2.1 × 107 g⋅mol-1. In a simulated reservoir environment, HAP has substantially greater solubility, thickening property, and salt resistance than conventional polyacrylamide (HPAM), with equivalent molecular weight. Finally, the injectivity and propagation of the two polymers in porous media were investigated. Compared with HPAM, which has a similar molecular weight, HAP solution with the concentration of 0.175% had a much better oil displacement effect in the porous medium, which can enhance oil recovery by 8.8%. These discoveries have the potential to pave the way for chemical EOR in offshore oilfields.

Highly sensitive analysis of low-molecular-mass aldehydes in beverages using a hydroxylamine reagent by high-performance liquid chromatography with fluorescence detection.

In this study, a fluorescent reagent, 4-((aminooxy)methyl)-7-hydroxycoumarin (AOHC), was for the first time applied to label the low-molecular-mass aldehydes (LMMAs) through reductive oxyamination reaction to afford single N,O-substituted oxyamine derivatives at room temperatures with derivatization efficiencies as high as 96.8%. In the following high-performance liquid chromatography with fluorescence detection analysis, 12 LMMAs, including furfurals, aromatic aldehydes, and aliphatic aldehydes, were baseline-separated on an ODS column and detected with low limits of detection (LODs) (0.2-50 nM), and good precisions (intraday relative standard deviations [RSDs] were 2.40-4.68%, and interday RSDs were 4.65-8.91%). This approach was then adopted to analyze six alcoholic beverages and five dairy products, and nine LMMAs with concentrations in the 0.28-798.16 µM range were successfully detected with excellent accuracies (recoveries were 92.2-106.2%). Finally, the results were statistically analyzed and discussed. The proposed method has several advantages, including high sensitivity, room-temperature labeling, and the avoidance of further extraction and/or enrichment procedures, demonstrating its great utility for monitoring LMMAs in various complex matrices.

A quinone electrode with reversible phase conversion for long-life rechargeable aqueous aluminum-metal batteries.

The exploration of high-performance cathode candidates is of great significance for aqueous aluminum-metal batteries (AAMBs). Here, we, for the first time, report tetrachloro-1,4-benzoquinone (TCQ) as a superior organic AAMB cathode. Owing to its high reversible conversion between the carbonyl and hydroxyl groups, the TCQ cathode delivers a remarkable electrochemical performance.

[Application of three-dimensional CT and image classification in percutaneous vertebraplasty for osteoporotic vertebral compression fractures].

OBJECTIVE: To explore the application of three-dimensional CT and image classification in the treatment of osteoporotic vertebral compression fracture(OVCFs) by percutaneous vertebroplasty(PVP). METHODS: A total of 90 patients with OVCFs who were treated with PVP in Linqu People's Hospital of Shandong Province from April 2016 to March 2018 were selected as subjects. There were 31 males and 59 females, aged from 63 to 84 years old. Bone mineral density measurements were performed in all patients to confirm the presence of osteoporosis and imaging examinations were performed to confirm the presence of vertebral fractures. The fracture area was determined by MRI fat surpressed image before operation and three-dimensional modeling was performed to calculate the volume of fracture area. Three dimensional CT imaging of bone cement in fracture area was performed after PVP and the volume ratio of bone cement in fracture area was calculated by computer aided design software, by which patients were divided into groups for study. Forty-one patients whose volume ratio of bone cement in fracture area less than 50% are control group and the rest of 90 patients are observation group. Visual analogue scale (VAS) and Oswestry Disability Index(ODI) were collected in two groups before operation and 1 day, 3 months after operation. The amount of bone cement was recorded after operation. RESULTS: All operations were successful. There were 3 cases of cement leakage in control group and 4 cases in observation group. All patients had no obvious clinical symptoms. After continuous observation and follow-up for 3 months, no complications such as adjacent vertebral fracture, infection, bone cement displacement were found. There was no significant difference in bone cement doses and bone cement leakage between two groups(P>0.05). There was no significant difference in preoperative VAS and ODI between two groups(P>0.05). All VAS and ODI obviously decreased(P<0.05) at 1 day after operation and in observation group the decrease was more significant (P<0.05). At 3 months after operation there was no significant difference between two groups. This may have been due to basically healing of vertebral fractures at 3 months after surgery and the pain was no longer significantly related. CONCLUSIONS: PVP can significantly improve clinical symptoms of OVCFs and bone cement filling in fracture area is the key to the short-term effect of PVP.

Giant cell tumour of tendon sheath with bone invasion in extremities: analysis of clinical and imaging findings.

PURPOSE: The purpose of this study was to review the clinical and imaging characteristics of giant cell tumour of tendon sheath (GCTTS) with bone invasion. MATERIALS AND METHODS: Radiography (n = 9), magnetic resonance imaging (MRI) (n = 7), computed tomography (CT) (n = 4) and clinical findings of nine patients with surgically and pathologically confirmed GCTTS with bone invasion were retrospectively reviewed. Specific imaging findings including tumour site, maximum tumour size, shape, margin, density or signal intensity, bone invasion, periosteal reaction, calcification, and cystic areas were documented. RESULTS: There were five males and four females, with median age of 34 years. Presenting symptoms were painless mass in five patients, painful mass in two, intermittent pain and swelling in one and pain without mass in one. Five tumours were in the ankle-foot region, two in the hand, one in the cubital fossa and one in the patellofemoral joint. The total symptom duration ranged from 5 months to 6 years (median 12 months). The maximum tumour size ranged from 1.0 to 6.8 cm (median 3.0 cm). Radiographically, all tumours appeared as cortical destruction with well-defined margins. Four patients underwent CT scanning that clearly showed an iso-attenuated mass with intraosseous soft tissue. MR scanning was performed in seven patients who demonstrated a round, oval, spindle-shaped or multilobular soft tissue mass near or inside the joint with cortical destruction and intraosseous soft tissue. Five lesions were homogeneous moderate signal on T1WI. Moderate (n = 1), slightly high or high (n = 2) and low (n = 2) signal intensities were evident on T2WI. Two lesions showed heterogeneous low-to-moderate signal intensities on T1WI and mixed low signal intensities on T2WI. CONCLUSIONS: GCTTS is a benign soft tissue mass that may present as an intraosseous lesion near extremity joints and frequently occurring in foot and hand on radiological examinations. GCTTS with bone invasion should be considered when MRI shows solid mass with characteristic low signal on T2-weighted images.

Salvianolic acid A shows selective cytotoxicity against multidrug-resistant MCF-7 breast cancer cells.

Multidrug resistance (MDR) is a major cause for incurable breast cancer. Salvianolic acid A (SAA), the hydrophilic polyphenolic derivative of Salvia miltiorrhiza Bunge (Danshen/Red Sage), was examined for cytotoxicities to MDR MCF-7 human breast cancer cells and their parental counterparts. We have shown that SAA inhibited proliferation, caused cell cycle arrest at the S phase, and induced apoptosis dose dependently to the two kinds of cancer cells. However, the resistant cells were significantly susceptible to the inhibition of SAA compared with the parental cells. SAA increased the level of reactive oxygen species (ROS) by 6.2-fold in the resistant cells, whereas the level of SAA-induced ROS changed only by 1.6-fold in their parental counterparts. Thus, the data showed that the selective cytotoxicity resulted from the hypersensitivity of the resistant cells to the strongly elevated ROS by SAA. In addition, SAA-triggered apoptosis was associated with increased caspase-3 activity, disrupted mitochondrial membrane potential, downregulated Bcl-2 expression, and upregulated Bax expression in the resistant cells. Moreover, SAA downregulated the level of P-glycoprotein, which was overexpressed in the resistant cells. This indicated that SAA modulated MDR. Furthermore, SAA showed higher antitumor activity than did doxorubicin in xenografts established from the resistant cells. The present work raised a possibility that SAA might be considered a potential choice to overcome MDR for the selective susceptibility of the resistant breast cancer cells to SAA treatment.

Giant cell tumours of the mobile spine: characteristic imaging features and differential diagnosis.

PURPOSE: The aim of this study was to investigate the characteristic imaging features of giant cell tumours (GCTs) of the mobile spine. MATERIALS AND METHODS: Thirty pathologically proven GCTs of the mobile spine were reviewed. X-ray (n = 18), computed tomography (CT) (n = 24) and magnetic resonance (MR) (n = 21) images were retrospectively evaluated. RESULTS: Five tumours were located in the cervical spine, 15 tumours were located in the thoracic spine and 10 tumours in the lumbar spine. The characteristic X-ray findings included an osteolytic and expansile lesion with a "soap bubble" or purely lytic appearance. Cortical destruction was commonly seen. Margin sclerosis was seen in two lesions. No mineralised tumour matrix or periosteal reaction appeared. The CT findings were similar but outlined the cortical alterations in a more accurate way. The characteristic MR findings included a well-defined and expansile mass with heterogeneous low-to-iso signal intensity on T2-weighted images. Cystic areas were commonly seen in 17 cases. Five cases presented fluid-fluid levels, suggesting the development of aneurysmal bone cyst. The solid portions of the tumours were enhanced with a very heterogeneous signal pattern reflecting high blood supply after contrast-enhanced scan. Tumour involvement in the epidural space occurred in 12 cases, causing spinal cord and/or nerve root compression. Involvement of intervertebral discs and/or adjacent vertebrae appeared in two cases. CONCLUSIONS: Although rare, GCT can occur in the mobile spine as a kind of benign but locally aggressive tumour. Radiologists should be familiar with its characteristic imaging features in order to make a correct diagnosis and to help preoperative evaluations.

Triple-phase dynamic MRI: a new clue to predict malignant transformation of giant cell tumor of bone.

OBJECTIVE: Our purpose was, through the comparison of the characteristics of time-intensity curve on triple-phase dynamic contrast-enhanced MRI among groups of giant cell tumor of bone (GCTB), recurrent benign giant cell tumor of bone (RBGCTB), and secondary malignant giant cell tumor of bone (SMGCTB), to find clues to predict the malignant transformation of GCTB. SUBJECTS AND METHODS: 21 patients diagnosed as GCTB were included in this study. All cases took recurrence after intralesional curettage. 9 cases were confirmed as SMGCTB and 12 cases were confirmed as RBGCTB. Cases were divided into four groups: group A, GCTB (n=9); group B, SMGCTB (n=9); group C, GCTB (n=12); group D, RBGCTB (n=12). Enhancement index(EI) of lesions on DCEMRI was calculated using formula: EI(t)=[S(t)-S(0)]/S(0), where S(0) was signal intensity of lesion on non-contrast-enhanced T1-weighted images and S(t) was signal intensity of lesion on DCEMRI (t=30, 60, 180s). Enhancement index of each group in each phase was compared using One-Way ANOVA analysis. Slope values of time-intensity curve were compared by the same way. RESULTS: Time-intensity curve of SMGCTB was characterized by a steep upward slope followed by an early and rapid washout phase. Time-intensity curve of GCTB and RBGCTB was characterized by a steep slope followed by a relatively slow washout phase. No significant difference in enhancement index was found in the first phase (p>0.05). There was significant difference in the second and the third phase (p<0.05). Enhancement index of group B (SMGCTB) was smaller. There was no difference in rising slope value (p>0.05). CONCLUSIONS: Dynamic contrast-enhanced MRI appears a helpful method to find new clues to predict malignant transformation of GCTB.

Differentiation of primary chordoma, giant cell tumor and schwannoma of the sacrum by CT and MRI.

OBJECTIVE: To evaluate criteria to differentiate sacral chordoma (SC), sacral giant cell tumor (SGCT) and giant sacral schwannoma (GSS) with CT and MRI. MATERIALS AND METHODS: CT and MR images of 22 SCs, 19 SGCTs and 8 GSSs were reviewed. The clinical and imaging features of each tumor were analyzed. RESULTS: The mean ages of SC, SGCT and GSS were 55.1 ± 10.7, 34.3 ± 10.7 and 42.4 ± 15.7 years old. SCs (77.3%) were predominantly located in the midline of lower sacrum, while most SGCTs (73.7%) and GSSs (87.5%) were eccentrically located in upper sacrum. There were significant differences in age, location, eccentricity, morphology of bone residues, intratumoral bleeding and septations. Multiple small cysts were mainly observed in SGCTs (73.7%) with large central cysts in GSSs (87.5%). SGCTs expanded mainly inside sacrum while SCs and GSSs often extended into pelvic cavity (P = 0.0022). Involvement of sacroiliac joints and muscles were also different. Ascending extension within sacral canal was only displayed in SCs. The preservation of intervertebral discs showed difference between large and small tumors (P = 0.0002), regardless of tumor type (P = 0.095). No significant difference was displayed in gender (P = 0.234) or tumor size (P = 0.0832) among three groups. CONCLUSION: Age, epicenter of the lesion (midline vs. eccentric and upper vs. lower sacral vertebra), bone residues, cysts, bleeding, septation, expanding pattern, muscles and sacroiliac joint involvement can be criteria for diagnosis. Fluid-fluid level is specific for SGCTs and ascending extension within the sacral canal for SCs. The preservation of intervertebral discs is related to tumor size rather than tumor type.

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.

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.

Recurrence in giant cell tumour of bone: imaging features and risk factors.

PURPOSE: This study was done to investigate X-ray, computed tomography (CT) and magnetic resonance (MR) imaging features of recurrence in giant cell tumour of bone (GCTB) and to evaluate risk factors. MATERIALS AND METHODS: Medical records and imaging data were reviewed for 55 cases of recurrent GCTB. All images were reviewed retrospectively and independently by two radiologists experienced in skeletal musculature. The common radiological findings; factors related to tumour recurrence such as gender, age, location; pathological fracture, Campanacci grading and surgical procedure were analysed by nonparametric test (Mann-Whitney U test for two independent samples test and Kruskal-Wallis H test for multiple independent samples test). p values <0.05 were considered to indicate a statistically significant difference. RESULTS: The imaging features of recurrent GCTB were as follows: osteolytic destruction or bone resorption of graft bone or around the polymethylmethacrylate (PMMA), soft tissue mass formation and expansile change. Tumour parenchyma showed markedly heterogeneous enhancement, except for necrotic cystic cavities, on contrast-enhanced MR images. Wide resection had a smaller (p=0.031) risk of local recurrence than did intralesional curettage. There was no statistical significance in gender, age, location, pathological fracture and Campanacci staging (p>0.05). CONCLUSIONS: The risk of recurrence in GCTB was influenced by the type of surgery and adjuvants. Bone transformaresorption, soft tissue mass formation and aggravated expansile change are reliable signs of recurrence on imaging.

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.

[Differentiation of recurrence rectal cancer and benign pelvic lesions after curative rectal operation with 3.0 T magnetic resonance].

OBJECTIVE: To evaluate the value of T2WI, DWI and 3D-VBIE at 3.0 T MR in the differentiation of recurrent rectal cancer and benign pelvic lesions after curative rectal operation. METHODS: A total of 28 patients with abnormal pelvic lesions confirmed by CT or MR from April 2007 to October 2010 were evaluated with MR imaging. All the patients received examinations of both T2WI and DWI, and 24 of them received additional examination of 3D-VIBE. Thirteen patients with MR imaging in the same period who were confirmed to have no diseases of the rectum were used as control group. The mean apparent diffusion coefficient(ADC) value and the ratio of the signal intensity(SI) of the lesions to the gluteus maximus in T2WI(SI(L)/SI(M)) and the ratio of the net added signal intensity of the lesions to the net added signal intensity of the iliac artery(SI(L)/SI(A)) at the time of 35 seconds after the iliac artery achieved its highest intensity were measured and calculated. The type of the time-intensity curve(TIC) was over viewed and classified as the benign type when the TIC was rising slowly or constantly and lasted for more than 90 s; however the malignant type when the TIC was rising significantly but lasted less than 90 s kept as a horizontal line for a period or was descending slowly or rising slowly. RESULTS: There were 29 lesions of different final diagnosis, including 17 recurrence rectal cancers, 4 fibrous masses, 6 stoma inflammations, 1 sinus and 1 abscess. Fourteen of them were confirmed by pathological examination. The ratio of SI(L)/SI(M) was 2.84±1.52 in the benign group, 2.58±0.80 in the malignant group, and 2.13±0.58 in the control group, the differences between the 3 groups were not statistically significant(F=1.620, P=0.211). When the ADC value of 1.21×10(-3) mm(2)/s was set as a diagnostic threshold, the sensitivity, specificity, accuracy and coherence for the diagnosis of the malignant lesions were 100%(17/17), 91.7%(11/12), 96.6%(28/29) and 0.928, respectively. When the SI(L)/SI(A) value of 0.28 was set as a diagnostic threshold, the sensitivity, specificity, accuracy and coherence for the diagnosis of the malignant lesions were 100%(13/13), 66.7%(8/12), 84.0%(21/25) and 0.675. When considering the TIC as the diagnostic standard, the sensitivity, specificity and accuracy for the diagnosis of the malignant lesions were 100%(13/13), 83.3%(10/12) and 92.0%(23/25), respectively. CONCLUSION: The signal intensity of T2WI has no specificity in the differentiation of malignant lesions and benign lesions while the DWI and the 3D-VIBE have high values in it.

[Application of 3.0T MRI 3D-VIBE dynamic contrast-enhanced in the diagnosis of small hepatocellular carcinomas].

OBJECTIVES: To investigate the detection rate of small hepatocellular carcinomas using 3.0T MRI 3D-volumetric interpolated breath-hold examination (VIBE) sequence dynamic contrast-enhanced scan, and to evaluate its application in the diagnosis of small hepatocellular carcinomas. METHODS: Imaging data of 61 cases of small hepatocellular carcinomas obtained using a 3.0 T Siemens Magnetom Trio Tim magnetic resonance scanner for plain scan and multi-phase dynamic contrast-enhanced scans of three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) were retrospectively analyzed with reference to their pathological diagnoses. The signal and enhanced features and the detection rates of the tumors in different phases of examination were analyzed. RESULTS: Sixty-six lesions were detected in the livers of the 61 patients by pathological examinations, of which 49 had pseudocapsule formation. In their T1WI plain scanning, 43 (65.15%) lesions were found, of which pseudocapsules were found in 19 (38.78%). In their T2WI imaging, 53 (80.30%) lesions were found. In dynamic enhanced 3D-VIBE sequence, 65 (98.48%) lesions were found, of which 35 (71.43%) were found with pseudocapsules. The sizes of the carcinomas ranged from 0.8 to 3.0 cm, 2.1cm on the average. The results of statistical analysis for the detection rates of the cancers of the three different sequences were significantly different (chi2=24.197, P less than 0.05). The differences of qualitative accuracy obtained by plain scan (T1WI + T2WI) and 3D-VIBE sequence were significantly different (chi2=66, P less than 0.05). CONCLUSION: 3.0 T MRI 3D-VIBE sequence dynamic contrast-enhanced scan is high-speed and can clearly demonstrate the arterial phase, the portal venous phase and the parenchymal phase images. It not only can find small lesions which can not be found with a plain scan, but also can assist diagnosis through a time-intensity curve. It is of great value for detection and differential diagnosis of small hepatocellular carcinomas.