Quality analysis of non-contrast-enhanced CT images synthesized from contrast-enhanced CT images by deep learning model / 中华放射医学与防护杂志

Objective:To synthesize non-contrast-enhanced CT images from enhanced CT images using deep learning method based on convolutional neural network, and to evaluate the similarity between synthesized non-contrast-enhanced CT images by deep learning(DL-SNCT) and plain CT images considered as gold standard subjectively and objectively, as well as to explore their potential clinical value.Methods:Thirty-four patients who underwent conventional plain scan and enhanced CT scan at the same time were enrolled. Using deep learning model, DL-SNCT images were generated from the enhanced CT images for each patient. With plain CT images as gold standard, the image quality of DL-SNCT images was evaluated subjectively. The evaluation indices included anatomical structure clarity, artifacts, noise level, image structure integrity and image deformation using a 4-point system). Paired t-test was used to compare the difference in CT values of different anatomical parts with different hemodynamics (aorta, kidney, liver parenchyma, gluteus maximus) and different liver diseases with distinct enhancement patterns (liver cancer, liver hemangioma, liver metastasis and liver cyst) between DL-SNCT images and plain CT images. Results:In subjective evaluation, the average scores of DL-SNCT images in artifact, noise, image structure integrity and image distortion were all 4 points, which were consistent with those of plain CT images ( P>0.05). However, the average score of anatomical clarity was slightly lower than that of plain CT images (3.59±0.70 vs. 4) with significant difference ( Z = -2.89, P<0.05). For different anatomical parts, the CT values of aorta and kidney in DL-SNCT images were significantly higher than those in plain CT images ( t=-12.89, -9.58, P<0.05). There was no statistical difference in the CT values of liver parenchyma and gluteus maximus between DL-SNCT images and plain CT images ( P>0.05). For liver lesions with different enhancement patterns, the CT values of liver cancer, liver hemangioma and liver metastasis in DL-SNCT images were significantly higher than those in plain CT images( t=-10.84, -3.42, -3.98, P<0.05). There was no statistical difference in the CT values of liver cysts between DL-SNCT iamges and plain CT images ( P>0.05). Conclusions:The DL-SNCT image quality as well as the CT values of some anatomical structures with simple enhancement patterns is comparable to those of plain CT images considered as gold-standard. For those anatomical structures with variable enhancement and those liver lesions with complex enhancement patterns, there is still vast space for DL-SNCT images to be improved before it can be readily used in clinical practice.

Value of multi-parameter MRI in the diagnosis of thyroid benign and malignant nodules / 中华放射学杂志

Objective:To explore the value of multi-parametric MRI for thyroid gland in differentiating benign and malignant thyroid nodules.Methods:From December 2018 to May 2020, 78 patients with 91 post-surgically pathologically confirmed thyroid nodules were enrolled in Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. For each patient, the following MRI findings were obtained including the nodules′ location, size, shape, margin, signal intensity, cystic change, degree and pattern of contrast enhancement, involvement of surrounding structure, and ADC values. The time-intensity curve (TIC) were plotted and subtyped based on dynamic contrast enhancement MRI. The MRI findings between the benign and malignant thyroid nodules were compared using Mann-Whitney U test, χ 2 test or Fisher exact test. Multiple logistic regression analysis was used to select independent predictive variables and build a combined model, and the ROC curve was used to evaluate the diagnostic performance of each MRI finding and the combined model. Results:Between the benign and malignant thyroid nodules, the significant differences were found in size, shape, margin, presence of cystic changes, T 1WI signal intensity, ADC value, enhancement homogeneity, TIC subtypes and presence of thyroid capsule involvement ( P<0.05). Multivariate logistic analysis showed that ill-defined margin (OR=77.61), no presence of cystic changes (OR=36.11) and difference between TIC subtypes (OR=83.41) were independent predictive variables, and the area under the ROC curve (AUC) was 0.879, 0.788, and 0.751, respectively. The AUC, sensitivity and specificity of the combined model were 0.977, 0.986, and 0.904, respectively. Conclusions:Thyroid multi-parametric MRI derived findings can be used for the differential diagnosis of benign and malignant nodules. Combined with the independent risk factors with ill-defined margin, no presence of cystic changes, TIC of type plateau or washout, the diagnostic model has a higher diagnostic efficiency.

Value of arterial spin label technique in 3.0 T MR scanner on evaluating blood flow of thyroid glands in healthy adults / 中华放射学杂志

Objective:To investigate the feasibility and reproducibility of using three-dimensional arterial spin labeling (3D-ASL) technique to evaluate the thyroid blood flow (TBF) in healthy adults and compare the difference in TBF between subjects with different gender and age.Methods:In this prospective study, 100 healthy adult subjects were enrolled from November 2018 to June 2019 in Chinese Academy of Medical Sciences Cancer Hospital, Shenzhen Hospital. All subjects received thyroid 3D-ASL MRI scanning, but several subjects were excluded from analysis for reasons including intolerance to examination ( n=1), overt artifacts ( n=11), abnormality detected in thyroid gland during conventional MRI ( n=15), resulting in 73 subjects included. Two attending radiologists independently evaluated the quality of ASL images and measured the TBF in upper, middle and lower poles of each lobe in thyroid gland bilaterally. Cohen’s Kappa was used to test the agreement in image quality between 2 radiologists, while intraclass correlation (ICC) analysis was implemented to evaluate the consistency in TBF measurements. Univariate variance analysis was used to compare the TBF in upper, middle and lower pole of thyroid gland unilaterally, and student t-test was performed to test the difference in TBF between two lobes, or in the same lobe but between different gender or age groups. Results:For image quality, 2 radiologists have good agreement (Kappa=0.753, P<0.001). In terms of TBF, consistency was moderate in the lower pole of left lobe between 2 radiologists (ICC=0.648, P<0.001), but good in the remaining parts of thyroid gland (all ICC>0.75, P<0.001). Unilaterally, TBF in the middle pole was significantly higher than those in the upper or lower pole ( P<0.001), but no significant difference was found between the upper and lower pole ( P>0.05). Regardless of upper, middle or lower pole, TBF in the right lobe was higher than the counterpart in the left lobe ( t=6.182, 6.294, 4.896, P<0.001). Between male subjects ( n=31) and female subjects ( n=42), no significant difference was found in the corresponding upper, middle or lower pole of thyroid lobe unilaterally ( P>0.05). As for age group, TBF in the middle pole of thyroid gland was higher in the middle age group (45-59 years old, n=12) than that in the young adult group (18-44 years old, n=61) ( t=3.868, P=0.003 for the left lobe, and t=2.647, P=0.022 for the right lobe), but no significant difference was found in the upper or lower pole of the unilateral thyroid lobe ( P>0.05). Conclusion:ASL can accurately measure blood flow perfusion in the thyroid gland with good reproducibility.

The value of semiquantitative parameters of DCE-MRI in predicting and monitoring efficacy of concurrent chemoradiotherapy in laryngeal and hypopharyngeal carcinoma / 实用放射学杂志

Objective To evaluate the value of semi-quantitative parameters of dynamic contrast-enhanced MRI (DCE-MRI)in predicting and monitoring therapeutic efficacy of concurrent chemoradiotherapy in laryngeal and hypopharyngeal carcinoma.Methods Forty-four patients with pathologically confirmed laryngeal and hypopharyngeal squamous cell carcinoma were collected.Time signal intensity curves (TIC)and related semi-quantitative parameters were obtained before (point 1 ),during (point 2)and after (point 3 )treatment. Tumor remission were assessed at the end of treatment and the statistical analyses were performed using SPSS.Results Twenty two patients had a complete remission as CR group and 22 had a partial remission as PR group.The parameters of time to peak (TTP), maximum signal enhancement ratio (SERmax ),positive enhancement integral (PEI),SER70 and SER84 at point 1 were higher than those at point 2,and there were significant differences between two groups (P <0.05).The values of SERmax ,SER42 ,SER56 ,SER70 and SER84 before treatment were higher in CR group than those in PR group,exhibiting significant differences between two groups (P <0.05).ROC curve analysis showed the threshold for SER56 was set to ≥129.4％ to predict complete remission,and the sensitivity and specificity were 60％ and 86.4％,respectively.Comparison of remission rates among different types of TIC showed complete remission rates in typeⅠTIC and type Ⅲ TIC were 87.5％ and 39.3％,respectively,exhibiting a significant difference between two groups (P =0.041). Conclusion TIC types and semi-quantitative parameters of DCE-MRI can predict therapeutic efficacy of concurrent chemoradiotherapy in laryngeal and hypopharyngeal carcinoma,SER56 is the most important predictive semi-quantitative parameter,and prognosis is much better in typeⅠTIC than type Ⅲ TIC before treatment.

The value of semiquantitative parameters of DCE-MRI in predicting and monitoring efficacy of concurrent chemoradiotherapy in laryngeal and hypopharyngeal carcinoma / 实用放射学杂志

Objective To evaluate the value of semi-quantitative parameters of dynamic contrast-enhanced MRI (DCE-MRI)in predicting and monitoring therapeutic efficacy of concurrent chemoradiotherapy in laryngeal and hypopharyngeal carcinoma.Methods Forty-four patients with pathologically confirmed laryngeal and hypopharyngeal squamous cell carcinoma were collected.Time signal intensity curves (TIC)and related semi-quantitative parameters were obtained before (point 1 ),during (point 2)and after (point 3 )treatment. Tumor remission were assessed at the end of treatment and the statistical analyses were performed using SPSS.Results Twenty two patients had a complete remission as CR group and 22 had a partial remission as PR group.The parameters of time to peak (TTP), maximum signal enhancement ratio (SERmax ),positive enhancement integral (PEI),SER70 and SER84 at point 1 were higher than those at point 2,and there were significant differences between two groups (P <0.05).The values of SERmax ,SER42 ,SER56 ,SER70 and SER84 before treatment were higher in CR group than those in PR group,exhibiting significant differences between two groups (P <0.05).ROC curve analysis showed the threshold for SER56 was set to ≥129.4％ to predict complete remission,and the sensitivity and specificity were 60％ and 86.4％,respectively.Comparison of remission rates among different types of TIC showed complete remission rates in typeⅠTIC and type Ⅲ TIC were 87.5％ and 39.3％,respectively,exhibiting a significant difference between two groups (P =0.041). Conclusion TIC types and semi-quantitative parameters of DCE-MRI can predict therapeutic efficacy of concurrent chemoradiotherapy in laryngeal and hypopharyngeal carcinoma,SER56 is the most important predictive semi-quantitative parameter,and prognosis is much better in typeⅠTIC than type Ⅲ TIC before treatment.

CT features of anaplastic thyroid carcinoma / 实用放射学杂志

Objective To summarize the CT features of anaplastic thyroid carcinoma (ATC).Methods CT manifestations of 12 patients with ATC confirmed by surgery or biopsy were analyzed retrospectively.Results 1 1 (91.7%)patients had single lesion. The lesions appeared as low attenuation mass with cord-like,flocculent or patchy high attenuation areas.The lesions had mild to moderate enhancement in 1 1 cases (91.7%).Coarse calcifications were detected in 8 cases (66.7%),4 of them were incomplete rim or eggshell.11 cases (91.7%)showed invasion into adjacent structures,including trachea (6 cases,50%),esophagus (4 cases,33.3%),strap muscles (7 cases,58.3%),larynx (2 cases,1 6.7%),blood vessels (6 cases,50%).5 cases (41.7%)had tumor thrombus in the internal jugular vein.10 cases (83.3%)had lymph nodes metastasis.The enhancements of lymph nodes were divided into 3 types:mild homogeneous enhancement (4 cases,40%),mild enhancement with internal low-attenuation areas (7 cases,70%)and ring-like enhancement without internal enhancement (7 cases,70%).Conclusion CT features of ATC include low-density mass with cords,flocculent and patchy high-density areas,coarse calcification and mild to moderate enhancement,invasion to adjacent structure and lymph node metastasis with necrosis are common.

Spectral parameters analysis of pathologic differentiation of laryngeal and hypopharyngeal squamous cell carcinoma / 实用放射学杂志

Objective To evaluate the discrepancy of parameters generated on dual-energy spectral CT (DECT)imaging in the different pathological grade of laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC),and to provide helpful information of the prognosis and the guide of clinical treatment.Methods 61 patients with pathologically confirmed LHSCC who underwent contrastenhanced DECT before therapy were retrospectively analyzed.The enhanced monochromatic data were analyzed with workstation.Iodine concentration of lesion (IC),water concentration of lesion (WC)and slope of spectral HU curve (s-SHC)were acquired.According to cell differentiation,all patients were divided into well,moderately and poorly differentiated groups.The difference of IC,WC,s-SHC,constituent ratio of T stage were compared among different groups.Results The IC and s-SHC had significant difference among well,moderately and poorly differentiated groups(F =3.56,3.96 respectively,P 0.05).There were no significant difference of WC among three groups respectively (H =0.84,P >0.05).χ2 test showed that there was no significant difference for the constituent ratio of T stage among three groups (P >0.05).Conclusion IC and s-SHC can help to judge the pathological grade of LHSCC,and they may be useful to evaluate the prognosis of LHSCC.

Value of apparent diffusion coefficient values in predicting induction chemotherapy response of advanced nasopharyngeal carcinoma / 实用放射学杂志

Objective To predict the response of induction chemotherapy in advanced nasopharyngeal carcinoma (NPC)by using pretreat-ment apparent diffusion coefficient (ADC)values.Methods 35 patients with advanced NPC underwent DWI examination prior to 2-week in-duction chemotherapy.The patients were divided into CR (complete response)group,PR (partial response)one and SD (stable disease)one according to the tumor response of treatment.The effective responders included CR and PR groups.The patients were divided into children-adolescents(below 20 years)group and adults one according to the age,into non-keratinizing undifferentiated carcinoma group and non-kera-tinizing differentiated carcinoma one according to the pathological type,and also into T2,T3 and T4 groups according to the T-staging (UICC2010).Statistical analysis was used to compare the pretreatment ADC values between different groups.Results The average pre-treatment ADC values of CR,PR,responders and SD groups were (0.70±0.06)×10 -3 mm2/s,(0.72±0.04)×10 -3 mm2/s,(0.71± 0.04)×10 -3 mm2/s and (0.85±0.02)×10 -3 mm2/s respectively.The average pretreatment ADC value of the SD group was signif-icantly higher than that of PR group and responders,and the differences were significant (P <0.05).The average pretreatment ADC value of children-adolescents and adults groups were (0.73±0.07)×10 -3 mm2/s and (0.75 ±0.07)× 10 -3 mm2/s,which showed no significant differences.The average pretreatment ADC value of non-keratinizing undifferentiated carcinoma and non-keratinizing dif-ferentiated carcinoma groups were (0.76 ±0.08)×10 -3 mm2/s and (0.74±0.06)×10 -3 mm2/s,which showed no significant differ-ences.The average pretreatment ADC values of T2,T3 and T4 groups were (0.78±0.05)×10 -3 mm2/s,(0.77 ±0.07)×10 -3 mm2/s and (0.75±0.08)×10 -3 mm2/s.Although there were no significant differences between T2,T3 and T4 groups,a trend towards lower ADC was observed with increasing tumor T-staging.Conclusion Pretreatment ADC value is a valuable quantitative parameter,and it can be used for predicting induction chemotherapy response in advanced naso-pharyngeal carcinoma.

The value of multi-parameters MRI of tongue carcinoma in predicting cervical node metastases / 中华放射学杂志

Objective The aim of this study was to determine whether multi?parameters MRI of tongue carcinoma have the potential to predict cervical lymph node metastases. Methods A total of 46 patients with tongue carcinoma, who underwent MRI scan preoperatively, were investigated retrospectively and were divided into cervical lymph node (LN) metastases group (unilateral LN+, n=16;bilateral LN+, n=14) and no cervical lymph node metastases group (LN-, n=16) according to their pathological grading. Of the 40 patients with tongue carcinoma underwent plain and contrast MRI scan, 6 patients have plain MRI scan, and 32 have DWI examination.The ADC value, tumor length, tumor thickness, sublingual distance between tumor and sublingual space, and para?lingual distance between tumor and tongue midlinedetermined from MRI, were preoperatively estimated and compared with the pathological findings of cervical lymph nodes. A unpaired t test was used to analyze normal distributed continuous data, and a Mann?Whitney U test was used to analyze abnormally distributeddata. The ROC was used to evaluate the efficacy of MRI in predicting the metastasis of cervical lymph nodes. Results The indexes of ADC value, tumor length, tumor thickness, and para?lingual distance between tumor and tongue midline, which all showed significant difference between LN+group and LN-group (all P0.05). The index of ADC value showed significant difference between unilateral LN+group and bilateral LN+group (P0.05). The ROC curve analysis of the ADC value, tumor length, tumor thickness, and para?lingual distance between tumor and tongue midline of the neck lymph node metastasis were carried out, with the cutoff set as 1.13×10?3 mm2/s, 31.08 mm, 17.33 mm and-2.26 mm. The corresponding area under curve(AUC), sensitivity, and specificity were 0.878, 90.9%and 90.0%; 0.822, 83.3% and 81.3%; 0.834, 86.7% and 81.3%; 0.794, 86.7% and 75.0%, respectively. The ROC curve analysis of the ADC of the bilateral neck lymph node metastasis was also carried out, with the cutoff of ADC value set as 1.07×10?3 mm2/s, the corresponding AUC, sensitivity, and specificity were 0.806, 80.0%and 75.0%. Conclusion The ADC value, tumor length ,tumor thickness and para?lingual distance between tumor and tongue midline,determined from MR imaging, all can be used as independent factors in predicting cervical lymph node metastasis, where ADC value may be helpful to predict bilateral neck lymph node metastasis.

Evaluation of radionuclide therapy for the residue after surgery in papillary thyroid carcinoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To assess the efficacy of radioactive iodine (RAI) for the treatment of residual papillary thyroid cancer (PTC) after surgery.</p><p><b>METHODS</b>A total of 20 patients diagnosed with PTC and underwent 2-6 courses of RAI therapy for residual PTC after surgery in other hospitals were included our study. Of these, 13 were in stage I, 3 in stage III and 4 in stage IV. All the cases were operated again due to the presence of suspicious residual tumors indicated by CT. Excision of thyroid tumor residue was performed in 5 cases and neck dissection in 15 cases (20 sides). The suspicious thyroid or neck residual tumors were examined pathologically after surgery. Response Evaluation Criteria in Solid Tumors (RECIST) was used to evaluate the efficacy of surgery treatment on residual tumor. T-test was used to identify variables associated to RAI and to calculate the propensity score to receive RAI after surgery.</p><p><b>RESULTS</b>The patients aged 22-58 years, with a median age of 40 years. The mean times of surgeries received before RAI was 1.5 and the mean dose of applied RAI was 318 mCi (210-660 mCi). No significant difference in tumor size between pre-RAI and post-RAI was found (t = 1.177, P > 0.05). With postoperative pathological examination, the suspicious thyroid or neck residual tumors were confirmed as PTC or the cervical lymph metastasis of PTC.</p><p><b>CONCLUSIONS</b>For the residue or metastasis of PTC after operation, reoperation should be a priority, while RAI therapy has no obvious therapeutic effect and it should be limited to selected cases such as those with distant metastasis or unsuitable for operation but with iodine uptake function, or taken as an adjuvant treatment after radical resection of cervical lesions.</p>

Analysis of the effectiveness of radiotherapy in postoperative residual tumors in patients with thyroid papillary carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>The aim of this study was to assess the impact of radiotherapy on patients with postoperative residual or recurrent papillary thyroid cancer (PTC).</p><p><b>METHODS</b>We retrospectively reviewed the medical records of 34 patients with PTC, who underwent surgery and radiotherapy in other hospitals, and treated at the Department of Head and Neck Surgery at Cancer Institute & Hospital CAMS from January 2011 to January 2014. Among the 34 cases, 22 were in stage I, 5 in stage II and 7 in stage IVa. The 34 patients received 1.5 times of surgery before radiotherapy in average. All the cases received radiotherapy (mean, 56 Gy; range, 50-70 Gy). The patients were re-operated in our hospital, and the specimens were examined by pathology. The pre- and post-radiotherapy images (CT and B-ultrasound) were compared, and the changes of tumor volume were examined. The objective effect of treatment on the tumor residual focus was evaluated using RECIST, and analyzed by t-test (SPSS 17.0).</p><p><b>RESULTS</b>All the re-resected lesions after radiotherapy were proved by pathology to be papillary thyroid cancer (PTC) or metastatic PTC in cervical lymph nodes. Among the 34 patients, 22 cases showed mild or moderate cell degeneration and the other 12 cases showed no obvious degeneration. The largest tumor diameter was 27.18 mm before radiotherapy and 27.76 mm after radiotherapy, with a non-significant difference between them (t=-1.618, P>0.05). Among the 34 patients, only 3 patients received reoperation, all other 31 cases had complete resection, and no severe complications were observed except recurrent laryngeal nerve injury in one case.</p><p><b>CONCLUSIONS</b>Radiotherapy has few therapeutic benefit to PTC patients after surgery with residual tumor or local recurrence. It should be used in the PTC patients, in which the tumor invasion involves important organ tissues and is difficult for a single operation to achieve safe resection margin, or in patients who can't bear a surgery because of severe coronary heart disease or others.</p>

Feasibility study on application of gemstone spectral CT material suppressed iodine as virtual non-contrast CT scan in head and neck neoplasms / 中华放射学杂志

Objective To evaluate the feasibility of applying spectral CT material suppressed iodine (MSI) imaging as virtual plain CT scan to replace traditional non-contrast (TNC) CT in head and neck neoplasms. Methods A total of 52 patients with initial diagnosis of head and neck neoplasms underwent TNC CT scanning and spectrum mode enhanced scanning in the head and neck with spectral CT. With GSI Volume Viewer software from GE AW4.6 workstation, the enhanced scanning data were processed and MSI images were acquired. The CT values of different tissues (fat, erector spinae, cervical vertebrae, thyroid, and brain parenchyma) and the enhancement rate in erector spinae, carotid sinus were compared between MSI and TNC images. Image quality was objectively evaluated in noise and SNR for MSI and TNC images, while the subjective evaluation included the visibility of lesions, subjective acceptance rate, diagnostic efficacy (with/without lesions or lesion calcification, necrosis). Radiation dose including volume CT dose index (CTDIvol) and effective dose (ED) was compared between MSI and TNC. Results (1) CT values of erector spinae on MSI and TNC imaging were(52 ± 6)and(52 ± 7)HU respectively, and the difference between the two image modes was not significant(t=0.39,P>0.05). CT values on MSI and TNC Imaging were[-74 (-86,-59)HU]and[-79(-73,-61)HU]for fat (Z=-2.71, P0.05). The difference of carotid sinus enhancement rate was significant 5.75(4.70,6.73) and 4.37(3.91,5.61) respectively, Z=-5.50, P0.05).Unacceptable and acceptable cases in imaging quality of MSI were 3 and 49 respectively, while those were 2 and 50 in TNC group. Subjective acceptance rate between MST and TNC images was not significantly different(?2=0.01,P>0.05). (5) Diagnostic performance evaluation showed that the consistency of two observers was good in detecting lesions, necrosis and calcification between MSI and TNC image, with K value 0.93, 0.83 and 0.90 respectively (P<0.05). (6) Radiation doses between pure energy spectrum enhanced mode and conventional pre plus post contrast enhanced mode were compared. And differences of CTDIvol[11.78(10.98,17.30) mGy]and[23.89 (22.42, 29.98) mGy] respectively],ED [1.89(1.63,2.29) mSv]and[3.77(3.21,4.16 ) mSv] respectively] were significant(Z=-6.28, P<0.05). Pure energy spectrum enhanced mode reduced 39.07% of CTDIvol and 45.75%of ED respectively. Conclusions MSI imaging can be a potential substitute for TNC imaging. And it has clinical values in the diagnosis of head and neck neoplasms.

Application of single-source dual-energy spectral CT in differentiating lymphoma and metastatic lymph nodes in the head and neck / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of differentiation of lymphoma, metastatic lymph nodes of squamous cell carcinoma (SCC) and papillary thyroid carcinoma (PTC) in the head and neck by single-source dual-energy spectral CT.</p><p><b>METHODS</b>25 cases of non-Hodgkin lymphoma (NHL) with 236 lymph nodes, 3 cases of Hodgkin's lymphoma (HL) with 32 lymph nodes, 21 cases of SCC with 86 lymph nodes and 19 cases of PTC with 92 lymph nodes were evaluated by enhanced GSI. CT attenuation of lymph nodes in the monochromatic images at different keV levels and the iodine and water contents of these lymph nodes were measured. The slope of spectral curve was calculated using CT value at 40 keVand 90 keV. All results were analyzed with ANOVA and t test.</p><p><b>RESULTS</b>70 keV had the best single energy images. Normalized Hounsfield unit (NHU) of diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), T lymphoblastic lymphoma (T-LBL), HL, PTC and SCC was 0.32 ± 0.10, 0.46 ± 0.08, 0.41 ± 0.11, 0.41 ± 0.11, 0.56 ± 0.15 and 0.34 ± 0.16, respectively. Normalized iodine concentration (NIC) of them was 0.20 ± 0.08, 0.32 ± 0.08, 0.25 ± 0.09, 0.30 ± 0.12, 0.49 ± 0.18 and 0.23 ± 0.18, respectively. The slope of spectral curve (k) of them was -1.92 ± 0.55, -2.45 ± 0.60, -1.82 ± 0.57, -2.57 ± 0.54, -5.44 ± 2.41 and -1.97 ± 0.81, respectively. Compared with the NHU, there was a statistically significant difference in each pair except DLBCL and SCC, and T-LBL and HL. Compared with the NIC, there was a statistically significant difference in each pair except DLBCL and SCC, FL and HL, T-LBL and SCC, and T-LBL and HL. Compared with the slope of spectral curve, there was statistically significant difference in each pair except DLBCL and T-LBL, DLBCL and SCC, FL and HL, and T-LBL and SCC.</p><p><b>CONCLUSIONS</b>Malignant lymph nodes of different types of diseases have certain different values of quantitative parameters in spectral CT imaging. By using CT attenuation, the shape and slope of spectral curve and the iodine content, single-source dual-energy CT may potentially provide a quantitative analysis tool for the diagnosis and differential diagnosis of lymph node alterations.</p>

Evaluation of magnetic resonance imaging criteria for carotid artery invasion / 实用放射学杂志

Objective To evaluate the diagnostic value of MR in carotid artery involvement using surgery and pathology as gold standard.Methods 37 patients with suspected neck masses underwent MR scan.One radiologist unaware of the pathological results measured the nine indexes as following:axial surrounding angle(AXA),long axis angle(LAA),the adjacent length of tumor long axis(LLA),the tumor long axis length(TLAL),the ratio of the adjacent length of tumor long axis and the tumor long axis length (LLA/TLAL),the perivascular fatty gap,vascular displacement,vascular deformation and magnetic resonance angiography(MRA) evaluation of artery involvement.The comparison of diagnostic value used ROC curve,sensitivity,specificity and accuracy.The cat-egorical data used Fisher orχ2 test,and measurement data used t test.Results Four indexes (AXA,LAA,LLA/TLAL and MRA) had significantly statistical value for evaluating the arterial invasion.The AUC of AXA,LAA,LLA/TLAL were 0.910,0.775 and 0.766 (P <0.05),respectively.Using 145°,61°,0.553 and MRA to indicate invasion for diagnostic value,the sensitivity and spe-cificity of those four indexes were 100.0% and 89.2%,66.7% and 89.2%,100.0% and 59.5%,33.3% and 100.0%,respective-ly.Conclusion The four indexes including AXA,LAA,LLA/TLAL and MRA evaluation of artery involvement have statistic value but with poor stability.MRA had limited diagnostic value although it’s beneficial to observe the carotid artery.

Pretreatment MR diffusion weighted imaging predicts the sensitivity of concurrent chemoradiation in nasopharyngeal carcinoma / 中华放射学杂志

Objective To investigate the value of DWI before treatment on predicting sensitivity of concurrent chemoradiation in nasopharyngeal carcinoma.Methods Seventy patients with nasopharyngeal carcinoma proved by nasopharyngoscope and biopsy pathology conducted DWI before concurrent chemoradiation and reexamined on receiving dose of 50 Gy.The mean, maximum and minimum ADC value of tumor were measured on DWI and maximum area of tumor before and during treatment ( on dose of 50 Gy) was delineated to calculate the tumor regression rate ( RS0-50 ).The patients were classified into three groups according to the RS0-50 as sensitive, moderate, and resistant therapeutic effect.Patients were classified into different groups according to the pathologic type and clinical stage respectively .Spearman correlation analysis was used between RS 0-50 and ADC values of all tumors , different pathologic types and clinical stages , respectively.ROC was used to evaluate the cutoff and value of ADC which had highest correlation to RS0-50 on predicting therapeutic effect.Results DWI of 3 patients were excluded due to obvious swallow artifact which influenced the measurement , and finally 67 patients were included in this study, with pathological type of nonkeratinized differentiated undifferentiated carcinoma in 49 cases, nonkeratinized undifferentiated carcinoma in 18 cases, clinical T1 stage in 7 cases, T2 in 14 cases, T3 in 17 cases and T4 in 29 cases.During treatment , there were 13 cases with sensitive therapeutic effect , 42 cases with moderate therapeutic effect and 12 cases with resistant therapeutic effect.RS0-50 [ ( 65.6 ± 3.1) %] showed mildly and moderately negative correlation to mean ADC [(1.06 ±0.19) ×10 -3 mm2/s] and maximum ADC [(1.29 ±0.33) ×10 -3 mm2/s] respectively ( r =-0.276, P =0.024 and r =-0.434, P=0.001, respectively).ROC showed when setting threshold at maximum ADC value of lower than 1.06 ×10 -3 mm2/s for predicting sensitive therapeutic effect , the specificity , sensitivity , and accuracy was 69.2%(9/13), 88.9%(48/54) and 85.1% (57/67), respectively, and when setting threshold at maximum ADC value of higher than and equal to 1.30 ×10 -3 mm2/s for predicting resistant therapeutic effect, the specificity, sensitivity, and accuracy was 75.0% (9/12), 65.5% (36/55) and 67.2%(45/67), respectively.Conclusion Pretreatment maximum ADC value were able to predict the tumor regression rate and sensitivity of concurrent chemoradiation in nasopharyngeal carcinoma .

CT features of medullary thyroid carcinoma / 实用放射学杂志

Objective To analyze and summarize the CT features of medullary thyroid carcinoma (MTC).Methods 30 patients with MTC proved by surgery and pathology were scanned by CT.And the CT manifestations were analyzed retrospectively.Results In a total of 30 patients,a single lesion in 25 (83.3%)patients and multiple ones in 5 (16.7%)were found with irregular shape in 27 (90.0%),unclear border in 26 (86.7%),heterogenous enhancement with irregular internal hypodensity in 27 (90.0%),cal-cifications in 4 (13.3%)and invasion of trachea in 4 (13.3%).As for the 29 patients underwent the neck surgery ,26 (89.7%) were pathologically confirmed with lymph nodes metastasis.CT showed the metastatic lymph nodes with well-defined border in 1 2 (46.2%)and ill-defined one in 14 (53.8%),calcifications in 5 (19.2%)and heterogenous enhancement with irregular internal hy-podensity in all (100.0%).Conclusion CT features of MTC and metastatic lymph nodes appeared as heterogenous enhancement with irregular internal low attenuation area,which can improve the accuracy of preoperative diagnosis.

Preliminary study on diffusion weighted imaging and LAVA dynamic contrast-enhanced MR imaging(DCE-MRI)of laryngeal and hypopharyngeal carcinoma / 实用放射学杂志

Objective To study the DCE-MRI findings of laryngeal and hypopharyngeal carcinoma.Methods 26 new patients di-agnosed laryngeal and hypopharyngeal cancer by pathology were collected and took DCE-MRI before therapy.The TIC type,ADC value,peak time (Tpeak),peak signal enhancement percentage (SERmax),positive enhancement integral(PEI),maximum slope of increase(MSI)and maximum slope of decrease(MSD)were obtained respectively.These semi-quantitative parameters of primary cancer,normal pharyngeal tissue and the same layer neck muscles were compared and P 0.05 )was found.Different b values (b = 300 s/mm2 , 500 s/mm2 )for ADC values were significantly different.There was statistical significance in semi-parameters among the primary cancer,normal pharyngeal wall tissue and the same layer neck muscles.Setting MSI value 58.32 threshold to distinguish abnormal and normal tissues,sensitivity and specificity both were 84.6%.Conclusion DCE-MRI can reflect morphology and signal differences among neck muscles,normal and abnormal laryngeal and hypopharyngeal tissues,providing help for diagnosis of primary carcino-ma.

Evaluation with low-dose dual-phase helical computed tomography of patients with thyroid lesions / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The incidence of thyroid cancer has been increasing. Our aim was to evaluate the efficacy of low-dose dual-phase helical computed tomography (CT) in the characterization of thyroid lesions, and to discuss the relationship between image characteristics and their pathology.</p><p><b>METHODS</b>One hundred and six patients with thyroid lesions underwent low-dose dual-phase helical CT after the injection of contrast material. CT scans were obtained at arterial and venous phase with delays of 25 and 65 seconds, and tube current of 60 and 120 mA, respectively. The attenuation change in the lesion between the arterial and venous phase was analyzed and categorized as "increased," "decreased," "mixed" or "no change."</p><p><b>RESULTS</b>Histopathologic diagnosis was obtained by surgery in 106 patients (115 lesions). Of the 106 patients, 45 had nodular goiter, 5 thyroid adenoma, 6 thyroiditis, and 50 papillary thyroid carcinoma (PTC) (59 lesions). The attenuation value showed a significant difference (P < 0.05) between the arterial and venous phase for the high attenuation area. There was statistical significant difference in terms of attenuation value in high attenuation areas at both phases and in low attenuation areas on arterial phase between nodular goiter and PTC (P < 0.05). However, there was no significant difference in attenuation value between adenoma and PTC. Twenty-nine cases (76.3%) of goiter manifested mixed type, 3 cases (3/5) of adenoma showed decreased type, 6 cases (6/6) of thyroiditis showed increased type, and 55 cases (93.2%) of PTC showed decreased type attenuation. The sensitivity, specificity for thyroid carcinoma by dual-phase CT were 94.9% and 80.4% respectively. The overall diagnostic accuracy for thyroid lesions by dual-phase CT was 87.8%.</p><p><b>CONCLUSIONS</b>The performance of dual-phase helical CT is related to the pathological structure of the lesions. The analysis of enhancement patterns by using dual-phase helical CT will be helpful in the differential diagnosis of thyroid lesions.</p>

The CT features of non-thyroidal masses of the neck / 中华放射学杂志

Objectives To evaluate the value of computed tomography (CT) features of non-thyroidal masses of the neck (NTMN).MethodsThe clinical data of 264 patients with NTMN proved by histology from 2005 to 2010 in our hospital were collected retrospectively.Among them,benign lesions were found in 159 patients (60.2％ ),malignant ones in 105 patients (39.8％ ),and in lymphadenopathy in 111 patients (42.0％ ),non-lymphadenopathy in 153 patients (58.0％).The CT features including lowdensity areas,low-density areas of enhancement ratio,the edge of lesion,lesion morphology and the clinical baselines including the sex,single or multiple lesions,lymphadenopathy or non lymphadenopathy were compared for appreciating the sensitivity and specificity of the diagnosis.Categorical variables were tested with the x2 or Fisher exact tests.Results Independently using each of those four radiological signs ( CT value of low density area,the enhancement ratio of low density area,border and morphology of lesion)and three clinical indexes (sex,single or multiple,lymphadenopathy or non lymphadenopathy) to diagnose the malignant tumors,the sensitivity and specificity were 77.1％ ( 81/105 ),81.9％ ( 86/105 ),71.4％(75/105),56.2％ ( 59/105 ),64.8％ ( 68/105 ),75.2％ ( 79/105 ),82.9％ ( 87/105 ) and 50.9％(81/159),44.7％ ( 71/159 ),73.0％ ( 116/159 ),67.3％ ( 107/159 ),51.6％ ( 82/159 ),73.0％(116/159),84.9％ (135/159) respectively.When four or more signs were showed,the sensitivity and specificity were 86.7％ (91/105) and 74.8％ (119/159) respectively.The special CT features were included mottled high density sign in schwannoma ( P =0.000,25/41 )and regular calcification in hemangioma(P =0.000,7/18 ).Carotid body tumor was often occurred at carotid artery (P =0.000,23/24),and the most of mass of paravertebral was neurogenic tumor(P =0.001,9/50).ConclusionsThe diagnosis of NTMN can be improved by combining CT features and clinical baseline.

Differential diagnosis of metastatic cervical lymph nodes in nasopharyngeal carcinoma patients with 3.0T MR diffusion weighted imaging / 中国医学影像技术

Objective To explore the capability of diffusion weighed imaging (DWI) in differentiating malignant cervical lymph nodes from benign ones in nasopharyngeal carcinoma (NPC) patients, and to assess the appropriate b value in 3.0T MR DWI. Methods Conventional MR and DWI scan were performed in 50 patients with histopathologically proven NPC and 20 healthy volunteers with GE 3.0T MR scanner, and neurovascular array 8 channels head and neck unite coil. DWI was performed with single shot spin-echo echo-planar imaging (SE-EPI) sequence at 4 different b values (600, 800, 1000,1200 s/mm~2). The apparent diffusion coefficient (ADC) values between metastatic lymph nodes of NPC patients and benign nodes of volunteers were compared. Results The mean ADC value (×10~(-3) mm~2/s) of metastatic cervical lymph nodes of NPC at different b value (600, 800, 1000, 1200 s/mm~2) was 0.808±0.112, 0.769±0.098, 0.732±0.095 and 0.696±0.083, respectively; the mean ADC value (×10~(-3) mm~2/s) of lymph nodes of volunteers was 0.993±0.172, 0.967±0.165, 0.903±0.157 and 0.855±0.122, respectively (P<0.05). When b value was 800 s/mm~2, and ROC cut-off point was 0.873×10~(-3) mm~2/s, the diagnostic sensitivity, specificity and accuracy was 88.41%, 69.43%, and 75.22%, respectively. Both the satisfying images and the accurate measurement were acquired. Conclusion As a rapid and sensitive new MR technique, DWI can offer help in discriminating benign and malignant cervical lymph nodes in NPC patients.