Given that all available guidelines for pulmonary nodule management are generally based on nodule size or changes, the standardization of nodule size measurements at CT is of great concern. The Fleischner Society put forward recommendations for measuring pulmonary nodules at CT at 2017, which introduced practical questions about nodule measurement that commonly arise in routine clinical practice and corresponding answers. The recommendations focused on the technical requirements for accurate nodule measurement, directions on how to accurately measure the size of nodules at the workstation, and how to report nodule size and changes in size. Finally, the areas of uncertainty were discussed, and topics needing future research were also highlighted. 

Rheumatic disease (RD) is a group of systemic diseases involving multiple systems, and its pathological change is chronic inflammation of blood vessels and connective tissue. Because 18F-FDG PET/CT can reveal functional and metabolic information, it can be used to semi-quantatively evaluate the severity and systemic involvement extent of the active RD and therapeutic effect at a molecular level. In this article the clinical application of 18F-FDG PET/CT in evaluation of active RD, such as rheumatoid arthritis, spondyloarthropathies, polymyalgia rheumatica, relapsing polychondritis, systemic vasculitis, polymyositis, dermatomyositis and adult onset Still’s disease, were reviewed.

Atlantoaxial dislocation is more common in the upper neck trauma, failed to timely diagnosis and treatment often progression, oppressive cervical spinal life-threatening. Daily work, common due to insufficient understanding of imaging findings of atlantoaxial rotatory subluxation and lead to misdiagnosis and missed diagnosis, delay treatment. In view of this, accurate understanding of X-ray and CT manifestations, on five points of lateral atlantodental space , bilateral lateral shape and size in coranary plane, bilateral atlantoaxial lateral space, bilateral lateral joint relations, and atlanto-dental interval,? of the normal atlantoaxial vertebral neutral position, relative parallel translation and the normal rotation, the atlantoaxial dislocation in various types，help to improve the diagnostic accuracy.

Intracranial vessel wall imaging (VWI) is a new MR technique which can detect the lesions on the vessel wall, and it is valuable in making diagnose of cerebrovascular disease. Now many sequences are available in VWI. According to the plain and enhanced VWI, it can determine the location and activity of atherosclerotic plaque, assess the activity of CNS vasculitis, and make diagnoses of reversible cerebral vasoconstriction syndrome (RCVS), Moyamoya disease, arterial dissection and aneurysm. VWI can provide valuable signs for diagnosis and treatment in clinical practice. We reviewed and summarized the principles of intracranial VWI and consensus recommendations for clinical practice which was formed by the American Society of Neuroradiology study group of VWI, and introduced the basic technology and clinical application of VWI.

Objective    To retrospectively investigate the value of breast MRI in evaluation of  breast imaging reporting and data system (BI-RADS) 4-5 mammographic microcalcifications. Methods    The clinicopathologic and radiological data of 118 patients (mean age, 46.6±9.3 years; range 27-66 years) who were confirmed by biopsy or surgical pathology were retrospectively analyzed. All mammography and MR images were reviewed with BI-RADS. The apparent diffusion coefficients (ADCs) of the lesions were measured on the ADC maps of diffusion-weighted imaging, and the tumor sizes were measured on mammography, MRI, and pathology, respectively. The comparison between the two groups was performed with chi-square test or t-test. The tumor sizes measured on mammography, MRI and pathology were compared using Wilcoxon signed ranks test. Using histopathological diagnosis as the golden standard, the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated on the basis of BI-RADS category. The diagnostic efficacy was evaluated with ROC curve. Z test was used to compare the areas under the ROC curves (AUC) of mammography and MRI in the diagnosis of microcalcification. The association and consistency of lesion sizes acquired by mammography, MRI, and pathology were assessed by Spearman rank correlation and Bland-Altman analysis. Results    Of the 119 lesions, 46 were benign and 73 were malignant. There were significant differences in the morphology, distribution of microcalcifications, and ADC between benign and malignant lesions (P<0.05). The sensitivity, specificity, accuracy, PPV and NPV of mammography and MRI were 84.93%, 32.61%, 64.71%, 66.67% and 57.59%, and 95.89%, 71.74%, 86.55%, 84.34%, and 91.67%, respectively. The AUC of MRI assessment was larger than that of mammography (P<0.05). The tumor sizes measured on mammography and MRI were larger than that on pathology (P<0.05). The sizes of tumors measured on mammography and MRI showed moderate correlation with the measurements obtained on pathology (rs=0.602, rs=0.603, P<0.05). Bland-Altman analysis showed that compared with pathological results, mammography and MRI overestimated the tumor sizes, and the consistencies were not good enough. Conclusions    In the evaluation of BI-RADS 4-5 mammographic microcalcifications, breast MR imaging provides additional information with high sensitivity and NPV. Both MRI and mammography overestimate tumor sizes.

Objective??? To improve the ability in diagnosing the tumors involved the maxillary sinus region through exploring the imaging characteristics of three kinds of diseases. Methods? The clinical features, CT, and MRI appearances of neurofibroma, adenoid cystic carcinoma, and ossifying fibroma involved the maxillary sinus were observed. The imaging similarities and differences were analyzed. Results??? Maxillary sinus adenoid cystic carcinoma showed unclear boundary and osteolytic bone destruction. MRI demonstrated heterogeneous signal on T1WI and T2WI, and heterogeneous enhancement. Neurofibroma at pterygopalatine fossa revealed clear boundary and compressive bony absorption in adjacent bone. MRI showed heterogeneous signal on T2WI, and heterogeneous enhancement. Ossifying fibroma showed clear boundary and expansile bony change with osseous shell. MRI revealed heterogeneous signal on T1WI and T2WI, and heterogeneous enhancement. Conclusions??? The bony change is the key point for differential diagnosing the tumors involved the maxillary sinus. The finial diagnosis relies on combining the clinical, CT, and MRI findings.

Objective    To evaluate the value of ultrasonic real-time shear wave elastography (SWE) in assessment of nonalcoholic fatty liver disease (NAFLD) and hepatic fibrosis in rabbits. Methods    Models with normal and various degrees of NAFLD severity were conducted in sixty 8-week-old New Zealand white rabbits by feeding a standard diet and high fat diet. Liver elastic modulus values (mean value, minimum value, and maximum value) were determined by SWE, then rabbits were dissected, and the livers were used for histological evaluation. The degree of hepatic fibrosis was determined under light miscroscop, and based on NAFLD activity score (NAS), the final pathologic NAFLD diagnosis were considered as normal (NAS=0), simple steatosis (SS) (NAS=1 or 2), borderline (NAS=3 or 4) and nonalcoholic steatohepatitis (NASH) (NAS≥5). Using the Kruskal-Wallis rank test to compare the differences in liver elastic modulus values among groups of NAFLD and different stages of liver fibrosis. The diagnostic accuracy of SWE in evaluating NAFLD severity and fibrosis stage was studied using ROC curve. Results    A total of 54 rabbits survived after the experiment. Among them, 11 rabbits were in normal group, 8 in SS group, 19 in borderline group and 16 in NASH group. In the stage of liver fibrosis, 32 rabbits were in stage S0, 7 in stage S1, 9 in stage S2, and 6 in stage S3. Taking mean value≥6.42 kPa as the diagnostic standard to differentiate normal rabbits from rabbits with NAFLD, and mean value≥8.64 kPa to differentiate SS from NASH, the area under ROC curve (AUC) were 0.759 and 0.969, respectively; the sensitivity and the specificity were 60.5% and 100%, respectively, for differentiating normal and NAFLD groups; and 93.8% and 87.5%, respectively, for differentiating SS and NASH group. For the diagnosis of hepatic fibrosis ≥S1, ≥S2 and S3, the AUC of mean value were 0.910, 0.961, and 0.974, respectively. Taking mean value ≥6.53 kPa, ≥8.30 kPa, and ≥12.38 kPa as critical values to predict hepatic fibrosis≥S1, ≥S2 and S3, the sensitivity were 90.9%, 100%, and 100%, respectively; the specificity were 84.4%, 82.1%, and 89.6%, respectively. Conclusion    SWE has a value in evaluating the severity of NAFLD and staging NAFLD hepatic fibrosis. 

Quantitative susceptibility mapping (QSM) is a MR imaging technology based on the gradient echo sequence. QSM reflects the difference of magnetic susceptibility between tissues by combining the magnetic map with the phase map. QSM can be quantitatively analyzed on susceptibility weighted imaging (SWI), and it has obvious advantages in detecting microvessels, mornitoring blood oxygen saturation, quantifying iron deposition, and identifying calcification and bleeding by measuring the susceptibility of tissues. QSM has been extensively applied in iron metabolism disease, intracranial hemorrhage, brain tumors and cerebrovascular diseases, it has also been used in the study of abdomen, joints and cartilage, cardiovascular and other systems. This paper introduces the principle and advantages of QSM and its clinical applications.

Pericardial adipose tissue is the fat around the coronary artery and the heart. The epicardial adipose tissue and perivascular adipose tissue are part of the pericardial adipose tissue, which are closely connected with the cardiovascular system and participate in the important pathophysiological processes of cardiovascular diseases(CVD).Currently, cardiac ultrasound, CT, MRI, positron emission tomography (PET) and radiomics can be used to non-invasively detect changes in pericardial adipose tissue.This article reviews the biological mechanism of pericardial fat participating in CVD,the progression of pericardial adipose tissue imaging technology，and its clinical application in evaluation of coronary artery disease, atrial fibrillation and heart failure.

Small cell lung cancer (SCLC) is the most common primary neuroendocrine malignancy of the lung and is characterized by a rapid doubling time, easy metastasis in early stage and poor prognosis. CT is the most commonly examination method. Familiar with the CT features of SCLC is essential. MRI can better show the brain metastasis of SCLC. DWI can provide molecular level information in the diagnosis and differential diagnosis of SCLC. PET/CT is more accurate than CT in the clinical staging of SCLC, and it is better to evaluate the therapeutic effect and prognosis. The main treatment of SCLC is radiotherapy and chemotherapy. Surgery should be considered in patients with stageⅠ (T1-2, N0), can improve the survival rate of patients. In this paper we reviewed imaging findings and progress in treatment of SCLC.

Objective    To investigate clinicopathological features and the imaging fingdings of intraductal tubulopapillary neoplasm (ITPN), in order to improve the recognition and imaging diagnosis for ITPN. Methods    Five patients with ITPN confirmed by surgical pathology were retrospectively collected to analyze the imaging findings and clinic data in combination with relevant literatures. Results    Four patients presented as soft tissue masses growing in the lumen of pancreatic duct. In the four patients, the tumors showed iso-or mild hypo-density and no calcifications on unenhanced CT, mild hypo- or iso-intensity on T1WI, mild hyper- and iso- or hypo-intensity on T2WI, hyper-intensity on DWI, and hypo-intensity on the ADC map compared with surrounding pancreatic parenchyma. The long axis of the lesions were consistent with the long axis of the main pancreatic duct in the four patients. In one patient, the tumor showed multiple cystic lesions and irregularly thickened cystic walls and septa without calcification on CT/MRI. The enhancement of the intraductal solid masses and solid components were slightly delayed and lower than that of the surrounding pancreatic parenchyma in each phases on CT and/or MRI. ITPN could presented as “the 2-tone duct sign” on CT/MRI, and “the cork-of-wine-bottle sign” on MRCP. Conclusion    ITPN is rare, and its intraductal growth behavior can be considered as a typical feature.

Hyperintense vessel sign (HVS) is defined as focal, serpentine, or tubular hyperintensity relative to gray matter in the subarachnoid space or extending into the parenchyma on fluid-attenuated inversion recovery images (FLAIR). HVS could be used for diagnosis of vascular stenosis or occlusion, prediction of ischemic penumbra, and evaluation of clinical outcome. HVS is time-dependent sign, often occurring in early stage of acute cerebral infarction. The degree or location of the artery stenosis can slowdown cerebral artery flow velocity in various degrees. When flow velocity decreases into a certain range, the HVS becomes prominent. The level of collateral circulation and other clinical related factors can affect collateral flow velocity, and the slow retrograde flow is also another important factor affecting HVS. MRI scanning parameters can affect the presentation of HVS on FLAIR. 

  影像学在急性缺血性脑卒中的诊疗中不可或缺，其主要作用是评估脑损伤的范围及指导治疗。一般以快速的平扫CT作为卒中早期初筛手段，运用Alberta卒中项目早期CT评分判断缺血范围。影像学中的缺血半暗带提示存在可挽救的脑组织，灌注加权成像/扩散加权成像、CT灌注成像等多种影像方法均可观察到缺血半暗带，指导积极的血管再通治疗。同时，对急性脑血管病病人侧支循环状况的影像评估也是非常重要的，除金标准数字减影血管造影外，多期相CT血管成像、动脉自旋标记等方法均有一定的诊断价值。血管再通治疗后也需要注重影像学监测，警惕再灌注损伤。

Purpose  To characterize the intracranial atherosclerotic plaques in patients with ischemic stroke and investigate the risk factors of vulnerable plaques by using 3.0 T high resolution MRI. Methods??? Forty nine patients (35 male, 14 female, age 31-81 years, mean age 60.73±12.4 years)with ischemic stroke underwent 3.0 T high resolution MRI. All plaques were categorized into 2 groups (culprit artery plaques and nonculprit artery plaques) according to the vascular territory of the stroke, and the characteristics of the plaques were investigated between the 2 groups. The plaques were also categorized into 2 groups (obvious enhancement/mild or none enhancement) according to the strength of plaque enhancement, then the clinical and laboratory characteristics were compared between the two groups, and the risk factors for vulnerable plaque were investigated. The chi-square test was used to compare the categorical variables, and the independent t-test was used to compare the continuous variables. Results??? Total 196 plaques were identified in 49 patients, seventy (35.7%) were culprit artery plaques, one hundred twenty seven (64.3%) were nonculprit artery plaques. There were significant differences between the 2 groups in the degree of luminal stenosis and the proportion of plaques obviously enhanced(P<0.001). The degree of luminal stenosis and plaque enhancement were significantly higher in the culprit artery plaque group than in the nonculprit artery plaque group (P<0.001). There was no significant difference in age, gender, hypertension, diabetes mellitus, smoking, past stroke history, and family history between the obvious enhancement group and the mild or none enhancement group.The LDL/HDL ratio was significantly lower in the mild or none enhancement group than obvious enhancement group (1.95±0.62 and 2.53±0.94, respectively, P=0.048). Conclusions? Obvious enhancement of intracranial artery plaquemay associate with ischemic stroke. The degree of plaque enhancement can reflect the stability of plaques.The common risk factors of intracranial atherosclerosis do not fully reflect the stability of plaques.LDL/HDL ratio may predict the vulnerability of the intracranial atherosclerotic plaques.

 Radiomics can quantify the tumor heterogeneity by extracting the features from different imaging methods that cannot be identified by naked eye, such as the gray histogram, morphology, and etc. At present, it has been widely used in the diagnosis and differential diagnosis, biological behavior evaluation and prognosis evaluation of breast cancer, and has shown great potential in the preoperative non-invasive evaluation of molecular subtype of breast cancer. This article reviews the application and progress of radiomics in classifying molecular subtype of breast cancer.

Objective  To explore correlation between white matter hyperintensity (WMH) and episodic memory in patients with type 2 diabetes mellitus (T2DM). Methods    Totally 132 T2DM patients (56 males, 76 females, mean age 58.5 ± 7.0 years) and 120 non diabetic controls (43 males, 77 females, mean age 57.4 ± 7.3 years) were prospectively enrolled. All subjects underwent MRI and a battery of tests. The modified Scheltens semi-quantitative rating scale was adopted to score deep WMH (dWMH) and paraventricular WMH (pvWMH). Differences in WMH score, fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), Rey-Osterrieth complex figure (ROCF) and Rey auditory verbal learning test (RAVLT) between the two groups were compared using either independent sample t tests or Mann-Whitney U tests. Chi-square test was adopted to compare the count data between the two groups. Kappa test was used to analyze the consistency of WMH scores of two physicians. Partial correlation analysis was used to detect the correlation between WMH scores and ROCF or RAVLT scores in the T2DM group. Results    Compared with the control group, the FBG and HbA1c were increased (P<0.001), and the scores of RAVLT and ROCF were decreased in the T2DM group (P<0.05). There was no significant difference of other parameters (P>0.05). In the T2DM group, the scores of dWMH were negatively correlated with the ROCF delay recall scores (r=-0.204, P=0.021). Conclusion    Episodic memory decrease in patients with T2DM and the episodic memory are related to WMH. This study suggests that WMH may be an imaging marker for the decreased episodic memory in patients with T2DM.

Liver?cancer?is?a?common?digestive?malignant?cancer.?Early?diagnosis?and?early?treatment?are?important?for?the?prognosis?of?the?patients?and?the?improvement?of?the?cure?rate.?As?an?advanced?imaging?technique,?spectral?CT?provides?plenty?of?information?for?the?diagnosis?with?the?advantages?of?high?scanning?speed,?multiple?imaging?parameters?and?low??radiation?dose,?hence?the?spectral?CT?has?been?rapidly?applied?in?recent?years.?In?this?review,?we?briefly?introduced?the?principle?of?spectral?CT,?and?summarized?the?research?progress?of?spectral?CT?in?the?diagnosis?of?liver?cancer.?Compared?to?the?previous?CT?techniques,?spectral?CT?can?provide?quantitative?measures?for?the?differential?diagnosis?of?liver?cancer,?and?is?a?new?tool?for?the?scientific?research?of?liver?cancer.

Objective    To investigate relevant MRI imaging features for posterior ankle impingement syndrome (PAIS). Methods    This retrospective study was conducted in 117 patients with clinically suspected PAIS on MRI examinations between April 2016 and May 2017, including 62 males and 55 females, age 17~72 years, average age 40.4±12.2 years. Logistic regression was used to evaluate the influence factors in the diagnosis of PAIS, including os trigonum, os trigonum marrow edema, os trigonum cystic change or/and hardening, stieda’s process long, stieda’s process marrow edema, stieda’s process cystic change or/and hardening, posterior ankle synovial inflammation, posterior ankle effusion, talus edge marrow edema, flexor hallucis longus tendon effusion, posterior ankle soft tissue swelling of 11 image signs. Results    Forty one(35.0%) of 117 patients were clinically diagnosed with PAIS, including os trigonum in 24 cases, os trigonum marrow edema in 13 cases, os trigonum cystic change or/and hardening in 3 cases, stieda’s process long in 17 cases, stieda’s process marrow edema in 7 cases, stieda’s process cystic change or/and hardening in 1 cases, posterior ankle synovial inflammation in 38 cases, posterior ankle effusion in 40 cases, talus edge marrow edema in 12 cases, flexor hallucis longus tendon effusion in 14 cases, posterior ankle soft tissue swelling in 10 cases. Single factor logistic regression analysis showed the differences in edema at os trigonum and os trigonum marrow were statistically significance (P<0.05). Multivariate logistic regression analysis showed the difference in edema at os trigonum marrow was statistically significance [OR 0.302 (95%CI: 0.108~0.839), P=0.022]. Conclusion    Os trigonum marrow edema is an influential factor in the diagnosis of PAIS, os trigonum marrow edema highly suggests the patient has PAIS.

Myocardial fibrosis (MF) is the root cause of ventricular remodeling and malignant arrhythmia. It eventually leads to the occurrence of major cardiac adverse events such as cardiac insufficiency and sudden death. Late gadolinium enhancement MRI (LGE-MRI) is a standard method in clinical setting for the detection of focal MF following myocardial infarction. T1 mapping has more advantages than LGE-MRI in the detection and quantitative evaluation of diffuse MF. Cardiac functional MRI such as diffusion tensor imaging (DTI) and diffusion weighted imaging (DWI) can be used to quantitatively assess myocardial micro-structures without using contrast media. DTI and DWI have shown great potentials in the detection of MF. This article reviews the progress of T1 mapping, DTI, DWI, and compare them with LGE-MRI.

Objective    To investigate the prediction and application values of dual-energy CT (DECT) contrast-enhanced scans in evaluating radiosensitivity of cervical lymph nodes metastases in nasopharyngeal carcinoma (NPC). Method    Between May 2014 and Dec. 2017, 52 NPC patients who had  metastatic lymph nodes in the neck (28 males and 24 females; mean age, 52.65±10.07 years, range 29-77 years) and underwent radiotherapy in our hospital were enrolled in the study. According to the curative effect, the patients were divided into effective [13 patients, 8 males, 5 females, average age 47.77±6.83 years] and ineffective group [39 patients, 20 males, 19 female, average age 54.62±10.66 years]. Dual-energy CT (DECT) enhanced scan of the neck was performed during the simulated positioning before radiotherapy, and the characteristics of energy spectrum curve were analyzed with a special post-processing software. The chi-square test was used to compare the difference in distribution of different T stages between the two groups. Independent sample t test was used for the comparison of standard iodide concentration (sIC), slope of energy spectrum curve (λHU), and area under curve (AUC) between the two groups. Sensitivity and specificity of radiotherapy efficacy were assessed by the sIC or λ_HU value of the lymph nodes before radiotherapy using operating characteristic curve (ROC). Results    There was no significant difference in the distribution of different T stages between the two groups (P>0.05). The sIC and λ_HU were higher in the effective group than in the ineffective group (all P<0.05). There was no significant difference in AUC between the radiotherapy ineffective and effective groups (P>0.05). Using sIC 26.50 ×10^-2 as the threshold of lymph nodes before radiotherapy, the AUC was 0.753, the sensitivity was 74.4%, and the specificity was 84.6%. Using λ_HU 4.90 as the threshold of the lymph nodes before radiotherapy, the AUC was 0.689, the sensitivity was 74.4%, and the specificity was 84.6%. Conclusion    The sIC and λ_HU, acquired from DECT contrast-enhanced scans, can be used to predict the effect of radiotherapy for cervical lymph nodes metastases in NPC as well as provide new strategies and bases for individual therapy in clinic.

 Breast cancer is one of the most common malignant tumors in women. The important factors, such as early and accurately diagnosis, and correct evaluation of its invasiveness, affect the prognosis. Many molecular imaging technologies, including ultrasonography, magnetic resonance imaging, radionuclide imaging and optical molecular imaging, play important roles in diagnosis, subtype diagnosis, treatment planning, and prognosis. Moreover, ultrasound-targeted microbubble therapy and optical molecular imaging guided surgery, are expected to become a new treatment method for breast cancer. In this article we reviewed and summarized the application of molecular imaging in breast cancer.

Objective??? To investigate spontaneous recanalization rate, course, infarct pattern, and recanalization mechanism of responsible artery in patients with acute stroke. Methods??? We conducted a retrospective review of 441 patients (male/female, 279/162; age 31-90 years, mean age 63.17±10.10 years) with acute stroke in the territory of the internal carotid artery (ICA) system from May 2015 to May 2016? in Tianjin Medical University General Hospital. All patients with cerebral infarction undergo routine MRI, DWI and MRA examinations.According to the MRA showed whether there is any stenosis or not in the infarct responsibility vessel, the whole patients are divided into recanalization group and non recanalization group. The differences in age and time interval from the onset to the MRA examination were compared with the two sample t test between the 2 groups, and the patient’s gender, lesion side, and other clinical data were compared with chi square test. Results??? There were 300 of 441 patients (68.03%, male 192 and female 108) with responsible arterial stenosis or occlusion, which were classified into recanalization group, whereas 141 patients (31.97%, male 87 and female 54) without responsible arterial stenosis or occlusion were classified into non recanalization group. The rate of spontaneous recanalization was 31.97%. There was no significant difference between the two groups in terms of age, sex, lesion side, and other clinical data (all P>0.05). The time interval from onset to MRA in the recanalization group was significantly shorter than that in the non-recanalization group (P=0.002). Most patients of both groups had single infarction, and the most common pattern was perforating artery infarction. The recanalization ratio within 3 days was 90.07% in the recanalization group, and within 3-7 days the recanalization ratio was 9.93%. Conclusion??? The incidence of early spontaneous recanalization is about 30%.? Spontaneous recanalization usually occurs approximately within the first 3 days. The recanalization rate is 90.07%. The spontaneous recanalization of small terminal arteries is high. Understanding the spontaneous recanalization after cerebral infarction may help clinicians to avoid aggressive treatment.

 Objective    To investigate the application value of 3D high resolution imaging sequences combined with magnetic resonance virtual endoscopy(MRVE) in preoperative assessment of trigeminal neuralgia in a 3.0 T MRI system. Methods    The data of 40 patients with primary trigeminal neuralgia were analyzed retrospectively. All of patients underwent the microvascular decompression (MVD) during April 2016 to December 2017. There were 21 males and 19 females, between 37-86 years old, with an average age of 59.6±2.2 years. All patients conducted three-dimensional (3D) high-resolution MR imaging, including fast imaging employing steady-state acquisition with phase cycling (FIESTA-c) and time-of-flight magnetic resonance angiography (TOF-MRA) in a 3.0 T MRI system, and data were reconstructed using MRVE. The χ2 test was used to compare the positive rate of the responsible vessels judged on 3D high-resolution imaging and 3D high-resolution imaging + MRVE, using operation results as the golden standard. Results    The positive rate on 3D high-resolution imaging sequence + MRVE (95%, 38/40) was significantly higher than on the pure 3D high-resolution imaging sequence (85%,34/40) (χ2=1.826, P=0.04). The responsible vessels were identified in all 40 patients during operation, including compression by artery in 33 patients (82.5%), simple venous in 3 patients (7.5%), and both artery and venous in 4 cases (10%). The detection rate of arterial compression by two imaging methods was 100%. The detection rate of venous and arteriovenous compression by 3D high resolution-imaging + MRVE (71.4%, 5/7) was higher than by the pure 3D high-resolution imaging (14.3%, 1/7). Conclusion    MR 3D high-resolution imaging sequence combined with MRVE technology may effectively display the 3D space between responsible vessels and nerves, and provide important value for the etiological diagnosis of trigeminal neuralgia.

Objective    To evaluate the application value of artificial intelligence (AI) assisted software in improving the detection efficiency of pulmonary nodules on CT by physicians with varied clinical experiences. Methods   A total of 181 patients with one or more pulmonary nodules were retrospectively collection. The diameters of nodules were 1 mm to 3 cm. All the patients underwent chest CT examination. Without and with assistance of AI software, the sensitivity in identifying pulmonary nodules with different densities (solid, pure ground glass, mixed ground glass, and calcification) and different sizes (<5 mm, 5-10 mm, and >10 mm) and the number of false positive nodules by residents and interns were calculated. The Chisquare test and paired t test or Wilcoxon rank sum test were used to compare the sensitivities and the numbers of false positive nodules between before and after AI assistance. Results    For the solid nodules and <5 mm nodules, the sensitivity in identifying the nodules by residents was higher than that by interns (all P<0.05). When under the assistance of AI, the sensitivity in identifying the solid nodules, pure ground glass nodules, calcified nodules, <5 mm nodules, and 5-10 mm nodules by residents were higher than that by interns (all P<0.05). With or without AI assistance, the number of false positive nodules of >10 mm nodules was not significantly different in both interns and residents (all P>0.05), but for identifying the other nodules, the number of false positive nodules in interns was higher than that in residents (all P<0.05). For the calcification nodules and >10 mm pulmonary nodules, AI assistance has no significant effect on the sensitivity in identifying the nodules by interns (P>0.05), but for other nodules, the sensitivity with AI assistance were significantly higher than that of independent reading (all P<0.05). AI assistance had no significant effect on the number of false positive nodules of >10 mm nodules in interns (P>0.05), and the number of false positive nodules in identifying the solid nodules, calcification nodules, <5 mm nodules, and 5-10 mm nodules were reduced by interns with AI assistance, however, the number of false positive nodules in identifying the pure ground glass nodules and mixed ground glass were increased (all P<0.05). In residents, AI assistance had no significantly effect on the sensitivity and the number of false positive nodules in identifying >10 mm nodules (all P>0.05), but when resident reading under AI-assistance, the sensitivities in identifying the other nodules were all significantly improved and the numbers of false positive nodules were reduced (all P<0.05). Conclusion    AI-assisted software can greatly improve the efficiency of intern and resident in detecting different pulmonary nodules on CT, thereby reducing the risk of missed diagnosis, but for interns, the number of false positive nodules is still high.

Objective    To investigate the feasibility of low-dose multi-slice spiral computed tomographic-colonography (MSCTC) combined with iDOSE4 iterative reconstruction technique to reduce the radiation dose while ensuring the accuracy of T staging of colon cancer. Methods    Patients with colon cancer diagnosed with colonoscopy were collected retrospectively. All of 73 patients (41 males and 32 females, mean age 60.8±11.0 years)who underwent low dose MSCTC scan before operation were taken as low dose group, and 65 patients (29 males and 36 females, mean age 64.6±11.6 years) who underwent conventional dose MSCTC scan before operation were taken as conventional dose group.All patients had preoperative T staging with CT. The total of dose length product (DLP) and volume CT dose index (CTDIvol) were recorded, and the effective dose (ED) was calculated. The surgical-pathological T staging was used as gold standard.Kappa test was used to analyze the consistency between the CT T staging and the surgical-pathological T staging,Chi-square test or Fisher exact probability test was used to compare the diagnostic efficacy of CT T staging evaluation, and independent sample t-test was used to compare the radiation dose between the two groups. Results    The consistency of preoperative CT T staging and surgical pathological T staging in both groups was moderate, the consistency of CT T staging and pathological T staging in the conventional dose group was higher than that in the low dose group. There was no significant difference in accuracy, sensitivity, specificity, positive predictive value and negative predictive value for≤T2, T3 and T4 between the two groups (all P>0.05). Compared with the conventional dose group, the accuracies, specificities and positive predictive values of ≤ T2 and T3 were slightly lower in the low dose group while those values of T4 were slightly higher; the sensitivities of ≤T2 and T4 were slightly lower, while the sensitivity of T3 were slightly higher; the negative predictive values of ≤ T2 and T3 were slightly higher, while that of T4 was slightly lower. The total DLP, CTDIvol and ED were significantly lower in the low dose group than in the conventional dose group,and decreased by about 67%, 69% and 67%, respectively(P<0.05). Conclusion    The low-dose MSCTC combined with iDOSE 4 iterative reconstruction technology can significantly reduce the radiation dose, and at the same time it has little effect on the evaluation of CT T staging, so it can be used as an effective method for preoperative staging of colon cancer.

Intracranial atherosclerosis is the most important cause of ischemic stroke. High-resolution magnetic resonance vessel wall imaging (VW-MRI) can directly image the vessel wall, and evaluate stenosis degree of vessel, vessel remodeling, plaque burden, plaque composition and distribution. VW-MRI is considered as the only noninvasive technique for intracranial vessel wall imaging. In recent years, intracranial VW-MRI has developed rapidly. We reviewed the VW-MRI techniques in evaluation of intracranial atherosclerotic plaque and clinical application.

Parkinson’s disease (PD) is a common neurodegenerative disease. Pathological changes mainly include degeneration and necrosis of dopaminergic neurons and formation of Lewy bodies in the nigrostriatal striatum pathway, resulting in a series of motor and non-motor symptoms. In recent years, with the development in multimodality MRI and brain network analysis,especially structural brain networks based on structural MRI, diffusion tensor imaging, and functional brain network based on functional MRI,the brain structure and functional changes of different PD subtypes can be studied from different aspects.This article reviews the researches on different PD subtypes based on multimodal MRI brain network imaging technology.

Objective??? To explore the feasibility of dual low-dose CT angiography (CTA) to assess plaque stability. Methods??? Forty-two cases (male n=29, female n= 13; age 62.3±7.69 years) who suffered from cerebral ischemic stroke? in our Department of Neurology during January 2015 to March 2016 were recruited. They were randomly divided into two groups, dual low-dose group and the conventional dose group, 21 cases in each group. Each group of patients received CTA with tube voltage and iodinated contrast agent dose 80 kV and 50 mL in dual low-dose group, and 120 kV and 100 mL in conventional dose group. Post processing of intracranial arterial plaque was conducted. The t-test was used to compare? the image quality, degree of vascular enhancement, and X-ray radiation dose between the two groups. Chi-square test was used to compare the difference in plaque detection rate between the two groups. Results??? The standard deviation was significantly higher in dual low-dose group than in the conventional dose group (P<0.05). The contrast noise ratio and signal? noise ratio did not significantly differ between the two groups(P>0.05). The dual low-dose group had higher CT values at middle cerebral artery M1 segment and vertebral basilar artery than that of conventional tube voltage group (all P<0.05). The image quality showed good in both groups (>2 points) and did not significantly differ from each other (P>0.05). The plaque detection rates had no statistical significance between the two groups (P>0.05). The CT dose index volume, dose length product, and effective dose in the dual low-dose group were lower than in the conventional dose group (all P<0.05). Conclusions??? CTA with dual low-dose technique can clearly demonstrate morphology and composition of intracranial arterial plaque, can lead to relatively accurate judgments on plaque stability,? and can effectively reduce doses of ionizing radiation and nephrotoxic iodine contrast agent. Therefore, dual low-dose CTA assessment of intracranial arterial plaque stability is feasible and worthy of promotion and has clinical application value.?

Brain metastases are the most common central nervous system tumors in adults, and clarifying the origin of the primary tumor is critical to the patient’s clinical decision and prognosis. With the continuous improvement of functional MRI such as MR spectroscopy, diffusion weighted imaging, diffusion tensor imaging, MR perfusion imaging, susceptibility weighted imaging, as well as the development of radiomics, it can provide physiological, metabolic and imaging characteristics information of brain metastases, and consequently can improve the accuracy of diagnosis of the origin or pathological type of primary malignant tumors. This article reviews the application progress of functional MRI and radiomics in identifying the origin of brain metastases.

Articular cartilage injury and degeneration is the primary important element in osteoarthritis (OA).Biochemical components alter at the early stage of OA and followed by the structure destruction. There is a minority of short T2/T2* components in articular cartilage, however conventional sequences show little or no signal for them because of the long echo times. While ultrashort echo time(UTE) sequences employ relatively short echo times and make it possible to image the short T2/T2* deep and calcified cartilage layer and to quantify the biochemical components directly, providing a promising method to probe the mechanism and early diagnosis of OA. This review emphasized on applications of UTE sequences in quantification study of early articular cartilage degeneration.