ObjectiveTo summarize the value of imaging in the evaluation of non-surgical therapy for pancreatic cancer.MethodThe relevant literatures about imaging evaluation of non-surgical therapy for pancreatic cancer were collected to make an review.ResultsAt present, most of the imaging evaluation of non-surgical therapy for pancreatic cancer were based on the assessment of morphological characteristics of tumors, such as contrast-enhanced CT and MRI. However, only morphological changes of tumors could not accurately evaluate the response of pancreatic cancer after non-surgical treatment. A few studies had explored the value of functional imaging and artificial intelligence.ConclusionsNon-surgical therapy provides new treatment opportunities for unresectable pancreatic cancer, especially the proposed of neoadjuvant therapy, which provides the possibility of operation for patients with advanced pancreatic cancer. More imaging indicators with stronger objectivity, higher accuracy, and wider universality need to be improved and developed in the future.
ObjectiveTo summarize the research progress of ultrasmall superparamagnetic iron oxide (USPIO) enhanced magnetic resonance imaging (MRI) in normal-sized lymph node metastasis of colorectal cancer.MethodThe relevant literatures published recently at domestic and abroad about USPIO enhanced MRI in normal-sized lymph node metastasis of colorectal cancer were collected and reviewed.ResultsUSPIO, a kind of lymph node targeted magnetic resonance contrast agent, could be used to evaluate lymph node metastasis of malignant tumors. USPIO enhanced MRI could detect normal-sized lymph node metastasis in colorectal cancer effectively compared with normal MRI. It provided a higher diagnostic performance than normal enhanced MRI. In addition, USPIO enhanced MRI could also distinguish inflammatory and metastatic lymph nodes better that were difficult to be distinguished by normal enhanced MRI.ConclusionUSPIO enhanced MRI shows a certain potential for clinical application in detecting normal-sized lymph node metastasis of colorectal cancer, but it has not been widely used in China.
Cryptogenic stroke (CS) accounts for 25% of ischemic stroke. The etiology of undetermined stroke is unclear leading to untargeted secondary prevention, high recurrence rate, so the clinical burden of cryptogenic stroke is substantial. Cardiac magnetic resonance (CMR) imaging can identify more occult cardiac embolism that cannot be identified by standard cardiac assessment based on its excellent spatial resolution and contrast, three-dimensional imaging capacity and ability to depict soft tissues, to accelerate the initiation of optimal secondary prevention and improve the prognosis of patients. This review summarizes the application of CMR in the field of CS in recent years. Based on the latest evidence of diagnosis and management strategies, this paper proposes a cardiac diagnostic examination plan for CS patients, thereby improving the secondary prevention strategy of CS patients and improving their quality of life.
ObjectiveTo help junior radiologists and surgeons better interpret MRI images of rectal cancer.MethodThe guidelines, expert consensus and research progress on the application of MR imaging in rectal cancer in recent years were reviewed.ResultsRectal MR had the ability to accurately evaluate a number of important findings that may impact patient’ management, including distance of the tumor to the mesorectal fascia, presence of extramural vascular invasion, and presence of lymph nodes.ConclusionsRectal MRI is an important basis for clinical staging and multidisciplinary diagnosis and treatment of rectal cancer. Surgeons and radiologists must master the key imaging anatomical basis and clinical practice points in order to accurately interpret the image information of MRI in rectal cancer.
Objective To clarify relationship between signal heterogeneity on hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI and prognosis of hepatocellular carcinoma (HCC). Methods From January 2014 to January 2017 in the First Affiliated Hospital of Chongqing Medical University, a total of 77 patients with the pathologically proved HCC underwent Gd-EOB-DTPA-enhanced MRI prior to surgery were included in this study. On the basis of the signal heterogeneity in the hepatobiliary phase, the included patients were designed to homogeneous hypointensity group and heterogeneous hyperintensity group. The disease-free survival time were compared between the 2 groups and it’s influencing factors were analyzed. Results Seventy-seven patients with HCC were included, including 45 cases of homogeneous hypointensity and 32 cases of heterogeneous hyperintensity. There were no significant differences in the age, gender, etiology, liver function, alpha-fetoprotein, differentiated degree, Child-Pugh grade, lesion diameter, lesion border, and number of lesions between the 2 groups (P>0.05). However, the HCC patients with heterogeneous hyperintensity had a later BCLC staging (P=0.001). The disease-free survival time of the patients with homogeneous hypointensity and heterogeneous hyperintensity was (17.0±9.8) months and (12.4±10.4)months, respectively. The Kaplan-Meier survival curve showed that the disease-free survival time in the patients with homogeneous hypointensity was significantly better than that in the patients with heterogeneous hyperintensity (P=0.020). The results of univariate analysis showed that the other confounding factors had no effect on the disease-free survival time of patients with hepatocellular carcinoma (P>0.05) except for the signal of hepatobiliary phase (P<0.05). Furthermore, the hepatobiliary phase signal, BCLC stage, and degree of differentiation, which might be clinically considered as potentially influencing for the prognosis of patients with HCC, were included in the Cox multivariate proportional hazard regression model and found that the heterogeneous hyperintensity was still the risk factor of the disease-free survival rate in patients with HCC (P=0.047). Conclusion Signal heterogeneity on hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI is related to prognosis of patients with HCC, heterogeneous hyperintensity may indicate a lower disease-free survival rate.
Nowadays, an increasing number of researches have shown that epilepsy, as a kind of neural network disease, not only affects the brain region of seizure onset, but also remote regions at which the brain network structures are damaged or dysfunctional. These changes are associated with abnormal network of epilepsy. Resting-state network is closely related to human cognitive function and plays an important role in cognitive process. Cognitive dysfunction, a common comorbidity of epilepsy, has adverse impacts on life quality of patients with epilepsy. The mechanism of cognitive dysfunction in epileptic patients is still incomprehensible, but the change of resting-state brain network may be associated with their cognitive impairment. In order to further understand the changes of resting-state network associated with the cognitive function and explore the brain network mechanism of the occurrence of cognitive dysfunction in patients with epilepsy, we review the related researches in recent years.
Objective To investigate the application of magnetic resonance imaging (MRI) in preoperative assessment of rectal cancer. Methods Combined with the literatures, the MRI features and measurements of rectal tumor staging, extramural vascular invasion, circumferential margin involvement, and the distance between distal margin of the tumor from the anorectal ring and the anal margin were described. Results On T2-weighted images (T2WI), T1 staging-tumors were those in which the normal submucosa was replaced by the iso-intensity of tumor tissue without invasion of muscularis propria; T2 staging-tumors were those with extension into the muscularis propria, but not invaded the high-intensity of mesorectal fat; T3 staging-tumors manifested as the rectal tumor penetrated into the muscularis propria and invaded the high-intensity of mesorectal fat; T4 staging-tumors manifested as the tumor invaded adjacent structures or organs. The metastatic lymph nodes were showed with irregular boundaries and mixed signals on T2WI. The tumor signals could be found in the extramural vascular on T1-weighted images (T1WI), accompanied by irregular distortion and expansion of the blood vessels. On T2WI, metastatic lymph nodes, extramural vascular invasion, and the distance between the residual tumor and the low-signal of mesorectal fascia was within 1 mm, indicated the positive circumferential margin. On T2WI, the distal margin of the tumor was located at the junction of hyperintense submucosa and iso-signal of tumor, the tip of the iso-signal puborectal muscle was the apex of the anorectal ring, and the lowest point of the iso-signal external sphincter was the anal margin. Conclusion MRI can provide reliable imaging information for preoperative staging, height measurement, and prognosis of rectal cancer, and it is helpful for early diagnosis and treatment of rectal cancer.
Objective To explore the accuracy of contrast-enhanced magnetic resonance imaging (MRI) in predicting pathological complete remission (pCR) in breast cancer patients after neoadjuvant therapy (NAC). Methods The clinicopathological data of 245 patients with invasive breast cancer who had completed the surgical resection after NAC in the Affiliated Hospital of Southwest Medical University from March 2020 to April 2022 were collected retrospectively. According to the results of hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) detected by immunohistochemistry, all patients were divided into four subgroups: HR+/HER2–, HR+/HER2+, HR–/HER2+ and HR–/HER2–. The value of MRI in evaluating the efficacy of NAC was analyzed by comparing the postoperative pathological results as the gold standard with the residual tumor size assessed by preoperative MRI. Meanwhile, the sensitivity, specificity and positive predictive value (PPV) of pCR predicted by the evaluation results of enhanced MRI were analyzed, and further analyzed its predictive value for pCR of different subtypes of breast cancer. Results There were 88 cases (35.9%) achieved radiological complete response (rCR) and 106 cases (43.3%) achieved pCR in 245 patients. Enhanced MRI in assessing the size of residual tumors overestimated and underestimated 12.7% (31/245) and 9.8% (24/245) of patients, respectively. When setting rCR as the MRI assessment index the specificity, sensitivity and PPV were 84.2% (117/139), 62.3% (66/106) and 75.0% (66/88), respectively. When setting near-rCR as the MRI assessment index the specificity, sensitivity and PPV were 70.5% (98/139), 81.1% (86/106), and 67.7% (86/127), respectively. The positive predictive value of both MRI-rCR and MRI-near-rCR in evaluating pCR of each subtype subgroup of breast cancer was the highest in the HR–/HER2+ subgroup (91.7% and 83.3%, respectively). In each subgroup, compared with rCR, the specificity of near-rCR to predict pCR decreased to different degrees, while the sensitivity increased to different degrees. Conclusions Breast contrast-enhanced MRI can more accurately evaluate the efficacy of localized breast lesions after NAC, and can also more accurately predict the breast pCR after NAC. The HR–/HER2+ subgroup may be a potentially predictable population with pCR exemption from breast surgery. However, the accuracy of the evaluation of pCR by breast enhancement MRI in HR+/HER2– subgroup is low.
The aim of the present study was to investigate the alternations of brain functional networks at resting state in the schizophrenia (SCH) patients using voxel-wise degree centrality (DC) method. The resting-state functional magnetic resonance imaging (rfMRI) data were collected from 41 SCH patients and 41 matched healthy control subjects and then analyzed by voxel-wise DC method. The DC maps between the patient group and the control group were compared using by two sample t test. The correlation analysis was also performed between DC values and clinical symptom and illness duration in SCH group. Results showed that compared with the control group, SCH patients exhibited significantly decreased DC value in primary sensorimotor network, and increased DC value in executive control network. In addition, DC value of the regions with obvious differences between the two groups significantly correlated to Positive and Negative Syndrome Scale (PANSS) scores and illness duration of SCH patients. The study showed the abnormal functional integration in primary sensorimotor network and executive control network in SCH patients.
To solve the problem of precise positioning of carp brain tissue coordinates, it is proposed in this paper for a method for transforming the coordinates of magnetic resonance imaging of carp brain tissue into the coordinates of electrode implantation using a brain stereotaxic apparatus. In this study, the 3.0T magnetic resonance imaging instrument was used to scan the carp brain. We independently established the three-dimensional positioning coordinate system of the brain, the three-dimensional coordinate assistance system of skull surface and the three-dimensional coordinate assistance system in brain tissue. After two coordinate transformations, the magnetic resonance image coordinates of the brain electrodes implantation sites were converted into the three-dimensional stereotactic coordinate system to guide the electrodes implantation. The experimental groups were divided into two groups, A and B. Group A was the group of magnetic resonance imaging apparatus combining with the brain stereotaxic apparatus, and group B was the group of brain atlas combining with the brain stereotaxic apparatus. Each group had 20 tails of carps (n = 20). This two methods were used to implant the electrodes into the cerebellar motor area. The underwater experiments of the carp robots were carried out to test the two methods. The results showed that the accuracy of the implanted electrodes were 90% in group A and 60% in group B. The success rate of group A was significantly higher than that of group B (P < 0.05). Therefore, the new method in this paper can accurately determine the coordinates of carp brain tissue.