ABSTRACT
Objective:To investigate CT manifestations of perivascular epithelioid cell tumors.Methods:The multi-slice spiral CT manifestations in 11 patients with perivascular epithelioid cell tumors which were pathologically confirmed in the First Affiliated Hospital of Shantou University Medical College between October 2012 and August 2021 were retrospectively analyzed.Results:Perivascular epithelioid cell tumors were located in the kidney of eight patients, in the right lobe of the liver of two patients, and in the descending colon of one patient. The largest tumor, approximately 20.0 cm × 26.0 cm × 11.0 cm, was located in the kidney. The smallest tumor, 2.4 cm × 2.6 cm × 3.4 cm, was located in the colon. CT plain scans showed uniform density without bleeding, calcification, or fat in two patients, and non-uniform density with fatty change in two patients. Contrast-enhanced CT images showed non-uniform enhancement in the arterial phase in 10 patients and uniform enhancement in one patient. Contrast-enhanced CT images showed decreased degrees of enhancement of the lesions in 11 patients from the portal venous phase to the delayed phase and dilated and tortuous vascular shadows in 11 patients.Conclusion:The multi-slice spiral CT manifestations of perivascular epithelioid cell tumors are characteristic and the multi-slice spiral CT is of value for the diagnosis of perivascular epithelioid cell tumors.
ABSTRACT
With the development of medical imaging technology, hemodynamics-based functional magnetic resonance imaging (fMRI) has gradually become one of the major tools to investigate human brain function, however, it is of limited temporal resolution. In recent years, neuronal current MRI (nc-MRI) was proposed as a new imaging method to directly map the magnetic field change caused by neural activities. Theoretically, nc-MRI can non-inva- sively locate brain activities with very high spatial and temporal resolution, thus it may greatly improve the study of human brain function. This paper reviews the construction mechanism of nc-MRI, including theoretical model of the neuronal magnetic field and signal source. Arithmetic simulation of nc-MRI signal with an illustration of our work on simulation of a dendrite branch magnetic field is presented. New development of the experimental studies and foreground of nc-MRI area are discussed.