2016年 · 第50卷第05期

Breast MRI has high resolution of soft tissue, especially high-field intensity MRI with high signal-to-noise ratio, which has advantages in the detection of breast lesions and the differentiation of benign and malignant lesions. It has been recognized as the most common auxiliary examination method for uncertain mammography lesions^[1]。 MRI of breast can not only show the morphological characteristics of lesions, but also reflect the formation of microvessels and cell metabolism at the molecular level. Quantitative MRI of breast is an important part of functional imaging, which can make quantitative judgment on the nature of disease by analyzing the changes of neovascularization in vivo. Quantitative MRI methods mainly include semi-quantitative dynamic enhanced MRI examination, quantitative dynamic enhanced MRI examination and DWI. The author summarizes the main progress and existing problems of these techniques, and looks forward to the future research and application directions.

In recent years, CT examination has been rapidly popularized and widely used in clinical diagnosis. By the end of 2013, the installed capacity of CT in China had exceeded 16,000 units. With the increasing frequency and frequency of CT examination, the radiation dose received by the subjects also increased greatly^[1,2,3]。 The radiation dose produced by CT scan accounts for about 1/2 of all medical radiation doses, and it has become the largest source of iatrogenic artificial radiation^[4]。 Studies have confirmed that the higher the radiation dose the subjects receive, the greater the risk of cancer, especially in children^[3]。 According to the data released by the International Commission for Radiological Protection, the incidence of malignant tumors will increase by 5/100,000 for every increase of 1 mSv of X-ray dose^[5]。 At present, the focus of research at home and abroad is mainly on how to reduce the radiation dose of subjects, and low-dose examination techniques and schemes are constantly introduced^[6,7,8]。 However, during the CT examination of some special patients (such as children, confused and uncooperative patients, and critically ill patients, etc.), family members or medical staff are required to accompany them in the computer room. The author intends to scan the standard CT water model, and use thermoluminescence dosimeter (TLD) to measure the radiation field in the CT room during 128-slice spiral CT routine head scanning, analyze the data and draw the schematic diagram of the radiation field in the CT room, so as to provide a basis for clinical protection.

intramuscular myxoma (IM) is a rare mucinous tumor that occurs in muscles. Unlike para-articular myxoma and other low-grade malignant soft tissue tumors, IM is a benign tumor, but it can grow invasively and rarely relapse after surgery. Therefore, the correct preoperative diagnosis is of important clinical significance to formulate the surgical plan and judge the prognosis. The author collected the clinical, pathological and MRI data of 7 patients with IM confirmed by postoperative pathology, and summarized their characteristics, aiming to improve the understanding of IM and the level of imaging diagnosis.

Palliative treatment has become an important treatment for hilar cholangiocarcinoma because of its difficulty in operation, low resection rate and many complications. Biliary stent insertion into the bile duct drainage is the first choice for palliative treatment^[1,2]。 However, the stent itself does not prevent tumor growth, and varying degrees of blockage or reobstruction will occur 4 to 12 months after surgery.¹²⁵I particle is a kind of low energy radioactive particle, which has been widely used in the treatment of malignant tumors^[3]。 Existing biliary stent combination¹²⁵A report of intracavitary irradiation of I particles in the treatment of malignant obstructive jaundice^[4,5]This study aimed to discuss its clinical efficacy in malignant obstructive jaundice caused by hilar cholangiocarcinoma.

A 14-year-old female was seen on April 9, 2015 due to headache for 9 months, aggravated with nausea and vomiting for 10 days. The muscle tone of the limbs of the patient was increased, and there were no positive signs in the residual nervous system examination, and no abnormalities were found in the laboratory examination. Imaging examination: MRI showed a partial lobular mass on the left parieto-occipital side, about 5 cm ×5 cm ×4 cm in size, with clear edges and uneven signals, T₁WI and T₂WI was dominated by isosignals, with linear empty blood vessel shadows locally, cerebrospinal fluid-like signals surrounding the tumor, compression and displacement of the adjacent cerebral gyrus, and obvious tumor enhancement on enhanced scan (Figure 1，Figure 2，Figure 3）。 MRS examination showed that the peak of choline (Cho) increased and the peak of N-acetyl aspartate (NAA) decreased in the left parieto-occipital lesion, and Cho/NAA =7.998.

A male child with a gestational age of 31 weeks was born naturally due to premature rupture of membranes, with an Apgar score of 9 and a birth weight of 1 965 g. He was discharged from hospital 3 days after birth. Her mother developed fever after being discharged from hospital, went to a hospital and was later diagnosed with tuberculosis. The child went to our hospital on June 17, 2015 due to the appearance of blue complexion for 4 hours after 3 days of discharge (6 days of age). The child developed fever after admission, with the highest temperature of 38.3℃ and no convulsions; Physical examination: on June 20th, the sputum smear test results were acid-fast staining (+); Cerebrospinal fluid was clear and clear, glucose 1.44 mmol/L, Pane's test (+). After admission, 4 bedside chest X-rays were taken, and the X-ray manifestations and diagnosis were as follows: on June 17, the first time showed scattered striped high-density blurred shadows on both lungs, with obvious inner middle zone, and the diagnosis was aspiration pneumonia (Figure 1）； On June 19th, the second time showed multiple flaky cystic solid blurred shadows scattered in both lung fields, which was significantly worse than the first time, and the diagnosis of caseous pneumonia was possible (Figure 2）； On June 29th, the lesions in both lung fields progressed for the third time compared with the previous film, with multiple cystic-solid cavities, and the diagnosis was caseous pneumonia (Figure 3）； After half a month of treatment, the fourth examination on July 6 showed that the lesions in both lung fields were absorbed compared with the previous ones (Figure 4), diagnosed with caseous pneumonia than the previous partial resorption.