[Use of Gd-DTPA in the nuclear magnetic resonance study of the breast]

Identification of Key Functional Modules and Immunomodulatory Regulators of Hepatocellular Carcinoma

Despite the advances in the treatment of hepatocellular carcinoma (HCC), the prognosis of HCC patients remains unsatisfactory due to postsurgical recurrence and treatment resistance. Therefore, it is important to reveal the mechanisms underlying HCC and identify potential therapeutic targets against HCC, which could facilitate the development of novel therapies. Based on 12 HCC samples and 12 paired paracancerous normal tissues, we identified differentially expressed mRNAs and lncRNAs using the "limma" package in R software. Moreover, we used the weighted gene coexpression network analysis (WGCNA) to analyze the expression data and screened hub genes. Furthermore, we performed pathway enrichment analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. In addition, the relative abundance of a given gene set was estimated by single-sample Gene Set Enrichment Analysis. We identified 687 differentially expressed mRNAs and 260 differentially expressed lncRNAs. A total of 6 modules were revealed by WGCNA, and MT1M and MT1E genes from the red module were identified as hub genes. Moreover, pathway analysis revealed the top 10 enriched KEGG pathways of upregulated or downregulated genes. Additionally, we also found that CD58 might act as an immune checkpoint gene in HCC via PD1/CTLA4 pathways and regulate the levels of tumor-infiltrating immune cells in HCC tissues, which might be an immunotherapeutic target in HCC. Our research identified key functional modules and immunomodulatory regulators for HCC, which might offer novel diagnostic biomarkers and/or therapeutic targets for cancer immunotherapy.

Large Non-enhancing Breast Cancer on Breast Magnetic Resonance Imaging: A Case Report

A 55-year-old female presented with vague symptoms in the lateral left breast. Digital breast tomosynthesis and breast ultrasound showed no focal lesion, and magnetic resonance imaging (MRI) was subsequently performed. No suspicious enhancement was seen on MRI; in particular, no suspicious lesion was seen in the area of clinical concern. In view of persisting focal mastalgia and vague parenchymal changes in the symptomatic area on repeat targeted ultrasound, a core biopsy was performed. Final pathology after left mastectomy with axillary clearance showed a 42 mm grade 2 invasive ductal carcinoma. Ten out of 15 lymph nodes contained metastatic carcinoma. This case report presents a large ductal breast cancer with no enhancement on breast MRI. Factors that may contribute to the non-detection of breast cancers on MRI studies will be discussed.

The role of parallel diffusion-weighted imaging and apparent diffusion coefficient (ADC) map values for evaluating breast lesions: preliminary results

RATIONALE AND OBJECTIVES

To evaluate the feasibility of using diffusion-weighted imaging (DWI) with an array spatial sensitivity encoding technique (ASSET) and apparent diffusion coefficient (ADC) map values with different b values to distinguish benign and malignant breast lesions.

MATERIALS AND METHODS

Fifty-six female patients with 60 histologically proven breast lesions and 20 healthy volunteers underwent magnetic resonance imaging. A subset of normal volunteers (n = 7) and patients (n = 16) underwent both conventional DWI and ASSET-DWI, and the image quality between the two methods was compared. Finally, ASSET-DWI with b = 0, 600 s/mm(2), and b = 0, 1000 s/mm(2), were compared for their ability to distinguish benign and malignant breast lesions.

RESULTS

The ASSET-DWI method had less distortion, fewer artifacts, and a lower acquisition time than other methods. No significant difference (P > .05) was detected in ADC map values between ASSET-DWI and conventional DWI. For ASSET-DWI, the sensitivity of ADC values for malignant lesions with a threshold of less than 1.44 x 10(-3) mm(2)/s (b = 600 s/mm(2)) and 1.18 x 10(-3) mm(2)/s (b = 1000 s/mm(2)) was 80% and 77.5%, respectively. The specificity of both groups was 95%.

CONCLUSION

ASSET-DWI evaluation of breast tissue offers decreased distortion, susceptibility to artifacts, and acquisition time relative to other methods. The use of ASSET-DWI is feasible with b values ranging from 600 to 1000 s/mm(2) and provides increased specificity compared to other techniques. Thus, the ADC value of a breast lesion can be used to further characterize malignant lesions from benign ones.

Value of MR mammography in the detection and exclusion of recurrent breast carcinoma

PURPOSE

This is a study of 140 patients undergoing MR mammography (MRM) for evaluation of possible local recurrent disease following breast-conserving surgical treatment of mammary carcinoma. MRI was performed 1-228 months (mean 28.3 months) postoperatively.

METHOD

MRM and interpretation of the dynamic measurements were performed in a standardized manner after positioning the patient in a double breast coil. A GRE sequence (Flash 3D, TE 5 ms, TR 12 ms, FA 25 degrees) was acquired before and 1, 2, 3, and 8 min after intravenous injection of Gd-DTPA in a dose of 0.15 mmol/kg body wt.

RESULTS

Recurrent disease was excluded in 82.8% of cases with MRM. In another 13.6% of patients, MRM was able to reliably detect recurrence of malignancy. In five cases (3.6%), MRM returned false-positive results.

CONCLUSION

MRM is a sensitive method for detecting or excluding recurrence of malignant disease. It remains to be determined whether early detection of recurrent disease can contribute significantly to improving the prognosis in these patients.

The use of Gd-DOTA in magnetic resonance imaging of experimentally induced mammary tumors

Gd-DOTA contrast enhancement of MR images was evaluated on induced mammary tumors in female rats. A single intravenous injection of the carcinogenic N-nitrosourea ENU was administered to Wistar rats; this simple treatment led to a high percentage of mammary tumors without causing death. All the induced tumors were adenocarcinoma and their heterogeneousness depended on their size. The induced tumors did not have intra- or extravascular inflammatory spaces caused by heterotopic lesions, as is the case with implanted tumors. Before injection of Gd-DOTA, appearance of the patchy internal structure was clearly demonstrated on spin-echo images performed with long repetition times. Three doses of the paramagnetic contrast agent (0.1, 0.2, and 0.5 mmol/kg) were evaluated on two different T1-weighted MR sequences. Images were recorded before and repeatedly after intravenous injection of Gd-DOTA, and signal intensities and relaxation times were measured. On images acquired with the spin-echo 500/28 as well as the inversion-recovery 928/26/300 sequences, the results showed that 0.2 mmol/kg Gd-DOTA was the optimal dose for contrast enhancement and for clear visualization of the heterogeneousness of the mammary tumor.