Study on clinical application of susceptibility weighted imaging ombined with diffusion weighted imaging in patients with Liver Cirrhosis complicated with small Hepatocellular Carcinoma

Narrative review of magnetic resonance imaging in quantifying liver iron load

Objective

To summarize the research progress of magnetic resonance imaging (MRI) in quantifying liver iron load.

Methods

To summarize the current status and progress of MRI technology in the quantitative study of liver iron load through reviewing the relevant literature at home and abroad.

Results

Different MRI sequence examination techniques have formed a series of non-invasive methods for the examination of liver iron load. These techniques have important clinical significance in the imaging diagnosis of liver iron load. So far, the main MRI methods used to assess liver iron load are: signal intensity measurement method (signal intensity, SI) [signal intensity ratio (SIR) and difference in in-phase and out-of-phase signal intensity], T2/R2 measurement (such as FerriScan technique), ultra-short echo time (UTE) imaging technique, and susceptibility weighted imaging (including conventional susceptibility weighted imaging) (SWI), quantitative susceptibility mapping (QSM), T2*/R2* measurement, Dixon and its derivative techniques.

Conclusion

MRI has become the first choice for the non-invasive examination of liver iron overload, and it is helpful to improve the early detection of liver injury, liver fibrosis, liver cirrhosis and liver cancer caused by liver iron overload.

Detection of tumour boundary in metastatic liver disease with 2D multibreath-hold susceptibility-weighted imaging

PURPOSE

To investigate the feasibility of susceptibility weighted imaging (SWI) in detecting tumour boundaries in metastatic liver disease (MLD) without contrast agent, and whether SWI can provide pathophysiologic information for preoperative evaluation.

METHODS

Thirty patients with MLD underwent tumour resection. All patients underwent conventional MRI (T1-weighted and T2-weighted imaging), contrast-enhanced (CE) MRI and multibreath-hold 2D SWI. The conspicuity of the tumour boundary was assessed using a 4-grade scale. The detection rate of tumour boundaries and areas were reviewed and measured. The longest dimension was used to estimate the tumour size from the MR image. The conspicuity of the tumour boundary and area were compared using a nonparametric multi-group comparison (Friedman M). The McNemar test was applied to examine differences in the detection rate of tumour boundaries.

RESULTS

Among four different MRI sequences, SWI exhibited increased conspicuity of the tumour boundary than the conventional MRI (P < 0.001). SWI (91.8%) and CE-MRI (64.4%) exhibited higher detection rates of the tumour boundary than T1WI and T2WI (6.8% and 12.3% respectively). Longer tumour maximum diameters were measured with SWI (29.1 ± 17.2 mm) and CE-MRI (28.2 ± 16.8) compared to conventional MRI (P < 0.05).

CONCLUSION

2D multibreath-hold SWI enables enhanced noninvasive detection of tumour boundaries in patients with MLD compared with conventional MRI and CE-MRI without using an exogenous contrast agent. SWI has the potential to become a preoperative assessment standard that complements conventional MRI.

Diagnosis and analysis of primary central nervous system lymphoma based on MRI segmentation algorithm

Objective:

This paper summarizes the MRI imaging findings of primary central nervous system lymphoma (PCNSL) in the posterior cranial fossa to improve the accuracy of PCNSL diagnosis in the posterior cranial fossa.

Methods:

This study retrospectively analyzed the MRI imaging manifestations of 15 PCNSL posterior cranial fossa cases confirmed by puncture or surgical pathology from June 2017 to May 2018, including their occurrence sites, the number of lesions, MRI plain and enhanced manifestations, and diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy. Imaging (MRS) performance.

Results:

A total of 15 cases were enrolled, including 10 cases of single lesion and five cases of multiple lesions. The total number of lesions was 25, which were in the cerebellar hemisphere and cerebellar vermis, midbrain, fourth ventricle, and pontine cerebellum. The lesions were round, irregular, nodular, patchy, with low or medium signals on T1WI, equal or slightly higher signals on T2WI, and enhanced with 25 meningiomas-like gray matter signals. All of them were significantly strengthened. “Acupoint sign” and “umbilical depression sign” were seen in eight lesions. There were 17 massive and nodular enhancements, four striped enhancements, three patchy enhancements, and one circular enhancement. five cases of DWI showed homogeneous high signal, two cases showed uneven high signal, and 3 cases showed medium signal. The ADC value of tumor parenchyma in 10 patients was (0.62±0.095)×10^-3mm²/s. MRS examination showed obvious Lip peak in two cases.

Conclusion:

PCNSL in posterior cranial fossa has certain characteristics. DWI, ADC value and MRS are helpful to improve the correct diagnosis rate of PCNSL.