Diffusion-weighted imaging of the liver in assessing chronic liver disease: effects of fat and iron deposition on ADC values

OBJECTIVE

This study was designed to evaluate whether fat and iron affect the apparent diffusion coefficient (ADC) values of the liver parenchyma in the settings of fibrosis and inflammation.

PATIENTS AND METHODS

We evaluated the diffusion-weighted images (DWIs) of 58 patients with chronic liver disease and 48 control subjects. Liver specimens of patients were assessed for fibrosis, necroinflammation, iron, and steatosis. Liver ADCs, spleen ADCs, and normalized liver ADCs (defined as the ratio of the liver ADC to spleen ADC) values were analyzed after stratifying patients with either fibrosis stages or histology activity index (HAI) scores. The relationship between ADC values and histopathological findings was studied using multiple linear regression analysis.

RESULTS

The median liver and normalized liver ADC values were significantly lower in higher stages of fibrosis and HAI scores. Compared to the control group, patients with the highest stages of fibrosis and inflammation had significantly higher spleen ADCs. The effect of the fibrosis stage on liver ADC and normalized liver ADC values was significant in the setting of inflammation, whereas the degree of steatosis and iron grade did not affect these ADC values.

CONCLUSIONS

ADC values can distinguish both later stages of liver fibrosis and inflammation. There is no significant effect of fat and iron on ADC values. Therefore, DWI may be reliable in evaluating liver fibrosis and inflammation.

Effect of surface flattening and phototherapy on shear bond strength immediately after bleaching with different modes of universal adhesive

Objective

The aim of this study was to compare to effect of phototherapy and surface flattening after immediately bleaching on the shear bond strength to bleached enamel.

Methods

Ninety-six human upper incisors were divided into 4 groups (n = 24). Group NB: no bleached, group P: phototherapy with YSGG laser, group F: 0.5 mm surface flattening, group PF: 0.5 mm surface flattening and phototherapy with Er;Cr:YSGG laser. Then, each group was assigned to 2 subgroups according to adhesive mode (n = 12) as; subgroup S (self-etching mode), subgroup T (total-etching mode) which are universal adhesives. All surface conditionings and restorations were performed with composite resin materials immediately after bleaching. Shear bond strength test was performed by using universal testing machine. The surfaces were also evaluated with SEM. The data were statistically analyzed with one-way ANOVA post-hoc Tukey tests.

Results

The lowest SBS values were achieved in FS (13.72 ± 2.29) while the highest ones in PT (28.01 ± 6.81). However, the differences were not significant (P > 0.05). All surface conditioning methods provided SBS values similar to the control (P > 0.05). All subgroups of self-etching mode were significantly lower than their total-etching counterparts (P < 0.05).

Conclusions

The present study showed that surface removal and phototherapy have a potential clinical application for eliminate to undesirable effect of bleaching treatment. Surface conditioning with either flattening and/or phototherapy may provide clinicians to restore bleached teeth at the same visit with bleaching and reduce chair-time.

Sudden-onset paraplegia during pregnancy caused by haemorrhage in a spinal cord haemangioblastoma: A case report

Spinal cord haemangioblastomas are rare central nervous systems tumours, and haemorrhage.It is an uncommon occurance. We report a 28-year-old pregnant patient who presented with paraplegia due to acute haemorrhage of a spinal haemangioblastoma. Magnetic resonance imaging showed extensive syrinx cavities, an intramedullary lesion at the T4-T5 spinal cord level e, and a subarachnoid haemorrhage. Digital subtraction angiography showed the feeding artery and dilated tortuous draining vein within the dural sac. The lesion was deemed a haemangioblastoma. The histopathological examination confirmed the diagnosis. Postoperatively, the paraplegia improved and the patient was able to walk within 2 weeks. Imaging is important for early diagnosis to prevent patients persistent neurological deficits.

Diffusion-weighted imaging (DWI) of the liver in assessing chronic liver disease: effects of the presence and the degree of ascites on ADC values

PURPOSE

The aim of this study was to determine the correlation between the liver and spleen apparent diffusion coefficient (ADC) values of patients with chronic liver disease and the presence and the degree of ascites.

MATERIALS AND METHOD

In this retrospective study, we assessed 107 patients with chronic liver disease and 39 control subjects who underwent upper abdominal MR imaging including echo-planar diffusion-weighted imaging (DWI). Among the 107 cirrhotic patients, 56 were classified as group 1, 25 as group 2, and 26 as group 3 according to the absence, the presence of minimal, and the presence of massive ascites, respectively. The scores of model for end-stage liver disease (MELD) were matched between groups as the standard reference. The liver ADC, spleen ADC, and normalized liver ADC values were compared between the control group and patients' groups.

RESULTS

Patients with massive ascites had significantly higher MELD score compared with the other groups. The MELD score was also significantly higher in patient groups than in control group. The liver and normalized liver ADCs of patients' groups were significantly lower than that of the control group. With some overlap among groups, the measured ADC values decreased as the amount of the ascites increased, and these relationships were statistically significant. Furthermore, compared to control group, patients with massive ascites had significantly higher spleen ADCs.

CONCLUSION

Our results indicate that the ADC value of the liver and spleen correlates with the presence and the degree of ascites in patients with chronic liver disease, and merits further study.

Image-guided percutaneous bone biopsy with a simulated van sonnenberg removable hub system

OBJECTIVE

To retrospectively examine the success and complication rates associated with image-guided percutaneous bone biopsy with a simulated Van Sonnenberg removable hub system.

MATERIALS AND METHODS

During a 3.5-year period, 27 bone lesions at different anatomic locations with an indication for biopsy based on plain film, computed tomography (CT) and/or magnetic resonance imaging (MRI) findings were determined, and a total of 28 image-guided (fluoroscopy or CT) percutaneous biopsies were performed using a simulated Van Sonnenberg -removable hub system. This technique entailed the use of a cut-out Chiba needle hub that performed as a guide for the insertion of a larger needle. Either core and aspiration biopsy or core biopsy alone was utilized.

RESULTS

The procedure yielded diagnostic material 89% of the cases (48% infection, 22% benign lesions, and 19% malignant lesions). Combined use of core and aspiration biopsy resulted in a higher diagnostic accuracy as compared to core biopsy alone. No false positive or false negative diagnoses were observed. No serious complications such as neurological deficits, bleeding, or organ injury were observed.

CONCLUSION

The simulated Van Sonnenberg removable hub system provides a useful technique for percutaneous bone biopsies and is particulary suitable for deep seated (such as vertebral) lesions with its ability to facilitate the accessibility of the lesion with its built-in guidance needle. The procedure is safe in light of the literature data.

A critical overview of the imaging arm of the ASAS criteria for diagnosing axial spondyloarthritis: what the radiologist should know

The Assessment in SpondyloArthritis international Society (ASAS) defined new criteria in 2009 for the classification of axial spondyloarthritis (SpA) in patients with ≥ 3 months of back pain who were aged <45 years at the onset of back pain. This represents a culmination of a number of efforts in the last 30 years starting with the 1984 modified New York criteria for ankylosing spondylitis, followed by the 1990 Amor criteria and the 1991 European Spondyloarthropathy Study Group criteria for SpA. The importance of new ASAS criteria for radiologists is that magnetic resonance imaging (MRI) takes center stage and is one of the major criteria for the diagnosis of axial SpA when active (or acute) inflammation is present on MRI that is highly suggestive of sacroiliitis associated with SpA. According to the new criteria, sacroiliitis on imaging plus ≥ 1 SpA features (such as inflammatory back pain, arthritis, heel enthesitis, uveitis, dactylitis, psoriasis, Crohn's disease/colitis, good response to non-steroidal anti-inflammatory drugs, family history for SpA, HLA-B27 positivity, or elevated C-reactive protein) is sufficient to make the diagnosis of axial SpA. A number of rules and pitfalls, however, are present in the diagnosis of active sacroiliitis on MRI. These points are highlighted in this review, and a potential shortcoming of the imaging arm of the ASAS criteria is addressed.