Update on MRI for Oral Cavity

ABSTRACT

Magnetic resonance imaging (MRI) is the imaging modality of choice to evaluate the complex anatomy and pathology of the oral cavity. In this article, an overview of MRI findings of common benign lesions in the oral cavity including congenital, vascular, and inflammatory/infectious lesions will be reviewed. In addition, MRI findings of common benign and malignant oral cavity tumors will be presented.

The utility of abdominopelvic CT in pregnant patients with abdominal pain and a negative or inconclusive abdominal MRI

Pregnant women with abdominal pain can pose a diagnostic dilemma due to the nonspecific nature of symptoms and the desire to avoid radiation to the conceptus. Many algorithms will suggest ultrasound (US) or Magnetic Resonance Imaging (MRI) as the first-line imaging choice in pregnant women with abdominal pain due to the lack of ionizing radiation. However, these studies can have limitations as well. Abdominopelvic MRI is susceptible to respiratory motion that could cause a study to be nondiagnostic (Zaitsev et al., 2015 [1]). In the current case series, we present 8 pregnant patients with abdominal pain who underwent CT abdomen and pelvis after negative or inconclusive abdominal MRI exams. To our knowledge, this is the only case series that describes CT findings in the pregnant population after negative or inconclusive MRI.

Coronary CT Calcium Score in Patients With Prior Nongated CT, Is it Necessary?

PURPOSE

To evaluate the percentage of patients undergoing gated coronary artery calcium score CTs that had a prior nongated chest CT. To assess the accuracy of prior nongated chest CTs in the detection of coronary calcium.

BACKGROUND

Cardiovascular disease is the most common cause of death worldwide. Quantifying coronary artery calcification on gated calcium score CT has proven to be strongly predictive of adverse coronary artery disease events. However, visual estimation and ordinal scoring on nongated chest CTs is predictive of coronary calcium burden.

METHODS

Consecutive gated calcium score CTs at a single institution from 10/2014 to 10/2016 were retrospectively evaluated with IRB approval/waiver of informed consent. The presence or absence of coronary calcium and ordinal score on nongated chest CT was compared to Agatston score on gated calcium score CT.

RESULTS

Forty-two of 441 patients (9.5%) with a gated calcium score had a prior nongated chest CT, with a mean time difference of 810 days. Of the 42 prior chest CTs, 69% had coronary artery calcium (CAC) and 31% did not, with 100% predictive accuracy for the presence or absence of CAC on subsequent gated calcium score CTs. There was 86% correlation of Agatston score on gated calcium score CT with ordinal score on the prior chest CT. Ordinal score divided into independent groups of severity was related to increased severity of Agatston score on the gated calcium score CT (P< 0.001). A majority of prior chest CT studies with coronary calcium failed to include this information in the final report.

CONCLUSIONS

A large percentage of gated calcium score CTs were performed despite a prior chest CT. The ordinal score on chest CTs correlated with Agatston score on gated calcium score CTs. The presence of CAC on chest CTs was underreported in a majority of cases.

Alterations in Blood-Brain Barrier Permeability in Patients with Systemic Lupus Erythematosus

BACKGROUND AND PURPOSE

Neuropsychiatric systemic lupus erythematosus refers to central and peripheral nervous system involvement, which may occur secondary to antineuronal antibodies crossing the blood-brain barrier that preferentially target cells in the hippocampus leading to abnormal hypermetabolism and atrophy. Thus, we hypothesized that alterations in BBB permeability, detected on dynamic contrast-enhanced MR imaging, occur in the hippocampus in patients with systemic lupus erythematosus before development of neuropsychiatric systemic lupus erythematosus.

MATERIALS AND METHODS

Six patients with systemic lupus erythematosus without neuropsychiatric systemic lupus erythematosus and 5 healthy controls underwent dynamic contrast-enhanced MR imaging with postprocessing into BBB permeability parameters (K ^trans and Ve) and CBF. Standardized methods selected ROI sampling of the abnormal brain regions detected on FDG-PET. The mean and SD of K ^trans, Ve, and CBF were calculated. Linear regression and nonparametric Spearman rank correlation analyses of K ^trans and Ve with CBF were performed. Dynamic contrast-enhanced curves and the area under the curve were generated for each brain region. Student t test comparisons were performed.

RESULTS

Quantitative data revealed that patients with systemic lupus erythematosus have statistically increased K ^trans (P < .001) and Ve (P < .001) compared with controls. In patients with systemic lupus erythematosus, statistically significant positive correlations were seen between K ^trans (P < .001) and Ve (P < .001) with CBF. Furthermore, the mean area under the curve revealed statistically increased BBB permeability in the hippocampus (P = .02) compared with other brain regions in patients with systemic lupus erythematosus compared with controls.

CONCLUSIONS

These initial findings are proof-of-concept to support the hypothesis that patients with systemic lupus erythematosus have increased BBB permeability, specifically in the hippocampus, compared with other brain regions. These findings may advance our understanding of the underlying pathophysiology affecting the brain in autoimmune diseases.

Dynamic Contrast-Enhanced MRI Reveals Unique Blood-Brain Barrier Permeability Characteristics in the Hippocampus in the Normal Brain

We report a prospective dynamic contrast-enhanced MR imaging analysis of region-specific blood-brain barrier permeability in 5 healthy subjects. By means of standardized postprocessing and ROI sampling methods, the hippocampi revealed significantly elevated area under the dynamic contrast-enhanced curve and significantly increased blood-brain barrier permeability metrics (volume transfer constant and volume in the extravascular extracellular space) from model-based quantitation. These findings suggest unique blood-brain barrier permeability characteristics in the hippocampus, which are concordant with previous animal studies, potentially laying the groundwork for future studies assessing patient populations in which hippocampal pathology plays a role.

[Detection and analysis of HBV antigen protein in kidney tissue and HBV DNA in serum and kidney tissue of patients with HBsAg+ IgA nephropathy.]

BACKGROUND

To explore the relationship between hepatitis B virus (HBV) infection and development of IgA nephropathy.

METHODS

HBsAg and HBcAg protein in renal biopsy specimens of 32 cases was detected on frozen sections and HBV DNA was detected in paraffin section of renal biopsies and in serum of 42 HBsAg positive cases.

RESULTS

The positive rate of HBAg in renal biopsies of IgA nephropathy was 59.1%, and 63.6% in non-IgA nephropathy, there was no significant difference between them. In 42 cases biopsies of renal tissues, only five were HBV-DNA positive (11.9%). The five cases were HBsAg, HBcAb and HBeAg positive, the pathological diagnosis of two cases were mesangial proliferative glomerulonephritis; one had minimal change of glomerulonephritis; and one had basement membrane change; and only one had IgA nephropathy. At the same time, in 42 HBsAg+ cases the serum specimens were detected; 12 cases were positive for HBsAg, HBcAg and HBeAg, in whom serum HBV-DNA was positive, but only 5 were positive for HBV-DNA in renal biopsy tissue, and HBV-DNA was negative in other 30 blood serum and tissue specimens.

CONCLUSION

The difference in expression of HBsAg, HBcAb and HBeAg protein between IgA nephropathy and non-IgA nephropathy tissue from renal biopsy was not significant. There is no direct relationship between HBV infection and IgA nephropathy.

[Hyperinsulinemia in obesity and diseases of internal medicine]

We analysed fasting serum insulin levels and its correlation with common internal medical diseases in 91 cases with obesity (BMI > 24) and that in 76 nonobese cases. The mean fasting serum insulin level in obese group was higher significantly than that in nonobese group (P < 0.001). The incidences of hypertension, coronary heart disease, cerebrovascular disease, non-insulin-dependent diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, combined hyperlipidemia and serum low level of HDL-C in obese group were also higher significantly than that in nonobese group (P < 0.05 and < 0.01 respectively). The main cause of many medical diseases coexisted with obesity is hyperinsulinemia. We think that the first choice of therapy to this kind of diseases should be to reduce the body weight and to decrease the insulin resistance.

[The effect of lovastatin in the treatment of primary hypercholesterolemia]

The effect of Lovastatin, an HMG. CoA reductase inhibitor, on serum lipids and apolipoproteins was studied in 40 cases of primary hypercholesterolemia in a 4-month period of treatment. The level of serum lipids did not change significantly after a 35-day period of placebo treatment as compared with that of the baseline (P greater than 0.5). The patients then took Lovastatin with the evening meal in a daily dose from 20 to 80 mg for 3 months. The results were as follows: Lovastatin reduced significantly the mean serum level of total cholesterol (TC) by 31.5% (P less than 0.001), LDL-C by 39.8% (P less than 0.001), Apo-B by 27.3% (P less than 0.002), and the ratio TC/HDL-C by 35.9% (P less than 0.01). It also reduced the mean serum level of triglycerides (TG) by 22.1% (P greater than 0.05) and increased that of HDL-C by 6.3% (P greater than 0.2) and Apo-AI by 1.6% (P greater than 0.5), but without much significance. The drug was well tolerated by all the patients. Transient elevation of CPK was noticed in 2 patients and AKP in one patient. 7 patients complained of gastrointestinal discomfort. All these side effects did not necessitate stop of the medication. We are, therefore, of the opinion that Lovastatin is an effective agent for lowering the serum level of TC, LDL-C and Apo-B.