Enhancing Diagnostic Precision: Evaluation of Preprocessing Filters in Simple Diffusion Kurtosis Imaging for Head and Neck Tumors.

Background: Our initial clinical study using simple diffusion kurtosis imaging (SDI), which simultaneously produces a diffusion kurtosis image (DKI) and an apparent diffusion coefficient map, confirmed the usefulness of SDI for tumor diagnosis. However, the obtained DKI had noticeable variability in the mean kurtosis (MK) values, which is inherent to SDI. We aimed to improve this variability in SDI by preprocessing with three different filters (Gaussian [G], median [M], and nonlocal mean) of the diffusion-weighted images used for SDI. Methods: The usefulness of filter parameters for diagnosis was examined in basic and clinical studies involving 13 patients with head and neck tumors. Results: The filter parameters, which did not change the median MK value, but reduced the variability and significantly homogenized the MK values in tumor and normal tissues in both basic and clinical studies, were identified. In the receiver operating characteristic curve analysis for distinguishing tumors from normal tissues using MK values, the area under curve values significantly improved from 0.627 without filters to 0.641 with G (σ = 0.5) and 0.638 with M (radius = 0.5). Conclusions: Thus, image pretreatment with G and M for SDI was shown to be useful for improving tumor diagnosis in clinical practice.

Imaging characteristics of incidentally detected cosmetic surgery-derived foreign bodies on CT images in the maxillofacial region.

OBJECTIVES: This study examined the imaging characteristics of cosmetic surgery-derived foreign bodies in the maxillofacial region through a retrospective review of cosmetic material foreign bodies incidentally detected on computed tomography (CT) images in routine clinical practice. METHODS: We retrospectively investigated cases of cosmetic surgery-derived foreign bodies other than dental materials in the maxillofacial region, using 5 years of CT image data stored on an imaging server. The imaging findings of these foreign bodies were investigated, along with patient age, patient sex, whether the foreign bodies were associated with the disease targeted by the CT scan, and the availability of cosmetic surgery information prior to examination. RESULTS: Foreign bodies were more common in women (19/21 cases), and affected patients displayed a wide age range (20-84 years). Four types of cosmetic surgery-derived foreign bodies in the maxillofacial region were detected by CT examination: nasal prostheses (nasal region), lifting sutures and injectable facial fillers (both in the buccal region), and silicone chin implants (chin region). CONCLUSIONS: A cosmetic surgery-derived foreign body should be suspected when a foreign body is identified without a dental source of infection. In addition, cosmetic surgery-derived foreign bodies may be present in numerous patients, regardless of age or sex.

Characteristic Mean Kurtosis Values in Simple Diffusion Kurtosis Imaging of Dentigerous Cysts.

We evaluated the usefulness of simple diffusion kurtosis (SD) imaging, which was developed to generate diffusion kurtosis images simultaneously with an apparent diffusion coefficient (ADC) map for 27 cystic disease lesions in the head and neck region. The mean kurtosis (MK) and ADC values were calculated for the cystic space. The MK values were dentigerous cyst (DC): 0.74, odontogenic keratocyst (OKC): 0.86, ranula (R): 0.13, and mucous cyst (M): 0, and the ADC values were DC: 1364 × 10-6 mm2/s, OKC: 925 × 10-6 mm2/s, R: 2718 × 10-6 mm2/s, and M: 2686 × 10-6 mm2/s. The MK values of DC and OKC were significantly higher than those of R and M, whereas their ADC values were significantly lower. One reason for the characteristic signal values in diffusion-weighted images of DC may be related to content components such as fibrous tissue and exudate cells. When imaging cystic disease in the head and neck region using SD imaging, the maximum b-value setting at the time of imaging should be limited to approximately 1200 s/mm2 for accurate MK value calculation. This study is the first to show that the MK values of DC are characteristically higher than those of other cysts.

Usefulness of Simple Diffusion Kurtosis Imaging for Head and Neck Tumors: An Early Clinical Study.

Diffusion kurtosis (DK) imaging (DKI), a type of restricted diffusion-weighted imaging, has been reported to be useful for tumor diagnoses in clinical studies. We developed a software program to simultaneously create DK images with apparent diffusion coefficient (ADC) maps and conducted an initial clinical study. Multi-shot echo-planar diffusion-weighted images were obtained at b-values of 0, 400, and 800 sec/mm2 for simple DKI, and DK images were created simultaneously with the ADC map. The usefulness of the DK image and ADC map was evaluated using a pixel analysis of all pixels and a median analysis of the pixels of each case. Tumor and normal tissues differed significantly in both pixel and median analyses. In the pixel analysis, the area under the curve was 0.64 for the mean kurtosis (MK) value and 0.77 for the ADC value. In the median analysis, the MK value was 0.74, and the ADC value was 0.75. The MK and ADC values correlated moderately in the pixel analysis and strongly in the median analysis. Our simple DKI system created DK images simultaneously with ADC maps, and the obtained MK and ADC values were useful for differentiating head and neck tumors from normal tissue.

Role of FGF10 on tumorigenesis by MS-K.

Murine MS-K and NFSA cell lines formed tumor after inoculation into mouse and both cell lines expressed high level of vascular endothelial growth factor-A (vegf-A) and produced same level of VEGF-A. However, poor blood vessel formation, and necrosis was significantly observed in NFSA-tumor, contrary to well-developed blood vessel formation in MS-K tumor. The microarray analysis showed high expression of fibroblast growth factor-10 (fgf-10) in MS-K than NFSA. In this report, the role of fgf-10 on tumor growth was studied. MS-K enhanced more proliferation of endothelial cells by direct co-culture than NFSA, and rFGF10 supported the proliferation of HUVEC in combination with VEGF-A. fgf-10-knocked down MS-K, MS-K (fgf-10-KD), proliferated slower in vitro and the tumorigenicity of them was also slower than control. The blood vessel formation in these MS-K (fgf-10-KD) clones was reduced compared with the MS-K (normal). qPCR analysis showed the suppression of vegf-A, vegf-C and fgfr-1-expression in the MS-K (fgf-10-KD) clones. Taken together, these results indicated that FGF10, which was produced from tumor cells, was essential for the proliferation of tumor cell itself and also supports proliferation of endothelial cells. Thus, FGF10 plays an important role for tumor growth by both paracrine and autocrine manner.

Diet-induced atherosclerosis in cynomolgus monkey aorta and regression by the sixth-month observation.

Pathomorphologic analysis was employed to evaluate diet-induced atherosclerosis in cynomolgus monkey aorta and regression by administration of a hypolipidemic agent for six months after the atherogenic ration. Twenty-seven male cynomolgus monkeys were divided into three groups. Group A was fed individually with a high-fat diet containing 0.3% cholesterol under identical conditions for six months. Group B was fed with normal monkey chow for six months after the same atherogenic ration. Group C was fed with normal monkey chow and administered a hypolipidemic agent 1% of 4-[2-(4-isopropylbenzamido)ethoxy] benzonic acid for six months after the same atherogenic ration. Each thoracic and abdominal aorta of animal models was separately analyzed. Lipid composition analysis and esterified cholesterol (CE) in aortic wall, ratio of free cholesterol to phospholipid, surface involvement, and atherosclerotic index after Sudan IV staining were studied for evaluation of progression and regression. The configurations of atherosclerotic involvement were histologically evaluated among each group. These observed lesions, features specific to cynomolgus lesions, mainly consisted of lipid-rich foam cells, lipid debris, and proliferated extracellular matrix. No different lesion composition was noted between the thoracic and abdominal aorta. This may suggest that some local factors play an important role for development of atherosclerosis after the initial event. Group C had remarkable reduction of foam cells and of CE accumulation in both the thoracic and abdominal aortic wall. Accelerated regression in group C as compared with group B was demonstrated both biochemically and pathohistologically. These results suggest that substantial regression of atherosclerosis in both the thoracic and abdominal aorta can be expected. This hypolipidemic agent exerts notable antiatherosclerotic activity, along with a lowering effect on plasma total cholesterol levels.

Effect of etodolac, a new nonsteroidal anti-inflammatory drug, in MRL/lpr mice with articular lesions.

Etodolac, a new nonsteroidal anti-inflammatory drug, was administered orally at doses of 1 and 5 mg/kg to MRL/MpJ-lpr/lpr (MRL/lpr) mice, and its effect on articular lesions was compared with that of indomethacin. Both etodolac and indomethacin significantly reduced swelling of the hind paw. Histopathological examination showed that etodolac significantly reduced cartilage and bone damage, whereas indomethacin treatment did not achieve a statistically significant effect. Rheumatoid factors were not affected by either etodolac or indomethacin. These results indicate that etodolac delays the development of arthritis in MRL/lpr mice, and reduces cartilage and bone damage.