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Objective To evaluate the diagnostic efficacy of mDIXON Quant for vertebral metastasis. Methods We retrospectively analyzed MRI images of 152 patients with clinically diagnosed malignant tumors and vertebral metastases. Scanning sequence included T1WI, STIR, mDIXON Quant and enhanced T1WI. We compared the diagnostic efficiency between T1WI and FF images for vertebral metastases. FF values between normal vertebral body and vertebral metastases were quantitatively compared, and the diagnostic efficacy of FF value was evaluated by ROC curve. Results The sensitivity, false positive rate, false negative rate, negative predictive value and accuracy of FF images in the diagnosis of vertebral metastases were all higher than those of T1WI images. The FF value of vertebral metastasis was significantly lower than that of normal vertebral body (Z=-21.792, P < 0.05), and the area under ROC curve was 0.987 and the cutoff value was 9.87%. The diagnostic sensitivity and specificity of vertebral metastasis were 99.6% and 92.0%. Conclusion mDIXON Quant can quantitatively determine the fat content of vertebral metastasis and has a high diagnostic efficiency for vertebral metastases.
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Pityriasis versicolor (PV), also known as tinea versicolor, is a chronic, mild, superficial and recurrent infection of the stratum corneum, caused by different Malassezia spp and seen predominantly in young age group and primarily in hot and humid climates. The aim of this study was to analyze epidemiological parameters and risk factors association in clinically diagnosed PV cases and also the mycological evaluation of those PV cases. Methods: A total of 116 patients attending the OPD of Dermatology were included and analysed for detailed history, clinical examination, epidemiological parameters, risk factors and investigations. Skin scrapings collected were processed by direct microscopy with 10% KOH and culture in modified Dixon agar (mDA). Isolates were identified by colony morphology, gram staining, biochemical characteristics & tween assimilation test. Results: Females were more affected (56.03%) than the males (43.97%) with F: M ratio 1.27:1. PV affected most commonly (36.21%) in 11-20 years of age group. Students (32.29%) were affected in maximum. Majority of affected patients (65.52%) used oily body creams, whereas 34.48% cases shared their body towels with others. 10.34% cases were associated with seborrheic dermatitis. Seasonal occurrence mostly seen in May - August. Patients with type III (Medium) complexion (56.03%) with normal skin texture (49.14%) were mostly affected. Maximum patients (74.14%) were associated with excessive sweating. 18.96% patients were associated with Type II DM. Most of the cases presented with macular, scaly hypopigmented, bilaterally asymmetrically distributed and having well defined margin. Neck was the most affected site (28.45%) followed by back (20.69%). Conclusion: M.furfur was the most common isolate (47.06%) followed by M. globosa (24.71%) and M. sympodialis (15.29%).
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OBJECTIVE: To compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain. MATERIALS AND METHODS: Vertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm³ voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results. RESULTS: There was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R² = 0.88, p 20%). CONCLUSION: Given its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.