Role of MRSI Major Metabolite Ratios in Differentiating Between Intracerebral Ring-Enhancing Neoplastic and Non-Neoplastic Lesions, High-Grade Gliomas and Metastases, and High-Grade and Low-Grade Gliomas.

Introduction The purpose of this study was to determine whether multi-voxel magnetic resonance spectroscopic imaging (MRSI) can differentiate between intracranial neoplastic and non-neoplastic and between neoplastic ring-enhancing lesions (RELs) based on differences in major metabolite ratios in their enhancing and peri-enhancing regions. Methods In a prospective observational study involving patients with an intracerebral RELs, MRSI using the two-dimensional multi-voxel point-resolved spectroscopy (PRESS) chemical-shift imaging (CSI) sequence at an echo time (TE) of 135 milliseconds (ms) was performed on a total of 38 patients. Of 38 lesions, 23 (60.5%) were neoplastic and 15 (39.5%) were non-neoplastic. Of the 23 neoplastic lesions, 12 were high-grade gliomas (HGGs), seven were metastases, and four were low-grade gliomas (LGGs). Major metabolite ratios, i.e., choline-to-N-acetylaspartate (Cho/NAA), choline-to-creatine (Cho/Cr), and N-acetylaspartate-to-creatine (NAA/Cr), were calculated in the enhancing and peri-enhancing regions of the RELs. A Mann-Whitney U test was run to determine differences in metabolite ratios at different voxel locations between neoplastic versus non-neoplastic lesions, HGGs versus metastatic lesions, and HGGs versus LGGs. A receiver operating characteristic (ROC) curve analysis was performed to derive cut-off values for Cho/NAA and NAA/Cr ratios in the enhancing and peri-enhancing portions of the lesions. Results The sensitivity, specificity, positive predictive value, and negative predictive value for categorizing an REL in either neoplastic or non-neoplastic lesions using MRSI with magnetic resonance imaging (MRI) were 91.3%, 73.3%, 84%, and 84.6%, respectively. There was a statistically significant difference between Cho/NAA (p = 0.006) and NAA/Cr (p = 0.021) ratios in the enhancing region of 23 neoplastic and 15 non-neoplastic lesions. In the voxel placed in the peri-enhancing portions, the differences between Cho/Cr ratios were just significant (p = 0.047). A cut-off score of Cho/NAA >1.67 in the enhancing regions gave a sensitivity of 82.6% and specificity of 60%. The cut-off score for NAA/Cr of <0.80 in the enhancing regions showed a sensitivity and specificity of 60.9% and 86.7%, respectively. Of the 23 neoplastic lesions, 12 HGGs and seven metastases were differentiated using the Cho/NAA ratio in the peri-enhancing region with a cut-off value of 1.21, sensitivity of 100%, and specificity of 85%. A cut-off value of Cho/Cr ≥1.45 in the peri-enhancing regions showed a sensitivity of 83% and a specificity of 71.4%. For discriminating between 12 HGGs and four LGGs both from the 23 neoplastic REL group, using the cut-off score for Cho/NAA in the enhancing portions ≥4.16 showed a sensitivity of 0.75 and specificity of 100%. In the peri-enhancing regions, a cut-off score of ≥2.07 provided a sensitivity and specificity of 83% and 100%, respectively. Conclusion Conventional MRI sometimes poses a diagnostic challenge in distinguishing between neoplastic and non-neoplastic lesions and other neoplastic RELs. Interpreting MRSI findings by comparing the major metabolite ratios in the enhancing and peri-enhancing regions of these lesions may enable distinction between the two.

Cavitary lung lesions in a neonate: Potential manifestation of COVID-19 related multisystem inflammatory syndrome.

BACKGROUND: The hyperinflammatory state of multisystem inflammatory syndrome in children (MIS-C) predisposes to thromboembolic complications. We report a neonate with multiple cavitary lesions in lung, which we suspect could be a manifestation of multisystem inflammatory syndrome in neonate (MIS-N) following maternal COVID-19 infection during pregnancy. CASE REPORT: Eight-day-old neonate was referred with fever and fast breathing. Mother was positive for COVID-19 in 29th week. COVID-19 reverse-transcription polymerase chain reaction was negative, however, antibodies were positive. He had increased leucocyte count, and elevated levels of C-reactive protein (CRP), procalcitonin, ferritin, lactate dehydrogenase, and d-dimer along with bilateral reticulonodular opacities on chest radiograph and multiple nodules with evidence of cavitation in both lungs on chest tomography. All cultures were negative. A possible diagnosis of MIS was made. Infant was treated with intravenous immunoglobulin (IVIG) which he responded to with resolution of symptoms. CONCLUSION: Neonates exposed to COVID-19 should be evaluated for thromboembolic complications and IVIG can be one of the treatment modalities.

Correlation of Strain Elastography with Conventional Sonography and FNAC/Biopsy.

INTRODUCTION: Elastography is a new promising technique that can be especially helpful when used as an adjunct to conventional B-mode ultrasound in evaluating breast lesions. AIM: To evaluate the diagnostic performance of four interpretation criteria for elastography and to compare the diagnostic performance of sonoelastography with that of conventional sonography in characterising breast lesions as benign or malignant with FNAC/biopsy correlation. MATERIALS AND METHODS: One hundred breast lesions were prospectively evaluated by ultrasound as well as by strain elastography followed by FNAC/ biopsy correlation. The criteria used were Elastography Score, Strain Ratio, Distance Ratio and Area Ratio. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated for each modality. The best cut-off point was calculated for each of the interpretation criteria using the MedCalc version 10.1 software. The diagnostic performance of the interpretation criteria was compared with that of conventional sonography by the area under the receiver operating characteristic curve using SPSS software. RESULTS: The elastography score was found to have the best performance among the 4 criteria used with a sensitivity and specificity of 100% and 82.66%, respectively at the best cut-off point between 3 and 4. At a best cut-off point for conventional sonography between BI-RADS categories 4A and 4B, the sensitivity and specificity were found to be 96% and 92% respectively. The area under the curve value was slightly greater for conventional sonography (0.980) than for the elastography score (0.913) using receiver operating characteristic curve analysis. CONCLUSION: While all interpretation criteria were able to differentiate benign and malignant lesions with statistical significance, the elastography score was found to be the most accurate. While conventional ultrasound remains the primary modality for the characterization of breast masses, elastography was found to have a role in low suspicion lesions (BI-RADS 3 and 4A) where it's greater specificity could justify avoiding unnecessary biopsy.

Enterolith with enterocolic fistula: the diagnostic approach.

An enterolith is a mixed concretion formed in GIT, usually rare in humans. Primary enteroliths are formed in small bowel, typically within a diverticulum and secondary enteroliths in gallbladder. This case report highlights the presence of an enterocolic fistula; probably a postradiotherapy complication; and an enterolith without associated small bowel or colonic diverticuli. We have discussed the various diagnostic modalities used to reach a preoperative diagnosis of this rare condition. Imaging plays an important role in the detection and management of acquired gastrointestinal fistulas. The more routine use of cross-sectional imaging (especially computed tomography and magnetic resonance imaging) has altered the standard sequence of radiologic evaluation for possible fistulas, but fluoroscopic studies remain a valuable complement, especially for confirming and defining the anomalous communications.