Background: Resistive index (RI), derived from color Doppler imaging (CDI), is a marker of vascular resistance used widely in varied clinical settings. The aim of this study was to analyze the association between RIs of the orbital vessels in a pure cohort of type 2 diabetic patients with or without retinopathy using CDI. Methods: Fifty patients having type 2 diabetes and 50 age-matched controls were evaluated in this prospective study. Diabetic retinopathy (DR) was diagnosed based on seven-field stereo fundus photography and diabetic patients were divided into two. Patients with no DR (n = 26) were taken as Group 1, while patients with DR (n = 24) were taken as Group 2. CDI was performed and the RIs of the ophthalmic artery (OA), posterior ciliary artery (PCA), central retinal artery (CRA), and central retinal vein (CRV) were measured. Results: Significant differences were observed in the mean RI values of all orbital arteries between controls and patients with DR (P < 0.05). Comparison of RI values between controls and Group 1 showed no significant differences. Mean RI values of the PCA and CRA were found to be significantly higher in the patients in Group 2 than in Group 1 (P = 0.03 and P < 0.001, respectively). The duration of diabetes correlated with the mean RI of all the orbital vessels. RI of the CRA was a reliable predictive indicator for DR (P = 0.001). Conclusion: RIs of the orbital arteries are significantly higher in patients with DR. RI of the orbital vessels can be a potentially useful biomarker in the early diagnosis and follow-up of patients with DR.

Background: The purpose of this study was to determine the utility and diagnostic performance of strain elastography (SE) in differentiating benign from malignant lesions of the breast. Methods: In this prospective study, 50 palpable breast masses in 50 patients were examined by mammography, B-mode ultrasound (US) and SE. Lesions were categorized using Breast Imaging Reporting and Data System (BIRADS) scoring based on mammographic and sonographic features. Elasticity scores were assessed on a five-point scale based on the distribution of strain, and the lesion size on SE imaging and B-mode (elasticity imaging/B mode [EI/B] ratio) was compared. Findings were correlated with the BIRADS assessment and diagnostic performance of sonoelastography was evaluated taking histopathology as reference standard. Results: Histopathology revealed 29 (58%) malignant and 21 (42%) benign lesions. Infiltrative ductal carcinoma and fibroadenoma were the most common malignant and benign lesions, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SE was 100%, 76.1%, 85.2%, 100%, and 90%, respectively. Higher elasticity score was significantly associated with malignant histopathology (P < 0.00001). The mean EI/B ratio for malignant lesions was 1.36 ± 0.24 while that of benign lesions was 1.03 ± 0.30 (P = 0.000). Conclusion: Real-time SE of the breast, with its superior sensitivity and specificity, could provide improved characterization of benign and malignant breast masses compared with mammography and conventional US. Due to greater diagnostic accuracy, SE can be an effective adjunctive tool to B-mode US in predicting malignancy of breast, as well as in reducing the need for biopsies in benign breast lesions.

Background: The purpose of this study was to evaluate the diagnostic value of transrectal real- time strain elastography (RTE) in identifying prostatic carcinoma (PCa). Methods: 60 patients suspected of having PCa based on abnormal digital rectal examination and raised prostate specific antigen levels underwent transrectal ultrasound (TRUS), color Doppler (CD) and RTE. Elastograms were scored on a five point scale based on distribution of strain in relation to hypoechoic area on TRUS. Twelve core systematic biopsy as well as targeted biopsy was performed from suspicious areas on TRUS and RTE. Diagnostic performance of sonoelastography was evaluated using histopathology as reference standard. Results: Histopathology revealed cancer in 28 out of 60 patients (47%) studied. Gleason score ranged from 6 to 9. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TRUS in detecting prostate cancer were 78.57%, 81.25%, 78.57%, and 81.25%, respectively. On CD evaluation 87.5% (n = 28) of benign lesions showed symmetric, radial flow compared to 14.3% (n = 4) of malignant lesions (P < 0.0001). The sensitivity and specificity of RTE was 89.29% and 56.25% with PPV and NPV being 58.13% and 82.35%, respectively. Higher elastography score was found to be significantly associated with malignant histopathology (P = 0.004). Cancer detection rate with RTE was greater for tumors with higher Gleason score. Conclusion: RTE was found to have better sensitivity than TRUS as well as combination of TRUS and CD. Although less specific, RTE can be an effective adjuvant tool to TRUS for guidance of biopsy and improve detection rate of PCa.

Background: Ultrasound elastography (USE) has emerged as a potentially useful tool in the evaluation of thyroid nodules. The aim of this study was to assess the efficacy of elastography in differentiating benign from malignant thyroid nodules with fine-needle aspiration cytology (FNAC) analysis as reference standard. Materials and Methods: This was a cross-sectional prospective study carried out at a tertiary care center in South India between May 2014 and March 2015. Consecutive patients with solid nodule in the thyroid gland on conventional ultrasound (US) underwent USE, followed by US-guided FNAC of the thyroid nodule. The findings of B-mode images and USE were correlated with cytology. Statistical analysis was performed using SPSS version 24. Descriptive statistics were presented as mean +/- standard deviation. The diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of USE were calculated. Results: A total of sixty patients with sixty solid thyroid nodules were enrolled in the study. The mean age of the patients was 48.27 +/- 16.10 years. About 83.3% were females. The frequency of benign nodules on cytopathologic analysis was 60% (n = 36). Seventy-five percent of the malignant lesions had irregular or poorly defined borders with lobulated margins on US. The sensitivity, specificity, positive predictive value, and negative predictive value of USE were 91.7%, 77.77%, 73.33%, and 93.3%, respectively, with FNAC as reference standard. Higher elastography scores were found to be significantly associated with malignant cytology (P = 0.0001). Conclusion: Elastography, with its fairly high diagnostic accuracy and correlation with malignant cytology, can be an effective noninvasive adjunctive tool in distinguishing benign from malignant thyroid nodules.

Background: Reversible posterior leukoencephalopathy syndrome (RPLS) or Posterior reversible encephalopathy syndrome (PRES) is a unique clinicoradiologic entity characterized by acute onset headache, seizures, blindness and altered mental state associated with reversible vasogenic edema of the brain. It is a major complication of eclampsia, but data on clinicoradiological features of PRES in late-onset postpartum eclampsia are scarce. The objective is to analyze the clinicoradiologic features and outcome in a cohort of late postpartum eclampsia patients with PRES. Subjects and Methods: Eighteen patients of late postpartum eclampsia with clinical as well as neuroimaging features consistent with PRES were included in this retrospective study. All had undergone magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) and apparent diffusion coefficient(ADC) mapping. Data on age, antepartum history, peak systolic and diastolic blood pressures, clinical features, time to neuroimaging, location of lesions on brain imaging and presence of associated ischemia or hemorrhage in MRI were collected and analyzed. Results: The mean age was 25.72 3.23 years. The average duration between labor and clinical symptoms was 8.5 days. 13/18 patients (72.2%) had elevated blood pressure at admission. Mean systolic and diastolic blood pressures were 143.88 (120-180) and 93.88 (80-100) mm Hg respectively. Headache was the presenting feature in 16 patients. The parieto-occipital regions were the most frequently involved followed by the cerebellum (7/18) and frontal lobe (4/18). Atypical regions were not involved. Clinical recovery had been noted in all. Conclusion: PRES associated with late postpartum eclampsia, an entity of limited awareness can present without antecedent preeclampsia. Radiological changes are the key to early diagnosis.

Aim: In this research work, radiation doses to frontal face of adult and pediatric procedures were measured from 50 panoramic and 35 cephalometric dental X-ray scanners from various regions in Tamil Nadu, India. Materials and Methods: Dose measurements were carried out using a polymethylmethacrylate tissue-equivalent phantom (10 cm diameter and 14 cm length) and two miniature electronic personnel dosimeters (PM1610). Results: Panoramic procedures and the radiation doses were measured on the frontal face of adult ranged from 80 μSv to 175 μSv and 20–66 μSv at the thyroid and eye level, respectively, and for pediatric were ranged from 52 μSv to 159 μSv and 17–58 μSv at the thyroid and eye level, respectively. For cephalometric, the frontal face dose of adult ranged from 45 μSv to 114 μSv and 45–111 μSv at the thyroid and eye level, respectively, and for pediatric, the doses were ranged from 43 μSv to 107 μSv and 43–107 μSv at the thyroid and eye level, respectively. Conclusions: Based on the detailed survey, the measured values were comparable with other literature values. It was observed that exposure parameters, beam quality, beam slit width, and beam length used in the tube head are the factors that increase facial dose during dental panoramic and cephalometric procedures.

Purpose: To investigate the retrobulbar circulatory parameters in type 2 diabetes mellitus patients with color Doppler imaging (CDI) and compare the results with nondiabetic controls. Methods: This prospective study included 50 type 2 diabetic patients and 50 age-matched controls. Seven field stereo fundus photography was used to diagnose and classify diabetic retinopathy (DR). Diabetic patients were further divided into two: Group 1, consisted of patients with no DR, mild and moderate non-proliferative DR (n = 36); Group 2, severe nonproliferative and proliferative DR (n = 14). CDI was performed using Philips iU22 xMATRIX ultrasound. The peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI) and pulsatile index (PI) of ophthalmic (OA), posterior ciliary artery (PCA), and central retinal artery (CRA) along with central retinal vein (CRV) were recorded. Results: RI in the ophthalmic artery was significantly higher in both DR groups than the control group (P = 0.000). Diabetic Group 1 had decreased blood flow velocity (PSV and EDV) in PCA compared to controls (P = 0.046 and P = 0.010, respectively). Group 2 DR had significantly reduced EDV and increased RI in CRA compared to Group 1 (P = 0.015). Binary logistic regression analysis revealed glycosylated hemoglobin and RI of OA to be independent risk factors of DR. Conclusion: Significant changes in resistivity index and flow velocities were observed in the retrobulbar vessels, especially in ophthalmic artery in diabetics compared to controls. CDI with results of increased resistance or decreased flow could be useful to predict individuals at higher risk for developing severe DR.

Background: The purpose of this study was to evaluate the usefulness of strain elastography and acoustic radiation force impulse (ARFI) imaging in the differentiation of benign and malignant cervical lymph nodes (LNs). Materials and Methods: In this prospective study, 50 enlarged cervical LNs (33 benign and 17 malignant) were examined by B-mode ultrasound (US), color Doppler, and strain elastography. Elastographic patterns (1–5) were categorized based on distribution of hard area within LN. The shear wave velocity (SWV) of LNs was evaluated by ARFI imaging. Diagnostic performance of sonoelastographic parameters was compared taking histopathology of LN as a reference standard. Optimal cutoff value of the mean SWV values for predicting malignancy was determined using receiver operating characteristic curve analysis. Results: Among US parameters, borders of LN had the highest diagnostic accuracy (80%), while echogenicity had the least (48%). Majority of benign LNs (n = 31) had elastography patterns 1 and 2, while majority of malignant LNs (n = 16) had patterns 3–5 (P = 0.000). The sensitivity, specificity, and accuracy of elastography were 94.1%, 93.9%, and 94%, respectively. The mean SWV of benign LNs (1.670 ± 0.367 m/s) differed significantly from malignant LNs (2.965 ± 0.826 m/s; P = 0.000). A cutoff value of 2.05 m/s predicted malignancy with 88.2% sensitivity and 84.8% specificity and gave an area under the curve of 0.949 (95% confidence interval: 0.70–1.20). Conclusion: Elastography has high diagnostic accuracy in differentiating benign and malignant cervical LNs and can be potentially useful in selecting the LN with high probability of malignancy, on which fine-needle aspiration cytology/biopsy can be performed.

AIM:The aim of this study was to calculate dose area product (DAP) and to determine diagnostic reference level (DRL) for adult panoramic procedures in Tamil Nadu.MATERIALS AND METHODS:In this study, air kerma on the front side of the secondary collimator was measured with a Black Piranha, RTI Electronics, Sweden and multiplied with the corresponding exposed area to calculate DAP. The obtained DAP values were further analyzed, and DRL was calculated using the Microsoft Excel software. The study was carried out with regular adult exposure parameters.RESULTS:The mean, range, and 3rd quartile values for 67 panoramic scanners in Tamil Nadu, India, were calculated as 94 mGycm2, 41 mGycm2-165 mGycm2, and 114.3 mGycm2, respectively. The results are comparable with other international studies.CONCLUSION:The present study suggests that further optimization can be achieved in many centers by the recruitment of professionally qualified radiographers and conducting periodic training programs on the optimization of exposure parameters. Considering this as the first study for the dental DRL assessment, further studies are suggested to establish national dental DRL in India.

Development of contrast agent for imaging modalities is very much essential to identify the cancer cells at an early stage. Due to the advances in the field of nanotechnology, nanoparticle-based contrast agents are being developed with better imaging capabilities at minimum concentrations. When the paramagnetic gadolinium oxide (Gd2O3) nanoparticles are doped with the luminescent europium (Eu3+) ions, it results in superior magneto-optical properties. This property makes the nanoparticles suitable for MRI and optical dual modal cancer imaging. In this article, europium doped Gd2O3 (Eu:Gd2O3) nanoparticles were synthesized by microwave-assisted combustion method. Citric acid (C6H8O7) which is a biocompatible and less reactive fuel was used to prepare the Eu:Gd2O3 nanoparticles for the first time. Silica was coated over the Eu:Gd2O3 nanoparticles for improving the biocompatibility. X-ray diffraction studies reveal that after coating, the crystallinity was found to decrease. The synthesized nanoparticles have spherical morphology with the average diameter of 10 nm. The presence of silica was observed in the Fourier transform infrared (FTIR) spectrum and transmission electron microscopy images. In the photoluminescence studies, the emission peak at 612 nm confirms the presence of Eu3+ ions. Decay times of the uncoated and silica-coated samples were calculated to be 1.1 and 0.9 ms respectively. The in vitro cytotoxicity analysis suggests that the silica-coated nanoparticles are slightly toxic up to the concentration of 200 µg/mL. The magnetic measurement confirms the paramagnetic behaviour of the synthesized nanoparticles. The nanoparticles shows bright contrast images with the relaxivity value of 5.01/(mM)/s, suggest that the silica-coated nanoparticles have potential applications in MRI.

This article reports the novel synthesis of europium doped gadolinium oxide (Eu:Gd2O3) nanoparticles at low temperature by the polyol method for the first time. The role of triethylene glycol (TEG) on the magnetic and optical properties was studied. The cytotoxicity of the nanoparticles and their applications in magnetic resonance imaging (MRI) and optical imaging was also reported. Silica is coated over the nanoparticles to improve the biocompatibility. Spherical nanoparticles with an average diameter of ∼40 nm were synthesized and silica with thickness around 5 nm was coated on the nanoparticles. In the photoluminescence studies, the characteristic emission of Eu3+ ions at 612 nm due to the 5D0 → 7F2 transition was observed. The lifetime of the uncoated and silica-coated nanoparticles were found to be 1.14 and 0.83 ms respectively. The cell viability was assessed in MG63 osteosarcoma cell line by the MTT assay. The results show that the silica-coated nanoparticles possess negligible toxicity till the concentration of 200 μg ml−1. Within this limit, as the concentration of the nanoparticle is increased, the MRI results reveal bright contrast images with the relaxivity value of 4.8 mM−1 s−1, which is higher than the commercially available contrast agents.

Introduction: The image based diagnosis of Hepatocellular Carcinoma (HCC) relies on assessment of arterial enhancement and venous or delayed phase washout. This assessment is based on visual analysis; however, studies quantifying such enhancement and washout are lacking. Aim: To qualitative assessment of the imaging characteristics of HCC and non HCC hypervascular liver tumours followed by quantitative assessment of the enhancement and washout kinetics, and also to derive objective values that may help in differentiating HCC from non HCC on Computed Tomography (CT). Materials and Methods: The present study was carried out in PSG hospitals, Coimbatore, Tamil Nadu, India. Retrospective analysis of hypervascular liver lesions was performed over a study period of four years (January 2012 to February 2016). These lesions were divided into two groups namely; HCC and non HCC. All non HCCs were pathologically proven, while HCC cases included those diagnosed on histopathology or typical imaging findings based on American Association for the Study of Liver Diseases (AASLD) (2010) and Liver Imaging Reporting and Data Systems (LIRADS) (2014) diagnostic criteria along with an elevated Alpha Fetoprotein (AFP) of more than 400 IU/mL. A qualitative analysis of the enhancement and washout patterns was done followed by quantitative analysis using Regions of Interest (ROI) measurement of attenuation in Hounsfield units (HU). The quantitative parameters assessed were; Mean Attenuation (MA) of lesions in different phases, Attenuation Gain Percentage (AGP) on arterial phase, Arterial Phase Attenuation Change (AAC), Attenuation Loss Percentage in venous and delayed phases (ALP-V, ALP-D), Percentage Attenuation Ratio in venous and delayed phases (PAR-V, PAR-D) and Relative Washout Ratios from arterial to venous/delayed (RWR A-V, RWR A-D) and from venous to delayed phases (RWR V-D). Sensitivity and specificity were calculated for qualitative washout. For quantitative variables comparative analysis between HCCs and non HCCs was done using Student's t-test. ANOVA was used to compare different categories. ROC curves were drawn for values that were significantly different to establish a cutoff value. Results: A total of 120 lesions were evaluated consisting of HCCs (n=88) and non HCCs (n=32). Qualitatively majority (81) of HCCs demonstrated arterial enhancement and washout with eight cases of these demonstrating subtle washout requiring settlement by consensus. Washout were absent in seven cases. True mimics of HCC on qualitative analysis were hepatic adenomas, few cases of metastasis and hepatoblastoma were also there. The overall sensitivity of the washout appearance for predicting HCC was 92% while specificity was 78%. On quantitative analysis a PAR-V >= 106 has sensitivity of 70% and specificity of 75%, RWR-V-D >= 41.79 has sensitivity of 75% and specificity of 70% for HCC detection. Additionally significant difference was seen between RWR V-D of HCC when compared to cholangiocarcinomas (p-value 0.035) and metastasis (p-value 0.026) and also between PAR-V of HCC and metastasis (p-value 0.033). Conclusion: The qualitative analysis combined with quantitative assessment of washout using percentage attenuation ratio in venous phase and relative washout ratio from venous to delayed phase offers good sensitivity and specificity in image based diagnosis of HCC.

Dual-modal imaging of cancer cells is possible with the silica-coated europium-doped gadolinium oxide nanorods due to their magnetic and luminescent properties. In the synthesized nanorods, europium ions serve as ‘luminescent centers’ facilitating optical imaging and gadolinium oxide acts as the contrast agent for magnetic resonance imaging (MRI). This article reports the synthesis method of the europium-doped gadolinium oxide (Eu:Gd 2 O[Formula: see text] nanorods by the co-precipitation method. The prepared nanorods are further coated with silica to improve its biocompatibility. From the x-ray diffraction (XRD) data, the crystallinity was found to decrease due to the amorphous nature of the silica. Transmission electron microscopy (TEM) studies show that Eu:Gd 2 O 3 nanorods with a length of [Formula: see text][Formula: see text]600[Formula: see text]nm and diameter of [Formula: see text][Formula: see text]40[Formula: see text]nm were formed. Silica was coated uniformly with the thickness of [Formula: see text][Formula: see text]15[Formula: see text]nm. Fourier transform infrared spectroscopy (FTIR) confirms the presence of silica in the prepared nanorods. Emission at 611[Formula: see text]nm due the presence of Eu[Formula: see text] ions was observed. The life time of uncoated and silica-coated nanorods was calculated to be 1.1[Formula: see text]ms and 0.9[Formula: see text]ms, respectively. In vitro cytotoxicity of the synthesized nanorods in MG63 (human osteosarcoma cell line) was assessed by MTT assay. In vitro MRI studies reveal that the prepared nanorods can be used for T 1 contrast enhancement.

The aim of this article is to assess Tamil Nadu pediatric computed tomography (CT) diagnostic reference levels (DRLs) by collecting radiation dose data for the most commonly performed CT examinations. This work was performed for thirty CT scanners installed in various parts of the Tamil Nadu region. The patient cohort was divided into two age groups: <1 year, and 1-5 years. CT dose indices were measured using a 10 cm3 pencil ion chamber with pediatric head and body polymethyl methacrylate phantoms. Dose data such as volumetric CT dose index (CTDIv) and dose length product (DLP) on a minimum of twenty average-sized pediatric patients in each category were recorded to calculate a mean site CTDIv and DLP value. The rounded 75th percentile was used to calculate a pediatric DRL for each hospital, and then region by compiling all results. Data were collected for 3600 pediatric patients. Pediatric CT DRL for two age groups: <1 year (CTDIv and DLP of head [20 mGy, 352 mGy.cm], chest [7 mGy, 120 mGy.cm] and abdomen [12 mGy, 252 mGy.cm]), and 1-5 years (CTDIv and DLP of head [38 mGy, 505 mGy.cm], chest [8 mGy, 132 mGy.cm] and abdomen [14 mGy, 270 mGy.cm]) for select procedures have been calculated. Proposed pediatric DRLs of CTDIv and DLP for head procedure were lower, and for chest and abdomen procedures were higher than European pediatric DRLs for both age groups.

Background: To suggest South India CT diagnostic reference levels (DRLs) by collecting radiation doses for the most commonly performed CT examinations. Materials and Methods: A pilot study investigated the most frequent CT examinations. 110 CT sites were asked to complete a survey booklet to allow the recording of CT parameters for each of 3 CT examinations during a 1 year time period. Dose data such Volumetric Computed Tomography Dose Index (CTDIv) and Dose length product (DLP) on a minimum of 50 average-sized patients in each category were recorded to calculate a mean site CTDIvol and DLP value. The rounded 75th percentile was used to calculate a DRL for each site and the region by compiling all results. Results are compared with international DRL data. Results: Data were collected for 16,500 patients. All equipment had multislice capability (2-256 slices). DRLs are proposed using CTDIvol (mGy) and DLP (mGy.cm) for CT head (47 and 1041 respectively), CT chest (10 and 445 respectively), and CT abdomen (12 and 550 respectively). These values are lower than current DRLs and comparable to other international studies. Wide variations in mean doses are noted across the region. Conclusion: Baseline figures for South India CT DRLs are provided on the most frequently performed CT examinations. It was noted that there was a wide variation in mean doses among the CT scanners used during diagnosis. The differences in CT doses between CT scanner departments as well as identical scanners suggest a large potential for optimization of examinations.