RESUMO
BACKGROUND AND PURPOSE: 3D intracranial vessel wall MRI techniques are time consuming and prone to artifacts, especially flow artifacts. Our aim was to compare the image quality of accelerated and flow-suppressed 3D intracranial vessel wall MR imaging techniques relative to conventional acquisitions. MATERIALS AND METHODS: Consecutive patients undergoing MR imaging had conventional postcontrast 3D T1-sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) and either postcontrast delay alternating with nutation for tailored excitation (DANTE) flow-suppressed or DANTE-controlled aliasing in parallel imaging results in higher acceleration (CAIPI) flow-suppressed and accelerated T1-SPACE sequences performed. The sequences were evaluated using 4- or 5-point Likert scales for overall image quality, SNR, extent/severity of artifacts, motion, blood suppression, sharpness, and lesion assessment. Quantitative assessment of lumen and wall-to-lumen contrast ratios was performed. RESULTS: Eighty-nine patients were included. T1-DANTE-SPACE had significantly better qualitative ratings relative to T1-SPACE for image quality, SNR, artifact impact, arterial and venous suppression, and lesion assessment (P < .001 for each, respectively), with the exception of motion (P = .16). T1-DANTE-CAIPI-SPACE had significantly better image quality, lesion assessment, arterial and venous blood suppression, less artifact impact, and less motion compared with T1-SPACE (P < .001 for each, respectively). The SNR was higher with T1-SPACE compared with T1-DANTE-CAIPI-SPACE (P < .001). T1-DANTE-CAIPI-SPACE showed significantly worse lumen (P = .005) and wall-to-lumen contrast ratios (P = .001) compared with T1-SPACE, without a significant difference between T1-SPACE and T1-DANTE-SPACE. T1-DANTE-CAIPI-SPACE scan time was 5:11 minutes compared with 8:08 and 8:41 minutes for conventional T1-SPACE and T1-DANTE-SPACE, respectively. CONCLUSIONS: Accelerated postcontrast T1-DANTE-CAIPI-SPACE had fewer image artifacts, less motion, improved blood suppression, and a shorter scan time, but lower qualitative and quantitative SNR ratings relative to conventional T1-SPACE intracranial vessel wall MR imaging. Postcontrast T1-DANTE-SPACE had superior SNR, blood suppression, higher image quality, and fewer image artifacts, but slightly longer scan times relative to T1-SPACE.
Assuntos
Imageamento Tridimensional , Imageamento por Ressonância Magnética , Aceleração , Artefatos , Humanos , Imageamento por Ressonância Magnética/métodos , Razão Sinal-RuídoRESUMO
Background & objectives: COVID-19 cases have been rising rapidly in countries where the SARS-CoV-2 variant of concern (VOC), Omicron (B.1.1.529) has been reported. We conducted a study to describe the epidemiological and clinical characteristics and outcomes of COVID-19 patients with 'S' gene target failure (SGTF, suspected Omicron). Furthermore, their clinical outcomes with COVID-19 patients with non-SGTF (non-Omicron) were also compared. Methods: This study was conducted in Tamil Nadu, India, between December 14, 2021 and January 7, 2022 among patients who underwent reverse transcription-PCR testing for SARS-CoV-2 in four laboratories with facilities for S gene screening. Consecutively selected COVID-19 patients with SGTF were telephonically contacted, seven and 14 days respectively after their date of positive result to collect information on the socio-demographic characteristics, previous history of COVID-19, vaccination status and clinical course of illness along with treatment details. To compare their outcomes with non-SGTF patients, one randomly suspected non-Omicron case for every two suspected Omicron cases from the line-list were selected, matching for the date of sample collection and the testing laboratory. Results: A total of 1175 SGTF COVID-19 patients were enrolled for this study. Almost 6 per cent (n=72) reported a history of previous infection. 141 (13.5%) suspected Omicron cases were non-vaccinated, while 148 (14.2%) and 703 (67.4%) had received valid one and two doses of COVID-19 vaccines, respectively. Predominant symptoms reported included fever (n=508, 43.2%), body pain (n=275, 23.4%), running nose (n=261, 22.2%) and cough (n=249, 21.2%). Five (0.4%) of the 1175 suspected Omicron cases required oxygen supplementation as compared to ten (1.6%) of the 634 suspected non-Omicron cases. No deaths were reported among omicron suspects, whereas there were four deaths among suspected non-Omicron cases. Interpretation & conclusions: Majority of the suspected Omicron cases had a mild course of illness. The overall severity of these cases was less compared to the suspected non-Omicron cases.
Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Vacinas contra COVID-19 , Humanos , Índia/epidemiologia , SARS-CoV-2/genéticaRESUMO
Four new novel donor-acceptor (A-π-D-A, A-D-π-D-A) compoundsâ (1 a, 1 b, 2 a and 2 b) based on ethylenedioxythiophene (EDOT) and phenothiazine (PTz) have been rationally designed and synthesized towards solid state emission ranging from yellow to near infrared (NIR). The compoundsâ 1 b and 2 b, in thin film form, showed an emission maximum at 713â nm and 696â nm, respectively, with the corresponding absolute solid-state quantum yield of 3.3 % and 9.0 %. The fluorophores showed high emission in the doped state as well when dispersed in polystyrene (PS) matrix with emission maximum ranging from 536â nm to 648â nm with quantum yield in the range 12.4 %-64.4 %. The presence of dicyanovinyl (DCV) group in both the fluorophores was exploited towards cyanide sensing in DMSO leading to turn-on fluorescence emission with high selectivity and sensitivity for cyanide ion with a detection limit of as low as 0.32â µm (8â ppb) for 1 b and 0.57â µm (14â ppb) for 2 b. DFT and TTDFT calculations suggested that the addition of cyanide ion prevented the intramolecular charge transfer (ICT) from the donor (PTz or EDOT) to acceptor (DCV), thereby turning the fluorescence "On". Using fluorescent spectral and color switching, we have explored logic gates with single and two input signal amplification by applying chemical and light inputs in the form of CN- ion and UV.
Assuntos
Doenças Biliares/diagnóstico por imagem , Colangiopancreatografia Retrógrada Endoscópica/métodos , Equinococose Hepática/diagnóstico por imagem , Endossonografia/métodos , Albendazol/uso terapêutico , Antibacterianos/uso terapêutico , Doenças Biliares/terapia , Terapia Combinada , Drenagem/métodos , Equinococose Hepática/terapia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Esfinterotomia Endoscópica/métodos , Resultado do TratamentoRESUMO
In a study of 95 patients with giardiasis it was shown that examination of duodenal aspirates for Giardia Lamblia can supplement but not replace examination of faeces in the detection and follow-up of cases. The chances of finding trophozoites in duodenal aspirate is greater in those with trophozoites in the faeces than in cyst passers. Patients were treated with metronidazole in either conventional dosage (400 mg.t.d.s. for 7 days) or with a single 'hammer dose' of 2400 mg. Results showed that the parasites may persist in the duodenum and faeces after conventional therapy, though the incidence was not very high; and it is suggested that a single large dose of metronidazole may be equally if not more effective than divided doses spread over a few days.