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Exposure to ionizing radiation (IR) is inevitable in various X-ray imaging examinations, with computed tomography (CT) being a major contributor to increased human radiation exposure. Ionizing radiation may cause structural damage to macromolecules, particularly DNA, mostly through an indirect pathway in diagnostic imaging. The indirect pathway primarily involves the generation of reactive oxygen species (ROS) due to water radiolysis induced by IR, leading to DNA damage, including double-strand breaks (DSB), which are highly cytotoxic. Antioxidants, substances that prevent oxidative damage, are proposed as potential radioprotective agents. This Study Protocol article presents the rationale for selecting vitamin C as a preventive measure against CT-associated IR-induced DNA damage, to be investigated in a randomized placebo-controlled trial, with a full in vivo design, using an oral easy-to-use schedule administration in the outpatient setting, for the single CT examination with the highest total global IR dose burden (contrast-enhanced abdomen and pelvis CT). The study also aims to explore the mediating role of oxidative stress, and it has been written in adherence to the Standard Protocol Items recommendations.
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Leiomyomas are the most common solid benign uterine neoplasms; they are usually asymptomatic and are identified incidentally. Yet, responsive to stimulation by estrogens, leiomyomas may expand, potentially outgrowing their blood supply to undergo hemorrhage, fibrosis, calcification, and atrophy. These pathologic mechanisms commonly lead to leiomyomas degeneration, i.e., red, hyaline, cystic, or myxoid. Magnetic resonance (MR) imaging is the most accurate imaging technique for the characterization of leiomyomas. In cases of degeneration, variable features on T2-weighted and contrast-enhanced images can be found. With no recent radiologic pathologic correlation literature available on this matter, herewith, we provide computed tomography (CT)/MR imaging along with histopathological specimens of two young women who were diagnosed with hyaline or hyaline and cyst degeneration of uterine leiomyomas at our university hospital. We report on the imaging features of uterine leiomyomas using CT and MR imaging and discuss the available literature on imaging signs that may be suggestive of hyaline or cyst degeneration using either of the imaging examination methods.
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BACKGROUND: To determine the effect of intramuscular administration of Neostigmine® on the visualization of the pancreatic duct on magnetic resonance cholangiopancreatography in patients with recurrent acute pancreatitis or abdominal pain. METHODS: We reviewed patients undergoing magnetic resonance cholangiopancreatography followed by a Neostigmine®-enhanced magnetic resonance cholangiopancreatography. Patients with a history of recurrent acute pancreatitis or abdominal pain who had a magnetic resonance cholangiopancreatography where the pancreatic duct was not entirely seen, were selected to undergo a second magnetic resonance cholangiopancreatography 40 minutes after 0.5 mg Neostigmine®. Images were analyzed by 2 radiologists. The diameter of the pancreatic duct was measured in the head, body, and tail of the pancreas on the baseline images and after Neostigmine®. RESULTS: Ten patients were included, with a median age of 33 years (range 15-61). The maximum diameter of the pancreatic duct increased significantly after Neostigmine® administration in all patients, from 1.84 ± 0.98 to 3.41 ± 1.27 mm in the head, 1.34 ± 0.42 mm to 2.5 ± 0.49 mm in the body and 0.72 ± 0.52 mm to 1.78 ± 0.43 mm in the tail (mean ± SD, P < .0001). Neostigmine® helped to provide better detail of the pancreatic duct anatomy in 4 patients. In 2 patients we confirmed pancreas divisum, in another the Santorini duct was not seen on the baseline images but it was clearly visualized after Neostigmine®, and in the fourth patient, Neostigmine® improved visualization of multiple pancreatic duct stenosis. CONCLUSION: Neostigmine®-magnetic resonance cholangiopancreatography significantly increases the diameter of the pancreatic duct, allowing an accurate morphological evaluation. It could be a cheap alternative to secretin, which is expensive and hardly available.
Assuntos
Pancreatite , Secretina , Dor Abdominal/diagnóstico por imagem , Dor Abdominal/tratamento farmacológico , Dor Abdominal/etiologia , Doença Aguda , Adolescente , Adulto , Colangiopancreatografia Retrógrada Endoscópica , Colangiopancreatografia por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Neostigmina , Pâncreas/patologia , Ductos Pancreáticos/diagnóstico por imagem , Ductos Pancreáticos/patologia , Pancreatite/patologia , Adulto JovemRESUMO
BACKGROUND: Sarcomatoid carcinoma of the pancreas (SCP) is a rare type of pancreatic neoplasm, and only a few cases have been described in the literature. Histologically, it is composed mostly of atypical spindle cells with apparent sarcomatous features. CASE SUMMARY: This is a report of a 61-year-old Chilean woman who underwent medical investigation for acute abdominal pain. Computed tomography identified a solid tumor in the tail of the pancreas with features suspicious of malignancy. En-bloc distal pancreatectomy and splenectomy were performed to excise the tumor. Histopathology and immunohistochemistry were confirmatory of sarcomatoid carcinoma with lymphovascular invasion. After surgery, the patient did not receive chemotherapy. Previous studies indicate a poor prognosis for this type of malignancy. However, our patient has survived for 35 mo with no recurrence to date. CONCLUSION: The case presented herein is a patient with an SCP with a rare presentation and long-term survival after surgery despite not receiving adjuvant chemotherapy.