MARIA CRISTINA CHAMMAS
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Radiologia, Hospital das Clínicas, Faculdade de Medicina
LIM/44 - Laboratório de Ressonância Magnética em Neurorradiologia, Hospital das Clínicas, Faculdade de Medicina
LIM/44 - Laboratório de Ressonância Magnética em Neurorradiologia, Hospital das Clínicas, Faculdade de Medicina
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bookPart Tireoide e paratireoide(2017) CARNEIRO, Felipe; CHAMMAS, Maria Cristina- Ultrasonography on the non-living. Current approaches.(2023) THOMSEN, Thomas; BLAIVAS, Michael; SADIVA, Paulo; KRIPFGANS, Oliver D.; CHAN, Hsun-Liang; DONG, Yi; CHAMMAS, Maria Cristina; HOFFMANN, Beatrice; DIETRICH, Christoph F.The vast majority of clinicians associate diagnostic ultrasound with a tool that is designed for the living patient. However, it is of course possible to apply this imaging technology to evaluate the recently deceased patient for postmortem diagnosis, or even just examine postmortem tissue. We describe several cases in which ultrasound-enabled providers obtain answers in postmortem examinations and discuss potential future strategies and applications. In addition, we will also illustrate the use of sonography in minimally invasive post-mortem tissue sampling (MITS), an approach that can be used in post-mortem minimally invasive autopsies as well as for establishing ultrasound diagnostic parameters in new medical fields such as periodontal and dental implant specialties.
bookPart Estudo por imagem das vias biliares(2017) OLIVEIRA, Thobias Nóbrega de; SAITO, Osmar de Cássio; CHAMMAS, Maria Cristina; CERRI, Giovanni Guido- Color Duplex Doppler US can Follow up the Response of Radioiodine in Graves' Disease by Evaluating the Thyroid Volume and Peak Systolic Velocity(2020) SANTOS, Thiago Adler Ralho Rodrigues; MARUI, Suemi; WATANABE, Tomoco; LIMA, Nicolau; OZAKI, Claudia Okanobo; CERRI, Giovanni Guido; CHAMMAS, Maria C.Purpose The objective of this study was to prove the efficacy of Doppler ultrasonography (US-Doppler) in the follow-up of patients with GD treated with radioactive iodine. Methods 97 patients (77 female and 20 male) with a mean age of 42 years (SD +/- 15) and with prior diagnosis of GD were treated with radioiodine. In total, 88.5 % achieved euthyroidism or hypothyroidism after treatment. The study was documented before treatment and one, three, and six months after treatment with radioactive iodine (131I) by a single investigator. The volume, echogenicity, echotexture and vascularization of the glands as well as the peak systolic velocity (PSV) of the inferior thyroid arteries were evaluated and compared with the laboratory data. Results Thyroid volume and PSV had a statistically significant correlation with hormone levels (p < 0.05). The mean pre-dose therapeutic thyroid volume was 43.01 +/- 3.88 cm(3) and was 11.58 +/- 11.26 cm(3) 6 months after treatment. The mean PSV before 131I was 90.06 +/- 44.13 cm/s and decreased significantly over time (p < 0.001). Six months after the therapeutic dose, the mean PSV was 32.95 +/- 16.36 cm/s. However, the subjective parameters did not have a significant correlation with the normalization of the thyroid hormones. Conclusion Doppler US was useful for monitoring the therapeutic response of GD patients after treatment with radioiodine by evaluating the thyroid volume and peak systolic velocity.
- Can contrast-enhanced ultrasound with second-generation contrast agents replace computed tomography angiography for distinguishing between occlusion and pseudo-occlusion of the internal carotid artery?(2015) VENTURA, Carlos Augusto Pinto; SILVA, Erasmo Simao da; CERRI, Giovanni Guido; LEAO, Pedro Puech; TACHIBANA, Adriano; CHAMMAS, Maria CristinaOBJECTIVE: The purpose of this study was to evaluate the effectiveness of contrast-enhanced ultrasound with a second-generation contrast agent in distinguishing between occlusion and pseudo-occlusion of the cervical internal carotid artery, comparing it with that of conventional Doppler ultrasound and the gold standard, computed tomography angiography. METHOD: Between June 2006 and June 2012, we screened 72 symptomatic vascular surgery outpatients at a public hospital. Among those patients, 78 cervical internal carotid arteries were previously classified as occluded by Doppler ultrasound (without contrast). The patients were examined again with Doppler ultrasound, as well as with contrast-enhanced ultrasound and computed tomography angiography. The diagnosis was based on the presence or absence of flow. RESULTS: Among the 78 cervical internal carotid arteries identified as occluded by Doppler ultrasound, occlusion was confirmed by computed tomography angiography in only 57 (73.1%), compared with 59 (77.5%) for which occlusion was confirmed by contrast-enhanced ultrasound (p>0.5 vs. computed tomography angiography). Comparing contrast-enhanced ultrasound with Doppler ultrasound, we found that the proportion of cervical internal carotid arteries classified as occluded was 24.4% higher when the latter was used (p<0.001). CONCLUSIONS: We conclude that, in making the differential diagnosis between occlusion and pseudo-occlusion of the cervical internal carotid artery, contrast-enhanced ultrasound with a second-generation contrast agent is significantly more effective than conventional Doppler ultrasound and is equally as effective as the gold standard (computed tomography angiography). Our findings suggest that contrast-enhanced ultrasound could replace computed tomography angiography in this regard.
- Evaluation of Parotid Salivary Gland Echo Texture by Ultrasound Examinations and Correlation With Whole-Body Scintigraphy After Radioiodine Therapy in Patients With Differentiated Thyroid Carcinoma(2020) LIMA, Graziele Aparecida Simoes; LOPEZ, Rossana Veronica Mendoza; FREITAS, Ricardo Miguel Costa de; WILLEGAIGNON, Jose; SAPIENZA, Marcelo Tatit; CHAMMAS, Maria Christina; COURA-FILHO, George BarberioObjectives This study aimed to evaluate the echo texture of the parotid salivary glands before and after radioiodine therapy (RIT) using ultrasound (US) images in patients with differentiated thyroid cancer and to evaluate the correlations between post-RIT whole-body scintigraphy (WBS) images and US image patterns in salivary and cervical areas. Methods A retrospective study was performed with data on demographic and clinical information, US examinations, and WBS images collected through medical recordings. Results Comparing the US features before and after RIT, significant echo texture heterogeneity was found in 31.3% of all patients evaluated. When evaluated according to the level of iodine 131 (I-131) radioactivity (<5.6, 5.6-<9.3, and >= 9.3 GBq), echo texture heterogeneity was significantly associated with the 5.6-GBq I-131 radioactivity group (P < .001). No association was found for any level of I-131 post-RIT WBS uptake intensity and changes in US feature patterns. Conclusions Ultrasound may be a useful tool for evaluating chronic sialadenitis after RIT, and the I-131 uptake intensity using a routine post-RIT WBS is not associated with US echo texture changes.
- Ultrasound elastography in the evaluation of thyroid nodules: evolution of a promising diagnostic tool for predicting the risk of malignancy(2019) MORAES, Pedro Henrique de Marqui; SIGRIST, Rosa; TAKAHASHI, Marcelo Straus; SCHELINI, Marcelo; CHAMMAS, Maria CristinaAbstract The elastic properties of tissue have always been of interest in clinical practice. In the past, the identification of structures that were stiffer on physical palpation would raise the suspicion that “there was something wrong”. With the development and advancement of medicine, there proved to be a true correlation in the prediction of malignancy of a lesion: malignant disease tends to stiffen the affected tissue, either by increased cell proliferation or fibrosis. Palpation is the oldest method for the detection of thyroid nodules, which is informed by the knowledge that malignant thyroid lesions tend to be much harder than benign ones. Unfortunately, palpation is a highly subjective method that is dependent on the size and location of the lesion, as well as on the skill of the physician. In cases where these nodules are very small or are located in deep regions, their detection by palpation is difficult or even impossible. In addition, although a malignant lesion differs in terms of elasticity, it may not have echogenic properties, preventing its detection by conventional ultrasound. Imaging that indicates the stiffness or deformation of tissues, through the use of ultrasound elastography techniques, adds new information related to their structural formation. In this article, we review the basic physical principles of elastography and the evolution of the method for the evaluation of thyroid nodules, as well as the limitations of and future perspectives for its use.
conferenceObject LOWLEVEL LASER THERAPY CAN IMPROVE THE THYROID VASCULARIZATION IN PATIENTS WITH CHRONIC AUTOIMMUNE THROIDITIS(2012) HOEFLING, Danilo; CHAVANTES, Maria Cristina; JULIANO, Adriana; CERRI, Giovanni; KNOBEL, Meyer; YOSHIMURA, Elisabeth; CHAMMAS, Maria CristinaBackground: Chronic autoimmune thyroiditis (CAT) frequently alters thyroid vascularization, likely as a result of the autoimmune process. Therefore, the objective of this study was to evaluate the effects of low-level laser therapy (LLLT) on the thyroid vascularization of patients with hypothyroidism induced by CAT using color Doppler ultrasound parameters. Study: A randomized clinical trial was conducted from 2006 to 2009 at the Hospital das Clínicas, University of Sao Paulo Medical School. Forty-three patients who underwent levothyroxine replacement for CAT-induced hypothyroidism were randomly assigned to receive either 10 sessions of LLLT (L group, n=23) or 10 sessions of a placebo treatment (P group, n=20). Color Doppler ultrasounds were performed before and 30 days after the end of the interventions. All of the patients in both groups continued taking their previous levothyroxine doses for the duration of the study. To verify the vascularization of the thyroid parenchyma, power Doppler was performed. The systolic peak velocity (SPV) and resistance index (RI) in the superior and inferior thyroid arteries were measured by pulsed Doppler. Results: All of the patients completed the study. The frequency of normal vascularization of the thyroid lobes observed in the post-intervention power Doppler examination was significantly higher in the L than in the P group (P=0.023). The pulsed Doppler examination revealed an increase in the SPV of the inferior thyroid arteries in the L group compared with the P group (P=0.016), whereas no significant difference in the SPV of the superior thyroid arteries was found between the groups. There was also no significant difference in the RI between the groups. Conclusion: These results suggest that LLLT can ameliorate thyroid parenchyma vascularization and increase the SPV of the inferior thyroid arteries of patients with hypothyroidism caused by CAT.- Diagnostic performance of thyroid ultrasound in Hurthle cell carcinomas(2019) SANTANA, Nathalie Oliveira; FREITAS, Ricardo Miguel Costa; MARCOS, Vinicius Neves; CHAMMAS, Maria Cristina; CAMARGO, Rosalinda Yossie Asato; SCHMERLING, Claudia Kliemann; VANDERLEI, Felipe Augusto Brasileiro; HOFF, Ana Oliveira; MARUIL, Suemi; DANILOVIC, Debora Lucia SeguroObjective: Hurthle cell carcinomas (HCCs) of the thyroid have been recently reclassified as a separate entity due to their distinct clinical and molecular profiles. Few studies have assessed the ability of preoperative characteristics in differentiating HCCs from Hurthle cell adenomas (HCAs) due to the low prevalence of both lesions. This study aimed to compare the preoperative features of HCCs and HCAs and evaluate the diagnostic performance of ultrasound in distinguishing between both. Subjetcs and methods: Retrospective study including 101 patients (52 HCCs and 49 HCAs) who underwent thyroid surgery from 2000 to 2016. Clinical, ultrasonographic, and histological data were reviewed. Diagnostic performance of suspicious sonographic features was analyzed in 51 cases (24 HCCs and 27 HCAs). Results: Hurthle cell neoplasms were predominant in females. Subjects >= 55 years represented 58% of the cases of HCCs and 53% of those of HCAs. Carcinomas were significantly larger (p < 0.001), and a tumor size >= 4 cm significantly increased the risk of malignancy (odds ratio 3.67). Other clinical, cytologic, and sonographic data were similar between HCCs and HCAs. Among the HCCs, the lesions were purely solid in 54.2%, hypoechoic in 37.5%, and had coarse calcifications in 12.5%, microcalcifications in 8.3%, irregular contours in 4.2%, and a taller-than-wide shape in 16.7%. Predominantly/exclusive intranodular vascularization was observed in 52.6%. Overall, 58% of the HCCs were classified as TI-RADS 4 or 5 compared with 48% of the HCAs. TI-RADS 4 or 5 had a specificity of only 51.8% and a positive likelihood ratio of 1.21. Conclusions: Apart from the lesion size, no other preoperative feature adequately distinguished HCCs from HCAs. Sonographic characteristics raising suspicion for malignancy, which are mostly present in papillary carcinomas, were infrequent in HCCs. New tools must be developed to improve preoperative diagnosis and deferral of surgery in cases of adenomas.
- Increased prevalence of simple renal cysts in patients with gout(2013) HASEGAWA, Eduardo Massato; FULLER, Ricardo; CHAMMAS, Maria Cristina; MELLO, Filipe Martins de; GOLDENSTEIN-SCHAINBERG, ClaudiaThe aim of this study was to determine the prevalence of simple renal cysts in gout patients and evaluate associated risk factors for its development. Hundred and forty-six patients followed at our outpatient Gout Unit and 47 sex- and age-matched healthy kidney donors who had undergone routine renal ultrasonography, using a static gray scale and real-time B-mode units with a 3.5- or 5.0-MHz transducer, were evaluated for the presence of renal cysts. Demographic and clinical characteristics of gout patients were evaluated considering possible risk factors for the occurrence of simple renal cysts such as age, male gender, hypertension, and renal impairment. The prevalence of simple renal cyst was 26.0 % in gout patients and 10.6 % in control group (P = 0.045). Gout patients with simple renal cysts presented less renal lithiasis than those without this complication (5.2 vs 25.9 %; P = 0.003) in spite of an overall higher frequency of renal stones in gout patients compared to control group (20.5 vs. 6.3 %, P = 0.025). The presence of simple renal cyst in gout was not associated with previously reported factors such as age (P = 0.296), male predominance (P = 0.688), hypertension (P = 0.314), and renal impairment (P = 254). Moreover, no association with disease duration (P = 0.843) or tophi (P = 0.616) was observed. In conclusion, gout patients have an increased prevalence of simple renal cysts associated with a lower occurrence of nephrolithiasis. Whether renal cysts have any protective effect in the development of nephrolithiasis in gout remains to be determined.