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1.
NMR Biomed ; 37(3): e5062, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37920145

RESUMO

In this study, we investigated the potential of the multivariate curve resolution alternating least squares (MCR-ALS) algorithm for analyzing three-dimensional (3D) 1 H-MRSI data of the prostate in prostate cancer (PCa) patients. MCR-ALS generates relative intensities of components representing spectral profiles derived from a large training set of patients, providing an interpretable model. Our objectives were to classify magnetic resonance (MR) spectra, differentiating tumor lesions from benign tissue, and to assess PCa aggressiveness. We included multicenter 3D 1 H-MRSI data from 106 PCa patients across eight centers. The patient cohort was divided into a training set (N = 63) and an independent test set (N = 43). Singular value decomposition determined that MR spectra were optimally represented by five components. The profiles of these components were extracted from the training set by MCR-ALS and assigned to specific tissue types. Using these components, MCR-ALS was applied to the test set for a quantitative analysis to discriminate tumor lesions from benign tissue and to assess tumor aggressiveness. Relative intensity maps of the components were reconstructed and compared with histopathology reports. The quantitative analysis demonstrated a significant separation between tumor and benign voxels (t-test, p < 0.001). This result was achieved including voxels with low-quality MR spectra. A receiver operating characteristic analysis of the relative intensity of the tumor component revealed that low- and high-risk tumor lesions could be distinguished with an area under the curve of 0.88. Maps of this component properly identified the extent of tumor lesions. Our study demonstrated that MCR-ALS analysis of 1 H-MRSI of the prostate can reliably identify tumor lesions and assess their aggressiveness. It handled multicenter data with minimal preprocessing and without using prior knowledge or quality control. These findings indicate that MCR-ALS can serve as an automated tool to assess the presence, extent, and aggressiveness of tumor lesions in the prostate, enhancing diagnostic capabilities and treatment planning of PCa patients.


Assuntos
Próstata , Neoplasias da Próstata , Masculino , Humanos , Próstata/diagnóstico por imagem , Próstata/patologia , Prótons , Neoplasias da Próstata/diagnóstico por imagem , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética/métodos , Análise dos Mínimos Quadrados
2.
NMR Biomed ; 37(2): e5054, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37794648

RESUMO

The aim of the current study was to compare the performance of fully automated software with human expert interpretation of single-voxel proton magnetic resonance spectroscopy (1H-MRS) spectra in the assessment of breast lesions. Breast magnetic resonance imaging (MRI) (including contrast-enhanced T1-weighted, T2-weighted, and diffusion-weighted imaging) and 1H-MRS images of 74 consecutive patients were acquired on a 3-T positron emission tomography-MRI scanner then automatically imported into and analyzed by SpecTec-ULR 1.1 software (LifeTec Solutions GmbH). All ensuing 117 spectra were additionally independently analyzed and interpreted by two blinded radiologists. Histopathology of at least 24 months of imaging follow-up served as the reference standard. Nonparametric Spearman's correlation coefficients for all measured parameters (signal-to-noise ratio [SNR] and integral of total choline [tCho]), Passing and Bablok regression, and receiver operating characteristic analysis, were calculated to assess test diagnostic performance, as well as to compare automated with manual reading. Based on 117 spectra of 74 patients, the area under the curve for tCho SNR and integrals ranged from 0.768 to 0.814 and from 0.721 to 0.784 to distinguish benign from malignant tissue, respectively. Neither method displayed significant differences between measurements (automated vs. human expert readers, p > 0.05), in line with the results from the univariate Spearman's rank correlation coefficients, as well as the Passing and Bablok regression analysis. It was concluded that this pilot study demonstrates that 1H-MRS data from breast MRI can be automatically exported and interpreted by SpecTec-ULR 1.1 software. The diagnostic performance of this software was not inferior to human expert readers.


Assuntos
Neoplasias da Mama , Colina , Humanos , Feminino , Espectroscopia de Prótons por Ressonância Magnética , Colina/análise , Projetos Piloto , Sensibilidade e Especificidade , Mama/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia
3.
Int J Legal Med ; 138(3): 971-981, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38240840

RESUMO

It is believed by many that reference data for age estimation purposes must be imaging-modality specific. A study from our department has however proven otherwise. We therefore found it interesting to investigate this further by looking at the level of agreement between different imaging modalities. The aim of this study was to investigate the level of agreement between the three radiological modalities, computed tomography (CT), magnetic resonance imaging (MRI), and digital radiography (DR), in assessing the ossification of the epiphyses of the knee. A total of 34 deceased individuals of 10-25 years of age, brought in for a medicolegal autopsy at our department, were scanned by CT, MRI, and DR. The ossification stages of the three bones of the right knee, distal femoral, proximal tibial, and proximal fibular epiphysis were assessed using the established combined staging method by Schmeling et al. and Kellinghaus et al. Analysis of the results by Cohen's weighted kappa showed a good agreement between CT and DR (K = 0.61-0.70), and MRI and DR (K = 0.68-0.79) but only moderate agreement between CT and MRI (K = 0.55-0.57). This leads us to conclude that different radiological images cannot be used interchangeably for age estimation purposes, so reference material needs to be imaging-modality specific. However, to make a more general conclusion research on a larger population is needed.


Assuntos
Determinação da Idade pelo Esqueleto , Antropologia Forense , Humanos , Determinação da Idade pelo Esqueleto/métodos , Imageamento por Ressonância Magnética/métodos , Articulação do Joelho/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Epífises/diagnóstico por imagem , Osteogênese
4.
Handb Exp Pharmacol ; 284: 153-189, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37566121

RESUMO

In this chapter, the visualization of nanocarriers and drugs in cells and tissue is reviewed. This topic is tightly connected to modern drug delivery, which relies on nanoscopic drug formulation approaches and the ability to probe nanoparticulate systems selectively in cells and tissue using advanced spectroscopic and microscopic techniques. We first give an overview of the breadth of this research field. Then, we mainly focus on topical drug delivery to the skin and discuss selected visualization techniques from spectromicroscopy, such as scanning transmission X-ray microscopy and fluorescence lifetime imaging. These techniques rely on the sensitive and quantitative detection of the topically applied drug delivery systems and active substances, either by exploiting their molecular properties or by introducing environmentally sensitive probes that facilitate their detection.


Assuntos
Sistemas de Liberação de Medicamentos , Pele , Humanos , Preparações Farmacêuticas
5.
J Ultrasound Med ; 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867553

RESUMO

OBJECTIVES: To assess the feasibility of acquiring adequate transperineal ultrasound (TPUS) volumes of the anal sphincter (AS) immediately after vaginal birth, the reproducibility of its measurements, and detecting defects therein. METHODS: Secondary analysis of TPUS volumes of the AS, acquired immediately after vaginal birth with a transversely oriented convex probe. Two independent experts ranked off-line image quality as "inadequate," "adequate," or "ideal" using the Point-of-Care Ultrasound Image Quality scale. On "adequate" and "ideal" quality volumes, the length of the external AS at 6 and 12 o'clock, and the volume of the external and internal AS were measured. Additionally, volumes were screened for AS defects on tomographic ultrasound imaging. Subsequently, we rated the intra- and interrater agreement on those findings. RESULTS: Of 183 volumes, 162 were considered "adequate" or of "ideal" quality (88.5%). Reasons for "inadequacy" were shadow artifacts (16/21), poor resolution (3/21), incomplete acquisition (1/21), or aberrant AS morphology (1/21). The intrarater reliability of two-dimensional (2D) and three-dimensional (3D) measurements was excellent, whereas interrater reliability was fair to good for 2D measurements and good for 3D measurements. In those tomographic ultrasound imaging (TUI) sequences including AS defects, the intra- and interrater reliability of the defect measurement were excellent [intraclass correlation coefficient (ICC) = 0.92 (0.80-0.94)] and moderate [ICC = 0.72 (0.63-0.79)]. In this cohort, there were only few (4/48; 8.3%) AS defects. However, grading them was poorly reproducible between experts. CONCLUSION: TPUS of the AS immediately after vaginal birth yields adequate image quality and allows for reproducible measurements. In the few patients with AS defects, there was good agreement on the presence, but it was poor for the extent of defects.

6.
J Clin Ultrasound ; 52(3): 338-340, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38155537

RESUMO

A middle-aged woman presented to our hospital with a chief complaint of a mass on the left shoulder for 1 year. The initial lump was small with no pain or tenderness, and the patient had not sought medical attention for numbness in the left shoulder. Clinical examination showed a mass on the left shoulder measuring 11 × 8 × 3 cm approximately with no apparent skin damage or ecchymosis. No limitations in left shoulder joint movements were observed, and the patient exhibited normal movement of the left elbow joint, wrist joint, and metacarpophalangeal joint. Moreover, the left radial artery was palpable.


Assuntos
Tumores de Células Gigantes , Ombro , Pessoa de Meia-Idade , Feminino , Humanos , Tumores de Células Gigantes/diagnóstico por imagem , Tumores de Células Gigantes/patologia , Ultrassonografia , Articulação do Punho , Tendões/diagnóstico por imagem
7.
Cas Lek Cesk ; 162(7-8): 279-282, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38981712

RESUMO

The current era witnesses a highly dynamic development of Artificial Intelligence (AI) applications, impacting various human activities. Medical imaging techniques are no exception. AI can find application in image acquisition, image processing and augmentation, as well as in the actual interpretation of images. Moreover, within the domain of radiomics, AI can be instrumental in advanced analysis surpassing the capacities of the human eye and experience. While several certified commercial solutions are available, the validation and accumulation of sufficient evidence regarding their positive impact on healthcare is currently constrained. The role of AI presently leans towards being assistive, yet further evolution is anticipated. Risks and disadvantages encompass dependency on computational power, the quality of input data, and their annotation for learning purposes. The transparency of algorithmic functioning is lacking, and issues pertaining to portability may arise. The integration and utilization of AI introduce entirely new ethical and legislative aspects. Predicting the future development of AI in imaging methods is challenging, with a further increase in implementation appearing more probable.


Assuntos
Inteligência Artificial , Diagnóstico por Imagem , Humanos , Diagnóstico por Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos
8.
Front Neuroendocrinol ; 67: 101031, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35998859

RESUMO

Worldwide over 150 million women use oral contraceptives (OCs), which are the most prescribed form of contraception in both the United States and in European countries. Sex hormones, such as estradiol and progesterone, are important endogenous hormones known for shaping the brain across the life span. Synthetic hormones, which are present in OCs, interfere with the natural hormonal balance by reducing the endogenous hormone levels. Little is known how this affects the brain, especially during the most vulnerable times of brain maturation. Here, we review studies that investigate differences in brain gray and white matter in women using OCs in comparison to naturally cycling women. We focus on two neuroimaging methods used to quantify structural gray and white matter changes, namely structural MRI and diffusion MRI. Finally, we discuss the potential of these imaging techniques to advance knowledge about the effects of OCs on the brain and wellbeing in women.


Assuntos
Anticoncepcionais Orais , Objetivos , Humanos , Feminino , Anticoncepcionais Orais/farmacologia , Progesterona/farmacologia , Estradiol , Encéfalo/diagnóstico por imagem
9.
Neuroendocrinology ; 113(1): 92-102, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35882186

RESUMO

INTRODUCTION: Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is a serious life-threatening disease. Tumor localization is crucial in EAS management. This underscores the importance of evaluating imaging methods and prognostic factors to provide a clear basis for patient diagnosis and management. OBJECTIVE: The aim of this study was to investigate imaging methods and analyze the relevant prognostic factors for EAS. METHODS: The retrospective study followed 64 cases of EAS diagnosed between 1992 and 2020. Clinical features, biochemical analysis, and imaging studies were collected, and survival data were followed up and analyzed. RESULTS: Of 64 patients, 41% were female with a mean (±SD) age at diagnosis of 47 ± 16 years. Computed tomography (CT), 18-F fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)-CT, and octreotide scintigraphy had similar sensitivity in localizing ectopic ACTH-secreting tumors. However, in cases with negative imaging on CT, both of 18F-FDG PET-CT and octreotide scintigraphy further localized 25% tumors. The combination of all three modalities failed to further increase the sensitivity. Patients with thymic tumors survived longer than those with pulmonary or pancreatic tumors (p = 0.013 and 0.047, respectively). Multivariate analyses showed that hypokalemia (p = 0.004) and treatment modality (p = 0.048) were independent prognostic factors. The optimal serum potassium cutoff based on maximum log-rank statistics (p = 0.012) was 2.90 mmol/L. CONCLUSION: CT is the first choice for tumor localization in EAS. CT in combination with a nuclear medicine or molecular imaging modality is necessary for further identification of an ectopic source. Serum potassium <2.90 mmol/L is associated with shorter overall survival, and tumor resection plays the most important role in the survival improvement.


Assuntos
Síndrome de ACTH Ectópico , Neoplasias do Timo , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Masculino , Estudos Retrospectivos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluordesoxiglucose F18 , Octreotida , Prognóstico , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de ACTH Ectópico/terapia , Hormônio Adrenocorticotrópico , Potássio
10.
Cardiol Young ; 33(2): 313-314, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35593426

RESUMO

The authors describe the case of a child with a history of relapsed acute lymphoblastic leukaemia with a giant intra-auricular lymphomatous mass, submitted to investigation by multiple imaging methods and biopsy.


Assuntos
Fibrilação Atrial , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Biópsia , Diagnóstico por Imagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico
11.
Wilderness Environ Med ; 34(2): 135-142, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36804375

RESUMO

INTRODUCTION: Point-of-care ultrasound (POCUS) is utilized in austere environments because it is lightweight, durable, battery powered, and portable. In austere settings, weight and space constraints are limitations to carrying dedicated ultrasound gel. Few studies have assessed commonly carried liquids as gel alternatives. The study objective was to assess the suitability of common food and personal care products as ultrasound coupling agents compared with that of commercial gel. METHODS: A noninferiority study compared 9 products to commercial gel. Each substance was independently tested on 2 subjects by 2 sonographers covering 8 standardized ultrasound windows. Clips were recorded, blinded, and independently graded by 2 ultrasound fellowship-trained physicians on the ability to make clinical decisions and technical details, including contrast, resolution, and artifact. A 20% noninferiority margin was set, which correlates to levels considered to be of reliably sufficient quality by American College of Emergency Physicians' guidelines. The substances included water, soap, shampoo, olive oil, energy gel, maple syrup, hand sanitizer, sunscreen, and lotion. RESULTS: A total of 300 of 318 (94%) clips met the primary endpoint of adequacy to make a clinical decision. All media, except sunscreen, were noninferior to commercial gel in the ability to make a clinical decision (α=0.05). In terms of secondary outcomes, resolution, artifact, and contrast, all substances were noninferior to commercial gel (α=0.05). The sonographers concluded that all gel alternatives' usability performed similarly to commercial gel, with the exception of energy gel. CONCLUSIONS: Of the 9 substances tested, 8 were noninferior to commercial gels for clinical decisions. Our study indicates that several POCUS gel substitutes are serviceable to produce clinically adequate images.


Assuntos
Médicos , Protetores Solares , Humanos , Ultrassonografia/métodos , Géis , Sistemas Automatizados de Assistência Junto ao Leito
12.
Biochemistry (Mosc) ; 87(9): 851-870, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36180985

RESUMO

Astrocytes are the most common type of glial cells that provide homeostasis and protection of the central nervous system. Important specific characteristic of astrocytes is manifestation of morphological heterogeneity, which is directly dependent on localization in a particular area of the brain. Astrocytes can integrate into neural networks and keep neurons active in various areas of the brain. Moreover, astrocytes express a variety of receptors, channels, and membrane transporters, which underlie their peculiar metabolic activity, and, hence, determine plasticity of the central nervous system during development and aging. Such complex structural and functional organization of astrocytes requires the use of modern methods for their identification and analysis. Considering the important fact that determining the most appropriate marker for polymorphic and multiple subgroups of astrocytes is of decisive importance for studying their multifunctionality, this review presents markers, modern imaging techniques, and identification of astrocytes, which comprise a valuable resource for studying structural and functional properties of astrocytes, as well as facilitate better understanding of the extent to which astrocytes contribute to neuronal activity.


Assuntos
Astrócitos , Neurogênese , Astrócitos/metabolismo , Sistema Nervoso Central , Proteínas de Membrana Transportadoras/metabolismo , Neuroglia
13.
Skeletal Radiol ; 51(8): 1585-1594, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35088162

RESUMO

OBJECTIVE: To qualitatively evaluate the utility of zero echo-time (ZTE) MRI sequences in identifying osseous findings and to compare ZTE with optimized spoiled gradient echo (SPGR) sequences in detecting knee osseous abnormalities. MATERIALS AND METHODS: ZTE and standard knee MRI sequences were acquired at 3T in 100 consecutive patients. Three radiologists rated confidence in evaluating osseous abnormalities and image quality on a 5-grade Likert scale in ZTE compared to standard sequences. In a subset of knees (n = 57) SPGR sequences were also obtained, and diagnostic confidence in identifying osseous structures was assessed, comparing ZTE and SPGR sequences. Statistical significance of using ZTE over SPGR was characterized with a paired t-test. RESULTS: Image quality of the ZTE sequences was rated high by all reviewers with 278 out of 299 (100 studies, 3 radiologists) scores ≥ 4 on the Likert scale. Diagnostic confidence in using ZTE sequences was rated "very high confidence" in 97%, 85%, 71%, and 73% of the cases for osteophytosis, subchondral cysts, fractures, and soft tissue calcifications/ossifications, respectively. In 74% of cases with osseous findings, reviewer scores indicated confidence levels (score ≥ 3) that ZTE sequences improved diagnostic certainty over standard sequences. The diagnostic confidence in using ZTE over SPGR sequences for osseous structures as well as abnormalities was favorable and statistically significant (p < 0.01). CONCLUSION: Incorporating ZTE sequences in the standard knee MRI protocol was technically feasible and improved diagnostic confidence for osseous findings in relation to standard MR sequences. In comparison to SPGR sequences, ZTE improved assessment of osseous abnormalities.


Assuntos
Osso e Ossos , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos
14.
Rozhl Chir ; 101(3): 101-107, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35387465

RESUMO

The ever-increasing incidence of prostate cancer is driving research and clinicians efforts to manage the disease more precisely. Leaving aside the progress we are making in the field of prostate cancer treatment, we can notice the pressure on accurate diagnosis in everyday practice. We often meet patients who are in the so-called gray zone and we are not sure whether to indicate a prostate biopsy or continue to monitor the patient. For diagnostics, we use a number of more or less proven methods that we have at our disposal. No clinical urologist wants to send their patient for a prostate biopsy unnecessarily. However, if the patient is finally planned for a prostate biopsy, there is no 100% certainty that we will detect the cancer. For this reason, there is an effort to develop other methods that would refine the collection of histological material and thus increase the capture of those patients who need treatment. The aim of this review is to show modern approaches to diagnostics and outline the direction in which diagnostics will go in the coming years.


Assuntos
Próstata , Neoplasias da Próstata , Biópsia , Humanos , Masculino , Pelve/patologia , Próstata/patologia , Neoplasias da Próstata/diagnóstico
15.
Cerebellum ; 20(3): 462-480, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33417160

RESUMO

Medulloblastoma is a malign posterior fossa brain tumor, mostly occurring in childhood. The CNS-directed chemoradiotherapy treatment can be very harmful to the developing brain and functional outcomes of these patients. However, what the underlying neurotoxic mechanisms are remain inconclusive. Hence, this review summarizes the existing literature on the association between advanced neuroimaging and neurocognitive changes in patients that were treated for pediatric medulloblastoma. The PubMed/Medline database was extensively screened for studies investigating the link between cognitive outcomes and multimodal magnetic resonance (MR) imaging in childhood medulloblastoma survivors. A behavioral meta-analysis was performed on the available IQ scores. A total of 649 studies were screened, of which 22 studies were included. Based on this literature review, we conclude medulloblastoma patients to be at risk for white matter volume loss, more frequent white matter lesions, and changes in white matter microstructure. Such microstructural alterations were associated with lower IQ, which reached the clinical cut-off in survivors across studies. Using functional MR scans, changes in activity were observed in cerebellar areas, associated with working memory and processing speed. Finally, cerebral microbleeds were encountered more often, but these were not associated with cognitive outcomes. Regarding intervention studies, computerized cognitive training was associated with changes in prefrontal and cerebellar activation and physical training might result in microstructural and cortical alterations. Hence, to better define the neural targets for interventions in pediatric medulloblastoma patients, this review suggests working towards neuroimaging-based predictions of cognitive outcomes. To reach this goal, large multimodal prospective imaging studies are highly recommended.


Assuntos
Neoplasias Cerebelares/diagnóstico por imagem , Neoplasias Cerebelares/psicologia , Meduloblastoma/diagnóstico por imagem , Meduloblastoma/psicologia , Adolescente , Biomarcadores , Criança , Pré-Escolar , Cognição , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Neuroimagem , Testes Neuropsicológicos
16.
Catheter Cardiovasc Interv ; 97(1): 48-55, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31912983

RESUMO

OBJECTIVES: We sought to describe the outcomes of BVS use from a single-center experience in which scaffold implantation was guided by intravascular imaging (ultrasound and/or optical coherence tomography) to identify and treat mechanical factors potentially related to BVS failure. BACKGROUND: The Absorb bioresorbable vascular scaffold (BVS) has been associated with an unexpectedly high incidence of thrombosis. METHODS: Between 11/2014 and 10/2016, 100 patients were treated with BVS. Intravascular imaging assessment before and after BVS implantation was performed in all cases. RESULTS: Mean age was 58.1 years; 88% were male, 31% had diabetes, and 28% presented with acute coronary syndromes. A total of 171 lesions in 141 vessels were treated with 190 BVS (mean 1.9 scaffolds/patient). Further intervention following intravascular imaging to optimize BVS implantation was required in 31% of patients. Procedure success was 100%. All patients completed a 1-year follow-up. The 1-year rate of target lesion failure was 4%, and there were no cases (0%) of scaffold thrombosis, myocardial infarction, or death. CONCLUSIONS: In this real-world experience, the use of intravascular imaging to guide BVS implantation was associated with a high 1-year event-free survival rate, with no scaffold thrombosis.


Assuntos
Doença da Artéria Coronariana , Stents Farmacológicos , Intervenção Coronária Percutânea , Implantes Absorvíveis , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Everolimo , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Desenho de Prótese , Resultado do Tratamento
17.
Endocr Pract ; 27(12): 1193-1198, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34298158

RESUMO

OBJECTIVE: We aimed to find and compare the efficacy of ultrasonography (US), technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy (MIBI-S), and single-photon emission computed tomography-computed tomography (SPECT-CT) in detecting the localization of parathyroid adenomas in patients with primary hyperparathyroidism. METHODS: In total, 348 patients were included in this study. Preoperative parathyroid imaging with US, MIBI-S, and SPECT-CT was evaluated and compared with operative findings. The results of the imaging methods were compared with pathology and operation reports. RESULTS: In 318 patients (91.3%), one of the imaging methods was able to localize the lesion correctly. US detected the localization of the parathyroid lesions correctly in 268 patients (77%), whereas SPECT-CT and MIBI-S were correct in 254 (73%) and 209 (60%) patients, respectively. There was a statistically significant relationship between the parathyroid hormone (PTH) level and 3 imaging methods' success rates (P < .05). The PTH cut-off value, which best determined the correct localization, was 152.5 pg/mL for US, 143 pg/mL for MIBI-S, and 143 pg/mL for SPECT-CT. It was observed that the correct localization rate for parathyroid lesions increased with higher PTH levels. CONCLUSION: In our study population, US was more successful, in most cases, than other imaging methods in localizing parathyroid lesions but SPECT-CT was more accurate in localizing mediastinal lesions. In addition, it was found that preoperative PTH levels affect the accuracy of imaging methods.


Assuntos
Hiperparatireoidismo Primário , Tecnécio , Humanos , Hiperparatireoidismo Primário/diagnóstico por imagem , Hiperparatireoidismo Primário/cirurgia , Glândulas Paratireoides/diagnóstico por imagem , Glândulas Paratireoides/cirurgia , Cintilografia , Compostos Radiofarmacêuticos , Sensibilidade e Especificidade , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton Único , Ultrassonografia
18.
NMR Biomed ; 33(12): e4308, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32342560

RESUMO

The development and implementation of novel MRI pulse sequences remains challenging and laborious. Gradient waveforms are typically designed using a combination of analytical and ad hoc methods to construct each gradient waveform axis independently. This strategy makes coding the pulse sequence complicated, in addition to being time inefficient. As a consequence, nearly all commercial MRI pulse sequences fail to maximize use of the available gradient hardware or efficiently mitigate physiological effects. This results in expensive MRI systems that underperform relative to their inherent hardware capabilities. To address this problem, a software solution is proposed that incorporates numerical optimization methods into MRI pulse sequence programming. Examples are shown for rotational variant vs. invariant waveform designs, acceleration nulled velocity encoding gradients, and mitigation of peripheral nerve stimulation for diffusion encoding. The application of optimization methods to MRI pulse sequence design incorporates gradient hardware limits and the prescribed MRI protocol parameters (e.g. field-of-view, resolution, gradient moments, and/or b-value) to simultaneously construct time-optimal gradient waveforms. In many cases, the resulting constrained gradient waveform design problem is convex and can be solved on-the-fly on the MRI scanner. The result is a set of multi-axis time-optimal gradient waveforms that satisfy the design constraints, thereby increasing SNR-efficiency. These optimization methods can also be used to mitigate imaging artifacts (e.g. eddy currents) or account for peripheral nerve stimulation. The result of the optimization method is to enable easier pulse sequence gradient waveform design and permit on-the-fly implementation for a range of MRI pulse sequences.


Assuntos
Imageamento por Ressonância Magnética/métodos , Análise de Ondaletas , Meios de Contraste/química , Difusão , Estimulação Elétrica , Humanos , Nervos Periféricos/diagnóstico por imagem , Nervos Periféricos/fisiologia , Rotação
19.
J Neuroradiol ; 47(5): 369-381, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31279838

RESUMO

Dural arteriovenous fistulas (DAVFs) are complex vascular abnormalities that account for 10-15% of intracranial vascular malformations. DAVFs are typically encountered in middle-aged adults, with a slightly female predominance. The causative factors are still uncertain; however, abnormal local hemodynamics and neoangiogenesis related to dural sinus or venous thrombosis can contribute to DAVF occurrence. The diagnosis is dependent on a high level of clinical suspicion and high-resolution imaging techniques. Computed tomography and/or magnetic resonance imaging aid in the diagnosis, but conventional angiography remains the most accurate method for the complete characterization and classification of DAVFs. The therapeutic approach can be conservative or more aggressive, based on symptom severity, sequelae risk and patient characteristics. This article is a pictorial review of adult intracranial DAVFs that highlights some tips and tricks for recognizing useful red flags in the suspicion of DAVFs.


Assuntos
Malformações Vasculares do Sistema Nervoso Central/diagnóstico por imagem , Neuroimagem/métodos , Meios de Contraste , Humanos , Prognóstico
20.
Eur Radiol ; 29(3): 1435-1443, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30120494

RESUMO

OBJECTIVES: To prospectively determine the feasibility of preoperative supine breast MRI in breast cancer patients scheduled for oncoplastic breast-conserving surgery. METHODS: In addition to a diagnostic prone breast MRI, a supplementary supine MRI was performed with the patient in the surgical position including skin markers. Tumours' locations were ink-marked on the skin according to findings obtained from supine MRI. Changes in tumours' largest diameter and locations between prone and supine MRI were measured and compared to histology. Nipple-to-tumour and tumour-to-chest wall distances were also measured. Tumours and suspicious areas were surgically removed according to skin ink-markings. The differences between MRI measurements with reference to histopathology were evaluated with the paired-sample t test. RESULTS: Fourteen consecutive patients, 15 breasts and 27 lesions were analysed. Compared to histology, prone MRI overestimated tumour size by 47.1% (p = 0.01) and supine MRI by 14.5% (p = 0.259). In supine MRI, lesions' mean diameters and areas were smaller compared to prone MRI (- 20.9%, p = 0.009 and - 38.3%, p = 0.016, respectively). This difference in diameter was more pronounced in non-mass lesions (- 31.2%, p = 0.031) compared to mass lesions (- 9.2%, p = 0.009). Tumours' mean distance from chest wall diminished by 69.4% (p < 0.001) and from nipple by 18.2% (p < 0.001). Free microscopic margins were achieved in first operation in all patients. CONCLUSIONS: Supine MRI in the surgical position is feasible and useful in the precise localisation of prone MRI-detected lesions and provides a helpful tool to implement in surgery. Supine MRI more accurately determines tumours' size and location and might have an important role to diminish overestimations. KEY POINTS: • Breath-hold supine breast MRI is feasible using commercially available coils and sequences. • Size and area of lesions on MRI were consistently smaller when measured from the supine position as compared to the prone position. • Supine breast MRI is useful in the precise preoperative localisation of prone MRI-detected lesions. •.


Assuntos
Neoplasias da Mama/diagnóstico , Imageamento por Ressonância Magnética/métodos , Mastectomia Segmentar/métodos , Decúbito Dorsal , Adulto , Idoso , Neoplasias da Mama/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
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