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1.
Neuroradiology ; 65(4): 719-727, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36670276

RESUMO

PURPOSE: Phase difference enhanced (PADRE) imaging can enhance myelin density and delineate the superior cerebellar peduncle (SCP). We aimed to determine if SCP atrophy was distinguishable on PADRE imaging and evaluate its diagnostic performance compared with previous MRI progressive supranuclear palsy (PSP) findings. METHODS: Two reviewers measured the SCP widths on PADRE in 20 PSP and 31 Parkinson's disease (PD) patients. The SCP and middle cerebellar peduncle (MCP) widths and the pons and midbrain areas were measured on 3D-T1WI, and the ratio of the area of the pons to the area of the midbrain, the MCP/SCP ratio, and the magnetic resonance parkinsonism index (MRPI) were calculated. We used the Steel-Dwass test to compare PSP, PD, and HS, and receiver operating characteristic curve (ROC) analyses to assess the sensitivity and specificity for diagnosing PSP from PD. A comparison of ROC curves was performed between the SCP on PADRE and these 3D-T1WI parameters. RESULTS: In radiologist 1, the SCP on PADRE in PSP (1.1 ± 0.3 mm) was significantly smaller than those in PD (2.4 ± 0.4 mm) (P < 0.001); the area under the curve (AUC) was 0.97. At a 1.75-mm cutoff value, the diagnostic sensitivity and specificity for differentiating PSP from PD were 93.5% and 100%, respectively. The AUC of the SCP on PADRE was significantly higher than the 3D-T1WI parameters (the SCP, MCP, pons area, MCP/SCP ratio, and MRPI). CONCLUSION: Assessing SCP with PADRE imaging may yield high diagnostic accuracy for discriminating PSP from PD.


Assuntos
Doença de Parkinson , Transtornos Parkinsonianos , Paralisia Supranuclear Progressiva , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/patologia , Paralisia Supranuclear Progressiva/diagnóstico por imagem , Paralisia Supranuclear Progressiva/patologia , Sensibilidade e Especificidade , Curva ROC , Imageamento por Ressonância Magnética/métodos , Diagnóstico Diferencial
2.
J Magn Reson Imaging ; 55(1): 37-47, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-32949073

RESUMO

The spectrum of soft-tissue mass is varied, including neoplastic and nonneoplastic/inflammatory lesions. However, soft-tissue tumors have similar imaging findings and, therefore, the diagnosis of soft-tissue mass is challenging. Although careful assessment of the internal characteristics on imaging can often narrow the differential diagnoses, the differential diagnosis may be out of the question if identification of the soft-tissue mass origin is missed. The purpose of this article is to review the imaging findings and the essential anatomy to identify the primary site of the soft-tissue mass, and discuss the associated potential pitfalls. In order not to fall into a pitfall, recognition of characteristic imaging findings indicating the origin of the soft-tissue mass and anatomical knowledge of the normal tissue distribution are necessary. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.


Assuntos
Imageamento por Ressonância Magnética
3.
Neuroradiology ; 63(12): 2013-2021, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34191098

RESUMO

PURPOSE: Model-based iterative reconstruction (MBIR) yields higher spatial resolution and a lower image noise than conventional reconstruction methods. We hypothesized that thin-slice MBIR designed for brain CT could improve the detectability of acute ischemic stroke in the middle cerebral artery (MCA) territory. METHODS: Included were 41 patients with acute ischemic stroke in the MCA territory; they were seen at 4 medical centers. The controls were 39 subjects without acute stroke. Images were reconstructed with hybrid IR and with MBIR designed for brain CT at slice thickness of 2 mm. We measured the image noise in the ventricle and compared the contrast-to-noise ratio (CNR) in the ischemic lesion. We analyzed the ability of reconstructed images to detect ischemic lesions using receiver operating characteristics (ROC) analysis; 8 observers read the routine clinical hybrid IR with 5 mm-thick images, while referring to 2 mm-thick hybrid IR images or MBIR images. RESULTS: The image noise was significantly lower on MBIR- than hybrid IR images (1.2 vs. 3.4, p < 0.001). The CNR was significantly higher with MBIR than hybrid IR (6.3 vs. 1.6, p < 0.001). The mean area under the ROC curve was also significantly higher on hybrid IR plus MBIR than hybrid IR (0.55 vs. 0.48, p < 0.036). Sensitivity, specificity, and accuracy were 41.2%, 88.8%, and 65.7%, respectively, for hybrid IR; they were 58.8%, 86.1%, and 72.9%, respectively, for hybrid IR plus MBIR. CONCLUSION: The additional thin-slice MBIR designed for brain CT may improve the detection of acute MCA stroke.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Algoritmos , Encéfalo , Isquemia Encefálica/diagnóstico por imagem , Humanos , Artéria Cerebral Média , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X
4.
J UOEH ; 43(3): 349-353, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483194

RESUMO

A 60-year-old woman with a 37-year history of rheumatoid arthritis (RA) had a sudden onset of headache. Head MRI showed acute multiple infarctions in the vertebrobasilar region, and MR angiography showed stenosis of the right vertebral artery (VA). 3D-CT angiography of the craniovertebral junction showed atlantoaxial subluxation and stenosis of the right VA just distal to the transverse foramen of C2, which was due to osteophytes and degenerative changes secondary to RA. Digital subtraction angiography clearly demonstrated occlusion of the right VA during rightward head rotation. Based on those findings, rotatory instability at C1-2 was considered as the primary cause of the vertebrobasilar infarctions, and Bow Hunter's syndrome was diagnosed. The patient underwent C1-5 posterior fixation, and brain infarction has not recurred.


Assuntos
Artrite Reumatoide , Mucopolissacaridose II , Insuficiência Vertebrobasilar , Artrite Reumatoide/complicações , Artrite Reumatoide/diagnóstico por imagem , Feminino , Humanos , Infarto , Pessoa de Meia-Idade , Artéria Vertebral/diagnóstico por imagem , Insuficiência Vertebrobasilar/diagnóstico por imagem , Insuficiência Vertebrobasilar/etiologia
5.
J UOEH ; 43(3): 355-361, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483195

RESUMO

A sufficient dose of radiation is difficult to administer in re-irradiation for local recurrence of cancer after radiotherapy because of the dose limitation to organs at risk. Re-irradiation cases also include radioresistant tumors that are difficult to control locally, and their prognosis is poor in general. The effect of re-irradiation using intensity-modulated radiotherapy (IMRT) has recently been reported to significantly reduce the dose to organs at risk, and the efficacy of hyperthermia has been reported for radioresistant tumors. We report a case of local recurrence after concurrent chemoradiotherapy treated with salvage re-irradiation using IMRT and chemotherapy combined with hyperthermia in a patient with nasopharyngeal carcinoma, and include a discussion of the literature.


Assuntos
Neoplasias Nasofaríngeas , Radioterapia de Intensidade Modulada , Reirradiação , Quimiorradioterapia , Humanos , Hipertermia , Carcinoma Nasofaríngeo/terapia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/radioterapia , Recidiva Local de Neoplasia/terapia , Estudos Retrospectivos
6.
J Magn Reson Imaging ; 51(3): 757-766, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31400058

RESUMO

BACKGROUND: In amyotrophic lateral sclerosis (ALS), motor neurons in the brainstem markedly deplete, whereas sensory neurons are less severely affected. PURPOSE: To determine whether facial nerve (FN) measurement on 3D fast imaging employing steady-state acquisition (FIESTA) is useful for ALS diagnosis. STUDY TYPE: Retrospective. SUBJECTS: Fifteen ALS patients and 16 controls. FIELD STRENGTH/SEQUENCE: 3T FIESTA MR. ASSESSMENT: The cross-sectional area of the FN and cochlear nerve (CN) were measured, and the FN/CN ratio (FCR) was assessed. For qualitative assessment, the FN cross-sectional area was compared with that of the CN and the following scores were assigned: score 1 (large), the FN is larger than the CN; score 2 (almost equal), the size difference between the FN and CN is within 10%; score 3 (small), the FN is smaller than the CN (10-50%); score 4 (significantly small), size of the FN is less than half the size of the CN. STATISTICAL TESTS: The differences in FCR between the ALS patients and the controls were tested using the Wilcoxon Mann-Whitney U-test. For the qualitative and quantitative assessments, we performed a receiver operating characteristic analysis for the diagnosis of ALS with an abnormal finding as score 3 or 4. RESULTS: The mean FCR was significantly smaller for ALS patients (0.71 ± 0.17) than for controls (0.95 ± 0.08) (P < 0.001) and the area under the curve was 0.93. When an FN score was 3 or 4, indicative of FN atrophy, the sensitivity and specificity values of FIESTA for discriminating ALS patients from controls were 93.3% (14/15) and 90.0% (18/20), respectively. DATA CONCLUSION: The FN atrophy revealed on FIESTA, which may reflect lower motor neuron impairment in ALS, allowed us to distinguish ALS patients from controls with a high degree of accuracy. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:757-766.


Assuntos
Esclerose Lateral Amiotrófica , Nervo Facial , Esclerose Lateral Amiotrófica/diagnóstico por imagem , Atrofia , Nervo Facial/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Estudos Retrospectivos
7.
Int J Mol Sci ; 21(9)2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32344826

RESUMO

OBJECTIVE: Hippocampal volume is reduced in patients with major depressive disorder (MDD) compared with healthy controls. The hippocampus is a limbic structure that has a critical role in MDD. The aim of the present study was to investigate the changes in the volume of the hippocampus and its subfields in MDD patients who responded to antidepressants and subsequently were in continuous remission. SUBJECTS AND METHODS: Eighteen patients who met the following criteria were enrolled in the present study: the DSM-IV-TR criteria for MDD, drug-naïve at least 8 weeks or more, scores on the 17-items of Hamilton Rating Scale for Depression (HAMD) of 14 points or more, and antidepressant treatment response within 8 weeks and continuous remission for at least 6 months. All participants underwent T1-weighted structural MRI and were treated with antidepressants for more than 8 weeks. We compared the volumes of the hippocampus, including its subfields, in responders at baseline to the volumes at 6 months. The volumes of the whole hippocampus and the hippocampal subfields were measured using FreeSurfer v6.0. RESULTS: The volumes of the left cornu Ammonis (CA) 3 (p = 0.016) and the granule cell layer of the dentate gyrus (GC-DG) region (p = 0.021) were significantly increased after 6 months of treatment compared with those at baseline. CONCLUSIONS: Increases in volume was observed in MDD patients who were in remission for at least 6 months.


Assuntos
Antidepressivos/uso terapêutico , Região CA3 Hipocampal/patologia , Giro Denteado/patologia , Transtorno Depressivo Maior/patologia , Adulto , Antidepressivos/farmacologia , Região CA3 Hipocampal/diagnóstico por imagem , Região CA3 Hipocampal/efeitos dos fármacos , Giro Denteado/diagnóstico por imagem , Giro Denteado/efeitos dos fármacos , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/tratamento farmacológico , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Tamanho do Órgão , Escalas de Graduação Psiquiátrica , Indução de Remissão
8.
J UOEH ; 42(3): 261-266, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879190

RESUMO

Radiation recall pneumonitis is a phenomenon in which a recall-triggering drug induces an acute inflammatory reaction in the lungs, corresponding to a previously irradiated area. Radiation recall reactions have been reported to occur following treatments with various cytotoxic anticancer agents and molecular-targeting drugs; however, only a few reports have described immune checkpoint inhibitor-induced radiation recall pneumonitis. We report a case of radiation recall pneumonitis induced by pembrolizumab in a patient with the postoperative local recurrence of non-small cell lung cancer. This case demonstrated that pembrolizumab might cause severe radiation recall pneumonitis, even after typical radiation pneumonitis has been resolved.


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Antineoplásicos/efeitos adversos , Doenças Assintomáticas , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Pneumonite por Radiação/etiologia , Radioterapia/efeitos adversos , Terapia Combinada , Humanos , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/radioterapia
9.
Eur Radiol ; 29(6): 3219-3223, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30178144

RESUMO

PURPOSE: To compare T2* values of the triangular fibrocartilage (TFC) obtained by ultrashort time-to-echo (UTE) techniques at the neutral position, ulnar flexion of the wrist, and pronation of the forearm. MATERIALS AND METHODS: MR imaging was performed in ten healthy volunteers with a 3-T MR system by using an eight-channel knee coil. Coronal wrist T2* maps from three-dimensional cone UTE pulse sequences were obtained at the neutral, ulnar flexion, and pronation positions (TR: 19 ms, TE: 0.032 ms/4 ms/8 ms/12 ms, FOV: 18 cm, matrix: 430 × 430, section thickness: 1.5 mm, scan time: 8 min 31 s). UTE-T2* maps were calculated on a pixel-by-pixel basis for all structures of the wrist visualized in the coronal planes. The entire region of interest (ROI) for TFC was manually delineated, and the average T2* value was calculated for each ROI by three radiologists. The Kruskal-Wallis test, Wilcoxon signed-rank test, or intraclass correlation coefficients (ICC) were used for statistics. RESULTS: The difference in the average T2* value among the three groups according to the forearm/wrist position was significant (p < 0.001). The T2* value of the TFC at pronation (mean ± 2 SD: 7.92 ± 1.37 ms) was significantly lower than those at the neutral (10.08 ± 1.90 ms) and ulnar flexion positions (9.15 ± 1.03 ms) (p < 0.017). The ICC showed a substantial interobserver agreement in the T2* value measurements of the TFC (ICC = 0.986). CONCLUSION: T2* relaxation time measurement of the TFC using UTE may be useful for assessing the loading effect by the forearm/wrist position. KEY POINTS: • The T2* value of the TFC may reflect the biomechanics of the wrist joint. • Acute loading at pronation results in a decrease in the T2* value of the TFC. • Quantitative wrist UTE MRI was successfully performed in vivo.


Assuntos
Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Fibrocartilagem Triangular/diagnóstico por imagem , Articulação do Punho/diagnóstico por imagem , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes
10.
Eur Radiol ; 29(9): 4538-4543, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30737566

RESUMO

OBJECTIVE: To investigate optimal beam quality for chest flat panel detector (FPD) system by semi-quantitatively assessment using a realistic lung phantom. MATERIALS AND METHODS: Chest FPD radiographs were obtained on a realistic lung phantom with simulated lung opacities using various X-ray tube voltage levels (90-140 kV) with/without copper filter. Entrance skin dose was set to maintain identical for all images (0.1 mGy). Three chest radiologists unaware of the exposure settings independently evaluated the image quality of each simulated opacity and normal structure using a 5-point scale (+ 2: clearly superior to the standard; + 1: slightly superior to the standard; 0: equal to the standard; - 1: slightly inferior to the standard; - 2: clearly inferior to the standard). The traditional FPD image obtained at a tube voltage of 120 kV was used as the standard. The scores of image quality were statistically compared using the Wilcoxon rank test with Bonferroni correction. RESULTS: FPD images using 90-kV shot with copper filter were superior to the traditional 120-kV shot without filter with respect to the visibility of vertebra, pulmonary vessels, and nodules overlapping diaphragm and heart (p < 0.05). There was no significant difference with respect to the visibility of all other simulated lung opacities (lung nodules except for overlying diaphragm/heart and honeycomb opacity) between each tube voltage level with/without copper filter and the traditional 120-kV shot without filter. CONCLUSION: Image quality of FPD images using 90 kV with copper filtration is superior to that using standard tube voltage when dose is identical. KEY POINTS: • FPD image quality using 90 kV with filter is superior to that using traditional beam. • Ninety-kilovolt shot with copper filter may be suitable for chest FPD image. • Clinical study dealing with chest FPD beam optimization would be warranted.


Assuntos
Radiografia Torácica/métodos , Doenças Torácicas/diagnóstico por imagem , Filtração/instrumentação , Humanos , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Imagens de Fantasmas , Doses de Radiação , Intensificação de Imagem Radiográfica/métodos , Radiografia Torácica/instrumentação , Estatísticas não Paramétricas , Ecrans Intensificadores para Raios X
11.
Eur Radiol ; 29(6): 3324, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30783788

RESUMO

The original version of this article, published on 03 September 2018, unfortunately contained a mistake.

12.
Neuroradiology ; 61(11): 1251-1259, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31267152

RESUMO

PURPOSE: The typical MRI findings in corticobasal degeneration (CBD), which have been described in previous reports, may be non-specific. We evaluated cerebral gyri (CG) using quantitative susceptibility mapping (QSM) images of patients with CBD, progressive supranuclear palsy (PSP), and Parkinson's disease (PD) to determine the possibility of discriminating them on an individual basis. METHODS: After reviewing the normal appearances on QSM on 16 healthy subjects, two radiologists assessed abnormal findings from 12 CBD, 14 PSP, and 30 PD patients. For conventional MRI, two radiologists independently reviewed typical CBD findings that have been previously reported. We also investigated three autopsy cases including one each of CBD, PSP, and PD to reveal the histopathological basis of MRI findings. RESULTS: CBD-specific findings included three layers; a higher susceptibility layer in superficial GM, a lower susceptibility layer, and a higher susceptibility layer in corticomedullary junction, with frequencies of 83% (10/12) in CBD, 21% (3/14) in PSP, and 0% (0/30) in PD patients. The typical CBD findings on conventional MRI were observed in only 42% (5/12) of CBD patients. Ferritin-positive microglia accumulated in the superficial gray matter (third cortical layer) and corticomedullary junction in CBD patients. CONCLUSIONS: The CG findings on QSM images may be more useful than those on conventional MRI for discriminating CBD from PD on an individual basis. Based on postmortem pathological data, cortical QSM hyperintensity might be an expression of ferritin-positive microglia.


Assuntos
Mapeamento Encefálico/métodos , Córtex Cerebral/patologia , Imageamento por Ressonância Magnética/métodos , Doença de Parkinson/patologia , Paralisia Supranuclear Progressiva/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Autopsia , Gânglios da Base/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
Eur Arch Psychiatry Clin Neurosci ; 269(7): 785-794, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30406404

RESUMO

Vascular endothelial growth factor (VEGF) is involved in the development of major depressive disorder (MDD). Recently, a genome-wide association study has revealed that four VEGF-related single nucleotide polymorphisms (SNPs) (i.e., rs4416670, rs6921438, rs6993770 and rs10738760) were independently associated with circulating VEGF levels. The current study investigated the relationship between brain volume and these four SNPs in first-episode drug-naïve MDD patients. A total of 38 first-episode drug-naïve MDD patients and 39 healthy subjects (HS) were recruited and underwent high-resolution T1-weighted imaging. Blood samples were collected from all the participants for serum VEGF assays and VEGF-related SNPs genotyping. Genotype-diagnosis interactions related to whole-brain cortical thickness and hippocampal subfield volumes were evaluated for the four SNPs. The results revealed a genotype-diagnosis interaction only for rs6921438 (i.e., the MDD patients and HS with the G/G genotype versus the MDD patients and HS with A-carrier genotype) in the subiculum of the left hippocampus (p < 0.05), and not the other SNPs. There was a volume reduction in the left subiculum of G/G genotype patients compared with the other groups. The "hypochondriasis" scores of the HAMD-17 scale were significantly higher in the G/G genotype patients than the A-carrier genotype patients. The association was observed between VEGF-related SNP rs6921438 and subiculum atrophy in first-episode drug-naïve MDD patients.


Assuntos
Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Transtorno Depressivo Maior/genética , Transtorno Depressivo Maior/patologia , Fator A de Crescimento do Endotélio Vascular/genética , Adulto , Córtex Cerebral/diagnóstico por imagem , Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/diagnóstico por imagem , Feminino , Hipocampo/diagnóstico por imagem , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
14.
J Magn Reson Imaging ; 48(5): 1237-1246, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29473985

RESUMO

BACKGROUND: Systemic lupus erythematosus (SLE) is related to vasculitis, which causes brain infarctions; however, the pathology of large cerebral vessels has not been fully established. PURPOSE: To demonstrate the prevalence of vessel wall lesions (VWLs) in SLE patients using 3D vessel wall imaging and to assess the relationship between VWLs and brain infarctions. STUDY TYPE: Retrospective. SUBJECTS: Sixty SLE patients and 50 healthy subjects (HS). FIELD STRENGTH/SEQUENCE: Each subject underwent 3T MRI, which included 3D FSE PDWI (CUBE). ASSESSMENT: For each of the 33 segments of the intracranial artery (internal carotid artery ∼ M3 segment of middle cerebral artery [MCA]), the VWLs were scored as either positive or negative, and the VWL score was calculated as the sum of the segments with VWLs. We also evaluated brain lesions on conventional MRI. STATISTICAL TESTS: We used logistic regression analyses to determine the clinical (serological test and cardiovascular risk factors) and imaging characteristics associated with infarctions in SLE patients. RESULTS: For the peripheral vessels such as MCA, VWLs were more common for SLE patients than for HS (43.3% versus 16.7% in M1 segment, 60.4% versus 16.7% in M2 segment, both P < 0.01). There were 21 infarctions in 13 patients (21.7%), and the median VWL score was larger in the patients with infarctions than in those without (13 versus 6, P < 0.01). Multivariate logistic regression analyses revealed a high VWL score ( ≥ 9) to be the only factor independently associated with the presence of infarctions (odds ratio: 10.1, 95% confidence interval: 1.01-101; P < 0.049). DATA CONCLUSION: We demonstrated a substantially high prevalence of VWLs among SLE patients, which were associated with brain infarctions. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1237-1246.


Assuntos
Encefalopatias/diagnóstico por imagem , Infarto Encefálico/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Lúpus Eritematoso Sistêmico/diagnóstico por imagem , Imageamento por Ressonância Magnética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Encefalopatias/complicações , Infarto Encefálico/complicações , Circulação Cerebrovascular , Feminino , Humanos , Lúpus Eritematoso Sistêmico/patologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Prevalência , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
15.
Eur Radiol ; 28(4): 1594-1599, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29063257

RESUMO

PURPOSE: To evaluate the usefulness of the CT temporal subtraction (TS) method for the detection of the lung cancer with predominant ground-glass opacity (LC-pGGO). MATERIALS AND METHODS: Twenty-five pairs of CT and their TS images in patients with LC-pGGO (31 lesions) and 25 pairs of those in patients without nodules were used for an observer performance study. Eight radiologists participated and the statistical significance of differences with and without the CT-TS was assessed by JAFROC analysis. RESULTS: The average figure-of-merit (FOM) values for all radiologists increased to a statistically significant degree, from 0.861 without CT-TS to 0.912 with CT-TS (p < .001). The average sensitivity for detecting the actionable lesions improved from 73.4 % to 85.9 % using CT-TS. The reading time with CT-TS was not significantly different from that without. CONCLUSION: The use of CT-TS improves the observer performance for the detection of LC-pGGO. KEY POINTS: • CT temporal subtraction can improve the detection accuracy of lung cancer. • Reading time with temporal subtraction is not different from that without. • CT temporal subtraction improves observer performance for ground-glass/subsolid nodule detection.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Técnica de Subtração , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Humanos , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Int J Hyperthermia ; 34(7): 1092-1103, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29108446

RESUMO

PURPOSE: To evaluate the feasibility and efficacy of deep regional hyperthermia with the use of mobile insulator sheets in a capacitively coupled heating device. MATERIALS AND METHODS: The heat was applied using an 8-MHz radiofrequency-capacitive device. The insulator sheet was inserted between the regular bolus and cooled overlay bolus in each of upper and lower side of the electrode. Several settings using the insulator sheets were investigated in an experimental study using an agar phantom to evaluate the temperature distributions. The specific absorption rate (SAR) distributions in several organs were also computed for the three-dimensional patient model. In a clinical prospective study, a total of five heating sessions were scheduled for the pelvic tumours, to assess the thermal parameters. The conventional setting was used during the first, third and fifth treatment sessions, and insulator sheets were used during the second and fourth treatment sessions. RESULTS: In the phantom study, the higher heating area improved towards the centre when the mobile insulator sheets were used. The subcutaneous fat/target ratios for the averaged SARs in the setting with the mobile insulator (median, 2.5) were significantly improved compared with those in the conventional setting (median, 3.4). In the clinical study, the thermal dose parameters of CEM43°CT90 in the sessions with the mobile insulator sheets (median, 1.9 min) were significantly better than those in the sessions using a conventional setting (median, 1.0 min). CONCLUSIONS: Our novel heating method using mobile insulator sheets was thus found to improve the thermal dose parameters. Further investigations are expected.


Assuntos
Hipertermia Induzida/métodos , Niacina/uso terapêutico , Imagens de Fantasmas/normas , Salicilatos/uso terapêutico , Humanos , Estudos Prospectivos
17.
J Magn Reson Imaging ; 46(4): 951-971, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28295954

RESUMO

Quantitative susceptibility mapping (QSM) has enabled magnetic resonance imaging (MRI) of tissue magnetic susceptibility to advance from simple qualitative detection of hypointense blooming artifacts to precise quantitative measurement of spatial biodistributions. QSM technology may be regarded to be sufficiently developed and validated to warrant wide dissemination for clinical applications of imaging isotropic susceptibility, which is dominated by metals in tissue, including iron and calcium. These biometals are highly regulated as vital participants in normal cellular biochemistry, and their dysregulations are manifested in a variety of pathologic processes. Therefore, QSM can be used to assess important tissue functions and disease. To facilitate QSM clinical translation, this review aims to organize pertinent information for implementing a robust automated QSM technique in routine MRI practice and to summarize available knowledge on diseases for which QSM can be used to improve patient care. In brief, QSM can be generated with postprocessing whenever gradient echo MRI is performed. QSM can be useful for diseases that involve neurodegeneration, inflammation, hemorrhage, abnormal oxygen consumption, substantial alterations in highly paramagnetic cellular iron, bone mineralization, or pathologic calcification; and for all disorders in which MRI diagnosis or surveillance requires contrast agent injection. Clinicians may consider integrating QSM into their routine imaging practices by including gradient echo sequences in all relevant MRI protocols. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2017;46:951-971.


Assuntos
Artefatos , Meios de Contraste , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Metais , Humanos
18.
Eur Radiol ; 27(8): 3554-3562, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28116516

RESUMO

OBJECTIVE: To assess the utility of the motion correction method with prospective motion correction (PROMO) in a voxel-based morphometry (VBM) analysis for 'uncooperative' patient populations. METHODS: High-resolution 3D T1-weighted imaging both with and without PROMO were performed in 33 uncooperative patients with Parkinson's disease (n = 11) or dementia (n = 22). We compared the grey matter (GM) volumes and cortical thickness between the scans with and without PROMO. RESULTS: For the mean total GM volume with the VBM analysis, the scan without PROMO showed a significantly smaller volume than that with PROMO (p < 0.05), which was caused by segmentation problems due to motion during acquisition. The whole-brain VBM analysis showed significant GM volume reductions in some regions in the scans without PROMO (familywise error corrected p < 0.05). In the cortical thickness analysis, the scans without PROMO also showed decreased cortical thickness compared to the scan with PROMO (p < 0.05). CONCLUSION: Our results with the uncooperative patients indicate that the use of PROMO can reduce misclassification during segmentation of the VBM analyses, although it may not prevent GM volume reduction. KEY POINTS: • Motion artifacts pose significant problems for VBM analyses. • PROMO correction can reduce the motion artifacts in high-resolution 3D T1WI. • The use of PROMO may improve the precision of VBM analyses.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Demência/diagnóstico por imagem , Aumento da Imagem/métodos , Doença de Parkinson/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Artefatos , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Cooperação do Paciente , Estudos Prospectivos
19.
Eur Radiol ; 27(10): 4316-4323, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28401339

RESUMO

OBJECTIVE: To correlate the R2* value obtained by iterative decomposition of water and fat with echo asymmetry and least-squares emission (IDEAL) with fibrotic focus (FF), microvessel density and hypoxic biomarker (HIF-1α) in breast carcinoma. METHODS: Forty-two patients who were diagnosed with invasive ductal carcinoma (IDC) of the breast underwent breast MRI including IDEAL before surgery. The entire region of interest (ROI) was delineated on the R2* map, and average tumour R2* value was calculated for each ROI. Histological specimens were evaluated for the presence of FF, the microvessel density (the average microvessel density and the ratio of peripheral to central microvessel density), and the grading of HIF-1α. RESULTS: FF was identified in 47.6% (20/42) of IDCs. Average R2* value for IDC with FF (42.4±13.2 Hz) was significantly higher than that without FF (28.5±13.9 Hz) (P = 0.01). Spearman rank correlation suggested that the average R2* value correlated with the grade of HIF-1α and the ratio of peripheral to central microvessel density for IDCs (P < 0.001). CONCLUSION: Quantification of tumour R2* using IDEAL is associated with the presence of FF and the overexpression of HIF-1α, and may therefore be useful in predicting hypoxia of breast carcinoma. KEY POINTS: • R2* value obtained by IDEAL correlates with the overexpression of HIF-1α. • R2* value obtained by IDEAL is associated with fibrotic focus. • R2* quantification may be useful in predicting hypoxia of breast carcinoma.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Carcinoma Ductal/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tecido Adiposo , Adulto , Idoso , Biomarcadores Tumorais/análise , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/patologia , Carcinoma Ductal/irrigação sanguínea , Carcinoma Ductal/patologia , Feminino , Fibrose , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Análise dos Mínimos Quadrados , Prognóstico , Estudos Retrospectivos , Água
20.
Depress Anxiety ; 34(5): 401-409, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28129464

RESUMO

BACKGROUND: We aimed to investigate the relationship between the hippocampal shape deformations and the serum cortisol levels in first-episode and drug-naïve major depression disorder (MDD) patients. METHODS: Thirty first-episode and drug-naïve MDD patients and 40 healthy subjects were recruited. High-resolution T1-weighted imaging and morning blood samples for cortisol measurement were obtained from all MDD patients and healthy subjects. In the hippocampal shape analysis, we compared the hippocampal shape between MDD patients and healthy subjects and evaluated the linear correlation between hippocampal shape deformations and the serum cortisol levels in MDD patients and healthy subjects. RESULTS: MDD patients showed significant inward deformations predominantly in the cornu ammonis (CA) 1 and subiculum in bilateral hippocampi compared to healthy subjects (false discovery rate (FDR) corrected, P < .05). Furthermore, in MDD patients, a significant linear correlation between inward deformations and high cortisol levels were found predominantly in the CA1 and subiculum, extending into the CA2-3 (FDR-corrected, P < .05), whereas no significant linear correlation was observed in healthy subjects. CONCLUSIONS: The serum cortisol levels are therefore considered to be associated with hippocampal shape abnormalities in MDD.


Assuntos
Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/patologia , Hipocampo/patologia , Hidrocortisona/sangue , Adulto , Idoso , Feminino , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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