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1.
Cytotherapy ; 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38678462

RESUMO

BACKGROUND: In drug-induced liver injury, vascular endothelial progenitor cells, specifically the CD34+ cell fractions, have been found to decrease liver fibrosis and promote regeneration. However, it is unclear whether CD34+ cell transplantation has anti-fibrogenic effects on MASH, which has previously been treated effectively with anti-angiogenic therapy. We investigated the efficacy of ex vivo-expanded CD34+ cells in treating MASH livers. MATERIALS AND METHODS: Diet-induced MASH mice were fed a choline-deficient, L-amino acid-defined, high-fat diet for 12 or 20 weeks, and were designated as a mild and a severe fibrosis model, respectively. Mouse bone marrow CD34+ cells were expanded for 7 days, transplanted into each mouse once or twice 2 weeks later, and sacrificed at 4 weeks after the first transplantation. RESULTS: Expanded CD34+ cell transplantation ameliorated liver fibrosis, regardless of fibrosis degree, as indicated by the decrease in α-smooth muscle actin-positive cells, hydroxyproline concentration, and fibrogenic gene expression of Col1a1 and Timp1. Furthermore, engrafted CD34+ cells reduced alanine transaminase levels, the number of TUNEL+ hepatocytes, and 8-OHdG concentration. RNA-sequencing data showed that "defense response to virus" was the most down-regulated category in the Gene Ontology analysis and subsequent analysis revealed the suppression of RIG-I-like receptors/Irf7/Stat1/Cxcl10 axis in expanded CD34+ cell-transplanted livers. Finally, the downregulation of CXCL10 expression inhibits the mobilization of inflammatory immune cells, macrophages, T cells, and natural killer cells to the MASH liver. CONCLUSIONS: These findings suggest that transplanted expanded CD34+ cells alleviate fibrotic liver injury in MASH mouse models through possible modulation of the innate immune response, which is abnormally activated by hepatocyte lipotoxicity.

3.
Eur J Radiol ; 149: 110202, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35196616

RESUMO

PURPOSE: We performed echo-planar imaging (EPI) and turbo spin-echo (TSE) diffusion-weighted imaging (DWI) using magnetic resonance imaging (MRI) to obtain basic clinical data of the apparent diffusion coefficient (ADC) in various parts of normal brains and compared the datasets using our retrospective distortion correction technique. MATERIALS AND METHODS: The normal brains of 32 patients who underwent health check were scanned on a 1.5-T MRI instrument using EPI- and TSE-DWI. Distortion was corrected by (1) segmentation: the b0 images were segmented based on the plural threshold values; (2) edge detection: the edge was detected in the images obtained in step (1); (3) non-rigid image registration: non-rigid image registration using Demons algorithm was achieved between the b0 images of EPI-DWI and TSE-DWI, thereby, creating a displacement field; and (4) image warp: the displacement field was applied to the b1000 image to warp. Twenty-six parts of the brain were measured from the images of b0 and b1000 and the ADCs were calculated. The signal-to-noise ratio (SNR) of the cerebrospinal fluid was measured to identify the cause of the difference between the two sequences. These were compared using Wilcoxon signed-rank test (P = 0.05). RESULTS: The ADC was significantly higher measured by EPI-DWI than by TSE-DWI. The SNR of EPI-DWI was significantly higher than that of the TSE-DWI. CONCLUSION: Care must be taken when measuring ADCs near the base of the skull, such as the brain stem, where the SNR of the imaging technique is likely to decrease or distort.


Assuntos
Imagem de Difusão por Ressonância Magnética , Imagem Ecoplanar , Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Humanos , Reprodutibilidade dos Testes , Estudos Retrospectivos
4.
Radiol Case Rep ; 16(11): 3300-3303, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34484535

RESUMO

Metaplastic meningioma is a rare World Health Organization Grade I meningioma subtype, accounting for 0.2%-1.6% of all meningiomas. Primary extradural meningiomas represent less than 2% of all meningiomas, with intraosseous meningioma as a subtype of primary extradural meningiomas. Herein, we report the case of a 65-year-old male presenting with headache. His computed tomography scans showed an osteolytic left parietal bone mass, and magnetic resonance imaging revealed hyperintense dots in the mass on T1-weighted images. The mass was then resected and diagnosed on histopathological examination as an intraosseous metaplastic meningioma.

5.
World Neurosurg ; 137: 345-349, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32059969

RESUMO

BACKGROUND: Late-onset aqueductal membranous occlusion (LAMO) is 1 of the few causes of noncommunicating hydrocephalus. Here, we report a case of LAMO and review the associated literature. CASE DESCRIPTION: A 36-year-old man had complained of headache and loss of consciousness. Conventional magnetic resonance imaging (MRI) showed dilatation of the lateral and third ventricles but not of the fourth ventricle. Phase-contrast cine MRI confirmed cessation of cerebrospinal fluid (CSF) flow in the aqueduct of Sylvius. Sagittal and coronal turbo spin echo T2-weighted imaging with 3-dimensional driven equilibrium pulse (3D-DRIVE) revealed a membranous occlusion at the aqueduct of Sylvius and LAMO was diagnosed. The patient underwent endoscopic third ventriculostomy. Occlusion of the aqueduct of Sylvius by a thin membrane was observed and endoscopic aqueductoplasty was also conducted. The patient's symptoms were ameliorated shortly after the operation. Postoperative phase-contrast cine and 3D-DRIVE MRI showed restored CSF flow in the aqueduct of Sylvius and at the bottom of the third ventricle. CONCLUSIONS: We treated a case of LAMO, which usually presents with headache as an initial symptom. 3D-DRIVE MRI is useful for detecting membranous occlusions and for evaluating pre- and postoperative CSF flow. LAMO can be cured by endoscopic third ventriculostomy and/or endoscopic aqueductoplasty.


Assuntos
Aqueduto do Mesencéfalo/diagnóstico por imagem , Hidrocefalia/diagnóstico por imagem , Adulto , Aqueduto do Mesencéfalo/cirurgia , Humanos , Hidrocefalia/cirurgia , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Imagem Cinética por Ressonância Magnética , Masculino , Neuroendoscopia , Ventriculostomia
6.
J Knee Surg ; 31(1): 92-98, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28460410

RESUMO

The use of portable, accelerometer-based navigation (PN) devices for positioning of the components of total knee arthroplasty (TKA) is emerging as an alternative to standard extramedullary (EM) systems, which was needed to the image intensifier. The aim of our study was to compare the accuracy of component positioning in TKA using an EM and PN systems. Data from 100 consecutive primary TKAs, performed by multiple surgeons in 87 patients between October 2010 and June 2015, were analyzed. Coronal and sagittal plane alignments of the TKA components, relative to the mechanical axis of the limb, were evaluated by radiography. The mean postoperative coronal alignment angle of the femoral (α) and tibial (ß) components was comparable between the groups (α: PN, 89.9 ± 2.2 degrees; EM, 89.9 ± 1.6 degrees and ß: PN, 90.1 ± 1.4 degrees; EM, 89.6 ± 1.3 degrees). Groups were also comparable with regard to mean postoperative sagittal alignment angle of the femoral and tibial components (γ: PN, 2.3 ± 3.3 degrees; EM, 1.8 ± 1.7 degrees and σ: PN, 89.7 ± 2.5 degrees; EM, 90.1 ± 1.3 degrees). The incidence rate of a component malalignment > 3 degrees in the coronal and sagittal planes of the mechanical axis of the knee was comparable between the groups. In conclusion, the coronal and sagittal alignments for the femoral components was less accurate compared with tibial component alignment, especially in the PN group, and the sagittal alignment of the femoral component was less accurate than coronal alignment for both groups. Both the PN and EM systems provide satisfactory coronal and sagittal component alignments in TKA. Further technical improvement of the PN system could further improve its application for accurate component implantation in TKAs.


Assuntos
Artroplastia do Joelho/instrumentação , Articulação do Joelho/cirurgia , Cirurgia Assistida por Computador/instrumentação , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/métodos , Feminino , Humanos , Articulação do Joelho/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade
7.
Phys Chem Chem Phys ; 19(36): 24769-24791, 2017 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-28868562

RESUMO

The fictitious spin-1/2 Hamiltonian approach is the putative method to analyze the fine-structure/hyperfine ESR spectra of high spin metallocomplexes having sizable zerofield splitting (ZFS), thus giving salient principal g-values far from around g = 2 without explicitly providing their ZFS parameters in most cases. Indeed, the significant departure of the g-values from g = 2 is indicative of the occurrence of their high spin states, but naturally they never agree with true g-values acquired by quantum chemical calculations such as sophisticated DFT or ab initio MO calculations. In this work, we propose facile approaches to determine the magnetic tensors of high spin metallocomplexes having sizable ZFS, instead of performing advanced high-field/high-frequency ESR spectroscopy. We have revisited analytical expressions for the relationship between effective g-values and true principal g-values for high spins. The useful analytical formulas for the geff-gtrue relationships are given for S's up to 7/2. The genuine Zeeman perturbation formalism gives the exact solutions for S = 3/2, and for higher S's it is much more accurate than the pseudo-Zeeman perturbation approach documented so far (A. Abragam and B. Bleaney, Electron Paramagnetic Resonance of Transition Metal Ions, 1970; J. R. Pilbrow, J. Magn. Reson., 1978, 31, 479; F. Trandafir et al., Appl. Magn. Reson., 2007, 31, 553; M. Fittipaldi et al., J. Phys. Chem. B, 2008, 112, 3859), in which the E(Sx2 - Sy2) term is putatively treated to the second order. To show the usefulness of the present approach, we exploit FeIII(Cl)OEP (S = 5/2) (OEP: 2,3,7,8,12,13,17,18-octaethylporphyrin) and CoIIOEP (S = 3/2) well magnetically diluted in the diamagnetic host crystal lattice of NiIIOEP. The advantage of single-crystal ESR spectroscopy lies in the fact that the molecular information on the principal axes of the magnetic tensors is crucial in comparing with reliable theoretical results. In high spin states of metallocomplexes with sizable ZFS in pseudo-octahedral symmetry, their fine-structure ESR transitions for the principal z-axis orientation appear in the lower field far from g = 2 at the X-band, disagreeing with the putative intuitive picture obtained using relevant ESR spectroscopy. A ReIII,IV dinuclear complex in a mixed valence state exemplifies the cases, whose fine-structure/hyperfine ESR spectra of the neat crystals have been analyzed in their principal-axis system. The DFT-based/ab initio MO calculations of the magnetic tensors for all the high spin entities in this work were carried out.

8.
Intern Med ; 55(23): 3529-3533, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27904123

RESUMO

Posterior reversible encephalopathy syndrome (PRES) typically affects the posterior subcortical white matter. We report the case of a 55-year-old man with atypical PRES, who had malignant hypertension and renal dysfunction. Magnetic resonance imaging of the brain revealed extensive vasogenic edema in the deep white matter including the temporal pole, as well as in the brainstem and cerebellum. Antihypertensive therapy and hemodialysis contributed to both clinical and radiological improvement. Involvement of the deep white matter including the temporal pole, which is rarely affected in an ischemic stroke, should be recognized as a potential sign of PRES.


Assuntos
Síndrome da Leucoencefalopatia Posterior/diagnóstico , Lobo Temporal/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade
9.
Arch Orthop Trauma Surg ; 135(12): 1743-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26388035

RESUMO

INTRODUCTION: We aimed to assess the accuracy of a new extramedullary guide system for achieving appropriate femoral component alignment in total knee arthroplasty (TKA) and to determine whether it differed between patients operated on by different surgeons. MATERIALS AND METHODS: We performed 100 consecutive primary TKAs in 100 patients using a newly developed extramedullary guide, the "S guide"; 50 were performed by author KM at A Hospital, and 50 by author NM at B Hospital. All patients received the Vanguard RP mobile-bearing prosthesis (Biomet Japan, Tokyo, Japan). We assessed the coronal and sagittal alignment of the femoral component with the mechanical axis using plane radiographs. Data were analyzed statistically using Prism 5.0 software, and a p value of <0.05 was regarded as indicating significance. RESULTS: The mean postoperative coronal alignment angle of the femoral component (α) was 0.1° ± 1.4°, with no significant differences between A Hospital and B Hospital (p = 0.67), and 98 % of patients had an α deviating by less than 3° from the mechanical axis. The mean postoperative sagittal alignment angle of the femoral component (γ) was 1.7° ± 1.7°, with no significant differences between the groups (p = 0.61), and 86 % of patients had a γ deviating by less than 3° from the mechanical axis. CONCLUSIONS: This study shows that the S-guide is reliable for use in TKA.


Assuntos
Artroplastia do Joelho/instrumentação , Fêmur/cirurgia , Osteoartrite do Joelho/cirurgia , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Fêmur/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/diagnóstico por imagem , Radiografia , Reprodutibilidade dos Testes
11.
J Orthop Sci ; 19(5): 750-5, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24996622

RESUMO

BACKGROUND: The patterns and magnitudes of axial femorotibial rotation are variable due to the prosthesis design, ligamentous balancing, and surgical procedures. We aimed to investigate the effects of the weight bearing (WB) condition on the kinematics of mobile-bearing total knee arthroplasty (TKA). METHODS: We examined 12 patients (19 knees) implanted with a low contact stress (LCS) mobile-bearing TKA system using a two-dimensional to three-dimensional registration technique. The in vivo kinematics of dynamic deep knee flexion under WB and non-WB (NWB) conditions were compared. We evaluated the knee range of motion, femoral axial rotation relative to the tibial component, anteroposterior translation, and kinematic pathway of the femorotibial contact point for both the medial and lateral sides. RESULTS: Under the WB condition, the mean range of motion was 117.8° ± 16.7°. Under the NWB condition, the mean range of motion was 111.0° ± 4.4°. The mean range of axial rotation from full extension to maximum flexion was 3.0° ± 1.5° under the WB condition and 2.2° ± 1.0° under the NWB condition. With regard to the anteroposterior translation, the LCS mobile-bearing TKA system showed the same kinematic patterns under both conditions, except for axial rotation at 0°, 10°, and 110°. From hyperextension to maximum flexion, the kinematic pattern reflected a central pivot under both conditions. CONCLUSIONS: In conclusion, this study demonstrated that, in an LCS mobile-bearing TKA system, knee kinematics showed the same patterns under NWB and WB conditions, except for axial rotation at the early phase. Further understanding of knee kinematics could provide us with useful information for future design concepts of TKA implants.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Osteoartrite do Joelho/fisiopatologia , Osteoartrite do Joelho/cirurgia , Amplitude de Movimento Articular/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Rotação , Resultado do Tratamento , Suporte de Carga/fisiologia
12.
BMJ Open ; 3(8): e003443, 2013 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-23996823

RESUMO

OBJECTIVE: To systematically evaluate the usefulness of assessing the cervical nerve roots by MRI for the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). DESIGN: Single-institution, retrospective case-control study. SETTING: A regional referral hospital. PARTICIPANTS: We retrospectively enrolled 15 consecutive patients with CIDP who satisfied the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) typical and definite criteria and underwent cervical MRI. 30 control patients who had also undergone cervical MRI were included, matched with regard to sex, age and MRI system. The diagnoses of the control patients included cervical spondylosis (n=19), cervical spine trauma (n=2), infection (n=1), malignancies (n=4), demyelinating disorders (n=2) and neurodegenerative disorders (n=2). MEASUREMENT: A radiologist determined the C5-C8 root diameters on the coronal short tau inversion recovery (STIR) images. Signal intensities of these roots were quantified as nerve-to-muscle contrast-to-noise ratios (CNRs), which were calculated using mean signal intensities of the roots and sternocleidomastoid muscle as well as SD of background noise. Statistical analyses were performed to determine the diagnostic accuracy of the diameters and nerve-to-muscle CNRs. Another radiologist reviewed MRI for ensuring reproducibility. RESULTS: The root diameters showed no significant differences between the patients with CIDP and control patients. The nerve-to-muscle CNRs were significantly higher in the patients with CIDP. We defined the sum of nerve-to-muscle CNRs of C5-C8 roots as the CNR score to serve as an index of overall signal intensity. The area under the receiver operating characteristic curve of CNR scores was 0.731. The reproducibility of the assessment procedure was satisfactory. CONCLUSIONS: Our results suggest that assessment of the cervical nerve roots by MRI is useful for CIDP diagnosis when the signal intensities, rather than the diameters, are paid more attention on STIR images.

13.
Eur Radiol ; 23(1): 3-11, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22811046

RESUMO

OBJECTIVES: To investigate the diagnostic capability of anterior temporal lobe white matter abnormal signal (ATLAS) for determining seizure focus laterality in temporal lobe epilepsy (TLE) by comparing different MR sequences. METHODS: This prospective study was approved by the institutional review board and written informed consent was obtained. Three 3D sequences (double inversion recovery (DIR), fluid-attenuated inversion recovery (FLAIR) and T2-weighted imaging (T2WI)) and two 2D sequences (FLAIR and T2WI) were acquired at 3 T. Signal changes in the anterior temporal white matter of 21 normal volunteers were evaluated. ATLAS laterality was evaluated in 21 TLE patients. Agreement of independent evaluations by two neuroradiologists was assessed using κ statistics. Differences in concordance between ATLAS laterality and clinically defined seizure focus laterality were analysed using McNemar's test with multiple comparisons. RESULTS: Pre-amygdala high signals (PAHS) were detected in all volunteers only on 3D-DIR. Inter-evaluator agreement was moderate to almost perfect for each sequence. Correct diagnosis of seizure laterality was significantly more frequent on 3D-DIR than on any other sequences (P ≤ 0.031 for each evaluator). CONCLUSIONS: The most sensitive sequence for detecting ATLAS laterality was 3D-DIR. ATLAS laterality on 3D-DIR can be a good indicator for determining seizure focus localization in TLE.


Assuntos
Epilepsia do Lobo Temporal/patologia , Imageamento por Ressonância Magnética/métodos , Fibras Nervosas Mielinizadas/patologia , Adolescente , Adulto , Idoso , Tonsila do Cerebelo/patologia , Criança , Pré-Escolar , Eletroencefalografia , Feminino , Humanos , Imageamento Tridimensional , Lactente , Magnetoencefalografia , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Estudos Prospectivos , Convulsões/patologia , Sensibilidade e Especificidade , Lobo Temporal/patologia
14.
Angew Chem Int Ed Engl ; 51(39): 9860-4, 2012 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-22936609

RESUMO

A quantum gate: A system of two coupled electron spins that is useful for simple quantum computing operations has been prepared by synthesis of a biradical 1 and co-crystallization with an isomorphous host molecule. The two weakly exchange-coupled quantum bits (target qubit blue and control qubit red) span four electron spin states. The electron spin transition is denoted by two black arrows.

15.
J Neuroinflammation ; 8: 143, 2011 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-22011386

RESUMO

BACKGROUND: Vasogenic edema dynamically accumulates in many brain disorders associated with brain inflammation, with the critical step of edema exacerbation feared in patient care. Water entrance through blood-brain barrier (BBB) opening is thought to have a role in edema formation. Nevertheless, the mechanisms of edema resolution remain poorly understood. Because the water channel aquaporin 4 (AQP4) provides an important route for vasogenic edema resolution, we studied the time course of AQP4 expression to better understand its potential effect in countering the exacerbation of vasogenic edema. METHODS: Focal inflammation was induced in the rat brain by a lysolecithin injection and was evaluated at 1, 3, 7, 14 and 20 days using a combination of in vivo MRI with apparent diffusion coefficient (ADC) measurements used as a marker of water content, and molecular and histological approaches for the quantification of AQP4 expression. Markers of active inflammation (macrophages, BBB permeability, and interleukin-1ß) and markers of scarring (gliosis) were also quantified. RESULTS: This animal model of brain inflammation demonstrated two phases of edema development: an initial edema build-up phase during active inflammation that peaked after 3 days (ADC increase) was followed by an edema resolution phase that lasted from 7 to 20 days post injection (ADC decrease) and was accompanied by glial scar formation. A moderate upregulation in AQP4 was observed during the build-up phase, but a much stronger transcriptional and translational level of AQP4 expression was observed during the secondary edema resolution phase. CONCLUSIONS: We conclude that a time lag in AQP4 expression occurs such that the more significant upregulation was achieved only after a delay period. This change in AQP4 expression appears to act as an important determinant in the exacerbation of edema, considering that AQP4 expression is insufficient to counter the water influx during the build-up phase, while the second more pronounced but delayed upregulation is involved in the resolution phase. A better pathophysiological understanding of edema exacerbation, which is observed in many clinical situations, is crucial in pursuing new therapeutic strategies.


Assuntos
Aquaporina 4/metabolismo , Edema Encefálico/patologia , Edema Encefálico/fisiopatologia , Encefalite/patologia , Encefalite/fisiopatologia , Animais , Aquaporina 4/genética , Barreira Hematoencefálica/patologia , Barreira Hematoencefálica/fisiopatologia , Modelos Animais de Doenças , Encefalite/induzido quimicamente , Humanos , Imageamento por Ressonância Magnética , Masculino , Permeabilidade , Ratos , Ratos Wistar
16.
Radiology ; 258(1): 222-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21045180

RESUMO

PURPOSE: To assess the frequency of hyperintensity in the dentate nucleus on T1-weighted magnetic resonance (MR) images and to establish correlations between such hyperintensity and clinical factors, including a history of brain irradiation. MATERIALS AND METHODS: This study was approved by the institutional review board, and each patient provided written informed consent. Three hundred sixty-two patients (164 men, 198 women; mean age, 62 years) were evaluated. Unenhanced T1-weighted MR images were obtained by using a spin-echo sequence at 3.0 T. Two neuroradiologists, who were blinded to clinical data, independently evaluated the signal intensity of the dentate nucleus compared with the signal intensity of the central white matter of the cerebellum by using a four-point graded response scale (grade 4 indicated prominent hyperintensity; grade 3, faint hyperintensity; grade 2, isointensity; and grade 1, hypointensity). Backward stepwise regression analysis was used to evaluate the relationship between signal intensity grades and the following clinical factors: sex, age, the interaction between age and sex, hypertension, dyslipidemia, diabetes mellitus, liver dysfunction, brain infarction, brain tumor, spinocerebellar degeneration, multiple sclerosis, a history of chemotherapy, and a history of brain irradiation. RESULTS: T1-hyperintense dentate nuclei were present in 41 (11%) of the 362 patients. Of these 41 patients, 31 (76%) had a history of brain irradiation. Signal intensity grade of the dentate nucleus on T1-weighted MR images correlated significantly with a history of brain irradiation (P < .001) but no other clinical factor. CONCLUSION: A hyperintense dentate nucleus may be seen on unenhanced T1-weighted MR images in some patients and may be associated with a history of brain irradiation.


Assuntos
Neoplasias do Sistema Nervoso Central/radioterapia , Núcleos Cerebelares/efeitos da radiação , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Estudos Retrospectivos
17.
Arch Orthop Trauma Surg ; 130(10): 1221-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19876636

RESUMO

BACKGROUND: Infection of a hip prosthesis is one of the most severe complications encountered in orthopedic practice. Two-stage reconstruction using an antibiotic-impregnated cement spacer has become a popular procedure for the treatment of this condition. However, there are some disadvantages with the use of antibiotic-loaded cement, including low biocompatibility, a very low release ratio, and the possibility of thermal damage to the antibiotic. We have developed an effective drug delivery system for osteomyelitis in which porous hydroxyapatite (HA) blocks are loaded with an antibiotic by the vacuum method. We report here a modification of this delivery system applied for the first stage of two-stage reconstruction surgery against infected hip prosthesis. PATIENTS AND METHODS: Eight consecutive patients who developed hip prosthesis infection underwent two-stage revision total hip arthroplasty (THA) using antibiotic-loaded porous HA blocks prepared by the vacuum method. Thorough debridement and insertion of antibiotic-loaded HA blocks was performed in the first stage, followed by conversion to THA after eradication of infection in the second stage. RESULTS: The mean interval between the stages was 16.8 weeks. There were no complications related to the use of the antibiotic-loaded HA blocks. The patients were followed up for an average of 49 months with no evidence of recurrent infection. The mean Japanese Orthopedic Association hip score improved from 45.1 before surgery to 79.6 at the latest follow-up. INTERPRETATION: This simple approach utilizing antibiotic-impregnated HA blocks prepared by the vacuum method is considered to be effective for treatment of hip prosthesis infection.


Assuntos
Antibacterianos/administração & dosagem , Artroplastia de Quadril/efeitos adversos , Bombas de Infusão Implantáveis , Infecções Relacionadas à Prótese/cirurgia , Idoso , Materiais Biocompatíveis , Desbridamento , Durapatita , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Relacionadas à Prótese/etiologia , Reoperação
18.
J Arthroplasty ; 25(3): 375-80, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19195831

RESUMO

A collarless, proximally porous-coated type of Spongiosa Metal II hip prosthesis was used for cementless total hip arthroplasty in 52 hips, and 48 hips were followed and assessed during a mean follow-up period of 6.3 years (minimum 5 years). There were 8 hips (16.7%) that had stress shielding, and 2 hips (4.2%) that had thigh pain. In terms of stability, the stem was bony stable in 39 hips, fibrous stable in 6, and unstable in 3. The stability of the stem was significantly correlated with the stem canal filling ratio. It was suggested that the much more proximal transfer of loading stress by a collarless, proximally porous-coated stem is not suitable for the Spongiosa Metal II series because it may unacceptably reduce the stability of the stem.


Assuntos
Artrite Reumatoide/cirurgia , Artroplastia de Quadril/instrumentação , Doenças do Desenvolvimento Ósseo/cirurgia , Prótese de Quadril , Osteonecrose/cirurgia , Óxido de Alumínio , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Fenômenos Biomecânicos , Feminino , Seguimentos , Articulação do Quadril/cirurgia , Prótese de Quadril/efeitos adversos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Estudos Retrospectivos , Resultado do Tratamento
19.
J Neuroimaging ; 20(3): 255-9, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19220709

RESUMO

OBJECTIVES: To reveal the characteristics of susceptibility-weighted imaging (SWI) under low cerebral blood flow (CBF) induced by hyperventilation (HV). MATERIALS AND METHODS: This study was approved by the institutional review board. Informed consent was obtained. Six healthy volunteers (5 men, 1 woman; mean age, 29 years; range, 24-33 years) underwent SWI and arterial spin labeling perfusion imaging under normal ventilation (NV) and HV at 3.0 T. Regions of interest (ROIs) were placed on gray matter (GM) and white matter (WM) of the frontal lobe (FL) and occipital lobe (OL). Intensities of ROIs were compared between NV and HV. Contrast of veins compared with adjacent cerebral parenchyma (CV) was also compared between NV and HV. RESULTS: CBF during HV (CBF(HV)) was decreased compared with CBF during NV (CBF(NV)) (29.1 +/- 4.6%). FL-GM(HV) and OL-GM(HV) showed significant signal decreases compared with FL-GM(NV) and OL-GM(NV), respectively (P= .018, .017). CV(HV) was significantly increased compared with CV(NV) (164.1 +/- 29.9%) (P= .00019). CONCLUSIONS: SWI sensitively reflects HV-induced decreases in CBF. The present results might assist in the interpretation of SWI in clinical practice, since CBF decreases might also influence signal changes on SWI.


Assuntos
Encéfalo/fisiopatologia , Circulação Cerebrovascular , Hiperventilação/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Adulto , Encéfalo/irrigação sanguínea , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Marcadores de Spin
20.
Acad Radiol ; 16(7): 852-7, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19375955

RESUMO

RATIONALE AND OBJECTIVES: Although spin-echo (SE) sequence has some advantages over gradient-echo sequence in brain imaging, gradient-echo sequence is commonly used for T1-weighted imaging (T1WI) at 3 T because contrast on SE T1WI is widely believed to be poor at 3 T. Recently, gray-white matter contrast on single-slice and multi-slice SE imaging with interslice gap was reported as better at 3 T than at 1.5 T. This study examined the feasibility of interleaved SE T1WI of the brain at 3 T. This study also examined whether presaturation pulse (PP) sufficiently suppresses intra-arterial signals because these signals tend to be hyperintense due to longer T1 at 3 T. MATERIALS AND METHODS: Subjects consisted of 18 healthy volunteers. Two sets of T1WI were performed using SE sequence. One set consisted of imaging without PP, and the other consisted of imaging with PP. Each set contained three types of gapless imaging as follows; sequential, 100% interleaved, and 200% interleaved imaging. In each subject, contrast-to-noise ratio between gray-matter and white-matter (CNR(GM-WM)) and intra-arterial signals were evaluated. RESULTS: CNR(GM-WM) was significantly higher on interleaved images than on sequential images, regardless of PP (P < .0001). PP sufficiently suppressed intra-arterial signals (P < .0001). CONCLUSION: CNR(GM-WM) on SE T1WI at 3 T can be improved by interleaved acquisition, and PP sufficiently suppressed intra-arterial signals. Interleaved SE T1WI with PP appears clinically feasible at 3 T.


Assuntos
Algoritmos , Encéfalo/anatomia & histologia , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Projetos Piloto , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Marcadores de Spin
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