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BACKGROUND: Breath-hold volumetric interpolated breath-hold examination (BH-VIBE) of multiphase contrast-enhanced liver magnetic resonance imaging (MPCE-LMRI) requires good cooperative individuals to comply with multiple breath-holds. PURPOSE: To develop a free-breathing modified VIBE (FB-mVIBE) as a substitute of BH-VIBE in MPCE-LMRI. MATERIAL AND METHODS: We modified VIBE with a high acceleration factor (2 × 2) and four averages to produce the mVIBE scan. A total of 90 individuals (40 men; mean age = 54.6 ± 10.0 years) who had received MPCE-LMRI as part of a voluntary health check-up for oncology survey were enrolled. Each participant was scanned in four phases (pre-contrast, arterial phase, venous phase, and delay phase), and each phase had two sequential scans. To encounter the timing effect of contrast enhancement, three scan orders were designed: BH-VIBE and FB-mVIBE (group A, n = 30); BH-VIBE and FB-VIBE (group B, n = 30); and FB-mVIBE and BH-VIBE (group C, n = 30). The comparisons included the objective measurements and 25 visual-score by two abdominal radiologists independently. RESULTS: Consistency between raters was observed for all three sequences (intraclass correlation coefficient [ICC] = 0.741-0.829). For rater 1, the mean scores of FB-mVIBE (23.67 ± 1.32) were equal to those of BH-VIBE (23.83 ± 1.98) in groups C and B (P = 0.852). The mean scores of FB-mVIBE (22.07 ± 3.02), but significantly higher than those of FB-VIBE (14.7 ± 3.41) in groups A and B (P <0.001). Similar scores were found for rater 2. The objective measurement of FB-mVIBE were equal to or higher than BH-VIBE and markedly superior to FB-VIBE. CONCLUSION: FB-mVIBE is a practical alternative to BH-VIBE for individuals who cannot cooperate with multiple breath-holds for MPCE-LMRI.
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Suspensão da Respiração , Meios de Contraste , Fígado , Imageamento por Ressonância Magnética , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Imageamento por Ressonância Magnética/métodos , Fígado/diagnóstico por imagem , Aumento da Imagem/métodos , Idoso , Reprodutibilidade dos Testes , Adulto , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Hepatopatias/diagnóstico por imagemRESUMO
BACKGROUND: Focal fibrocartilaginous dysplasia is a rare benign bone lesion of young children that causes deformities in the extremities. However, the pathogenesis and treatments have not been defined and the MR manifestations have been less well described. OBJECTIVE: To describe the MR manifestations of focal fibrocartilaginous dysplasia, especially on the T1-W three-dimensional (3-D) volumetric interpolated breath-hold examination (VIBE) sequence. MATERIALS AND METHODS: In this retrospective study, the authors reviewed the MR and radiographic images, pathology and medical records of 21 cases of focal fibrocartilaginous dysplasia. All cases were evaluated by spin-echo MRI sequence. Among them, 17 cases were evaluated by T1-W 3-D VIBE sequence. RESULTS: The cohort consisted of 13 boys and 8 girls ages 4-75 months. In 14 cases, focal fibrocartilaginous dysplasia was located in the tibia, 3 in the femur and 4 in the ulna. MRI 3-D VIBE sequence findings showed all cases had hypointense fiber band structures in the bone defect areas. The fibrous bands in the lower extremities ended in the epiphysis or epiphyseal plate, and in the upper extremities the epiphysis or carpal bone. Ten cases had hyperintensities that might represent cartilage composition. Four cases had cartilage signals that were continuous with the epiphyseal cartilage. MR spin-echo sequence findings showed that bone marrow edema of the adjacent joint was observed in eight cases, enlargement of the epiphyseal plate in three cases and medial meniscus injury in five cases. CONCLUSION: The 3-D VIBE sequence reveals useful details in focal fibrocartilaginous dysplasia.
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Imageamento por Ressonância Magnética , Ulna , Criança , Pré-Escolar , Feminino , Humanos , Imageamento Tridimensional , Lactente , Masculino , Estudos RetrospectivosRESUMO
BACKGROUND: Vascular calcification is an independent predictor of cardiovascular disease in patients with chronic kidney disease. Computed tomography (CT) is the gold-standard for detecting vascular calcification. Radial volumetric-interpolated breath-hold examination (radial-VIBE), a free-breathing gradient-echo cardiovascular magnetic resonance (CMR) sequence, has advantages over CT as it is ionising radiation-free. However, its capability in detecting thoracic aortic calcification (TAC) has not been investigated. This study aims to compare radial-VIBE to CT for the detection of TAC in the descending aorta of patients with end-stage renal disease (ESRD) using semi-automated methods, and to investigate the association between TAC and coronary artery calcification (CAC). METHODS: Paired cardiac CT and radial-VIBE CMR scans from ESRD patients participating in 2 prospective studies were obtained. Calcification volume was quantified using semi-automated methods in a 9 cm segment of the thoracic aorta. Correlation and agreement between TAC volume measured on CMR and CT were assessed with Spearman's correlation coefficient (ρ), linear regression, Bland-Altman plots and intraclass correlation coefficient (ICC). Association between CAC Agatston score and TAC volume determined by CT and CMR was measured with Spearman's correlation coefficient. RESULTS: Scans from 96 participants were analysed. Positive correlation was found between CMR and CT calcification volume [ρ = 0.61, 95% confidence interval (CI) 0.45-0.73]. ICC for consistency was 0.537 (95% CI 0.378-0.665). Bland-Altman plot revealed that compared to CT, CMR volumes were systematically higher at low calcification volume, and lower at high calcification volume. CT did not detect calcification in 41.7% of participants, while radial-VIBE CMR detected signal which the semi-quantitative algorithm reported as calcification in all of those individuals. Instances of suboptimal radial-VIBE CMR image quality were deemed to be the major contributors to the discrepancy. Correlations between CAC Agatston score and TAC volume measured by CT and CMR were ρ = 0.404 (95% CI 0.214-0.565) and ρ = 0.211 (95% CI 0.008-0.396), respectively. CONCLUSION: Radial-VIBE CMR can detect TAC with strong positive association to CT, albeit with the presence of proportional bias. Quantification of vascular calcification by radial-VIBE remains a promising area for future research, but improvements in image quality are necessary.
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Doença da Artéria Coronariana , Falência Renal Crônica , Aorta Torácica/diagnóstico por imagem , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/diagnóstico por imagem , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Valor Preditivo dos Testes , Estudos ProspectivosRESUMO
BACKGROUND: Bell's palsy (BP) is the most common form of acute facial nerve disorder and is characterized by rapid onset peripheral facial palsy of unknown etiology. PURPOSE: To explore the diagnostic value of dynamic contrast-enhanced (DCE) magnetic resonance imagine (MRI) in patients with BP particularly in involved segments. MATERIAL AND METHODS: A retrospective analysis was performed on the patients with BP who underwent routine MRI examinations and volumetric interpolated breath-hold examination (VIBE) sequence-based DCE-MRI before surgery in our department from January 2015 to July 2020. DCE-MRI data postprocessing was performed on Siemens Workstation Extended MR Work Space 2.6.3.5. Statistical analyses were performed using SPSS®v.19.0. The inter-observer reliability was evaluated with kappa identity test and McNemar's test. RESULTS: Twenty-three patients were included. On conventional contrast-enhanced MRI, the two observers were inconsistent in their diagnosis of lesion segments of facial nerve (Kappa 0.426, P = 0.009). Compared to the results of the surgery, the diagnostic consistency of both observers was general (Kappa 0.476, P < 0.001 and Kappa 0.430, P < 0.001, respectively). The diagnostic results of DCE-MRI for lesion segments of the facial nerve were consistent between the two observers (Kappa 0.929, P < 0.001). Compared to the results of the surgery, the diagnostic consistency of both observers was good (Kappa 0.753, P < 0.001 and Kappa 0.731, P < 0.001, respectively). CONCLUSION: Compared to conventional MRI, DCE-MRI has good stability and repeatability in the diagnosis of the lesion segments of the facial nerve as well as a good specificity and accuracy.
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Paralisia de Bell/diagnóstico por imagem , Meios de Contraste , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto JovemRESUMO
PURPOSE: We examined whether the shortened breath-hold 3-dimensional volumetric interpolated breath-hold examination (3D-VIBE) sequence for high acceleration factor (AF) using the controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) could substitute for the conventional sequence using generalized autocalibrating partially parallel acquisition (GRAPPA) in patients undergoing routine gadoxetic acid-enhanced liver MRI. MATERIALS AND METHODS: Thirty patients with clinically suspected focal liver lesions were scanned using 3D-VIBE sequences with GRAPPA with AF = 2 and AF = 4 and CAIPIRINHA with AF = 4 (acquisition times: 21, 14, and 12 s, respectively) during the hepatobiliary phase. Visual evaluations using a 3- or 5-point scale and signal-to-noise ratio (SNR) analysis were performed for the 3 sequences. RESULTS: For CAIPIRINHA with AF = 4, there was significantly less image noise in both visual evaluation and SNR analysis and fewer parallel imaging artifacts than for GRAPPA with AF = 4 (P < 0.0005); it was equal to GRAPPA with AF = 2 and had fewer motion artifacts than GRAPPA with AF = 2 and 4 (P < 0.0012). The liver edge sharpness and hepatic vessel clarity, lesion conspicuity, and overall image quality were rated significantly higher with CAIPIRINHA with AF = 4 than GRAPPA with AF = 2 and AF = 4 (P < 0.009). For GRAPPA with AF = 4, lesion conspicuity and overall image quality were rated significantly lower than for GRAPPA with AF = 2 (P < 0.012). CONCLUSION: The shortened breath-hold 3D-VIBE sequence using the new CAIPIRINHA technique with a high AF of 4 was superior to the conventional GRAPPA sequence. The shortened breath-hold sequence using GRAPPA with a high AF of 4 worsened the image quality and lesion conspicuity.
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Suspensão da Respiração , Meios de Contraste , Aumento da Imagem , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/patologia , Fígado/patologia , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Artefatos , Feminino , Gadolínio DTPA , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto JovemRESUMO
OBJECTIVE: Traditional fat-suppressed T1-weighted spin-echo or turbo spin-echo (TSE) sequences (T1-weighted images) may be degraded by motion and pulsation artifacts in head-and-neck studies. Our purpose is to evaluate the role of a fat-suppressed T1-weighted 3D radial gradient-recalled echo sequence (radial-volumetric interpolated breath-hold examination [VIBE]) in the head and neck as compared with standard contrast-enhanced fat-suppressed T1-weighted images. MATERIALS AND METHODS: We retrospectively evaluated 21 patients (age range, 9-67 years) who underwent head-and-neck MRI at 1.5 T. Both contrast-enhanced radial-VIBE and conventional fat-suppressed TSE contrast-enhanced T1-weighted imaging were performed. Two radiologists evaluated multiple parameters of image quality, graded on a 5-point scale. Mixed-model analysis of variance and interobserver variability assessment were performed. RESULTS: The following parameters were scored as significantly better for the contrast-enhanced radial-VIBE sequence than for conventional contrast-enhanced T1-weighted imaging: overall image quality (p < 0.0001), degree of fat suppression (p = 0.006), mucosal enhancement (p = 0.004), muscle edge clarity (p = 0.049), vessel clarity (p < 0.0001), respiratory motion artifact (p = 0.002), pulsation artifact (p < 0.0001), and lesion edge sharpness (p = 0.004). Interobserver agreement in qualitative evaluation of the two sequences showed fair-to-good agreement for the following variables: overall image quality (intraclass correlation coefficient [ICC], 0.779), degree of fat suppression (ICC, 0.716), mucosal enhancement (ICC, 0.693), muscle edge clarity (ICC, 0.675), respiratory motion artifact (ICC, 0.516), lesion enhancement (ICC, 0.410), and lesion edge sharpness (ICC, 0.538). Excellent agreement was shown for vessel clarity (ICC, 0.846) and pulsation artifact (ICC, 0.808). CONCLUSION: The radial-VIBE sequence is a viable motion-robust improvement on the conventional fat-suppressed T1-weighted sequence.
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Tecido Adiposo/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Gadolínio , Neoplasias de Cabeça e Pescoço/patologia , Aumento da Imagem/métodos , Imageamento Tridimensional/métodos , Adolescente , Adulto , Idoso , Criança , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Técnica de Subtração , Adulto JovemRESUMO
OBJECTIVES: To evaluate whether the use of Maximum Intensity Projection (MIP) images derived from contrast-enhanced 3D-T1-weighted volumetric interpolated breath-hold examination (VIBE) would allow more sensitive detection of small (≤5 mm) brain metastases (BM) compared with source as well as 2D-T1-weighted spin-echo (SE) images. METHODS: We performed a single center retrospective study on subjects with BM who underwent 1.5 tesla brain magnetic resonance imaging. Two readers counted the number of small BM for each of the seven sets of contrast-enhanced images created: axial 2D-T1-weighted SE, 3D-T1-weighted VIBE, 2.5 mm-thick-MIP T1-weighted VIBE, and 5 mm-thick-MIP T1-weighted VIBE; sagittal 3D-T1-weighted VIBE, 2.5 mm-thick-MIP T1-weighted VIBE, and 5 mm-thick-MIP T1-weighted VIBE. Total number of lesions detected on each image type was compared. Sensitivity, the average rates of false negatives and false positives, and the mean discrepancy were evaluated. RESULTS: A total of 403 small BM were identified in 49 patients. Significant differences were found: in the number of true positives and false negatives between the axial 2D-T1-weighted SE sequence and all other imaging techniques; in the number of false positives between the axial 2D-T1-weighted SE and the axial 3D-T1-weighted VIBE sequences. The two image types that combined offered the highest sensitivity were 2D-T1-weighted SE and axial 2.5 mm-thick-MIP T1-weighted VIBE. The axial 2D-T1-weighted SE sequence differed significantly in sensitivity from all other sequences. CONCLUSION: MIP images did not show a significant difference in sensitivity for the detection of small BM compared with native images.
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OBJECT: The pterygopalatine fossa (PPF) is a covert neurovascular pathway in the skull base and connects with numerous intracranial and extracranial spaces. The aim of this study was to explore the magnetic resonance imaging (MRI) features of PPF invasion in patients with nasopharyngeal carcinoma (NPC). MATERIAL AND METHODS: The medical records of 88 patients with stage T3 or T4 NPC were retrospectively analyzed. The 3-Dimensional (3D) volumetric images of MRI were reconstructed for the tiny connecting conduits of the invaded PPFs in the NPC patients. The infiltration incidence of conduits and connected further structures were calculated. RESULTS: Forty-six PPFs from 37 patients were invaded by NPC. The proportions of stage T4 NPC and intracranial extension were higher in patients with PPF invasion than that without PPF invasion (P < 0.05). Each connecting conduit of the PPF had corresponding optimal reconstructed orientation based on 3D volumetric MRI images. The first three most common infiltrated conduits were palatovaginal canal, vidian canal and sphenopalatine foramen, which were adjacent to the nasopharynx. Among the conduits connecting with further structures, the most common infiltrated conduit was pterygomaxillary fissure, followed by foramen rotundum and inferior orbital fissure. Furthermore, The NPC lesions involved stage T4 structures via the conduits from 19.6% of the invaded PPFs. CONCLUSIONS: The application of high-quality reconstruction images based on 3D sequence of MRI in NPC patients proved to be feasible and beneficial for the manifestation of the invaded PPFs and connecting conduits.
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Neoplasias Nasofaríngeas , Fossa Pterigopalatina , Humanos , Carcinoma Nasofaríngeo/diagnóstico por imagem , Fossa Pterigopalatina/diagnóstico por imagem , Fossa Pterigopalatina/patologia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Imageamento por Ressonância Magnética , Neoplasias Nasofaríngeas/diagnóstico por imagem , Neoplasias Nasofaríngeas/patologiaRESUMO
We report a case of intrahepatic inferior vena cava interruption with azygos and transhepatic venous continuation discovered incidentally on CT angiography for acute aortic syndrome. The lesion was initially misdiagnosed as a congenital portosystemic shunt on multiphase CT of the liver but subsequent fluoroscopic venogram revealed no evidence of portosystemic shunting. While intrahepatic IVC interruption with azygos continuation is an uncommon but well-known anatomical variant, transhepatic venous continuation is extremely rare and only a few cases have been published. Excluding portosystemic shunting is important for determining management as persistent congenital portosystemic shunts can be associated with significant morbidity.
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PURPOSE: To compare volumetric interpolated breath-hold examination (VIBE) with different slice thicknesses to T1-weighted turbo-echo (T1 TSE) for identification of sacroiliac joint structural lesions in patients suspected of spondyloarthritis (SpA) using CT as the gold standard. METHODS: 192 sacroiliac joints (including VIBE with both 1.2 mm and 3 mm slice thickness, T1 TSE) from 96 patients suspected of SpA were included. Joint space changes and sclerosis were evaluated for each joint. Erosions were assessed both at the level of the individual sacral and iliac bones and at the level of the entire joint for calculation of sensitivity, specificity, and accuracy. MRI and CT correlation was performed and inter-reader reliability was determined. Fat infiltration on MRI was scored. RESULTS: VIBE with a 1.2 mm slice thickness was the most sensitive and accurate for erosion detection at the bone level followed by 3 mm thickness VIBE and then T1 TSE (p < 0.05). At the whole-joint level, only the 1.2 mm slice thickness VIBE was superior to T1 TSE in sensitivity and accuracy (p > 0.05). For joint space changes, both VIBE sequences were superior to T1 TSE in sensitivity and accuracy (p < 0.05) and had more consistency with CT. T1 TSE was slightly more sensitive for detection of sclerosis (p < 0.05). The MR sequences did not differ in detection of fat infiltration. CONCLUSION: A VIBE sequence with 1.2 mm slice thickness and less than one-minute acquisition time was superior to T1 TSE for detection of sacroiliac joint space changes and erosions in patients with suspected SpA, while the utility of the 3 mm slice thickness VIBE remains questionable.
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Imageamento por Ressonância Magnética/métodos , Articulação Sacroilíaca/diagnóstico por imagem , Espondilartrite/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Suspensão da Respiração , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto JovemRESUMO
OBJECTIVECavernous sinus invasion (CSI) in Cushing's disease (CD) negatively affects the probability of complete resection, biochemical cure, and need for adjuvant therapy. However, the prediction of CSI based on MRI findings has been inconsistent and variable. Among macroadenomas, the Knosp classification is the most widely utilized radiographic predictor of CSI, but its accuracy in predicting CSI and the probability of gross-total resection is limited in the setting of microadenomas or Knosp grade 0-2 macroadenomas. The authors noticed that the presence of a triangular shape of adenomas adjacent to the cavernous sinus on coronal MR images is frequently associated with CSI. The authors aimed to determine the correlation of this radiographic finding ("sail sign" [SS]) with CSI.METHODSThe authors performed a retrospective review of all patients with a pituitary lesion < 20 mm and a biochemical diagnosis of CD treated with endoscopic or microscopic transsphenoidal resection from November 2007 to May 2017. Overall 185 patients with CD were identified: 27 were excluded for negative preoperative imaging, 32 for lacking tumors adjacent to the sinus, 7 for Knosp grade 3 or higher, and 4 for inadequate intraoperative assessment of the CSI. Following application of inclusion and exclusion criteria, 115 cases were available for statistical analysis. Intraoperative CSI was prospectively evaluated at the time of surgery by one of two neurosurgical attending surgeons, and MRI data were evaluated retrospectively by a neurosurgical resident and attending neuroradiologist blinded to the intraoperative results.RESULTSA positive SS was identified in 23 patients (20%). Among patients with positive SS, 91% demonstrated CSI compared to 10% without an SS (p < 0.001). Using the SS as a predictor of CSI provided a sensitivity of 0.7 and a specificity of 0.98, with a positive predictive value (PPV) of 0.91 and a negative predictive value of 0.9. Among patients with positive SS, 30% did not achieve immediate postoperative remission, compared to 3.3% of patients without an SS (p < 0.001).CONCLUSIONSThe presence of a positive SS among Cushing's adenomas adjacent to the CS provides strong PPV, specificity, and positive likelihood ratio for the prediction of CSI. This can be a useful tool for preoperative planning and for predicting the likelihood of long-term biochemical remission and the need for adjuvant radiosurgery.
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OBJECTIVE Many centers use conventional and dynamic contrast-enhanced MRI (DMRI) sequences in patients with Cushing's disease. The authors assessed the utility of the 3D volumetric interpolated breath-hold examination, a spoiled-gradient echo 3D T1 sequence (SGE) characterized by superior soft tissue contrast and improved resolution, compared with DMRI and conventional MRI (CMRI) for detecting microadenomas in patients with Cushing's disease. METHODS This study was a blinded assessment of pituitary MRI in patients with proven Cushing's disease. Fifty-seven patients who had undergone surgery for Cushing's disease (10 male, 47 female; age range 13-69 years), whose surgical findings were considered to represent a microadenoma, and who had been examined with all 3 imaging techniques were included. Thus, selection emphasized patients with prior negative or equivocal MRI on referral. The MRI annotations were anonymized and 4 separate imaging sets were independently read by 3 blinded, experienced clinicians: a neuroradiologist and 2 pituitary surgeons. RESULTS Forty-eight surgical specimens contained an adenoma (46 ACTH-staining adenomas, 1 prolactinoma, and 1 nonfunctioning microadenoma). DMRI detected 5 adenomas that were not evident on CMRI, SGE detected 8 adenomas not evident on CMRI, including 3 that were not evident on DMRI. One adenoma was detected on DMRI that was not detected on SGE. McNemar's test for efficacy between the different MRI sets for tumor detection showed that the addition of SGE to CMRI increased the number of tumors detected from 18 to 26 (p = 0.02) based on agreement of at least 2 of 3 readers. CONCLUSIONS SGE shows higher sensitivity than DMRI for detecting and localizing pituitary microadenomas, although rarely an adenoma is detected exclusively by DMRI. SGE should be part of the standard MRI protocol for patients with Cushing's disease.
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Adenoma/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Hipersecreção Hipofisária de ACTH/diagnóstico por imagem , Neoplasias Hipofisárias/diagnóstico por imagem , Adenoma/cirurgia , Adolescente , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Idoso , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Hipersecreção Hipofisária de ACTH/cirurgia , Hipófise/diagnóstico por imagem , Hipófise/cirurgia , Neoplasias Hipofisárias/cirurgia , Adulto JovemRESUMO
Giant dorsolumbar spinal arachnoid cysts are a complex, poorly understood, and difficult to manage clinical entity. Traditional CT myelography is technically difficult to use in these cases to detect the site of leakage preoperatively. The authors report a novel technique for detecting the site of the leak by using sequential, dynamic intraoperative MR myelography. To the authors' knowledge, there is no other similar report in the literature.
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Cistos Aracnóideos/diagnóstico por imagem , Cistos Aracnóideos/cirurgia , Laminectomia , Imageamento por Ressonância Magnética , Cirurgia Assistida por Computador , Adulto , Meios de Contraste , Feminino , Gadolínio , Humanos , Imageamento Tridimensional , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , MielografiaRESUMO
OBJECTIVE: To differentiate prostate cancer lesions in transition zone by diffusion-weighted-MRI (DW-MRI). METHODS: Data from a total of 63 patients who underwent preoperative DWI (b of 0-1000 s/mm2) were prospectively collected and processed by a monoexponential (DWI) model and compared with a biexponential (IVIM) model for quantitation of apparent diffusion coefficients (ADCs), perfusion fraction f, diffusivity D and pseudo-diffusivity D*. Histogram analyses were performed by outlining entire-tumor regions of interest (ROIs). These parameters (separately and combined in a logistic regression model) were used to differentiate lesions depending on histopathological analysis of Magnetic Resonance/transrectal Ultrasound (MR/TRUS) fusion-guided biopsy. The diagnostic ability of differentiate the PCa from BHP in TZ was analyzed by ROC regression. Histogram analysis of quantitative parameters and Gleason score were assessed with Spearman correlation. RESULTS: Thirty (30 foci) cases of PCa in PZ and 33 (36 foci) cases of BPH were confirmed by pathology. Mean ADC, median ADC, 10th percentile ADC, 90th percentile ADC, kurtosis and skewness of ADC and mean D values, median D and 90th percentile D differed significantly between PCa and BHP in TZ. The highest classification accuracy was achieved by the mean ADC (0.841) and mean D (0.809). A logistic regression model based on mean ADC and mean D led to an AUC of 0.873, however, the difference is not significant. There were 7 Gleason 6 areas, 9 Gleason 7 areas, 8 Gleason 8 areas, 5 Gleason 9 areas and 2 Gleason 10 areas detected from the 31 prostate cancer areas, the mean Gleason value was(7.5 ± 1.2). The mean ADC and mean D had correlation with Gleason score(r = -0.522 and r = -0.407 respectively, P < 0.05). CONCLUSION: The diagnosis efficiency of IVIM parameters was not superior to ADC in the diagnosis of PCa in TZ. Moreover, the combination of mean ADC and mean D did not perform better than the parameters alone significantly; It is feasible to stratify the pathological grade of prostate cancer by mean ADC.
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AIM: To compare differences between volumetric interpolated breath-hold examination (VIBE) using two-point Dixon fat-water separation (Dixon-VIBE) and chemically selective fat saturation (FS-VIBE) with magnetic resonance imaging examination. METHODS: Forty-nine patients were included, who were scanned with two VIBE sequences (Dixon-VIBE and FS-VIBE) in hepatobiliary phase after gadoxetic acid administration. Subjective evaluations including sharpness of tumor, sharpness of vessels, strength and homogeneity of fat suppression, and artifacts that were scored using a 4-point scale. The liver-to-lesion contrast was also calculated and compared. RESULTS: Dixon-VIBE with water reconstruction had significantly higher subjective scores than FS-VIBE in strength and homogeneity of fat suppression (< 0.0001) but lower scores in sharpness of tumor (P < 0.0001), sharpness of vessels (P = 0.0001), and artifacts (P = 0.034). The liver-to-lesion contrast on Dixon-VIBE images was significantly lower than that on FS-VIBE (16.6% ± 9.4% vs 23.9% ± 12.1%, P = 0.0001). CONCLUSION: Dixon-VIBE provides stronger and more homogenous fat suppression than FS-VIBE, while has lower clarity of focal liver lesions in hepatobiliary phase after gadoxetic acid administration.