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O câncer de mama é um dos mais frequentes entre as mulheres, e seu diagnóstico pode ser realizado por meio de ultrassonografia, mamografia ou ressonância magnética, juntamente com biópsia. Em pacientes que apresentam mamas densas, a ressonância magnética é considerada o melhor método de diagnóstico, por apresentar alta sensibilidade quando comparado às outras técnicas, devido principalmente à aplicação do meio de contraste gadolínio, que se impregna no tecido acometido, facilitando a visualização do tumor e a possibilidade de saturar seletivamente o sinal da gordura, auxiliando desse modo no diagnóstico do câncer de mama.
Breast cancer is the most frequent cancer among women, and its diagnosis can be made by ultrasound, mammography or MRI, along with biopsy. In patients with dense breasts, MRI is considered the best diagnostic method for its high sensitivity when compared to other techniques. Plus, there's the application of gadolinium contrast medium, which is impregnated in the affected tissue for easier viewing the tumor and the possibility of selectively saturate the fat signal, helping thus the diagnosis of breast cancer.
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Objective:To explore the values of fat saturation sequence in MRI for juvenile arthritis.Methods:A total of 1 131 cases with juvenile arthritis and 1 601 with symptomatic arthritis were examined by MRI normal T1 weighted imaging (T1WI) and T2 weighted imaging (T2WI)sequence and spectral presaturation attenuatedinversion recovery (SPAIR) T2 fat saturation sequence.All the images were independently evaluated by two senior doctors from the Department of Radiology and the Department of Pediatric Rheumatology and Immunology respectively to confirm the types and degree of pathological changes of joint tissues.Results:Among the subjects,847 patients demonstrated positive in MRI,accounting for 52.9％;409 patients showed positive in normal sequence,accounting for 48.3％;816 patients showed positive in fat saturation sequence,accounting for 96.3％.Joint hydrops accounted for 59.5％.Bone marrow edema accounted for 39.7％.The relevant ratio of bone marrow edema,joint hydrops,thickening of synovium and cartilage injuries in fat saturation sequence were higher than that in normal sequence (P＜0.05).The relevant ratio of bone erosion in normal sequence was higher than that in fat saturation sequence (P＜0.05).However,no significant difference of joint cysts was found between the fat saturation sequence and normal sequence (P＜0.05).Conclusion:Application of fat saturation sequence by MRI to check juvenile arthritis could obviously improve the positive MRI relevant ratio.In addition,the relevant ratio of the early pathological changes of juvenile arthritis (such as bone marrow edema and joint hydrops) was high,which might provide references for the early diagnosis of juvenile arthritis.
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PURPOSE: To quantitatively and qualitatively compare fat-suppressed MRI quality using iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) with that using frequency selective fat-suppression (FSFS) T2- and postcontrast T1-weighted fast spin-echo images of the head and neck at 3T. MATERIALS AND METHODS: The study was approved by our Institutional Review Board. Prospective MR image analysis was performed in 36 individuals at a single-center. Axial fat suppressed T2- and postcontrast T1-weighted images with IDEAL and FSFS were compared. Visual assessment was performed by two independent readers with respect to; 1) metallic artifacts around oral cavity, 2) susceptibility artifacts around upper airway, paranasal sinus, and head-neck junction, 3) homogeneity of fat suppression, 4) image sharpness, 5) tissue contrast of pathologies and lymph nodes. The signal-to-noise ratios (SNR) for each image sequence were assessed. RESULTS: Both IDEAL fat suppressed T2- and T1-weighted images significantly reduced artifacts around airway, paranasal sinus, and head-neck junction, and significantly improved homogeneous fat suppression in compared to those using FSFS (P < 0.05 for all). IDEAL significantly decreased artifacts around oral cavity on T2-weighted images (P < 0.05, respectively) and improved sharpness, lesion-to-tissue, and lymph node-to-tissue contrast on T1-weighted images (P < 0.05 for all). The mean SNRs were significantly improved on both T1- and T2-weighted IDEAL images (P < 0.05 for all). CONCLUSIONS: IDEAL technique improves image quality in the head and neck by reducing artifacts with homogeneous fat suppression, while maintaining a high SNR.
Subject(s)
Artifacts , Ethics Committees, Research , Head , Lymph Nodes , Magnetic Resonance Imaging , Mouth , Neck , Pathology , Prospective Studies , Signal-To-Noise Ratio , WaterABSTRACT
Conventional MRI and MRI-myelography studies were classified as positive when morphological alterations noted correlated with clinical presentations. This study was to analyse the usefulness of MRI myelography of the cervical spine using technique of moderate T2-weighted Three Dimensional Turbo Spin Echo-Fat Sequence pulse sequence in identifying nerve root compression in patients with cervical spondylotic radiculopathy. MRI myelogram detected less nerve root compression 5% but conventional MRI 8%. Clinical findings were significantly associated with imaging findings in both imaging techniques (p<0.001). MRI myelogram overreported 45 and conventional MRI over-reported 80 nerve roots compression when correlated with clinical presentation (p<0.001). There was 50% alteration on conventional MRI when viewed together with MRI myelogram. There was significant difference with nerve root compression and clinical findings between MRI myelogram and conventional MRI (p<0.001). MRI myelogram underestimated the number of nerve roots compressed but it altered the interpretation of conventional MRI in 5% cases when viewed together. The addition of MRI myelogram increased the number of positive nerve roots. MRI myelogram is a useful adjunct to conventional axial and sagittal imaging in the investigation of cervical spondylotic radiculopathy.
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Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.
Subject(s)
Anterior Cruciate Ligament , Artifacts , Cartilage , Knee Joint , Knee , Pathology , Protons , Relaxation , WaterABSTRACT
Objective To further study the value of MR T2WI fat saturation sequence in acute Spinal Trauma. Methods 109 cases of acute Spinal Trauma underwent MR imaging were analysed retrospectively. The detection rate of lesions with bone marrow edema, Vertebral fracture and spinal cord injury was compared in T2WI and FS T2WI. Results FS T2WI could detect more lesions of obscure fracture and bone marrow edema than that in T2WI,and it could accurately show the extent and the feature of anatomic structure in acute injury of bone. Conclusion FS T2WI can improve the diagnostic sensition and accuracy in Spinal Trauma, and it should be used as a routine MR sequence for detecting Spinal Trauma.
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Objective To search a kind ofphotograph system which can be confirmed immediately to photograph a picture after expose and never needed to carry on a dark box again to replace or the IP plank read. Methods Pass to usher in a DaoJin company numeral to turn to move the type X line to photograph system to carry out. Results The DR bedside photographs to photograph with CR bedside to compare, saved time, raised picture resolution and quality, lowered a sufferer to hurt and saved a luck camp cost. Conclusion Carried out to photograph a picture after expose can immediately get confirmation, have never need is carry on a dark box to replace or the IP plank read.