The role of 3D volumetric MR sequences in diagnosing intraventricular neurocysticercosis: preliminar results / Papel das sequencias volumétricas 3D de RM no diagnóstico da neurocisticercose intraventricular: resultados preliminares

OBJECTIVE: The purpose of this paper was to investigate the role of two three-dimensional magnetic resonance (MRI) sequences: enhanced spoiled gradient recalled echo (SPGR), and fast imaging employing steady-state acquisition (FIESTA) in the evaluation of intraventricular neurocysticercosis cysts and scolices. METHOD: Seven neurocysticercosis patients suspected of presenting intraventricular lesions were evaluated by magnetic resonance imaging using enhanced SPGR, and FIESTA. RESULTS: Enhanced SPGR detected eight cystic lesions, with scolices in four. Contrast enhancement was observed in three cysts. FIESTA also detected eight cystic lesions with the presence of scolices in seven of those cystic lesions. Four patients presented parenchymal involvement, while the remaining three presented the racemose form. CONCLUSION: FIESTA and SPGR are sequences that can detect intraventricular cysts of neurocysticercosis, and FIESTA also is good for the detection of the scolex. Considering this information we suggest that FIESTA and SPGR should be included in the MRI protocol for the investigation of intraventricular neurocysticercosis.

OBJETIVO: O objetivo deste trabalho foi investigar o papel de duas sequências de ressonância magnética (RM) volumétricas tridimensionais: spoiled gradient recalled echo (SPGR) pós-contraste e fast imaging employing steady-state acquisition (FIESTA) na avaliação de cistos e escólex na neurocisticercose intraventricular. MÉTODO: Sete pacientes suspeitos de neurocisticercose intraventricular foram avaliados pela ressonância magnética com SPGR pós-contraste e FIESTA. RESULTADOS: SPGR pós-contraste evidenciou oito lesões císticas com presença de escólex em quatro. Realce foi observado em três destes cistos. FIESTA também detectou oito lesões císticas, com presença de escólex em sete destas lesões. Envolvimento do parênquima cerebral foi observado em quatro pacientes e forma racemosa em três. CONCLUSÃO: FIESTA e SPGR são sequências que permitem a detecção de cistos intraventriculares de neurocisticercose e FIESTA é uma boa sequência para a detecção de escólex. Considerando estes achados nós sugerimos que estas sequências (FIESTA e SPGR) devam ser incluídas no protocolo de RM na investigação de neurocisticercose intraventricular.

Anatomic Illustrations of Cranial Ultrasound Images Obtained Through the Mastoid Fontanelle in Neonates

PURPOSE: Neonatal cranial sonongraphy performed through the mastoid fontanelle is more useful to evaluate the peripheral structures at the convexity of the cerebral hemispheres and brainstem rather than that performed through the anterior fontanelle. The purpose of this study is to demonstrate the anatomy of the extracerebral CSF space and brainstem and to suggest appropriate scan planes for performing neonatal cranial sonography through the mastoid fontanelle using MRI and multiplanar reconstruction programs. MATERIALS AND METHODS: A neonate with normal features on ultrasonography and good image quality on MRI, including the 3D-SPGR axial scans, was selected. We made the reconstructed MR images corresponding to the sonongraphic planes and the anatomic models of the neonatal cranial sonographic images by using axial MRI as the standard reference on the same screen. We demonstrated the sonographic images at the levels of the body of the caudate nucleus and lentiform nucleus, the head of the caudate nucleus and thalamus, the third ventricle and midbrain, and the midbrain and cerebellar vermis on the oblique axial scans. Four oblique coronal images at the levels of the periventricular white matter, basal ganglia, thalamus and tentorium were also obtained. RESULTS: We illustrated the anatomic atlas with including four oblique axial scans and four oblique coronal scans that corresponded to the neonatal cranial sonographic images through the mastoid fontanelle. CONCLUSION: We objectively analyzed the anatomy of the extracerebral CSF space and brainstem by using MRI and multiplanar reconstruction programs and we provided the standardized sonographic scan planes through the mastoid fontanelle. This study will be very helpful for evaluating the abnormalities of the peripheral structures at the convexity of the cerebral hemispheres and brainstem.

Anatomic Illustrations of Cranial Ultrasound Images Through the Posterior Fontanelle in Neonates: Objective Analysis of Oblique Sonographic Scans using MRI and a Reconstruction Program

PURPOSE: Neonatal cranial sonongraphy through the posterior fontanelle is more useful than through the anterior approach for the evaluation of posterior brain structures. The aims of this study were to determine the appropriate neonatal cranial sonography scan planes through the posterior fontanelle, and to objectively evaluate the anatomy of neonatal cranial sonographic images. MATERIALS AND METHODS: Neonates who underwent cranial sonography and MRI including 3D-SPGR axial scans and showed normal features on both modalities were enrolled. We reconstructed MR images corresponding to sonongraphic planes, then constructed anatomic models of the neonatal cranial sonographic images using axial MRI as the standard reference on the same screen. RESULTS: We successfully created anatomic atlas that represents 8 oblique coronal and 4 oblique sagittal scans and planes that corresponded to the neonatal cranial sonographic images through the posterior fontanelle. CONCLUSION: The objective manner of this anatomic research provided standardized sonographic scan planes and created anatomic model through the posterior fontanelle. Cranial sonographic models through the posterior fontanelle using MRI and multi-planar reconstruction program will be helpful in the evaluation of sonographic anatomy and detection of abnormalities in the basal ganglia, thalamus and posterior part of the brain.

Fat-suppressed 3D SPGR MR Imaging of Articular Cartilage Lesion of Medial Femoral Condyle in Osteoarthritic Knee / 대한정형외과학회잡지

PURPOSE: To evaluate the efficacy of sagittal fat-suppressed 3D SPGR MR imaging of the osteoarthritic medial femoral condyle in terms of extent and degree of a focal articular cartilage defect of the knee. MATERIALS AND METHODS: The MRI findings (Disler scale) of normal and osteoarthritic medial femoral condyles from 112 knees were prospectively compared with the arthroscopic findings (Jackson staging). The arthroscopic findings were normal in 10 cases, stage I in 26 cases, stage II in 36 cases, stage III in 21 cases and stage IV in 19 cases on arthroscopy. RESULTS: All 10 cases arthroscopy findings were grade 0 in MRI. Among the 26 knees in arthroscopic stage I, only 11 knees (42.3%) showed surface irregularities on MRI that were consistent with grade 1, otherwise grade 2. All cases of arthroscopic stage II showed grade 2 or grade 3. Stage III was grade 3 in all cases on MRI. Among the 19 knees in arthroscopic stage IV, 16 knees (84.2%) with a large defect showed grade 4 on MRI. The sensitivity, specificity and accuracy of the MRI compared with the arthroscopic findings was 97%, 100% and 97.3%, respectively. The weighted kappa index was 0.7194 and the SE (standard error) was 0.053, suggesting significant consistency. CONCLUSION: The sagittal fat-suppressed 3D SPGR MR imaging is valuable for determining the extent and degree of the articular cartilage lesion of the medial femoral condyle in an osteoarthritic knee.

Functional MR Imaging of Cerbral Motor Cortex: Comparison between Conventional Gradient Echo and EPI Techniques

PURPOSE: To evaluate the differences of functional imaging patterns between conventional spoiled gradient echo(SPGR) and echo planar imaging(EPI) methods in cerebral motor cortex activation. MATERIALS AND METHODS: Functional MR imaging of cerebral motor cortex activation was examined on a 1.5T MR unit with SPGR (TR/TE/flip angle=50ms/40ms/30degree, FOV=300mm, matrix size=256x256, slice thickness=5mm) and an interleaved single shot gradient echo EPI (TR/TE/flip angle=3000ms/40ms/90 degree, FOV=300mm, matrix size=128x128, slice thickness=5mm) techniques in five male healthy volunteers. A total of 160 imaging in one slice and 960 images in 6 slices were obtained with SPGR and EPI, respectively. A right finger movement was accomplished with a paradigm of an 8 activation/ 8 rest periods. The cross-correlation was used for a statistical mapping algorithm. We evaluated any differences of the time series and the signal intensity changes between the rest and activation periods obtained with two techniques. Also, the locations and areas of the activation sites were compared between two techniques. RESULTS: The acivation sites in the motor cortex were accurately localized with both methods. In the signal intensity changes between the rest and activation periods at the activation regions, no significant differences were found between EPI and SPGR. Signal to noise ratio (SNR) of the time series data was higher in EPI than in SPGR by two folds. Also, larger pixels distributed over small p-values at the activation sites in EPI. CONCLUSIONS: Good quality functional MR imaging of the cerebral motor cortex activation could be obtained with both SPGR and EPI. However, EPI os preferable because it provides more precise information on hemodynamics related to neural activities than SPGR due to high sensitivity.