Heverton C. de Oliveira

Aplicação da ressonância magnética de corpo inteiro para o estadiamento e acompanhamento de pacientes com linfoma de Hodgkin na faixa etária infanto-juvenil: comparação entre diferentes sequências

OBJECTIVE: To compare the performance of the T1, T2, STIR and DWIBS (diffusion-weighted whole-body imaging with background body signal suppression) sequences in the staging and follow-up of pediatric patients with Hodgkins lymphoma in lymph node chains, parenchymal organs and bone marrow, and to evaluate interobserver agreement. MATERIALS AND METHODS: The authors studied 12 patients with confirmed diagnosis of Hodgkins lymphoma. The patients were referred for whole body magnetic resonance imaging with T1-weighted, T2-weighted, STIR and DWIBS sequences. RESULTS: The number of lymph node sites characterized as affected by the disease on T1- and T2-weighted sequences showed similar results (8 sites for both sequences), but lower than DWIBS and STIR sequences (11 and 12 sites, respectively). The bone marrow involvement by lymphoma showed the same values for the T1-, T2-weighted and DWIBS sequences (17 lesions), higher than the value found on STIR (13 lesions). A high rate of interobserver agreement was observed as the four sequences were analyzed. CONCLUSION: STIR and DWIBS sequences detected the highest number of lymph node sites characterized as affected by the disease. Similar results were demonstrated by all the sequences in the evaluation of parenchymal organs and bone marrow. A high interobserver agreement was observed as the four sequences were analyzed.

Ultrasonographic study of the femoropatellar joint and its attachments in normal infants from birth to 24 months of age: part I.

Eighty knees of 40 musculoskeletally normal infants whose age ranged from 0 to 24 months (average 9.65 months) were ultrasonographically analyzed. The lengths of the patella, patellar ligament – and the Insall–Salvati index, knee being flexed at 30°, were assessed. The angles of the femoral cartilaginous sulcus knee flexed at 0, 30, 60, and 90° were also defined. Patellar length varied from 1.84 to 2.02 cm (mean, 93.3 cm; standard deviation, 0.35); patellar ligament length varied from 1.67 to 1.86 (mean, 1.76 cm; standard deviation, 0.25); the Insall–Salvati index varied from 1.04 to 1.13, (mean, 1.09; standard deviation, 0.14); and femoral cartilaginous sulcus angle ranged from 148.7 to 149.3° (average, 148.9° and standard deviation, 6.20). Statistical tests showed no significant difference in the proposed measures according to sex and side (right/left). Moreover, we did not observe significant difference in the femoral cartilaginous sulcus angle with respect to the various degrees of knee flexion. Thus, we conclude that ultrasonography is useful for determining the normal values of the Insall–Salvati index and femoral cartilaginous sulcus angle in infants from 0 to 24 months. Then, we suggest standardization of this imaging procedure for the early diagnosis of deformities, which might impair the knee in infants within this range of age.

Ultrasonographic study of the femoro-patellar joint and its attachments in infants from birth to 24 months of age. Part II: children with Down syndrome.

An ultrasonographic study was carried out in 25 infants (50 knees) with Down syndrome, whose age ranged from zero to 24 months, average being 13.2 months; 13 were males and 12 were females. The ultrasonographic investigation was performed with the knee being in full extension for the transversal view and in 30° flexion for the sagittal view. The Insall–Salvati index and femoral cartilaginous sulcus angle were measured. Insall–Salvati index values ranged from 1.06 to 1.15 (average 1.10), with standard deviation of 0.16. No significant differences were observed with regard to Insall–Salvati index values in normal children. The femoral cartilaginous sulcus angle in infants with Down syndrome ranged from 152.7 to 155.8° (average 154.3) with standard deviation of 7.959. In Down syndrome we noticed significant difference as compared to the normal values. The authors suggest that ultrasonography is useful in Down syndrome for an early diagnosis of instability of the patella.

Meniscal tears: comparison of the conventional spin-echo and fast spin-echo techniques through image processing.

BackgroundConventional spin-echo (PD-CSE) and fast spin-echo (PD-FSE) techniques are frequently used to detect meniscal tears. However, the time delay for imaging with PD-CSE has resulted in its replacement with faster techniques, such as proton density fast spin-echo (PD-FSE), which has become a frequent tool at most diagnostic centres.Qualitative analysis shows that the PD-CSE technique is more sensitive, but other authors have not found significant differences between the aforementioned techniques. Therefore, we performed a quantitative analysis in this study that aims to measure differences in the quality of the images obtained with both techniques.MethodsWe compared the PD-CSE and PD-FSE techniques by quantitatively analysing the obtained proton density images: the area shown, as well as the brightness and lesion contrast of the obtained image.A set of 100 images from 50 patients thought to contain meniscal tears of the knee were selected. These 100 images were obtained from all individuals using both the PD-CSE and PD-FSE techniques. The images were processed using software developed in Delphi. In addition to these quantifications, three physicians, who are specialists in radiology and capable of analysing magnetic resonance (MR) images of the musculoskeletal system, qualitatively analysed the diagnostic sensitivity of both techniques.ResultsOn average, samples obtained via the PD-CSE technique contained 22% more pixels in the lesion area. The contrast differed by 28%, and the brightness differed by 31%. The two techniques were correlated using Student’s t-test, which showed a statistically significant difference. The specialists detected meniscal tears in 30 of the images obtained via the PD-CSE technique, while only 72% of these cases were detected via the PD-FSE technique.ConclusionsThe PD-CSE technique was shown to be superior to PD-FSE for all of the evaluated properties, making its selection preferable.

Proposal of a magnetic resonance technique for the evaluation of the calcaneofibular ligament minimizing false positive results.

BackgroundMagnetic resonance (MR) techniques used to detect lesions of the ligament complex for articulation of the ankle lack the desired accuracy for the study of the calcaneofibular ligament (CFL). The lack of sensitivity of the conventional techniques is due to variations in the dimensions of the CFL. The best results are obtained when the image plane is oriented parallel to the ligament. This study aims to develop a model that addresses the width, length and angle parameters of the CFL and the orientation of the MR image plane, and thus determine a technique in the oblique transversal plane with the foot in anatomical flexion, that is adequate for the majority of patients.MethodTo determine this orientation and adapt it to the majority of people, images of the articulation of the ankle in the 3D isotropic, volumetric, sagittal plane of 100 volunteers were taken using the MR technique. None of the volunteers had a clinical history of ligament lesions, serious pathologies, or surgeries. A measurement of the length, width, and angle of the CFL relative to the sole of the foot was performed using the MR tools. A virtual model was developed that simulated the visualization of the CFL in the oblique transversal image plane from 35° to 45° using the CFL dimensions of 100 volunteers. The comparison of the simulations with the reconstructed images validated the model and permitted the calculation of the agreement and sensitivity of each technique in the detection of the complete CFL.ResultsUsing the simulator, it was possible to obtain the limit angle for complete CFL visualization as a function of its dimensions for any angle of the oblique transversal image plane of the MR.ConclusionThe results suggest that a single image acquisition technique in the oblique transversal plane at 38° with the foot in anatomical flexion would serve the majority of patients.

Actinomicose cutânea primária do pé simulando neoplasia de partes moles: relato de caso

We report a case of a patient with primary cutaneous actinomycosis of the foot mimicking a soft tissue neoplasm. A literature review on the incidence, clinical features, pathology and imaging findings is also presented. The plain films and magnetic resonance imaging findings and the pathology results are presented. This paper reports a rare disease occurring in an atypical location, simulating a soft tissue neoplasm.