Polyorquidism: case report comparing ultrasonography and magnetic resonance imaging / Poliorquidismo: relato de caso comparando a ultrassonografia e a ressonância magnética

Abstract Introduction: polyorchidism is an unusual pathology, about 200 cases in the world literature. Case report: we reported a case of polyorchidism in a 16-year-old male patient diagnosed by ultrasound and confirmed by magnetic resonance imaging. Discussion: most of the cases presented, there is a supernumerary testis, but there are reports on more than three, up to five testicles with supranumerical gonads on both sides of the scrotum. The diagnosis is usually performed in late puberty, incidentally, with a painless scrotal mass or at the emergency room, presenting a testicular torsion of the whole hemiscrotum or supernumerary testisalone, and the differential diagnosis should be made with epididymal cyst and spermatocele, besides other extra-testicular masses (hydroceles, varicoceles, lipomas, tumors.) and para-testicular masses (hernias, scrotal calculi). After the initial clinical evaluation, ultrasound is the first line subsidiary exam. Magnetic Resonance Imaging is very helpful, just in case the ultrasound diagnosis is uncertain. The supernumerary testishave the same Magnetic Resonance Imaging characteristics as the normal testes (intermediate signal intensity on T1- weighted images and high signal intensity on T2-weighted images).

Resumo Introdução: o poliorquidismo é uma patologia incomum, contando cerca de 200 casos na literatura mundial. Relato de caso: relatamos um caso de poliorquidismo em um paciente do sexo masculino de 16 anos, diagnosticado por ultrassom e confirmado por ressonância magnética. Discussão: na maioria dos casos apresentados, há um testículo supranumérico, mas há relatos de mais de três, até cinco testículos, com gônadas supranuméricas em ambos os lados do escroto. O diagnóstico geralmente é feito no final da puberdade, aliás, com massa escrotal indolor ou no pronto-socorro, apresentando torção de todo o hemiscroto ou somente do testículo supranumerário, e o diagnóstico diferencial deve ser feito com cisto epididimário e espermatocele, além de outros massas extratesticulares (hidroceles, varicoceles, lipomas, tumores) e massas paratesticulares (hérnias, cálculos escrotais). Após a avaliação clínica inicial, o ultrassom é a primeira linha do exame subsidiário. A ressonância magnética é muito útil se o diagnóstico por ultrassom não for certo. Os testículos supranumerários têm as mesmas características de ressonância magnética que os testículos normais (intensidade do sinal intermediário nas imagens ponderadas em T1 e alta intensidade do sinal nas imagens ponderadas em T2).

Reliability Analysis of Magnetic Resonance Imaging Equipment Based on Non-homogeneous Poisson Process / 中国医疗器械杂志

In order to evaluate the quality of different brands of magnetic resonance imaging system, optimize the quality of equipment repair and maintenance, and ensure the quality and safety of the equipment in clinical use. Meanwhile build the reliability evaluation model of magnetic resonance imaging equipment based on the large failure data collected by magnetic resonance repair system. In this paper, using the fault data of a certain brand of magnetic resonance in the past two years, applying the statistical judgment criterion, selecting the appropriate statistical distribution model, and finally fitting the equipment reliability evaluation model based on the non-homogeneous Poisson process, and then obtaining the magnetic resonance imaging equipment. Reliability evaluation indicators such as cumulative fault strength function, magnetic resonance imaging equipment fault density function, and mean time between failures. According to the calculated reliability index, on the one hand, it can evaluate the system reliability quality of a certain brand of magnetic resonance imaging equipment, and then evaluate the quality of different brands of magnetic resonance imaging equipment, on the other hand, it can help hospital equipment managers to carry out operational optimization, maintenance strategy development and safety management of magnetic resonance imaging equipment.

Application of magnetic resonance imaging-compatible incubator in cranial magnetic resonance imaging for neonates: a multicenter prospective randomized clinical trial / 中国当代儿科杂志

OBJECTIVE@#To study the safety and efficacy of magnetic resonance imaging (MRI)-compatible incubator in cranial MRI examination for neonates.@*METHODS@#A total of 120 neonates who were hospitalized in three hospitals and needed to undergo MRI examination were randomly divided into a control group and an experimental group, with 60 neonates in each group. The neonates in the experimental group were transferred with MRI-compatible incubator and underwent cranial MRI examination inside the MRI-compatible incubator, and those in the control group were transferred using a conventional neonatal transfer incubator and then underwent MRI examination outside the incubator. The two groups were compared in terms of the primary efficacy index (total examination time), secondary efficacy indices (times of examination, MRI completion rate on the first day of use), and safety indices (incidence rate of adverse events and vital signs).@*RESULTS@#There were no significant differences in total examination time, times of examination, and MRI completion rate on the first day of use between the two groups (@*CONCLUSIONS@#The use of MRI-compatible incubator does not significantly shorten the examination time of cranial MRI, but it does provide a relatively stable environment for examination with acceptable safety. There is a need for further studies with a larger population.

Machine learning techniques for computer-aided classification of active inflammatory sacroiliitis in magnetic resonance imaging

Abstract Background: Currently, magnetic resonance imaging (MRI) is used to evaluate active inflammatory sacroiliitis related to axial spondyloarthritis (axSpA). The qualitative and semiquantitative diagnosis performed by expert radiologists and rheumatologists remains subject to significant intrapersonal and interpersonal variation. This encouraged us to use machine-learning methods for this task. Methods: In this retrospective study including 56 sacroiliac joint MRI exams, 24 patients had positive and 32 had negative findings for inflammatory sacroiliitis according to the ASAS group criteria. The dataset was randomly split with ∼ 80% (46 samples, 20 positive and 26 negative) as training and ∼ 20% as external test (10 samples, 4 positive and 6 negative). After manual segmentation of the images by a musculoskeletal radiologist, multiple features were extracted. The classifiers used were the Support Vector Machine, the Multilayer Perceptron (MLP), and the Instance-Based Algorithm, combined with the Relief and Wrapper methods for feature selection. Results: Based on 10-fold cross-validation using the training dataset, the MLP classifier obtained the best performance with sensitivity = 100%, specificity = 95.6% and accuracy = 84.7%, using 6 features selected by the Wrapper method. Using the test dataset (external validation) the same MLP classifier obtained sensitivity = 100%, specificity = 66.7% and accuracy = 80%. Conclusions: Our results show the potential of machine learning methods to identify SIJ subchondral bone marrow edema in axSpA patients and are promising to aid in the detection of active inflammatory sacroiliitis on MRI STIR sequences. Multilayer Perceptron (MLP) achieved the best results.(AU)

Resonancia magnética nuclear en cardiología infantil / Magnetic resonance imaging in pediatric cardiology

Los innegables progresos en la supervivencia de los pacientes con cardiopatía congénita en los últimos años fue acompañado de los avances en todas las áreas concurrentes a la cirugía cardiovascular, incluyendo la recuperación y los métodos diagnósticos que permiten una mejor comprensión de la patología cardíaca congénita o adquirida. La velocidad con que se desarrollan estas herramientas en el arsenal médico, exige una mejor comprensión a la hora de definir la estrategia diagnóstica para cada paciente en particular. Tradicionalmente, las imágenes diagnósticas de las cardiopatías congénitas eran dominio de la ecocardiografía y el cateterismo. En los últimos 10 años, la Resonancia y la Tomografía Computada fueron ganando terreno. La principal ventaja de la Resonancia es que no utiliza Rayos X para obtener las imágenes, diferencia de la angiografía por cateterismo y la tomografía axial computada. La resonancia magnética cardíaca se ha convertido en una herramienta importante para evaluar la enfermedad cardíaca congénita y también la adquirida en niños y adultos. La variedad y complejidad de la patología y sus posibilidades quirúrgicas hace indispensable la presencia del cardiólogo infantil durante la adquisición de las imágenes y su post procesamiento. En esta sección se presentarán algunas de las herramientas o secuencias que utiliza la Resonancia Magnética Cardíaca y su utilización práctica en el diagnóstico de las cardiopatías más frecuentes (AU)

The undeniable progress in survival of patients with congenital heart defects in recent years has been accompanied by advances in all areas related to cardiovascular surgery, including recovery and diagnostic methods that allow for a better understanding of congenital or acquired heart disease. The speed with which these tools are developed in the medical arsenal requires a better understanding when defining the diagnostic strategy for each individual patient. Traditionally, diagnostic images of choice for congenital heart disease were echocardiography and catheterization. Over the last 10 years, MRI. and CT scan have become more important. The main advantage of MRI is that it does not use X-rays to obtain the images, unlike catheterization and computed tomography angiogram. Cardiac MRI has become an important tool for assessing congenital and acquired heart disease in children and adults. The variety and complexity of the disease and its surgical possibilities warrant the presence of the child cardiologist during imaging acquisition and processing. This section will present some of the MRI tools and sequences and their practical use in the diagnosis of the most common heart diseases (AU)

7. 0T ultrahigh-field MRI directly visualized the pedunculopontine nucleus in Parkinson's disease patients

OBJECTIVES: The pedunculopontine nucleus (PPN) is considered a promising new target for neurostimulation in Parkinson's disease (PD) patients with postural instability and gait disturbance that is refractory to other treatment modalities. However, the PPN is typically difficult to visualize with magnetic resonance imaging (MRI) at clinical field strengths, which greatly limits the PPN as a viable surgical target for deep brain stimulation (DBS). Thus, the aim of this study is to directly visualize the PPN based on 7.0T ultrahigh-field MRI. METHODS: Five PD patients were enrolled and scanned using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI scanner. Then, the MP2RAGE sequences were imported into a commercially available navigation system. The coordinates of the directly localized PPN poles were recorded in the navigation system relative to the anterior commissure-posterior commissure plane. RESULTS: Our results indicated that the PPN presented intermediate signal intensity in the 7.0T ultrahigh-field MR images in comparison with the surrounding structure, such as the hypo-intensity of the periaqueductal gray and the hyperintensity of the neighboring white matter tracts, in PD patients. The mean coordinates for the rostral and caudal poles of PPN were 6.50 mm and 7.20 mm lateral, 1.58 mm and 2.21 mm posterior, and 8.89 mm and 13.83 mm relative to the posterior commissure. CONCLUSION: Our findings provide, for the first time, direct visualization of the PPN using the MP2RAGE sequence on a 7.0T ultrahigh-field MRI, which may improve the accuracy of stereotactic targeting of the PPN and improve the outcomes in patients undergoing DBS.

Foot drop: an iatrogenic complication of spinal anesthesia / Pé caído: uma complicação iatrogênica da anestesia espinhal

Abstract Background and objectives Foot drop in postoperative period is very rare after spinal anesthesia. Early clinical assessment and diagnostic interventions is of prime importance to establish the etiology and to start appropriate management. Close follow-up is warranted in early postoperative period in cases when patient complain paresthesia or pain during needle insertion or drug injection. Case report A 22-year-old male was undergone lower limb orthopedic surgery in spinal anesthesia. During shifting from postoperative ward footdrop was suspected during routine assessment of regression of spinal level. Immediately the patient was referred to a neurologist and magnetic resonance imaging was done, which was inconclusive. Conservative management was started and nerve conduction study was done on the 4th postoperative day that confirmed pure motor neuropathy of right peroneal nerve. Patient was discharged with ankle splint and physiotherapy after slight improvement in motor power (2/5). Conclusions Foot drop is very rare after spinal anesthesia. Any suspected patient must undergo emergent neurological consultation and magnetic resonance imaging to exclude major finding and need for early surgical intervention.

Resumo Justificativa e objetivos Pé caído no período pós-operatório é muito raro após a anestesia espinhal. Avaliação clínica e intervenções diagnósticas precoces são de primordial importância para estabelecer a etiologia e iniciar o tratamento adequado. Um acompanhamento atento é justificado no pós-operatório imediato nos casos em que o paciente se queixa de parestesia ou dor durante a inserção da agulha ou da injeção de fármacos. Relato de caso Paciente do sexo masculino, 22 anos, submetido a cirurgia ortopédica de membros inferiores sob anestesia espinhal. Durante a transferência para a sala de recuperação pós-operatória, houve suspeita de pé caído durante a avaliação rotineira da regressão do nível espinhal. O paciente foi imediatamente enviado ao neurologista e uma ressonância magnética foi feita, mas não foi conclusiva. O manejo conservador foi iniciado e o estudo de condução nervosa foi feito no 4° dia de pós-operatório, o que confirmou a neuropatia motora pura do nervo fibular direito. O paciente foi dispensado com imobilizador de tornozelo e fisioterapia após ligeira melhoria da força motora (2/5). Conclusões Pé caído é muito raro após a anestesia espinhal. Qualquer paciente suspeito deve ser submetido à consulta neurológica de emergência e ressonância magnética para excluir o principal achado e a necessidade de intervenção cirúrgica precoce.

Atrial myxoma in a patient with patent foramen ovale: evaluation with multimodal imaging. Case report / Mixoma auricular en un paciente con foramen oval permeable: evaluación con imágenes multimodales. Reporte de un caso

Abstract: Primary cardiac tumors in adults are rare and mostly benign, approximately 75%, being the myxoma the most frequent in half of that percentage. One-fourth of the primary cardiac tumors are malignant and 95% of the cases are sarcomas. Metastases are more frequent than primary tumors. Cardiac surgery is indicated specially in benign masses and therapies such as chemotherapy and/or radiotherapy should be reserved for unresectable or metastatic malignancies. Hence the importance of a diagnostic approach, which leads to the best therapeutic conduct and in many cases, a multimodal image approach is necessary, as it is exposed in our case.(AU)

Resumen: Los tumores cardiacos primarios en adultos son raros y en su mayoría benignos, aproximadamente el 75%, siendo el mixoma el más frecuente en la mitad de ese porcentaje. Un cuarto de los tumores cardiacos primarios son malignos y el 95% de los casos son sarcomas. Las metástasis son más frecuentes que los tumores primarios. La cirugía cardiaca está indicada especialmente en masas benignas y las terapias como la quimioterapia y/o la radioterapia deben reservarse para tumores malignos o metástasis irresecables. De ahí la importancia de un enfoque de diagnóstico, que conduzca a la mejor conducta terapéutica y, en muchos casos, es necesario un enfoque de imagen multimodal, como está expuesto en nuestro caso.(AU)

Prostate cancer detection using multiparametric 3 – tesla MRI and fusion biopsy: preliminary results

ABSTRACT Objective: To evaluate the diagnostic efficacy of transrectal ultrasonography (US) biopsy with imaging fusion using multiparametric (mp) magnetic resonance imaging (MRI) in patients with suspicion of prostate cancer (PCa), with an emphasis on clinically significant tumors according to histological criteria. Materials and Methods: A total of 189 consecutive US/MRI fusion biopsies were performed obtaining systematic and guided samples of suspicious areas on mpMRI using a 3 Tesla magnet without endorectal coil. Clinical significance for prostate cancer was established based on Epstein criteria. Results: In our casuistic, the average Gleason score was 7 and the average PSA was 5.0ng/mL. Of the 189 patients that received US/MRI biopsies, 110 (58.2%) were positive for PCa. Of those cases, 88 (80%) were clinically significant, accounting for 46.6% of all patients. We divided the MRI findings into 5 Likert scales of probability of having clinically significant PCa. The positivity of US/MRI biopsy for clinically significant PCa was 0%, 17.6% 23.5%, 53.4% and 84.4% for Likert scores 1, 2, 3, 4 and 5, respectively. There was a statistically significant difference in terms of biopsy results between different levels of suspicion on mpMRI and also when biopsy results were divided into groups of clinically non-significant versus clinically significant between different levels of suspicion on mpMRI (p-value <0.05 in both analyzes). Conclusion: We found that there is a significant difference in cancer detection using US/MRI fusion biopsy between low-probability and intermediate/high probability Likert scores using mpMRI.

Ressonância magnética de tórax em portadores de dispositivos cardíacos eletrônicos implantáveis condicionais para ressonância magnética: contraindicação clássica ou exame seguro / Chest magnetic resonance imaging in patients with magnetic resonance imagingconditional pacemakers: classical contraindication or a safe test

Introdução: Este estudo teve por objetivo verificar o impacto do artefato de suscetibilidade magnéticaproduzido pelo gerador de pulsos e pelos cabos-eletrodos dos dispositivos cardíacos eletrônicos implantáveis nasimagens geradas pela ressonância magnética de tórax, avaliando, assim, sua interferência no resultado final doexame, além de analisar as possíveis alterações no funcionamento dos dispositivos, por meio da avaliação e dacomparação dos parâmetros (limiares de estimulação atriais e ventriculares, impedâncias dos cabos-eletrodosatriais e ventriculares, amplitudes das ondas P e R e status da bateria) pré - e pós-ressonância magnética. Método:Foram realizados exames de ressonância magnética de tórax em 20 portadores de dispositivos cardíacos eletrônicosimplantáveis ProMRI®, sendo 11 do sexo masculino e 9 do sexo feminino. As imagens e os artefatos gerados e ofuncionamento pré- e pós-exame dos dispositivos cardíacos eletrônicos implantáveis foram avaliados e comparados.Resultados: A avaliação da imagem gerada mostrou que o artefato de suscetibilidade magnética produzido poresses dispositivos não provocou interferência significativa na imagem, não afetando a avaliação do resultado e,consequentemente, o diagnóstico. As avaliações dos dispositivos pré- e pós-exame de ressonância magnéticademonstraram que não ocorreram danos na interface cabo-eletrodo/miocárdio, alterações na impedância esensibilidade dos cabos-eletrodos, e alterações nas capacidade remanescente das baterias. Conclusão: O examede ressonância magnética de tórax em portadores de dispositivos cardíacos eletrônicos implantáveis ProMRI®pode ser realizado com segurança, sem alterar o funcionamento dos dispositivos e sem prejudicar a imagem daressonância magnética, desde que algumas regras e condições sejam seguidas corretamente.

This study was aimed at assessing the impact of magnetic susceptibility artifactproduced by the pulse generator and the leads of cardiac implantable electronic devices on the images generatedby chest magnetic resonance imaging, and therefore evaluate its impact on the final result of the test, in additionto analyzing possible changes in the operation of these devices, by means of the evaluation and comparisonof parameters (atrial and ventricular pacing thresholds, atrial and ventricular lead impedance, P and Rwave amplitudes and battery status) before and after magnetic resonance imaging. Method: Chest magneticresonance imaging was performed in 20 patients with ProMRITM cardiac implantable electronic device, 11 malesand 9 females. The images and the artifacts and pre and post test operation of cardiac implantable electronic devices were evaluated and compared. Results: The analysis of the generated image showed that the magneticsusceptibility artifact produced by these devices did not cause significant interference in the image and did notaffect the evaluation of the outcome and consequently, the diagnosis. Evaluations of the device before and aftermagnetic resonance imaging showed that there were no damages on the lead/myocardium interface, and nor inthe impedance and sensitivity of the leads and there were no changes in the remaining capacity of the batteries.Conclusion: Chest magnetic resonance imaging in patients with the ProMRITM cardiac implantable electronicdevice can be performed safely with no impact on the operation of the devices and on the image generated bymagnetic resonance imaging, as long as certain rules and conditions are followed.

Comparison of Multi-Echo Dixon Methods with Volume Interpolated Breath-Hold Gradient Echo Magnetic Resonance Imaging in Fat-Signal Fraction Quantification of Paravertebral Muscle

OBJECTIVE: To assess whether multi-echo Dixon magnetic resonance (MR) imaging with simultaneous T2* estimation and correction yields more accurate fat-signal fraction (FF) measurement of the lumbar paravertebral muscles, in comparison with non-T2*-corrected two-echo Dixon or T2*-corrected three-echo Dixon, using the FF measurements from single-voxel MR spectroscopy as the reference standard. MATERIALS AND METHODS: Sixty patients with low back pain underwent MR imaging with a 1.5T scanner. FF mapping images automatically obtained using T2*-corrected Dixon technique with two (non-T2*-corrected), three, and six echoes, were compared with images from single-voxel MR spectroscopy at the paravertebral muscles on levels L4 through L5. FFs were measured directly by two radiologists, who independently drew the region of interest on the mapping images from the three sequences. RESULTS: A total of 117 spectroscopic measurements were performed either bilaterally (57 of 60 subjects) or unilaterally (3 of 60 subjects). The mean spectroscopic FF was 14.3 +/- 11.7% (range, 1.9-63.7%). Interobserver agreement was excellent between the two radiologists. Lin's concordance correlation between the spectroscopic findings and all the imaging-based FFs were statistically significant (p < 0.001). FFs obtained from the T2*-corrected six-echo Dixon sequences showed a significantly better concordance with the spectroscopic data, with its concordance correlation coefficient being 0.99 and 0.98 (p < 0.001), as compared with two- or three-echo methods. CONCLUSION: T2*-corrected six-echo Dixon sequence would be a better option than two- or three-echo methods for noninvasive quantification of lumbar muscle fat quantification.

Permeability Parameters Measured with Dynamic Contrast-Enhanced MRI: Correlation with the Extravasation of Evans Blue in a Rat Model of Transient Cerebral Ischemia

OBJECTIVE: The purpose of this study was to correlate permeability parameters measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a clinical 3-tesla scanner with extravasation of Evans blue in a rat model with transient cerebral ischemia. MATERIALS AND METHODS: Sprague-Dawley rats (n = 13) with transient middle cerebral artery occlusion were imaged using a 3-tesla MRI with an 8-channel wrist coil. DCE-MRI was performed 12 hours, 18 hours, and 36 hours after reperfusion. Permeability parameters (K(trans), v(e), and v(p)) from DCE-MRI were calculated. Evans blue was injected after DCE-MRI and extravasation of Evans blue was correlated as a reference with the integrity of the blood-brain barrier. Correlation analysis was performed between permeability parameters and the extravasation of Evans blue. RESULTS: All permeability parameters (K(trans), v(e), and v(p)) showed a linear correlation with extravasation of Evans blue. Among them, K(trans) showed highest values of both the correlation coefficient and the coefficient of determination (0.687 and 0.473 respectively, p < 0.001). CONCLUSION: Permeability parameters obtained by DCE-MRI at 3-T are well-correlated with Evans blue extravasation, and K(trans) shows the strongest correlation among the tested parameters.

Application and preventive maintenance of neurology medical equipment in Isfahan Alzahra hospital

Nowadays Medical equipment plays an important role in the treatment and in the medical education. Using outdated preventive maintenance [PM] system may cause problems in the cutting edge medical equipment, Nervous system disease's equipment [In diagnosis and treatment] which are crucial for every medical center. Based on above facts we focused on nervous system treat units' equipment and informed the supervisors and their colleagues about the latest equipment maintenance status and promoted methodical and correct method to be used for medical equipment maintenance. This research is an analytical descriptive and has been done on the base information from a particular time to past. We gathered our required information of 2009 from Alzahra Medical Center. We divided this research info 2 main phases. In the first phase, we picked out Neurosurgery and Neourology diseases medical equipment [diagnosis and therapy equipment] and in the second phase, we need to implement a methodical PM for every equipment. Research has shown that there are 19 nervous system equipment in Alzahra Medical center, categorized in diagnostic [13 pcs], therapeutic [4 pcs] and diagnostic therapeutic [2 pcs]. As we declare in methods part of this research, we categorized medical equipment in Food and Drug Administration [FDA] segmentation. Capital-scarce equipment: Magnetic resonance imaging, Eco Doppler, Kamalaarak ultrasonic surgical aspirator, Stereotactic, computed tomography-scan, euroendoscope/vital-scarce equipment: Coblation, Sonoco, vaterjet/ scarce equipment: Transcranial color Doppler, electroencephalogram, electromyography, surgical microscope. Survey of application and preventive maintenance of neurology medical equipment in Isfahan Alzahra hospital show there is no P.M system. Implementing a complete P.M system for this medical center is crucial to preventing cause problems for these medical equipment and decreasing maintenance costs and gaining uptime. Researchers of this article have tried to provide PM, use of texts, web and experts

Accuracy of Preoperative MRI with Microscopy Coil in Evaluation of Primary Tumor Thickness of Malignant Melanoma of the Skin with Histopathologic Correlation

OBJECTIVE: The purpose of this study was to evaluate the accuracy of a preoperative MRI with microscopy coils in determining the primary tumor thickness of malignant melanoma with histopathologic correlation. MATERIALS AND METHODS: Eleven patients with histopathologically confirmed malignant melanoma were included in this study. MR images of the tumors were obtained with a 47-mm microscopy coil on 1.5T MR scanners and were evaluated by two radiologists, who assessed the thickness of the primary tumor on T2-weighted images (T2WI) and gadolinium-enhanced T1-weighted images with fat suppression (Gd-T1WI) and compared the results with the histopathologic findings as the reference standard. Correlations between tumor thickness on MRI and histopathologic examination were assessed using concordance correlation coefficients (CCCs). Inter- and intraobserver variabilities of tumor measurements were also assessed by intraclass correlation coefficient (ICC). RESULTS: Among the 11 cases included in the study, 10 cases from the same number of patients were managed with surgical excision and one case was confirmed with punch biopsy. The primary tumor thickness measured on T2WI showed better correlation with histopathologic results, as compared with measurements taken on Gd-T1WI: the CCC of measurements on T2WI ranged from 0.64 to 0.78, indicating a substantial agreement, whereas the CCC of measurements on Gd-T1WI ranged from 0.50 to 0.61, indicating a moderate to substantial agreement. Inter- and intraobserver agreements of readers 1 and 2 were excellent for both T2WI and Gd-T1WI, with ICC ranging from 0.86 to 0.99. CONCLUSION: MR imaging with microscopy coils may be an accurate technique in the preoperative assessment of tumor thickness in malignant melanoma, especially on T2-weighted images.

MRI-Guided Intervention for Breast Lesions Using the Freehand Technique in a 3.0-T Closed-Bore MRI Scanner: Feasibility and Initial Results

OBJECTIVE: To report the feasibility of magnetic resonance imaging (MRI)-guided intervention for diagnosing suspicious breast lesions detectable by MRI only, using the freehand technique with a 3.0-T closed-bore MRI scanner. MATERIALS AND METHODS: Five women with 5 consecutive MRI-only breast lesions underwent MRI-guided intervention: 3 underwent MRI-guided needle localization and 2, MRI-guided vacuum-assisted biopsy. The interventions were performed in a 3.0-T closed-bore MRI system using a dedicated phased-array breast coil with the patients in the prone position; the freehand technique was used. Technical success and histopathologic outcome were analyzed. RESULTS: MRI showed that four lesions were masses (mean size, 11.5 mm; range, 7-18 mm); and 1, a nonmass-like enhancement (maximum diameter, 21 mm). The locations of the lesions with respect to the breast with index cancer were as follows: different quadrant, same breast - 3 cases; same quadrant, same breast - 1 case; and contralateral breast - 1 case. Histopathologic evaluation of the lesions treated with needle localization disclosed perilobular hemangioma, fibrocystic change, and fibroadenomatous change. The lesions treated with vacuum-assisted biopsy demonstrated a radial scar and atypical apocrine hyperplasia. Follow-up MRI after 2-7 months (mean, 4.6 months) confirmed complete lesion removal in all cases. CONCLUSION: MRI-guided intervention for breast lesions using the freehand technique with a 3.0-T closed-bore MRI scanner is feasible and accurate for diagnosing MRI-only lesions.