84 research outputs found
The role of 3 Tesla diffusion-weighted imaging in the differential diagnosis of benign versus malignant cervical lymph nodes in patients with head and neck squamous cell carcinoma.
No full texthe aim of this study was to validate the role of diffusion-weighted imaging (DWI) at 3 Tesla in the differential diagnosis between benign and malignant laterocervical lymph nodes in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods. Before undergoing surgery, 80 patients, with biopsy proven HNSCC, underwent a magnetic resonance exam. Sensitivity (Se) and specificity (Spe) of conventional criteria and DWI in detecting laterocervical lymph node metastases were calculated. Histological results from neck dissection were used as standard of reference. Results. In the 239 histologically proven metastatic lymphadenopathies, the mean apparent diffusion coefficient (ADC) value was 0.903 x 10-3 mm2/sec. In the 412 pathologically confirmed benign lymph nodes, an average ADC value of 1.650 x 10"3 mm2/sec was found. For differentiating between benign versus metastatic lymph nodes, DWI showed Se of 97% and Spe of 93%, whereas morphological criteria displayed Se of 61% and Spe of 98%. DWI showed an area under the ROC curve (AUC) of 0.964, while morphological criteria displayed an AUC of 0.715. Conclusions. In a DWI negative neck for malignant lymph nodes, the planned dissection could be converted to a wait-and-scan policy, whereas DWI positive neck would support the decision to perform a neck dissection
High resolution 3-T MR imaging in the evaluation of the trigeminal nerve course
No full textBACKGROUND: The evaluation of the trigeminal course and his anatomical relationships with surrounding structures, is important for the assessment of the injury that may occur in tumors and several orofacial trauma and for avoiding the damage during surgeries. AIM: The aim of this retrospective study was to assess the use of 3-T MRI in the evaluation of the course of the four segments of the trigeminal nerve: cisternal and Meckels's cave, cavernous sinus, skull base and mandibular extracranial segments. PATIENTS AND METHODS: 78 patients were studied, for a total of 156 trigeminal nerves examined. T2-weighted 3D Fast imaging employing steady-state acquisition and T1-weighted Fast spoiled gradient recalled echo sequences were used. Two radiologists (reader A and B), independently, evaluated the course of the four segments of the trigeminal nerve according to a qualitative scale. The Intraclass correlation coefficient (ICC) and Pearson correlation coefficient were used to assess the intraobserver and interobserver variability in the nerve course evaluation. RESULTS: Reader A evaluated 47 trigeminal nerves excellent, 94 good, 12 fair and 3 poor. Reader B rated 43 trigeminal nerves excellent, 92 good, 16 fair and 5 poor. The intraobserver variability was ICC = 0.937 in reader A and ICC = 0.894 in reader B. The interobserver variability was 0.734 (p = 0.01). CONCLUSIONS: High resolution 3-T MRI imaging allows an accurate study of the trigeminal nerve and especially of its mandibular branch. The knowledge of the course and of the anatomic relationships of these nerve bundles with surrounding structures, as well as of the anatomical variants, allow oral and maxillofacial surgical plannings thus reducing the risk of nerve damage
Atypical localization and atypical magnetic resonance imaging findings of a paraganglioma at the mouth mucosa.
No full textWe present a case of a paraganglioma located at the cheek. The benign nature of the lesion was certainly suggested by the patient's anamnesis, ecotomography, and needle biopsy; nevertheless, before the excision, the surgeon requested magnetic resonance imaging with contrast stain only to better evaluate the relationship between the lesion and the surrounding structures and not to have a precise diagnosis.Under magnetic resonance examination by using T1, T2, and T1 before and after contrast sequences, it showed an aspect different from the conventionally described features for this kind of lesion. After excision, the mass showed a yellowish color and a liquid content. Histologic examination described it as having the features of a glomus tumor
Comparing proton density and turbo spin echo T2 weighted static sequences with dynamic half-Fourier single-shot TSE pulse sequence at 3.0 T in diagnosis of temporomandibular joint disorders: a prospective study.
No full textObjectives: The aim of this prospective study was to compare dynamic and static sequences in the evaluation of temporomandibular joint disorders using a 3.0-T imaging unit. Methods: 194 patients were evaluated by static (double echo proton density weighted/turbo spin echo T-2 weighted sequences) and dynamic (half-Fourier single-shot turbo spin echo sequences) imaging. Two radiologists evaluated in consensus the quality of images, the disc position and morphological alterations. The Kendall rank correlation coefficient (tau-b) was used to compare the qualitative rating between static and dynamic sequences. Cohen's kappa coefficient (k) was used to assess the agreement of disc position and morphological alterations between both sequences. The intraclass correlation coefficient was used to calculate the intraobserver variability. The significance was set at p <= 0.05. Results: The correlation between both sequences in the qualitative evaluation was tau-b = 0.632. The agreement between both techniques in the evaluation of disc position was k = 0.856. The agreement between both techniques in assessing the morphological alterations was k = 0.487. In the static sequences, the intraclass correlation coefficient was 0.915 in the qualitative evaluation, 0.873 in the evaluation of disc position and 0.934 in the assessment of morphological alterations. In the dynamic sequences, the intraclass correlation coefficient was 0.785 in the qualitative evaluation, 0.935 in the evaluation of disc position and 0.826 in the assessment of morphological alterations. Conclusions: Static imaging remains the gold standard in the evaluation of the temporomandibular joint. Dynamic imaging is a valuable tool that can provide additional information about topographic changes in the disc condyle relationship
Surveillance of patients affected by Peutz-Jeghers syndrome: Diagnostic value of MR enterography in prone and supine position
No full textIntroduction: Peutz-Jeghers syndrome (PJS) is a familial polyposis syndrome characterized by multiple hamartomatous polyps throughout the gastrointestinal tract. The aim of our study was to retrospectively determine the diagnostic value of MR enterography (MRE), performed in supine and prone position, in the detection of small bowel polyps in PJ patients. Materials and methods: We retrospectively reviewed MRE examinations of 8 PJS patients who underwent MRE, pushed-double-ballon enteroscopy, laparoscopic endoscopy or surgery, within 3 months. Polietilenglicole was orally administered before the examination. True FISP and HASTE sequences were acquired in supine and prone position; 3D VIBE Gd-enhanced sequences in prone position only. Results: Concordance between MRE and endoscopy was 72.6% for polyps 15 mm. In supine and prone position concordance with endoscopy for polyps <15 mm was 63% and 66.8%, respectively. In the detection of smaller polyps the difference between supine position only and supine plus prone position was statistically significant (P < 0.027). Discussion: MRE performed by combining prone and supine position was accurate in the detection of PJS polyps, with 93% concordance with enteroscopy for larger and more risky polyps. MRE offers a promising and non invasive alternative to capsule endoscopy, suggesting the possibility of an effective yearly surveillance in PJ patients. © Springer Science+Business Media, LLC 2011
Pitfalls in Interpreting mp-MRI of the Prostate: A Pictorial Review with Pathologic Correlation
No full textObjectives: The purpose of this pictorial review is to present a wide spectrum of prostate multiparametric MRI (mp-MRI) pitfalls that may occur in clinical practice, with radiological and pathological correlation. Methods: All examinations were performed according to ESUR Guidelines protocols. Results and Conclusion: mp-MRI imaging of the prostate often leads to interpreting doubts and misdiagnosis due to the many interpretative pitfalls that a tissue, whether healthy or treated, may cause. These “false-positive” findings may occur in each stage of the disease history, from the primary diagnosis and staging, to the post-treatment stage, and whether they are caused by the tissue itself or are iatrogenic, their recognition is critical for proper treatment and management. Knowledge of these known pitfalls and their interpretation in the anatomical-radiological context can help radiologists avoid misdiagnosis and consequently mistreatment. Main Messages: • Some physiological changes in the peripheral and central zone may simulate prostate cancer. • Technical errors, such as mispositioned endorectal coils, can affect the mp-MRI interpretation. • Physiological changes post-treatment can simulate recurrenc
Including Nomadic People in Collaborative E-learning: Experiences in Research Projects
No full textThe focus of this chapter is the design of a solution for Computer-Supported Cooperative Learning (CSCL) that is able to connect both stationary and mobile users in live shared-learning sessions. The authors started from experiences that were mainly technology-driven to arrive at the development of two subsystems, OpenWebTalk and MobileWebTalk, that build, flexibly and simply, mixed reality environments in which users cooperate to perform the same learning task. From these experiences, the authors argue that heterogeneous learning environments (stationary and mobile) can only be really effective if they are designed from a unique abstract model. Therefore the challenge is to derive a conceptual model to describe a collaborative learning session that can be deployed in different devices
Incidental discovery of testicular microlithiasis: What is the importance of ultrasound surveillance? Two case reports
No full textMany studies have demonstrated an association between diffuse bilateral testicular microlithiasis (TM) and gonadal and extragonadal germ cell tumors. Nevertheless, it is still uncertain whether ultrasound surveillance is really necessary in patients with TM in the absence of other risk factors such as previous testicular cancer, a history of cryptorchidism or testicular atrophy. We report the cases of a 33- and a 39-year-old man presenting with a retroperitoneal extragonadal tumor. The first patient underwent an MRI examination in order to rule out a lumbosacral hernia: MRI images showed no slipped disks but a voluminous retroperitoneal solid mass. The histological analysis revealed an immature teratoma. The second patient came to the emergency department complaining of abdominal pain, vomiting, weight loss and mild jaundice: ultrasound examination showed a large, ill-defined heterogeneous abdominal mass, confirmed by CT and MRI examination. The histology diagnosed a yolk sac tumor. In both patients, the testicular sonography was performed to rule out a focal lesion, but it displayed bilateral TM without a focal testicular mass. Based on our direct experience, we highlight the importance of annual ultrasonographic surveillance of the testis and the retroperitoneal space in patients with occasionally detected TM
Dynamic Contrast-enhanced Magnetic Resonance Imaging in the Early Evaluation of Anti-angiogenic Therapy in Metastatic Renal Cell Carcinoma
No full textAim: To evaluate the efficacy of dynamic contrast-enhanced magnetic resonance (DCE-MR) in the response to anti-angiogenic-targeted agents in patients with metastatic renal cell cancer (mRCC). Patients and Methods: Twenty-eight consecutive patients with sub-diaphragmatic metastases from mRCC were included in the protocol after signed informed consent. Baseline characteristics were collected and patients were first evaluated with a baseline computed tomography (CT) and DCE-MR, subsequently with a new DCE-MRI after 28 days of therapy and followed-up with CT until progression. Treatments were administered at standard doses. The changes of peak enhancement (Delta PE) and of the sum of longest tumor diameters (Delta LTD) were related to progression-free survival (PFS) and overall survival (OS). Results: The median PFS was 11.4 months [95% Confidence Interval (CI): 7.9-14.7 months) and the parametric two-tailed Pearson's test showed a positive correlation between the median Delta PE and the median PFS (rp=0.809; p=0.015); no significant correlation was found between the median Delta LTD and the median PFS (rp=-0.446; p=0.27). The median OS was 23.3 months (95% CI: 13.6-33.0 months) and no significant correlation was found with the median Delta PE (rp=0.218; p=0.60) or with the median Delta LTD (rp=0.012; p=0.98). Conclusion: The APE but not the Delta LTD was found to be significantly related to PFS; these preliminary results suggest extending the number of patients and investigating the possible relationship with other tumor characteristics and MRI parameters
3.0 Tesla MRI in the early evaluation of inferior alveolar nerve neurological complications after mandibular third molar extraction: a prospective study.
No full textObjectives: To evaluate the use of 3.0 T MRI in the prognosis of inferior alveolar nerve (IAN) sensory disorders after mandibular third molar extraction, in the early post-operative period. Methods: 343 IANs were examined before and 3 days after surgery. Two radiologists evaluated the course of the nerve and the relative signal intensity (RSI). Cohen's kappa coefficient (κ) and intraclass correlation coefficient (ICC) were used to evaluate the interobserver (k = 0.891) and intra-observer variability (ICC = 0.927; 0.914, respectively). The IANs were divided into four groups on the basis of neurosensory disorders recovery time. ANOVA was used to evaluate the differences among the RSIs of the four groups, and multiple comparisons were performed with Tukey's range test. Results: No differences in the course of IANs were found before and after surgery. In 280 IANs, no iatrogenic paraesthesia was found (Group A). 63 IANs showed a neurosensory impairment. 38 IANs showed recovery of post-operative paraesthesia at 3-month follow-up (Group B). 16 IANs showed a full recovery of iatrogenic paraesthesia at 6-month follow-up (Group C). Seven IANs displayed a full recovery at 12-month follow-up and two IANs showed persistence of neurosensory disorders at 18-month follow-up (Group D). The one-way ANOVA results indicated statistically significant difference among all groups (p < 0.05), except between Groups C and D (p = 0.504). Conclusions: The early evaluation of RSI values represents a valid tool to determine the prognosis of IAN sensory disorders after mandibular third molar extraction
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