Effect of Magnetic Resonance Imaging at 1.5 T and 3 T on Temperature and Bond Strength of Orthodontic Bands with Welded Tubes: An In Vitro Study.

Magnetic resonance imaging (MRI) is a widely used diagnostic technique. Patients wearing orthodontic devices are often requested to remove their appliances before an MRI exam, even when the exam involves anatomical areas far from the head, in order to prevent the heating and detachment of the appliances. The present report aims to evaluate changes in temperature and adhesive forces of molar bands after MRI at two different strength outputs. Sixty stainless steel molar bands were bonded on permanent human upper molars using two different cements: Unitek Multi-Cure Glass Ionomer Band Cement (3M Unitek, Monrovia, CA, USA) and Transbond Plus Light Cure Band Adhesive (3M Unitek). Appliances were subjected to MRI with two different strengths (1.5 Tesla and 3 Tesla). Tubes and band temperature was measured before and after MRI. Subsequently, the shear bond strength (SBS) test was calculated. Data underwent statistical analysis (p < 0.05). After MRI, molar bands exhibited significant heating, even though not clinically relevant, with a temperature increase ranging between 0.48 °C and 1.25 °C (p < 0.05). SBS did not show significant differences (p > 0.05). The present study suggests that, under MRI, the molar bands tested are safe; therefore, their removal could be not recommended for non-head and neck MRI exams. Removal would be necessary just in artifact risk areas.

Bilateral metachronous ovarian metastases from clear cell renal carcinoma: a case report.

INTRODUCTION: Bilateral ovarian metastases from a clear cell renal carcinoma are uncommon findings and need to be differentiated from primary cancers. Diagnostic imaging and histopathological features are often inconclusive, unless they are combined. CASE PRESENTATION: A 56-year-old woman with a history of right radical nephrectomy for a renal clear cell carcinoma diagnosed 10 years earlier was referred for abdominal distension and pelvic pain. Color-Doppler US and Computer Tomography scan revealed the presence of bilateral ovarian masses with regular margins, a low resistance index and poor contrast enhancement. Immunohistochemistry showed positive epithelial membrane antigen, cytokeratin, vimentin and CD10, suggesting clear cells from the previously diagnosed kidney cancer. CONCLUSION: Although bilateral metachronous ovarian metastases from clear cell renal carcinoma are a very uncommon finding, they can be considered in the differential diagnosis and investigated with imaging and immunohistochemistry. The 6 cases reported in the literature indicate a good prognosis for this condition.

MRI features of cotyledonoid dissecting leiomyoma of the uterus.

Imaging evaluation of uterine masses is important to assess the type of lesion and to target surgery, if surgical excision is necessary. This can be decisive in fertile women with benign masses resembling malignancies, in order to avoid overtreatment. In this study, the magnetic resonance imaging (MRI) appearance of cotyledonoid dissecting leiomyoma of the uterus, a rare benign variant of leiomyoma mimicking malignancy, is presented.

Unusual abdominal findings of all-trans-retinoic acid syndrome: role of diagnostic imaging.

The standard therapy for patients affected by acute promyelocytic leukemia is based on all-trans-retinoic acid (ATRA), whose rare complication is a syndrome known as retinoic acid syndrome. We describe for the first time the computed tomography findings of a case of ATRA syndrome with typical pulmonary findings, along with the involvement of the upper abdomen organs (liver and spleen) as a further complication of the pathology.

Diagnostic imaging of lung cancer after heart transplantation.

AIMS AND BACKGROUND: In heart transplant recipients pulmonary neoplasms are among the most frequent solid tumors; they have a rapid and aggressive course, and therefore require an early diagnosis. We describe the role that diagnostic imaging plays in different diagnostic moments of this disease. METHODS: We evaluated the incidence and diagnosis of lung cancer in patients who underwent heart transplants at our institution. Taking into account the few different diagnostic imaging techniques (chest X-ray, high-resolution computed tomography [CT], staging CT and CT-guided biopsy) used in standard surveillance protocols or indicated by clinical symptoms, we evaluated their diagnostic accuracy, their efficacy in tumor staging, and their impact on the therapeutic choices. RESULTS: Seventeen neoplasms in a total of 712 patients were diagnosed (2.4%). In 16 of these 17 cases chest X-ray (routinely performed as follow-up in 11 cases, indicated by symptoms in 5 cases) was diagnostic. In another 11 cases chest X-ray was false positive. The diagnostic accuracy, sensitivity, specificity, positive and negative predictive value of chest X-ray was 98%, 91%, 98%, 50%, and 99%, respectively. Total-body CT correctly staged the tumors and provided information as to whether surgery was indicated or not (stage II or advanced). CONCLUSIONS: Chest X-ray is still the surveillance radiological technique in heart transplant recipients. Considering its low specificity and sensitivity, we propose high-resolution CT imaging during follow-up to identify pulmonary lesions as soon as possible and enable a differential diagnosis with parenchymal inflammation. The use of CT-guided fine-needle biopsy and culture examinations permits to differentiate neoplastic from inflammatory parenchymal opacities. Use of CT in cancer staging is effective for subsequent treatment choices.

Unusual CT findings in urachus carcinoma with an extensive and atypical pattern of metastasis. A case report.

Carcinoma of the urachus is very rare. Usually it has a typical appearance on computed tomography, with calcifications in a midline supravesical mass, but advanced stages of this neoplasm require malignancy evaluation that is not easy to establish. We report a case of a urachal tumor where CT scan did not properly assess the response to chemotherapy, while it did show an uncommon metastatic localization in the laterocervical soft tissues.