Multiple Imaging Examinations Research Articles

Sonographic Findings in a Case of Crohn Disease

Crohn disease is an incurable inflammatory bowel disease that can involve the large or small bowel but typically is located at the terminal ileum. The disease ranges from mild inflammation to bowel obstruction, fistula, and abscess formation and is typically diagnosed during adolescence or the early 20s. Patients with Crohn disease undergo multiple follow-up imaging examinations for the disease during the course of their lives. Sonographic findings in an adolescent patient diagnosed with Crohn disease are discussed. Sonography is emerging not only as an effective imaging modality for long-term disease follow-up but also, with the addition of hydrosonography and improved transducer technology, as a primary diagnostic tool.

Clinical observation of extraocular extension of choroidal melanoma

To evaluate the clinical features, diagnostic methods and treatment of extraocular extension of choroidal melanoma. It was a retrospective case series study. The records of 12 consecutive cases with extraocular extension of choroidal melanoma confirmed by pathologic examination were analyzed with special attention to the case histories, clinical manifestations, imaging findings, treatment and follow up results. Four patients were misdiagnosed as glaucoma. Another 4 patients were confirmed the diagnosis of melanoma and 3 of them received the operations of transscleral local resection. The common clinical manifestations included: impaired vision, exophthalmos, blepharoptosis, limited ocular motility, conjunctival hyperemia, and increased ocular or orbital pressure, etc. Characteristic sign was raised mass on the surface of sclera. All cases underwent orbital MRI preoperatively, 6 underwent ocular B-scan echography, and 6 underwent orbital CT scanning to evaluate for extraocular extension of tumor. Typical ultrasonography revealed the discontinued ocular wall and an intraocular mass with a continuous hypoechoic extraocular mass. In some cases the extraocular mass showed hypoechoic with medium echo area. CT scan showed a well-defined homogeneous intraconal mass connecting with intraocular lesion in 6 cases, which could infiltrate eye or optic nerve. The MR signal features of intraocular tumors with extraocular extension showed 4 patterns in all patients. The typical pattern was the tumor showed hyperintensity on T(1) and hypointensity on T(2)-weighted image. The maximum diameter of extraocular tumor was measured over 4 mm in 9 cases. MRI was useful for demonstrating multiple extraocular lesions, remote metastatic lesion or micro extraocular tumor, of which minimal diameter was 3 mm in our cases. Orbital exenteration was performed in 11 cases and ocular enucleation with excision of extraocular tumor was in 1 cases. Microscopic examination showed the epithelioid-cell-type tumors were the most common. The tumor extended out of the eye by three types of way in our cases. Follow-up ranged from 1 to 5 years in 8 cases, who underwent chemotherapy, radiotherapy or interferon. Six cases had no recurrences and general health. Death and metastasis was respectively recorded in one case. Delayed treatment could induce the growth of choroidal melanoma to the stage of extraocular extension, which has few specific clinical manifestations. The combination of multiple imaging examinations was helpful for the correct diagnosis. Surgical operation with adjunctive therapies could partly reduce recurrence and metastasis of melanoma.

Guide to magnetic resonance in Crohnʼs disease

Considering that multiple imaging examinations are often necessary for monitoring Crohn's disease (CD) activity and severity in order to guide and monitor appropriate treatment, the ideal imaging test would be reproducible, well tolerated by patients, and free of ionizing radiation. For these reasons recent studies have highlighted the role of a magnetic resonance imaging (MRI) technique optimized for small bowel imaging in the evaluation of small bowel disorders. In this regard there are two main methodological approaches represented by MR enterography, following administration of an oral contrast medium, and MR enteroclysis, following administration of contrast medium through a nasojejuneal tube. MRI may be used to demonstrate the pathologic findings and complications of CD. In particular, MR has excellent sensitivity and specificity, ranging from 88%-98% and 78%-100%, respectively, for the detection of active inflammation, wall thickening, ulcerations, increased wall enhancement, increased vascularity, perienteric inflammation, and reactive adenopathy. MR also allows more accurate identification of associated complications including penetrating and fibrostenotic disease as well as the more rare extraintestinal manifestations that are usually associated with severe and longstanding intestinal inflammation, the latter often guiding the therapeutic approach. In the progression of CD some rare complications can occur that, to our knowledge, were only briefly or never mentioned in the radiological literature regarding MR enterography or enteroclysis and in which the application of these techniques play a key role.

Object-specific Attenuation Correction at SPECT/CT in Thorax: Optimization of Respiratory Protocol for Image Registration

Institutional review board approval was obtained for multiple imaging examinations in healthy volunteers and patients and for the analysis of images. The purpose of the study, and the risks associated with radiation exposure with regard to stochastic effects that might result in cancer and/or genetic mutations, were explained to all subjects, and all questions from subjects were answered. Each subject provided written informed consent. The purpose of the study was to prospectively determine the respiratory protocol at computed tomography (CT) that results in the best registration of CT images with images acquired at single photon emission computed tomography (SPECT) in the thorax. Errors of registration between myocardial SPECT images and CT images obtained with different respiratory protocols (postinhalation breath hold, postexhalation breath hold, and free breathing) in 13 healthy subjects were compared. CT scans obtained with free breathing and postexhalation breath hold better matched SPECT images than did those obtained with postinhalation breath hold (one-way analysis of variance, P < .01). Fewer SPECT/CT images showed artifacts with registration performed by using internal landmarks (four, two, and one of 13 images with postinhalation breath-hold, postexhalation breath-hold, and free-breathing protocols, respectively) than with registration performed by using external markers (nine, four, and two of 13 images). CT data acquisition with a free-breathing or postexhalation breath-hold protocol and image registration by using internal landmarks are recommended for attenuation correction.