Benjamin Peters

Diffusion Kurtosis Imaging: A Possible MRI Biomarker for AD Diagnosis?

Abstract The purpose of this explorative study was to investigate whether diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) parameter changes are reliable measures of white matter integrity changes in Alzheimer’s disease (AD) patients using a whole brain voxel-based analysis (VBA). Therefore, age- and gender-matched patients with mild cognitive impairment (MCI) due to AD (n = 18), dementia due to AD (n = 19), and age-matched cognitively healthy controls (n = 14) were prospectively included. The magnetic resonance imaging protocol included routine structural brain imaging and DKI. Datasets were transformed to a population-specific atlas space. Groups were compared using VBA. Differences in diffusion and mean kurtosis measures between MCI and AD patients and controls were shown, and were mainly found in the splenium of the corpus callosum and the corona radiata. Hence, DTI and DKI parameter changes are suggestive of white matter changes in AD.

Resting state functional MRI as a possible biomarker for Alzheimer’s disease: An innovative approach for robust extraction of the default mode network

P4-248 RESTING STATE FUNCTIONAL MRI AS A POSSIBLE BIOMARKER FOR ALZHEIMER’S DISEASE: AN INNOVATIVE APPROACH FOR ROBUST EXTRACTION OF THE DEFAULT MODE NETWORK Hanne Struyfs, Dirk Smeets, Vasilis Terzopoulos, Sylvie Slaets, Laura Wuyts, Benjamin Peters, Frank De Belder, Paul M. Parizel, Wim Van Hecke, Sebastiaan Engelborghs, Reference Center for Biological Markers of Dementia (BIODEM), Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; icoMetrix, Leuven, Belgium; icoMetrix, Leuven, Belgium; University of Antwerp, Antwerp, Belgium; Antwerp University Hospital & University of Antwerp, Antwerp, Belgium; Department of Neurology and Memory Clinic, Hospital Network Antwerp, Middelheim and Hoge Beuken, Antwerp, Belgium; Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; Hospital Network Antwerp (ZNA), Antwerp, Belgium. Contact e-mail: hanne.struyfs@uantwerpen.be

Imaging and Staging of Thymic Tumors

The thymus is a primary lymphoid organ located in the upper prevascular mediastinum. A number of masses arise in relation to the thymus. Accurate knowledge of anatomy and imaging features is essential for the differentiation between non-tumoral thymic pathology and malignant thymic tumors. In general, a benign hyperplasia of the thymus occurs in children and young adults, while in adults thymoma is the most common tumor. Furthermore imaging is of great importance in the preoperative staging and (oncological) follow-up. Computed tomography (CT) is the imaging modality of choice to assess the mediastinal structures, including the thymus. Medical imaging is essential to further characterize those lesions that warrant further workup. Surgery is the gold standard for the treatment of thymoma with the aim of complete resection. We provide an overview of thymic masses with typically imaging features: thymic hyperplasia, thymic cyst, thymolipoma, thymoma, thymic carcinoma, and thymic carcinoid. Lymphoma will be discussed in Chapter 15: Imaging of Non-thymic Mediastinal Tumors.

5-Year survival after splenectomy in a patient with recurrent cutaneous melanoma: a case report

Abstract Objective: Splenic metastases of melanoma are uncommon and generally part of a disseminated disease with a poor prognosis. In case of solitary visceral metastasis, surgical resection often remains an effective treatment. This case describes a long-term survival after splenectomy for a recurrent melanoma. Methods: We present a 55-year-old female with a solitary splenic metastasis. Her medical history revealed a melanoma of the foot in 2007 and an in-transit metastasis in 2011. A PET-CT revealed in 2012 the presence of a small aspecific lesion in the spleen. Close follow-up was chosen. Since PET-CT and MRI showed a progressive lesion, a laparoscopic splenectomy was performed. Results: Histological report confirmed the diagnosis of a metastatic lesion. Sixty months after the first radiographic evidence of the splenic metastasis, follow-up revealed no signs of residual disease. Conclusions: Although current systemic approaches demonstrate to provide clinically important benefit, patients with oligometastatic disease should be evaluated for surgical metastasectomy. A laparoscopic approach for splenic metastasis is shown to be a safe treatment. This disease-free survival of 60 months in a patient with a history of an in-transit metastasis has not been published before. A splenectomy for a solitary metastasis could prolong the survival, even in a recurrent melanoma.

Pear-Shaped Lesion of the Fossa of Rosenmüller

Retention cyst of the pharyngeal mucosal space is an accumulation of trapped mucous in the mucosa or adenoids of the pharynx. It is a benign lesion, often seen on routine imaging of the head and spine. It is typically a simple cyst originating from the pharyngeal mucosa, without invasion of the surrounding structures. It is important not to misinterpret a retention cyst as a malignant tumor. Patients are usually asymptomatic and do not need treatment.

Imaging Patterns of Metastatic Melanoma

Malignant melanoma is an aggressive tumor, which may spread to all organ systems either by local invasion, or lymphatic or hematogenous dissemination. Skin, subcutaneous tissue, and regional lymph nodes account for up to 59% of metastasis. Lung, liver, and brain are other commonly involved organs, but any organ can be affected. Although there is no use for imaging in early staging of melanoma, imaging can play an important role in advanced disease. In this chapter we will discuss the value of each imaging technique and illustrate the metastatic pattern of malignant melanoma.

Hepatosplenic Sarcoidosis Complicated by Liver Cirrhosis

Sarcoidosis is a multisystemic disease usually affecting the lungs and mediastinal lymph nodes. Other organs, such as the liver and the spleen, are less commonly involved. Patients usually present with mild nonspecific symptoms. On imaging, hepatosplenomegaly with or without multiple focal lesions within the spleen may be seen in the active disease stage. Rarely, the disease may evolve to cirrhosis and liver failure. We report such a rare case of hepatosplenic sarcoidosis complicated by acute esophageal bleeding due to portal hypertension.

DIFFUSION KURTOSIS IMAGING: A BIOMARKER FOR EARLY DIAGNOSIS OF ALZHEIMER'S DISEASE?

O2-03-05 HYPOMETABOLISM AND CORTICAL ATROPHY IN [18F]FLORBETAPIR ACCUMULATORS AND NON-ACCUMULATORS Sara Mohades, Sulantha Sanjeewa Mathotaarachchi, Maxime Parent, Monica Shin, Seqian Wang, Andrea Lessa Benedet, Antoine Leuzy, Thomas Beaudry, Eduardo Rigon Zimmer, Laksanun Cheewakriengkrai, Daliah Farajat, Vladmir Fonov, Simon Eskildsen, Serge Gauthier, Pedro Rosa-Neto, McGill Center for Studies in Aging, Montreal, Quebec, Canada; McGill University, Montreal, Quebec, Canada; McGill Centre for Studies in Aging, Montreal, Quebec, Canada; McGill University, Montreal, Quebec, Canada; McGill University, Montreal, Quebec, Canada; McGill University, Montreal, Quebec, Canada; Aarhus University, Aarhus, Denmark; McGill Center for Studies in Aging, Montreal, Quebec, Canada; MCSA, Montreal, Quebec, Canada. Contact e-mail: sara.mohades@gmail.com