New frontiers in imaging including radiomics updates for pancreatic neuroendocrine neoplasms.

OBJECTIVE: To illustrate the applications of various imaging tools including conventional MDCT, MRI including DWI, CT & MRI radiomics, FDG & DOTATATE PET-CT for diagnosis, staging, grading, prognostication, treatment planning and assessing treatment response in cases of pancreatic neuroendocrine neoplasms (PNENs). BACKGROUND: Gastroenteropancreatic neuroendocrine neoplasms (GEP NENs) are very diverse clinically & biologically. Their treatment and prognosis depend on staging and primary site, as well as histological grading, the importance of which is also reflected in the recently updated WHO classification of GEP NENs. Grade 3 poorly differentiated neuroendocrine carcinomas (NECs) are aggressive & nearly always advanced at diagnosis with poor prognosis; whereas Grades-1 and 2 well-differentiated neuroendocrine tumors (NETs) can be quite indolent. Grade 3 well-differentiated NETs represent a new category of neoplasm with an intermediate prognosis. Importantly, the evidence suggest grade heterogeneity can occur within a given tumor and even grade progression can occur over time. Emerging evidence suggests that several non-invasive qualitative and quantitative imaging features on CT, dual-energy CT (DECT), MRI, PET and somatostatin receptor imaging with new tracers, as well as texture analysis, may be useful to grade, prognosticate, and accurately stage primary NENs. Imaging features may also help to inform choice of treatment and follow these neoplasms post-treatment. CONCLUSION: GEP NENs treatment and prognosis depend on the stage as well as histological grade of the tumor. Traditional ways of imaging evaluation for diagnosis and staging does not yet yield sufficient information to replace operative and histological evaluation. Recognition of important qualitative imaging features together with quantitative features and advanced imaging tools including functional imaging with DWI MRI, DOTATATE PET/CT, texture analysis with radiomics and radiogenomic features appear promising for more accurate staging, tumor risk stratification, guiding management and assessing treatment response.

Role of portable ultrasound during a short-term medical service trip to rural Guatemala: a collaborative mission of trainees and physicians.

INTRODUCTION: Access to health care in developing countries is scarce. One solution to this problem has been for doctors from the USA to provide single-visit care through short-term medical service trips. There is interest in using ultrasound imaging as a portable diagnostic tool; however, data describing its usefulness are scarce. Therefore, the goal of this study was to determine the usefulness of portable ultrasound imaging during a medical service trip to rural Guatemala. METHODS: A multidisciplinary team of physicians examined patients at a mobile clinic in Antigua, Guatemala. Patients with clinical indications for ultrasound had their suspected diagnoses recorded before ultrasound testing. After imaging, updated diagnoses were recorded and compared with the pre-test suspected diagnoses to determine how often ultrasound results changed the medical management of the patients and to assess the most common indications for ultrasound imaging. RESULTS: During the trip, 205 patients were seen. Of these, 24 (12%) were given ultrasound exams. The results of 13 (54%) exams altered their medical management, and the remaining 11 (46%) exams confirmed the pre-test suspected diagnoses. The most common indications for ultrasound testing were suspected cardiac (11 patients, 46%) and gastrointestinal (8 patients, 33%) diseases. CONCLUSION: Portable ultrasound imaging improved the medical team's ability to diagnose disease and clinically manage patients in a rural medical service trip. Ultrasound imaging may provide a low-cost solution to the growing demand for care in developing countries.

Data from a terminated study on iron oxide nanoparticle magnetic resonance imaging for head and neck tumors.

Node positive head and neck squamous cell carcinomas (HNSCCs) patients exhibit worse outcomes in terms of regional neck control, risk for distant metastases and overall survival. Smaller non-palpable lymph nodes may be inflammatory or may harbor clinically occult metastases, a characterization that can be challenging to make using routine imaging modalities. Ferumoxytol has been previously investigated as an intra-tumoral contrast agent for magnetic resonance imaging (MRI) for intracranial malignancies and lymph node agent in prostate cancer. Hence, our group was motivated to carry out a prospective feasibility study to assess the feasibility of ferumoxytol dynamic contrast enhanced (DCE)-weighted MRI relative to that of gadolinium-based DCE-MRI for nodal and primary tumor imaging in patients with biopsy-proven node-positive HNSCC or melanoma. Although this institutional review board (IRB)-approved study was prematurely terminated because of an FDA black box warning, the investigators sought to curate and publish this unique dataset of matched clinical, and anatomical and DCE MRI data for the enrolled five patients to be available for scientists interested in molecular imaging.

Disease Characteristics, Radiologic Patterns, Comorbid Diseases, and Ethnic Differences in 32 Patients With Rosai-Dorfman Disease.

OBJECTIVE: Rosai-Dorfman disease (RDD) is a rare and idiopathic nonneoplastic disease of histiocytes that is characterized by lymphadenopathy and extranodal disease. In this study, we documented anatomical preferences, imaging findings, comorbid diseases, and ethnic differences in 32 RDD patients. METHODS: We conducted a retrospective review of pathologically confirmed cases seen at our institution from 1998 to 2016. These cases were analyzed for (a) anatomical locations, (b) radiologic appearance, (c) comorbid diseases, and (d) differences between ethnic groups. RESULTS: We found 32 patients with RDD, 18 were women and 14 were men. There were 51 lesions in all patients, 23.5% of which were nodal, involving 11 lymph node regions, and 76.5% were extranodal. Cervical lymph nodes and maxillofacial area were the most common affected nodal and extranodal locations, respectively. Only 4 (12.5%) of 32 patients had pure nodal involvement, whereas 20 (62.5%) of 32 had pure extranodal disease and 8 (25%) of 32 had mixed nodal and extranodal disease.Anatomically, RDD affected multiple organs in our cohort, including the lymphatic system, maxillofacial area (glandular and nonglandular tissues), superficial soft tissue, central nervous system, breast, peritoneum, gastrointestinal tract, and lungs.Radiologically, RDD presentation was variable from an organ to another. However, most lesions were hypermetabolic on 18F-fluorodeoxyglucose positron-emission tomography/computed tomography and isointense on T1-weighted magnetic resonance imaging. Computed tomographic findings were extremely variable between organs.Comorbid diseases were found in 11 patients. Those patients had 17 comorbid diseases; the most common were autoimmune diseases, viral diseases, and cancer.The organ distribution of RDD was slightly different between ethnic groups. The most frequent disease location for African Americans was lymph nodes; for whites, central nervous system and nonglandular maxillofacial (27.3% each); for Asians, lymph nodes, subcutaneous tissue, and nonglandular maxillofacial (25% each); and for Hispanics, lymph nodes and glandular maxillofacial (33.3% each). CONCLUSIONS: Rosai-Dorfman disease represents a wide-spectrum disease not limited to lymph nodes. Radiologically, RDD has diverse imaging findings. However, most lesions were hypermetabolic on 18F-fluorodeoxyglucose positron-emission tomography/computed tomography and isointense on T1-weighted imaging. Patients with RDD have a high rate of comorbid diseases including autoimmune disease, viral infections, and cancer.