Prevalence of unsuspected thyroid nodules in adults on contrast enhanced 16-and 64-MDCT of the chest

AIM: To determine the prevalence of unsuspected thyroid nodules on contrast enhanced 16and 64-modified discrete cosine transform (MDCT) of the chest, in a population of adult outpatients imaged for indications other than thyroid disease. METHODS: This retrospective study involved review of intravascular contrast-enhanced MDCT scans of the chest from 3077 consecutive adult outpatients, to identify unsuspected thyroid nodules. Exclusion criteria included history of thyroid cancer, known thyroid nodules or thyroid disease and risk factors for thyroid cancer, as evidenced by their medical records. One of 9 radiologists recorded number of nodules, location and bidirectional measurement of largest nodule, as well as amount of thyroid visualized on the chest computed tomography (CT). Presence of nodule was correlated with age, gender, race and percentage of thyroid imaged. RESULTS: A total of 2510 (2510/3077 or 81.6%) study subjects were included in the data analysis; among them,one or more nodules were identified in 629 subjects (629/2510 or 25.1%), with 242 (242/629 or 38.5%) having multiple nodules. Patients with nodule(s) were significantly older than those without (64 ± 13 years vs 58 ± 14 years, P < 0.0001), and female gender was associated with presence of nodule(s) (373/1222 or 30.5% vs 256/1288 or 19.9%, P < 0.0001). Women were also more likely having multiple nodules (167/373 or 44.8%) compared to men (75/256 or 29.3%, P < 0.0001). The majority of nodules (427/629 or 67.9%) were less than 1 cm. CONCLUSION: This retrospective review revealed a prevalence of 25.1% for unsuspected thyroid nodules on contrast-enhanced chest CT.

Role of computed tomography angiography in detection and staging of small bowel carcinoid tumors

Small-bowel carcinoid tumors are the most common form(42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare(3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common(20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.

Computed tomography of Crohn's disease:The role of three dimensional technique

Crohn's disease,a transmural inflammatory bowel disease,remains a difficult entity to diagnose clinically.Over the last decade,multidetector computed tomography(CT) has become the method of choice for noninvasive evaluation of the small bowel,and has proved to be of significant value in the diagnosis of Crohn's disease.Advancements in CT enterography protocol design,three dimensional(3-D) post-processing software,and CT scanner technology have allowed increasing accuracy in diagnosis,and the acquisition of studies at a much lower radiation dose.The cases in this review will illustrate that the use of 3-D technique,proper enterography protocol design,and a detailed understanding of the different manifestations of Crohn's disease are all critical in properly diagnosing the full range of possible complications in Crohn's patients.In particular,CT enterography has proven to be effective in identifying involvement of the small and large bowel(including active inflammation,stigmata of chronic inflammation,and Crohn's-related bowel neoplasia) by Crohn's disease,as well as the extra-enteric manifestations of the disease,including fistulae,sinus tracts,abscesses,and urologic/hepatobiliary/osseous complications.Moreover,the proper use of 3-D technique(including volume rendering and maximum intensity projection) as a routine component of enterography interpretation can play a vital role in improving diagnostic accuracy.