The Advantages and Limitations of Ultrasound Elastography in Diagnosis of Thyroid Carcinoma

Thyroid nodules have high prevalence in the general population. Only minorities of thyroid nodules are malignant; nevertheless, still biopsies are performed in differential diagnosis of malignant and benign thyroid nodules. Conventional ultrasound is widely used in diagnosis and characterization of thyroid nodules. There are several suspicious ultrasound features that predict thyroid cancer, such as solid consistence, marked hypoechogenicity, taller-than-wide shape, irregular or microlobulated or spiculated margins, no peripheral hypoechoic halo, and micro- or macrocalcifications. However, none of these signs have high sensitivity or specificity nor high degree of confidence for diagnosis or exclusion of thyroid carcinoma. Ultrasound elastography, recently developed, promising, noninvasive technique that evaluates tissue stiffness, has become one of the main focuses in thyroid imaging. There are two ultrasound elastography methods: strain ultrasound elastography (also known as real-time elastography or qualitative elastography) and shear wave elastography (quantitative elastography and acoustic radiation force impulse imaging). The purpose of this chapter is to present the principles of thyroid application, advantages, and limitations of both ultrasound elastography techniques

Pseudoprogression; discussion of the concept of pseudoprogression on the characteristics of tomographic changes in liver metastases of colorectal cancer patients receiving bevacizumab therapy

In this study, we aimed to investigate the concept of pseudoprogression in colorectal cancer patients with liver metastases receiving bevacizumab treatment by considering the changes in the shape, size, and density of liver metastases by abdominal Computed Tomography (CT) scans taken before and after treatment. This study is a retrospective evaluation of 16 patients with metastatic colorectal cancer treated with 5-fluorouracil, leucovorin, irinotecan and bevacizumab and is based on computed tissue analysis of the dominant liver lesion at baseline and 2 months after chemotherapy. The borders of all metastatic lesions observed in the livers of patients treated with bevacizumab after adjuvant chemotherapy were sharpened, the size of some lesions remained the same while others increased, and the density of most metastatic lesions decreased. In our study, we concluded that the evaluation of response to treatment based only on size and number should be avoided by noting a pseudoprogression in liver metastases that shows an increase in size but no progression on clinical/laboratory and follow-up images. [Med-Science 2023; 12(3.000): 951-4

If You See It Once, You Do Not Forget: Lhermitte-Duclos Disease

Lhermitte- Duclos disease (LDD) is a rare disorder of unknown pathogenesis, characterized by typical magnetic resonance (MR) findings. LDD can be associated with Cowden’s syndrome. So preoperative diagnosis is important for excluding the other associated tumors. Herein we present two cases of LDD and describe typical MR signal characteristics

Magnetic resonance imaging findings in childhood period nasopharynx cancer

BACKGROUND: Nasopharyngeal carcinoma is a rarely seen tumor in childhood. It is mostly detected late as the clinical features are similar to other childhood tumors which affect the nasopharynx and adenoidal hypertrophy. Therefore, the radiological features of childhood tumors of the nasopharynx must be well known. The aim of this study was to investigate the contribution of MR imaging features of childhood nasopharynx cancer. MATERIAL AND METHODS: The study included 10 nasopharyngeal carcinoma patients under the age of 18 years who presented at hospital between February 2008 and March 2014 and who had tissue diagnosis and MRI of the nasopharynx region. The MRI scans were evaluated by two radiologists. Loco-regional spread, asymmetry, signal intensity of the tumors, and lymph nodes were evaluated. RESULTS: In all the patients there was a mass which narrowed the nasopharynx. In all cases, unilateral mastoid opacification was observed. In 9 cases (90%), parapharyngeal extension was found. In 8 cases (80%), the mass showed an extension into the nasal cavity or oropharynx. In 5 cases (50%), there was an involvement of the skull base. In 3 patients (30%), an extension to the masticator space and pterygopalatine fossa was found. There were enlarged cervical lymph nodes bilaterally in 10 cases (100%). In 4 cases (40%), a lateral retropharyngeal lymph node was detected. CONCLUSIONS: Childhood nasopharyngeal cancers are often diagnosed at an advanced stage. MR imaging can be helpful in diagnosis and differential diagnosis of childhood nasopharynx cancer from other diseases of the nasopharynx