Which organ should be considered a reference in diffusion weighted imaging of the abdomen?: The reproducibility of ADC measurements of the spleen and the renal cortex on a 1.5T MR.

BACKGROUND: Diffusion weighted imaging (DWI) is a useful tool for the evaluation of focal lesions in the liver or kidneys, as well as for the diagnosis and assessment of the liver fibrosis process. Some reports show that the spleen and kidneys may serve as reference organs in the staging of liver fibrosis or the evaluation of focal liver lesions. OBJECTIVES: The aim of the study was to determine whether the spleen and renal cortex can be used as reference organs in the DWI technique. MATERIAL AND METHODS: The study group included 36 patients with no liver, spleen or renal pathologies and without any infections or hematologic disease. All the examinations were performed using a 1.5T MR unit with a conventional phased array body coil. Image interpretation and apparent diffusion coefficient (ADC) measurements were done by 3 experienced radiologists. RESULTS: There was a statistically significant difference between the ADC values noted by 2 of the examiners in the upper/middle and lower part of the spleen parenchyma. There were no statistically significant differences between the ADC values obtained by all 3 examiners in all the parts of each kidney. There were no statistically significant differences between the examiners' ADC values for the spleen and kidneys. The mean ADC values for the left kidney showed the highest measurement reproducibility. CONCLUSIONS: The study showed that the renal cortex seems to be an appropriate region for performing reference ADC measurements. Further studies on a larger group of patients and using various DWI protocols should be performed to ascertain the best conditions for maximizing the reproducibility of ADC measurements.

Shear wave elastography of the spleen: evaluation of spleen stiffness in healthy volunteers.

PURPOSE: The aim of this study was to assess the mean value of spleen stiffness measured by Shear wave elastography in healthy patients and its dependence on age, sex, and spleen dimensions, and to evaluate the repeatability of this method. METHODS: The final study group included 59 healthy volunteers without any clinical evidence of liver disease, portal hypertension, hematological disorders, and without any pathological ultrasonographic spleen findings. Each patient underwent abdominal ultrasound examination and elastography of the liver and the spleen. RESULTS: The mean value of spleen stiffness was 16.6 ± 2.5 kPa. In the group of men (N = 25), it was 17.3 ± 2.7 kPa, and in the group of women (N = 34), it was 16.1 ± 2.2 kPa. The study confirmed no correlation between spleen stiffness and sex, age of patients, and spleen size. Coefficient of repeatability and correlation coefficient between the results of the first and the second measurement showed good but not ideal repeatability of the measurement results. CONCLUSION: Our outcomes may be a reference point for evaluating spleen stiffness in research on patients with various illnesses.

A Rare Case of Aggressive Fibromatosis Infiltrating Dorsal Muscles in a 6-Year-Old Patient - CT, MRI and Elastography Evaluation.

BACKGROUND: The term fibromatosis or desmoid tumor refers to a group of benign fibrous growths without metastatic potential but with a significant risk of local recurrence. These lesions typically present infiltrative growth pattern with local invasion of adjacent tissues. This tendency is the reason for a relatively high rate of local recurrence, even after surgical removal. Fibromatosis is a very rare condition in general population but occurs more frequently in one of the familial cancer predispositions known as familial adenomatous polyposis (FAP) or Gardner syndrome. There are two main groups of fibromatosis: superficial (small, slow-growing lesions) and deep, also known as aggressive fibromatosis (large, rapid-growing lesions). CASE REPORT: We report a case of a 6-year-old boy suffering from an aggressive form of fibromatosis. The patient developed a large pathological mass extending from the neck to the loins. After incisional biopsy and histpoathological examination of the sample, a diagnosis of aggressive fibromatosis was established. During the whole diagnostic process, different imaging techniques including CT, MRI and sonoelastography were used. As the surgical treatment was not possible, the patient was finally qualified for chemotherapy. CONCLUSIONS: Eventual diagnosis of aggressive fibromatosis is based on histopathological examination. However, it is an important condition that should be included in differential diagnosis of soft-tissue masses found in diagnostic imaging. Radiologists should be careful especially in defining the margins of infiltration in case of potential surgical treatment.

Ultrasound elastography - review of techniques and its clinical applications.

Sonoelastography is a modern ultrasound method, which enables the representation of tissues and organs with the evaluation of their elasticity, "stiffness". The principle of elastography is to use repeated, slight pressure on the examined organ with the ultrasound transducer. Changes in elasticity and deformation of tissues arising whilst the compression is processed and presented in real time with color-coded maps, is called elastograms. The method is applicable mainly in diagnosing malignant lesions. Tumor tissues have different elasticity and undergo different deformations under pressure than healthy tissues. As a result of computer analysis, images in various colors are generated. Based on the nature of areas of normal and increased stiffness classifications of the images in point scales have been developed. Ultrasound devices equipped with sonoelastography option enable more accurate imaging and evaluation of the nature of lesions situated at small depth, e.g. breast, thyroid, testicles, prostate, some groups of lymph nodes. They increase the accuracy of ultrasound in diagnostics and the evaluation of the stage of malignant lesions. This also helps to indicate more precisely the areas that require the biopsy.