MRI evaluation of soft tissue hydatid disease.

Infestation in soft tissue by Echinococcus granulosus is not a common disease, and its diagnosis is based on clinical, laboratory data and radiological findings. The aim of our retrospective study is to give an overview of the different signs and patterns shown by MRI that can be useful in characterizing soft tissue hydatid disease. The MRI images obtained in seven patients with soft tissue and subcutaneous hydatidosis were reviewed. Typical signs of hydatidosis were multivesicular lesions with or without hypointense peripheral ring ("rim sign"). Related to the presence and absence, respectively,of viable scolices in the microscopic exam, daughter cysts were presented either as high signal intensity or low signal intensity on T2-weighted images. Low-intensity detached layers within the cyst and peripheral enhancement with gadolinium-DTPA were also presented. Atypical signs were presented in an infected muscular cyst, a subcutaneous unilocular cyst and several unilocular cysts. Knowledge of the different patterns in MRI of soft tissue hydatid disease can be useful in diagnosing this entity. We observed that the "rim sign" is not as common as in other locations, and in addition, MRI seems to be of assistance when evaluating the vitality of the cysts.

Cardiac rhabdomyosarcoma: diagnosis by MR imaging.

We report a case of cardiac rhabdomyosarcoma the initial clinical features of which were pericardial effusion, clinical symptoms of congestive heart failure and probable pulmonary thromboembolism, in which echocardiography constituted the first approach to the diagnosis of cardiac tumor and MRI confirmed it, precisely delimiting the tumoral extension and possible infiltration of pericardiac structures. A brief literature review of this entity is given, the MRI findings obtained in our case are described, and we discuss the advantages and limitations of this technique as compared with other alternatives of image diagnosis.