Journal De Radiologie最新文献

Tarsal tunnel syndrome is a condition that is caused by compression of the tibial nerve or its associated branches. Diagnosis is based on clinical findings but imaging is performed to exclude a cause of compression, identified in 60 to 80% of cases. Ultrasound is a useful examination because of its high spatial resolution and ability to rapidly perform an axial survey of the nerves. The ultrasound imaging features of the tarsal tunnel are described. The etiologies and different types are illustrated through a review of clinical cases.

Blood supply to the human thalami is complex and multiple variants exist. The artery of Percheron is one of those variants and is characterized by a solitary arterial trunk that branches from one of the proximal segments of either posterior cerebral artery and supplies blood to the paramedian thalami. Its occlusion results in bilateral paramedian thalamic infarction sometimes extending to the midbrain. We report six cases of bithalamic infarction secondary to occlusion of the artery of Percheron. We will illustrate the complex clinical symptomatology and underscore the role of imaging, especially MRI, for diagnosis.

Purpose

The purpose of this multicenter study was to determine the doses received by patients during interventional neuroradiology procedures and to consider establishing reference standards.

Materials and methods

A retrospective study of nine interventional neuroradiology departments was conducted. Seven diagnostic (cerebral and spinal angiography) and therapeutic (embolization and vertebroplasty) procedures were reviewed. For each procedure, three dosimetric parameters were recorded: dose-area product (DAP), fluoroscopy time, and number of images.

Results

Results showed interdepartment variations, up to four-fold for diagnostic procedures and seven-fold for therapeutic procedures. However, applying the 75th percentile method to the entire dataset, reference standards can be proposed for six types of procedures including diagnostic cerebral angiography (230 Gy cm²), follow-up selective cerebral angiography (80 Gy cm²), aneurysm embolization (350 Gy cm²), AVM embolization (440 Gy cm²). Reference standards are also proposed with regards to fluoroscopy time and number of images.

Conclusion

Such standards are useful for clinicians to evaluate and improve their practices.

Multiple artefacts and pitfalls may occur with breast MRI. Artefacts are secondary to the MR technique itself while pitfalls often are the result of human error. The most common artefacts include motion, pulsation, chemical shift and magnetic susceptibility. The most common pitfalls include improper contrast injection, poor patient positioning, improper placement of the ROI and improper characterization of physiological and iatrogenic contrast enhancement. The identification of these artefacts and pitfalls on breast MR images may reduce their impact or even eliminate them. The use of optimized protocols is necessary. It is important to explain to patients the sequence of the examination, ensure proper placement of the breasts in the coil and optimize the contrast injection. The ROI should always be placed over the most suspicious region of the lesion. Finally, it is recommended to perform the MRI during the second week of the menstrual cycle and to discontinue the use of HRT 2 months prior to scanning when possible.

Purpose

To demonstrate the value of contrast-enhanced ultrasound (CEUS) in the management of Bosniak type 2F and 3 renal cysts on CT.

Patients and methods

Retrospective study of 14 patients with 15 Bosniak type 2F and 3 renal cysts on contrast enhanced CT. All patients underwent CEUS of the kidneys after injection of SonoVue^®. Using predetermined criteria, the lesions were classified as benign, malignant or indeterminate. Patients either underwent surgery or follow-up CT at one to three years.

Results

From the 15 indeterminate cysts on CT, 12 were either benign (n = 8) or malignant (n = 4) on CEUS. From the eight cysts considered benign on CEUS, seven remained stable on follow-up CT after a minimum of one year interval and one was surgically resected and confirmed to be benign. All four cysts considered malignant on CEUS were surgically resected and three were confirmed to be malignant and one was confirmed to be benign. Three cysts were indeterminate: two lesions were surgically resected and one was benign while the other was malignant and one lesion was stable at one year follow-up CT.

Conclusion

CEUS was able to characterize indeterminate lesions as benign or malignant in 80% of cases with 92% reliability. Twenty percent of cysts remained indeterminate on CEUS. CEUS is reliable as a complement to CT in the evaluation of Bosniak type 2F and 3 renal cysts.