Jacques Frija

In a first part, the different techniques of digital thoracic radiography are described. Since computed radiography with phosphore plates are the most commercialized it is more emphasized. But the other detectors are also described, as the drum coated with selenium and the direct digital radiography with selenium detectors. The other detectors are also studied in particular indirect flat panels detectors and the system with four high resolution CCD cameras. In a second step the most important image processing are discussed: the gradation curves, the unsharp mask processing, the system MUSICA, the dynamic range compression or reduction, the soustraction with dual energy. In the last part the advantages and the drawbacks of computed thoracic radiography are emphasized. The most important are the almost constant good quality of the pictures and the possibilities of image processing.

BACKGROUND It is now commonly admitted that the diagnosis of recurrence of lymphoma can be assessed by image‐guided needle biopsy (IGNB). However, the means of obtaining tissue for the original diagnosis of lymphoma is often surgery. The aim of this study was to compare the accuracy of IGNB at the time of diagnosis and at the time of recurrence or progression. METHODS The authors performed 212 IGNBs on 194 patients who eventually had a diagnosis of lymphoma. One hundred three IGNBs were obtained at original diagnosis and 109 at recurrence or progression. Large‐cutting core‐biopsy needles, ranging in size from 20 gauge to 14 gauge, were used. Immunohistochemistry studies were performed in all lymphoma cases. RESULTS A diagnosis of lymphoma with subtyping was obtained in 88% of all cases, in 85% at initial diagnosis, and in 89% at follow‐up. Therapy was initiated on the basis of IGNB in 93% of all cases, in 91% at initial diagnosis, and in 94% at follow‐up. Benign complications occurred in 7.5% of cases and did not require specific treatment. IGNB was equally effective for making a specific diagnosis of lymphoma and initiating therapy at the time of original diagnosis and at follow‐up. CONCLUSIONS The authors recommend that IGNB be performed as the initial procedure for the diagnosis of lymphoma in the absence of peripheral lymph nodes, either at presentation or at recurrence. Cancer 2000;89:647–52. © 2000 American Cancer Society.

ADVANTAGES AND LIMITATIONS: Magnetic resonance imaging of the breast is probably the most sensitive method for detecting or ruling out breast disease. It is however not as specific as expected. All examinations are performed with and without gadolinium intravenous administration, excepted in the case of silicone implant reconstruction mammoplasty. Dynamic contrast-enhanced MRI sequences are necessary with a permanent balance between temporal resolution, spatial resolution, and signal. MRI of the breast is not indicated as a routine examination in a screening program, neither to improve the specificity of infra-clinic lesions, nor in simply dense breasts without any known risk factor or in circumscribed masses. MRI is best used to improved the sensitivity of mammography and sonography in selected patients. The selected indications are: evaluation of the volume and extension of breast lesions evaluation of the therapeutic response after chemotherapy, and detection or exclusion of the local recurrence in patients with breast conservation therapy. The future indications and perspectives of MRI include interventional breast radiology (MRI-guided core biopsy), and thermocoagulation therapy. It may be interesting for the evaluation of patients with contrast enhanced MRI lesions with normal mammography and sonography, and also in woman with a genetically defined high breast cancer risk.