[Positron emission tomography-computed tomography in tumors of the locomotor apparatus]. / La tomografía por emisión de positrones asociada con la tomografía computarizada en tumores del aparato locomotor.

Positron emission tomography/computed tomography (PET/CT) is a hybrid imaging technique that combines the anatomic information from CT with the metabolic information acquired from PET after the administration of specific radiotracers, the most commonly used of which is F18-fluorodeoxyglucose (FDG). In oncology, this technique is based on the increased uptake of FDG by malignant lesions. In the locomotor apparatus, some uptake by bones and soft tissues is physiological or benign and this uptake must be differentiated from uptake by malignancies, whether primary or secondary. The most important limitations are active inflammatory or infectious processes, which are positive on PET images, and malignant lesions that are smaller than 1cm, cystic, necrotic, or low-grade, which are negative on PET images. PET/CT in the locomotor apparatus is especially useful for the detection of metastases from the most common tumors. It is also used for staging and monitoring the response to treatment of some hematological tumors like lymphoma, where it is fundamental to determine whether the bone marrow has been infiltrated, or myeloma. Lastly, although it is not yet an established indication, PET/CT is being increasingly used to study sarcomas, because it can provide additional information that can be useful for the characterization and grading of tumors, for guiding biopsies, for staging and re-staging, and for evaluating the response to neoadjuvant therapy as well as for evaluating new drugs in clinical trials.

Use of angioscanning in the surgical planning of perforator flaps in the lower extremities.

BACKGROUND: This is one of the few studies in the literature to describe angio-computed tomography (CT) as a planning tool in perforator flap surgery in the lower extremities. METHODS: Eighteen consecutive patients undergoing a perforator flap for lower-extremity reconstruction underwent preoperative CT angiography between September 2007 and November 2009. Eleven received propeller-type flaps, four medial sural artery perforator (MSAP) flaps, two lateral sural artery perforator (LSAP) flaps and one anterolateral thigh (ALT) flap. RESULTS: Preoperative CT angiography was highly specific (100%) and sensitive in mapping and visualising perforators in the lower limb. There were hardly any flap failures after angio-CT, and operative findings always correlated perfectly with preoperative imaging. Postoperative recoveries were uneventful except in three cases of peroneal artery perforator flaps that presented partial necrosis due to venous congestion. CONCLUSIONS: CT angiography is a valuable imaging tool for the preoperative assessment of the donor-site vascular supply for lower-extremity flaps. We recommend use of preoperative angio-CT for imaging vascular anatomy of the lower limb before defect reconstruction, especially in traumatic patients and patients with peripheral vascular disease. Its use can also reduce intra-operative dissection time and minimises surgical error in the identification of the vascular anatomy.