Several postoperative complications associated with pain may develop in the stump of an amputated lower limb. Clinical findings are often nonspecific; however, radiologic evaluation, especially with magnetic resonance (MR) imaging, is useful in the early diagnosis of these complications, thereby helping minimize physical disability with its psychologic and socioeconomic implications. Conventional radiography can demonstrate evidence of osseous origins of pain (eg, aggressive bone edge, heterotopic ossification, osteomyelitis) and should be the first imaging study performed after clinical examination. Videofluoroscopy can help evaluate improper prosthetic fit by demonstrating abnormal residual limb motion, piston action, rolling of soft tissues, and abnormal angle between the limb axis and the prosthesis during gait. Ultrasonography can demonstrate inflammatory changes in the stump as well as soft-tissue fluid collections. However, MR imaging is the modality of choice when clinical and other imaging findings are indeterminate. Because of its high spatial and contrast resolution, MR imaging can demonstrate subtle inflammatory changes, fluid collections, cancers, neuromas, and subtle traumatic bone lesions. Knowledge of various surgical and rehabilitation techniques is required for accurate diagnosis of complications associated with stump pain. Correct diagnosis allows choice of the most appropriate therapy, which may involve treating the stump, remodeling the prosthesis, or both.

Microcalcifications are actually indirect signs of pathological processes, and only a few of these processes may be correctly correlated to the morphologic pattern of calcifications. This is true of the microcalcifications typically classified as benign by the 4th edition of the BI-RADS Atlas, except for round and punctuate microcalcifications. This is also the case of polymorphous fine and linear fine microcalcifications most often, but not exclusively, associated with DCIS with necrosis. For other types of microcalcifications, other parameters are analyzed in a more global approach: the associated clinical or mammographical signs; the context, especially genetic; the spatial distribution; the number; the evolution over time. The radiologist should compare the images with the anatomy of the terminal ductal-lobular unit, from where most cancers arise, and estimates the risk by taking into account the clinical context and the antecedents.

Imaging has been widely demonstrated to be important in local staging of head and neck malignancies as a complement to clinical examination, including endoscopy. Recent developments in multidetector row computed tomography (CT) provide better anatomic resolution within a shorter acquisition time and wider anatomic coverage. However, in many cases lesions still remain undefined. In such cases, performance of dynamic maneuvers could provide useful information about the local extent of a tumor. The usefulness of dynamic maneuvers has increased with the improvement in temporal and spatial resolution that resulted from the most recent techniques of multidetector row CT. The puffed cheek technique and the modified Valsalva maneuver allow evaluation of a lesion that was poorly demonstrated owing to apposition of mucosal surfaces. In some cases, phonation improves demonstration of small lesions of the vocal cords and allows more precise anatomic localization. The open mouth technique allows demonstration of a lesion that was previously overlooked due to dental amalgam artifacts.

PURPOSE We evaluated the addition of breast magnetic resonance imaging (MRI) to standard radiologic evaluation on the re-intervention rate in women with ductal carcinoma in situ (DCIS) undergoing breast-conserving surgery. PATIENTS AND METHODS Women with biopsy-proven DCIS corresponding to a unifocal microcalcification cluster or a mass less than 30 mm were randomly assigned to undergo MRI or standard evaluation. The primary end point was the re-intervention rate for positive or close margins (< 2 mm) in the 6 months after randomization ( ClinicalTrials.gov identifier: NCT01112254). RESULTS A total of 360 patients from 10 hospitals in France were included in the study. Of the 352 analyzable patients, 178 were randomly assigned to the MRI arm, and 174 were assigned to the control arm. In the intent-to-treat analysis, 82 of 345 patients with the assessable end point were reoperated for positive or close margins within 6 months, resulting in a re-intervention rate of 20% (35 of 173) in the MRI arm and 27% (47 of 172) in the control arm. The absolute difference of 7% (95% CI, −2% to 16%) corresponded to a relative reduction of 26% (stratified odds ratio, 0.68; 95% CI, 0.41 to 1.1; P = .13). When considering only the per-protocol population with an assessable end point, the difference was 9% (stratified odds ratio, 0.59; 95% CI, 0.35 to 1.0; P = .05). Total mastectomy rates were 18% (31 of 176) in the MRI arm and 17% (30 of 173) in the control arm (stratified P = .93). For 100 lesions seen on MRI, nonmass-like enhancement was more predominant (82%) than mass enhancement (20%). Nevertheless, no specific morphologic and kinetic parameters for DCIS were identified. CONCLUSION The study did not show sufficient surgical improvement with the use of preoperative MRI to be clinically relevant in DCIS staging. However, this could be reconsidered with the improvement of new MRI sequences and new modalities in magnetic resonance techniques.

BackgroundTo evaluate the MRI features of a tumor response, local control, and predictive factors of local control after stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC).MethodsThirty-five consecutive patients with 48 HCCs who were treated by SBRT were included in this retrospective study. All patients provided written informed consent to be treated by SBRT, and prior to inclusion they authorized use of the treatment data for further studies. The assessment was made using MRI, with determination of local and hepatic responses according to Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST (mRECIST) criteria during a two-year follow-up.ResultsThe local response rate according to mRECIST was higher than with RECIST. A tumor diameter less than 20 mm at baseline was an independent predictive factor for RECIST and mRECIST responses, as was diffusion-weighted signal for RECIST. During follow-up, a tumor diameter of <20 mm (p = 0.034) and absence of a high intensity on T2-weighted (p = 0.006) and diffusion-weighted images (p = 0.039) were associated with a better response according to RECIST. Post-treatment changes include peritumoral ring-like enhanced changes with high intensity on T2-weighted images.ConclusionsSBRT is a promising technique for the treatment of inoperable HCC. Post-treatment changes on MRI images can resemble tumor progression and as such must be adequately distinguished. The regression of tumorous enhancement is variable over time, although diffusion-weighted and T2-weighted intensities are predictive factors for tumor RECIST responses on subsequent MRIs. They hence provide a way to reliably predict treatment responses.