Chronic recurrent multifocal osteomyelitis: typical patterns of bone involvement in whole-body bone scintigraphy.

Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease of unknown etiology. It affects children and adolescents predominantly and occurs mostly in the female population. It is characterized by the insidious onset of pain and swelling, with a fluctuating clinical course of relapses and remissions. Typically, several bones are affected, either synchronously or metachronously, and bilateral involvement is common. CRMO most commonly affects the metaphysis of long bones, especially the tibia, femur, and clavicle. The spine, pelvis, ribs, sternum, and mandible may also be affected. Although lesions are mostly multiple, patients may present with a single symptomatic focus. Radiographic findings may be negative early in the course of the disease. Bone scintigraphy is useful in determining the presence of abnormality and the extent of disease. The imaging and clinical features of CRMO overlap with those of infectious osteomyelitis, bone malignancy, and inflammatory arthritis. Nonetheless, CRMO can be confidently diagnosed with the recognition of typical imaging patterns in the appropriate clinical setting. This article reviews imaging findings with special emphasis on bone scintigraphy and specific disease sites.

Update on pediatric leukemia and lymphoma imaging.

Together, leukemia and lymphoma account for half of all childhood malignancies. Leukemia and lymphoma arise from similar cell lines and can have overlapping imaging features; however, the clinical presentation, imaging strategies, and treatment protocols can vary substantially based on the specific subtype. Although imaging does not play a central role in staging or monitoring disease in childhood leukemia, findings on imaging may be the first indication of the diagnosis. Advanced imaging, especially positron emission tomography/computed tomography, has moved to the forefront of staging and treatment response evaluation in Hodgkin's disease and non-Hodgkin's lymphoma. Imaging also plays a key role in evaluating the myriad of treatment complications that are commonly seen with chemotherapy and associated neutropenia. Future efforts will be largely focused on decreasing radiation exposure to these children, utilizing reduced or radiation-free modalities, such as positron emission tomography/magnetic resonance and diffusion-weighted whole-body imaging with background suppression, as well as refining surveillance imaging strategies. The purpose of this article is to briefly review the classification of pediatric leukemia and lymphoma, illustrate common imaging findings at presentation throughout the body, describe staging and therapeutic response evaluation, and show a spectrum of commonly encountered complications of treatment.

FDG PET in detecting primary and recurrent malignant salivary gland tumors.

PURPOSE: The aim of this study was to assess the role of PET in the management of patients with primary malignant salivary gland (SG) tumor. MATERIAL AND METHODS: Sixty-one FDG PET studies in 48 patients (median age 58, range 28-89 years, 20 female, 28 male) who were diagnosed with malignant SG tumors were retrospectively analyzed. Thirteen were referred for initial diagnosis and staging while there was a suspicion of recurrence and/or metastatic disease in 48 patients during the follow-up period. RESULTS: On PET examinations of 13 patients on initial presentation, 12 showed increased uptake in the primary lesion, while conventional methods (CT, MRI) were positive in 11 and were equivocal for 2 patients. Six patients with multiple nodal and 2 patients with distant metastases were detected by PET. Conventional methods demonstrated lymph node metastases in 5 of these patients. In the follow-up patient group, PET was inaccurate (false-negative or positive) in 4 (8%) patients with local recurrence, and in 4 (8%) with metastatic disease. However, 15 (31%) studies for recurrence and 7 (15%) for metastasis were false-negative with conventional radiologic methods. The sensitivity, specificity, and positive and negative predictive values for the detection of recurrent disease were 83%, 93%, 63%, and 98% for PET; 67%, 69%, 24%, and 94% for conventional methods, respectively. Overall sensitivity, specificity, positive and negative predictive values of PET for detecting metastatic disease were 93%, 96%, 82%, and 99%, while those of conventional methods were 80%, 95%, 75%, and 96%, respectively. CONCLUSION: These results demonstrate that FDG PET is not only superior to CT and/or MRI for staging at the initial presentation but also superior to conventional imaging methodologies for detecting local recurrence and regional lymph node and distant metastases in patients with malignant SG tumor.

Pulmonary lymphangitic carcinomatosis (PLC): spectrum of FDG-PET findings.

The lungs are among the most common sites for metastases from a multitude of cancers. The majority of pulmonary metastases appear nodular on radiologic images. Interstitial spread of tumor through pulmonary lymphatics, also known as pulmonary lymphangitic carcinomatosis (PLC), is not uncommon and constitutes approximately 7% of pulmonary metastases. PLC is most often seen with adenocarcinoma of a variety of histologies such as thyroid carcinoma, and melanoma. It is usually noted in late stages of malignancy and therefore is indicative of a poor prognosis. Diagnosis of PLC is usually based on a combination of clinical and radiologic findings. However, the diagnosis is difficult when patients have limited clinical findings or have a history of or the possibility of other interstitial lung diseases. High-resolution computed tomography (HRCT) has been the modality of choice in the radiologic diagnosis of PLC. Imaging features of PLC on HRCT include thickening of interlobular septa, fissures, and bronchovascular bundles. Distribution of PLC may be focal or diffuse, unilateral or bilateral, and symmetric or asymmetric. Although FDG-PET has been extensively used in primary or secondary lung malignancies, its role and appearance in PLC have not been well determined in the literature. In this communication, we describe a spectrum of FDG-PET and CT findings in 5 cases with PLC. Similar to CT, the distribution of PLC can be extensive or limited on the FDG-PET. Diffuse, lobar, or segmental FDG uptake in the lungs is seen in extensive PLC. In limited PLC, a linear or a hazy area of FDG uptake extending from the tumor can be seen. Recognition of various patterns related to PLC on FDG-PET may allow accurate diagnosis of disease and could potentially influence the management of these patients.