Femoral Neck Fracture with Avascular Necrosis.

Hip fractures are common in the aging population, with complications such as avascular necrosis. We describe a case of an 85-y-old woman with early avascular necrosis as a complication from femoral neck fracture discovered on routine bone densitometry screening.

EANM practice guideline/SNMMI procedure standard for RAIU and thyroid scintigraphy.

INTRODUCTION: Scintigraphic evaluation of the thyroid gland enables determination of the iodine-123 iodide or the 99mTc-pertechnetate uptake and distribution and remains the most accurate method for the diagnosis and quantification of thyroid autonomy and the detection of ectopic thyroid tissue. In addition, thyroid scintigraphy and radioiodine uptake test are useful to discriminate hyperthyroidism from destructive thyrotoxicosis and iodine-induced hyperthyroidism, respectively. METHODS: Several radiopharmaceuticals are available to help in differentiating benign from malignant cytologically indeterminate thyroid nodules and for supporting clinical decision-making. This joint practice guideline/procedure standard from the European Association of Nuclear Medicine (EANM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) provides recommendations based on the available evidence in the literature. CONCLUSION: The purpose of this practice guideline/procedure standard is to assist imaging specialists and clinicians in recommending, performing, and interpreting the results of thyroid scintigraphy (including positron emission tomography) with various radiopharmaceuticals and radioiodine uptake test in patients with different thyroid diseases.

Hot shoulder PET/CT lesion: Unusual presentation of tenosynovial giant cell tumor.

We present a case of a tenosynovial giant cell tumor (TGCT) incidentally discovered at the shoulder on PET/CT, in a patient with history of thyroid cancer. Many documented cases of TGCT have been incidentally imaged by PET/CT and have been found to have varying levels of metabolic activity, however the shoulder location is unusual. This type of musculoskeletal lesion often has MRI characteristics, such as gradient echo blooming, which can render a confident diagnosis without need for biopsy.

Perfusion Imaging in Acute Traumatic Brain Injury.

Traumatic brain injury (TBI) is a significant problem worldwide and neuroimaging plays a critical role in diagnosis and management. Recently, perfusion neuroimaging techniques have been explored in TBI to determine and characterize potential perfusion neuroimaging biomarkers to aid in diagnosis, treatment, and prognosis. In this article, computed tomography (CT) bolus perfusion, MR imaging bolus perfusion, MR imaging arterial spin labeling perfusion, and xenon CT are reviewed with a focus on their applications in acute TBI. Future research directions are also discussed.

18F-FDG PET/CT Imaging of Primary Gastric Lymphoma.

Primary gastric lymphoma (PGL) accounts for less than 4% of gastric neoplasms. 18F-FDG PET with simultaneously acquired CT (18F-FDG PET/CT) allows for staging and differentiation from other gastric cancers. Rapid diagnosis and staging are important because chemotherapeutic response is generally favorable. We describe a case of an 83-y-old woman with stage II1 PGL. 18F-FDG PET/CT can be helpful to differentiate various gastric masses and is an important factor in the staging of PGL.

Ectopic Parathyroid Adenoma in the Carotid Sheath.

Primary hyperparathyroidism is predominantly caused by a single parathyroid adenoma. Knowledge of normal and ectopic locations of parathyroid glands is crucial to help guide surgeons who plan targeted unilateral parathyroidectomy to reduce surgical time and risk. We describe a female patient with clinical primary hyperparathyroidism who underwent a failed initial parathyroidectomy, with subsequent imaging localizing an ectopic parathyroid adenoma in the carotid sheath.

Bisphosphonate-associated atypical subtrochanteric femur fracture.

Bisphosphonates help prevent progressive bone mineralization loss and subsequent osteoporotic fractures. However, long-term bisphosphonate therapy paradoxically increases the risk of a unique injury called an atypical subtrochanteric femur fracture. Despite this, the benefits of bisphosphonates outweigh the risks, because far more pathologic fractures are prevented than induced. The early identification of atypical subtrochanteric femur fractures is important as there is high associated morbidity and mortality. We describe a case of a 76-y-old woman with a completed bisphosphonate-associated atypical subtrochanteric femur fracture.

Current controversies in the initial post-surgical radioactive iodine therapy for thyroid cancer: a narrative review.

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy and the fifth most common cancer in women. DTC therapy requires a multimodal approach, including surgery, which is beyond the scope of this paper. However, for over 50 years, the post-operative management of the DTC post-thyroidectomy patient has included radioactive iodine (RAI) ablation and/or therapy. Before 2000, a typical RAI post-operative dose recommendation was 100 mCi for remnant ablation, 150 mCi for locoregional nodal disease, and 175-200 mCi for distant metastases. Recent recommendations have been made to decrease the dose in order to limit the perceived adverse effects of RAI including salivary gland dysfunction and inducing secondary primary malignancies. A significant controversy has thus arisen regarding the use of RAI, particularly in the management of the low-risk DTC patient. This debate includes the definition of the low-risk patient, RAI dose selection, and whether or not RAI is needed in all patients. To allow the reader to form an opinion regarding post-operative RAI therapy in DTC, a literature review of the risks and benefits is presented.

Nephrographic and pyelographic analysis of CT urography: differential diagnosis.

OBJECTIVE: The differential diagnosis of renal disease is extensive. The purpose of this article is to enable the reader to recognize and understand the abnormal nephrographic patterns encountered in practice. CONCLUSION: Recognizing the different nephrographic patterns on CT urography can be invaluable in understanding the morphologic and physiologic condition of the kidney and ultimately diagnosing the disease process.

Nephrographic and pyelographic analysis of CT urography: principles, patterns, and pathophysiology.

OBJECTIVE: Careful analysis of the nephrogram is an integral component of the evaluation of the kidneys during CT urography. This is a review of the anatomy and physiology required to produce a normal nephrogram, as well as the basic principles affecting the interpretation of the nephrogram. CONCLUSION: The eight abnormal nephrographic patterns will be illustrated and discussed. This review will enable the reader to recognize and understand the abnormal nephrographic patterns encountered in practice.