Items in AFP with MESH term: Magnetic Resonance Imaging
ABSTRACT: The most common endogenous cause of Cushing's syndrome is Cushing's disease. Frequent clinical findings include weight gain, truncal obesity, striae, hypertension, glucose intolerance and infections. Cranial nerve II may be affected by enlarging pituitary adenomas in Cushing's disease; cranial nerves III, IV and VI may also be affected. The evaluation of patients with suspected Cushing's disease and syndrome requires an understanding of the proper use and limitations of the tests commonly included in the diagnostic work-up. The best screening test for Cushing's syndrome is a 24-hour urine collection with analysis for urinary free cortisol excretion. Low-dose and high-dose dexamethasone suppression tests, corticotropin assays, a corticotropin-releasing hormone stimulation test and inferior petrosal sinus catheterization may be required for a definitive diagnosis. Magnetic resonance imaging is useful in localizing the lesion. Surgical removal of the lesion by a transphenoidal approach is usually successful, but long-term follow-up is required. Some patients require lifetime glucocorticoid replacement therapy.
Evaluation of Acute Headaches in Adults - Article
ABSTRACT: Classifying headaches as primary (migraine, tension-type or cluster) or secondary can facilitate evaluation and management A detailed headache history helps to distinguish among the primary headache disorders. "Red flags" for secondary disorders include sudden onset of headache, onset of headache after 50 years of age, increased frequency or severity of headache, new onset of headache with an underlying medical condition, headache with concomitant systemic illness, focal neurologic signs or symptoms, papilledema and headache subsequent to head trauma. A thorough neurologic examination should be performed, with abnormal findings warranting neuroimaging to rule out intracranial pathology. The preferred imaging modality to rule out hemorrhage is noncontrast computed tomographic (CT) scanning followed by lumbar puncture if the CT scan is normal. Magnetic resonance imaging (MRI) is more expensive than CT scanning and less widely available; however, MRI reveals more detail and is necessary for imaging the posterior fossa. Cerebrospinal fluid (CSF) analysis can help to confirm or rule out hemorrhage, infection, tumor and disorders related to CSF hypertension or hypotension. Referral is appropriate for patients with headaches that are difficult to diagnose, or that worsen or fail to respond to management
ABSTRACT: Incidental renal or adrenal masses are sometimes found during imaging for problems unrelated to the kidneys and adrenal glands. Knowledgeable family physicians can reliably diagnose these masses, thereby avoiding unnecessary worry and procedures for their patients. A practical and cost-efficient means of evaluating renal lesions combines ultrasonography and computed tomographic scanning, with close communication between the family physician and the radiologist. Asymptomatic patients with simple renal cysts require no further evaluation. Patients with minimally complicated renal cysts can be followed radiographically. Magnetic resonance imaging is indicated in patients with indeterminate renal masses, and referral is required in patients with symptoms or solid masses. The need for referral of patients with adrenal masses is determined by careful assessment of clinical signs and symptoms, as well as the results of screening laboratory studies and appropriate radiologic studies. Referral is indicated for patients with incidental adrenal masses more than 6 cm in greatest diameter. Appropriate laboratory screening tests include the following: a 24-hour urinary free cortisol measurement for patients with evidence of Cushing's syndrome; a 24-hour urinary metanephrine, vanillylmandelic acid or catecholamine measurement for patients with evidence of pheochromocytoma; and a serum potassium level for patients with evidence of hyperaldosteronism.
ABSTRACT: Acute osteomyelitis is the clinical term for a new infection in bone. This infection occurs predominantly in children and is often seeded hematogenously. In adults, osteomyelitis is usually a subacute or chronic infection that develops secondary to an open injury to bone and surrounding soft tissue. The specific organism isolated in bacterial osteomyelitis is often associated with the age of the patient or a common clinical scenario (i.e., trauma or recent surgery). Staphylococcus aureus is implicated in most patients with acute hematogenous osteomyelitis. Staphylococcus epidermidis, S. aureus, Pseudomonas aeruginosa, Serratia marcescens and Escherichia coli are commonly isolated in patients with chronic osteomyelitis. For optimal results, antibiotic therapy must be started early, with antimicrobial agents administered parenterally for at least four to six weeks. Treatment generally involves evaluation, staging, determination of microbial etiology and susceptibilities, antimicrobial therapy and, if necessary, debridement, dead-space management and stabilization of bone.
ABSTRACT: Hematuria, symptomatic and incidental, that involves more than three red blood cells per high-power field on two of three properly collected urinalysis specimens warrants some type of imaging to evaluate the upper tracts. Traditionally, excretory urography or the intravenous pyelogram has been the mainstay of the hematuria work-up, but computed tomography urography has more recently been recognized to have significant advantages. Multidetector computed tomography urography, a cross-sectional technique, is less susceptible to overlying bowel gas and more sensitive for detection of small tumors and calculi. Moreover, intravenous-pyelogram-like images can be obtained by using reconstruction techniques. In specific cases, ultrasound examination and magnetic resonance imaging can also be useful, and are particularly helpful in children and pregnant women. Neither modality has the sensitivity of computed tomography for calculi, but small tumors may be visible on magnetic resonance imaging. This article reviews the appropriateness criteria for the various radiologic imaging tests used in the evaluation of hematuria, as proposed by the American College of Radiology.
Progressive Skin Fibrosis - Photo Quiz
Acute Stroke Diagnosis - Article
ABSTRACT: Stroke can be categorized as ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. Awakening with or experiencing the abrupt onset of focal neurologic deficits is the hallmark of ischemic stroke diagnosis. The most common presenting symptoms for ischemic stroke are difficulty with speech and weakness on one half of the body. Many stroke mimics exist; two of the most common are a postictal seizure and hypoglycemia. Taking a detailed history and performing ancillary testing will usually exclude stroke mimics. Neuroimaging is required to differentiate ischemic stroke from intracerebral hemorrhage, as well as to diagnose entities other than stroke. The choice of neuroimaging depends on its availability, eligibility for acute stroke interventions, and the presence of patient contraindications. Subarachnoid hemorrhage presents most commonly with severe headache and may require analysis of cerebrospinal fluid when neuroimaging is not definitive. Public education of common presenting stroke symptoms is needed for patients to activate emergency medical services as soon as possible after the onset of stroke.
ABSTRACT: The population of adults with congenital heart disease is increasing in North America. Radiologic imaging is critical for the initial assessment and for surveillance in this population. Chest radiography and echocardiography are valuable first-line tools for evaluation. However, magnetic resonance imaging and computed tomography are often necessary, particularly for assessment of extracardiac anatomy or specific vascular connections or relationships, which may be complex in postoperative patients. Although magnetic resonance imaging and computed tomography can provide volumetric data for more comprehensive evaluation of cardiac anatomy and function, magnetic resonance imaging does not require patient exposure to ionizing radiation or nephrotoxic iodinated contrast media. Magnetic resonance imaging also can measure blood flow for quantification of left-to-right shunts, regurgitant fractions, and pressure gradients. Although noninvasive imaging techniques have limitations, they can evaluate most lesions and preclude the need for cardiac catheterization. Noninvasive imaging is particularly useful for serial evaluation of patients with surgically corrected congenital heart disease, because nearly one half of these patients will require two or more surgeries.
ABSTRACT: Cervical radiculopathy is a disease process marked by nerve compression from herniated disk material or arthritic bone spurs. This impingement typically produces neck and radiating arm pain or numbness, sensory deficits, or motor dysfunction in the neck and upper extremities. Magnetic resonance imaging or computed tomographic myelography can confirm neurologic compression. The overall prognosis of persons with cervical radiculopathy is favorable. Most patients improve over time with a focused, nonoperative treatment course. There is little high-quality evidence on the best nonoperative therapy for cervical radiculopathy. Cervical collars may be used for a short period of immobilization, and traction may temporarily decompress nerve impingement. Medications may help alleviate pain and neuropathic symptoms. Physical therapy and manipulation may improve neck discomfort, and selective nerve blocks target nerve root pain. Although the effectiveness of individual treatments is controversial, a multimodal approach may benefit patients with cervical radiculopathy and associated neck pain.