Items in AFP with MESH term: Tomography, X-Ray Computed
Imaging for Suspected Appendicitis - Article
ABSTRACT: Acute appendicitis is the most common reason for emergency abdominal surgery and must be distinguished from other causes of abdominal pain. Family physicians play a valuable role in the early diagnosis and management of this condition. However, the overall diagnostic accuracy achieved by traditional history, physical examination, and laboratory tests has been approximately 80 percent. The ease and accuracy of diagnosis varies by the patient's sex and age, and is more difficult in women of childbearing age, children, and elderly persons. If th diagnosis of acute appendicitis is clear from the history and physical examination, prompt surgical referral is warranted. In atypical cases, ultrasonography and computed tomography (CT) may help lower the rate of false-negative appendicitis diagnoses, reduce morbidity from perforation, and lower hospital expenses. Ultrasonography is safe and readily available, with accuracy rates between 71 and 97 percent, although it is highly operator dependent and difficult in patients with a large body habitus. While there is controversy regarding the use of contrast media and which CT technique is best, the accuracy rate of CT scanning is between 93 and 98 percent. Disadvantages of CT include radiation exposure, cost, and possible complications from contrast media.
ABSTRACT: Dementia is a common disorder among older persons, and projections indicate that the number of patients with dementia in the United States will continue to grow. Alzheimer's disease and vascular dementia account for the majority of cases of dementia. After a thorough history and physical examination, including a discussion with other family members, a baseline measurement of cognitive function should be obtained. The Mini-Mental State Examination is the most commonly used instrument to document cognitive impairment. Initial laboratory evaluation includes tests for thyroid-stimulating hormone and vitamin B12 levels. Structural neuroimaging with noncontrast computed tomography or magnetic resonance imaging also is recommended. Other testing should be guided by the history and physical examination. Neuropsychologic testing can help determine the extent of cognitive impairment, but it is not recommended on a routine basis. Neuropsychologic testing may be most helpful in situations where screening tests are normal or equivocal, but there remains a high level of concern that the person may be cognitively impaired.
Diabetic Ketoacidosis - Article
ABSTRACT: A diagnosis of diabetic ketoacidosis requires the patient's plasma glucose concentration to be above 250 mg per dL (although it usually is much higher), the pH level to be less than 7.30, and the bicarbonate level to be 18 mEq per L or less. Beta-hydroxybutyrate is a better measurement of the degree of ketosis than serum ketones. Intravenous insulin and fluid replacement are the mainstays of therapy, with careful monitoring of potassium levels. Phosphorous and magnesium also may need to be replaced. Bicarbonate therapy rarely is needed. Infection, insulin omission, and other problems that may have precipitated ketoacidosis should be treated. Myocardial infarction is a precipitating cause of diabetic ketoacidosis that is especially important to look for in older patients with diabetes. Cerebral edema is a major complication that occurs primarily in children. Education to prevent recurrence should be offered to all patients, including how to manage sick days and when to call a physician.
ABSTRACT: The first step in the evaluation of patients with pleural effusion is to determine whether the effusion is a transudate or an exudate. An exudative effusion is diagnosed if the patient meets Light's criteria. The serum to pleural fluid protein or albumin gradients may help better categorize the occasional transudate misidentified as an exudate by these criteria. If the patient has a transudative effusion, therapy should be directed toward the underlying heart failure or cirrhosis. If the patient has an exudative effusion, attempts should be made to define the etiology. Pneumonia, cancer, tuberculosis, and pulmonary embolism account for most exudative effusions. Many pleural fluid tests are useful in the differential diagnosis of exudative effusions. Other tests helpful for diagnosis include helical computed tomography and thoracoscopy.
ABSTRACT: Cirrhosis and chronic liver failure are leading causes of morbidity and mortality in the United States, with the majority of preventable cases attributed to excessive alcohol consumption, viral hepatitis, or nonalcoholic fatty liver disease. Cirrhosis often is an indolent disease; most patients remain asymptomatic until the occurrence of decompensation, characterized by ascites, spontaneous bacterial peritonitis, hepatic encephalopathy, or variceal bleeding from portal hypertension. Physical examination of patients with cirrhosis may reveal a variety of findings that necessitate a hepatic- or gastrointestinal-based work-up to determine the etiology. Some patients already may have had laboratory or radiographic tests that incidentally uncovered signs of cirrhosis and its comorbidities. No serologic or radiographic test can accurately diagnose cirrhosis. A significant correlation has been demonstrated between persistently elevated liver function tests and biopsy-proven underlying hepatic disease; thus, a more targeted serologic work-up is indicated in patients whose liver function test results are persistently abnormal. Unnecessary medications and surgical procedures should be avoided in patients with cirrhosis. Referral for liver biopsy should be considered only after a thorough, non-invasive serologic and radiographic evaluation has failed to confirm a diagnosis of cirrhosis; the benefit of biopsy outweighs the risk; and it is postulated that biopsy will have a favorable impact on the treatment of chronic liver disease.
Noninvasive Cardiac Imaging - Article
ABSTRACT: Noninvasive cardiac imaging can be used for the diagnostic and prognostic assessment of patients with suspected or known coronary artery disease. It is central to the treatment of patients with myocardial infarction, coronary artery disease, or acute coronary syndromes with or without angina. Radionuclide cardiac imaging; echocardiography; and, increasingly, cardiac computed tomography and cardiac magnetic resonance imaging techniques play an important role in the diagnosis of coronary artery disease, which is the leading cause of mortality in adults in the United States. Contemporary imaging techniques, with either stress nuclear myocardial perfusion imaging or stress echocardiography, provide a high sensitivity and specificity in the detection and risk assessment of coronary artery disease, and have incremental value over exercise electrocardiography and clinical variables. They also are recommended for patients at intermediate to high pretest likelihood of coronary artery disease based on symptoms and risk factors. Cardiac magnetic resonance imaging and cardiac computed tomography are newly emerging modalities in the evaluation of patients with coronary artery disease. Cardiac magnetic resonance imaging is useful in the assessment of myocardial perfusion and viability, as well as function. It also is considered a first-line tool for the diagnosis of arrhythmogenic right ventricular dysplasia. Cardiac computed tomography detects and quantifies coronary calcium and evaluates the lumen and wall of the coronary artery. It is a clinical tool for the detection of subclinical coronary artery disease in select asymptomatic patients with an intermediate Framingham 10-year risk estimate of 10 to 20 percent. In addition, cardiac computed tomography is evolving as a noninvasive tool for the detection and quantification of coronary artery stenosis. Although guidelines can help with treating patients, treatment ultimately should be tailored to each person based on clinical judgment of the a priori risk of a cardiac event, symptoms, and the cardiac risk profile.
Acute Pericarditis - Article
ABSTRACT: Although acute pericarditis is most often associated with viral infection, it may also be caused by many diseases, drugs, invasive cardiothoracic procedures, and chest trauma. Diagnosing acute pericarditis is often a process of exclusion. A history of abrupt-onset chest pain, the presence of a pericardial friction rub, and changes on electrocardiography suggest acute pericarditis, as do PR-segment depression and upwardly concave ST-segment elevation. Although highly specific for pericarditis, the pericardial friction rub is often absent or transient. Auscultation during end expiration with the patient sitting up and leaning forward increases the likelihood of observing this physical finding. Echocardiography is recommended for most patients to confirm the diagnosis and to exclude tamponade. Outpatient management of select patients with acute pericarditis is an option. Complications may include pericardial effusion with tamponade, recurrence, and chronic constrictive pericarditis. Use of colchicine as an adjunct to conventional nonsteroidal anti-inflammatory drug therapy for acute viral pericarditis may hasten symptom resolution and reduce recurrences.
Chronic Pancreatitis - Article
ABSTRACT: Chronic pancreatitis is the progressive and permanent destruction of the pancreas resulting in exocrine and endocrine insufficiency and, often, chronic disabling pain. The etiology is multifactorial. Alcoholism plays a significant role in adults, whereas genetic and structural defects predominate in children. The average age at diagnosis is 35 to 55 years. Morbidity and mortality are secondary to chronic pain and complications (e.g., diabetes, pancreatic cancer). Contrast-enhanced computed tomography is the radiographic test of choice for diagnosis, with ductal calcifications being pathognomonic. Newer modalities, such as endoscopic ultrasonography and magnetic resonance cholangiopancreatography, provide diagnostic results similar to those of endoscopic retrograde cholangiopancreatography. Management begins with lifestyle modifications (e.g., cessation of alcohol and tobacco use) and dietary changes followed by analgesics and pancreatic enzyme supplementation. Before proceeding with endoscopic or surgical interventions, physicians and patients should weigh the risks and benefits of each procedure. Therapeutic endoscopy is indicated for symptomatic or complicated pseudocyst, biliary obstruction, and decompression of pancreatic duct. Surgical procedures include decompression for large duct disease (pancreatic duct dilatation of 7 mm or more) and resection for small duct disease. Lateral pancreaticojejunostomy is the most commonly performed surgery in patients with large duct disease. Pancreatoduodenectomy is indicated for the treatment of chronic pancreatitis with pancreatic head enlargement. Patients with chronic pancreatitis are at increased risk of pancreatic neoplasm; regular surveillance is sometimes advocated, but formal guidelines and evidence of clinical benefit are lacking.
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.
The Role of Chest CT in Diagnosing Pulmonary Embolism - AFP Journal Club