Items in AFP with MESH term: Magnetic Resonance Imaging
ABSTRACT: The treatment of osteosarcoma requires a multidisciplinary approach involving the family physician, orthopedic oncologist, medical oncologist, radiologist and pathologist. Osteosarcoma is a mesenchymally derived, high-grade bone sarcoma. It is the third most common malignancy in children and adolescents. The most frequent sites of origin are the distal femur, proximal tibia and proximal humerus. Patients typically present with pain, swelling, localized enlargement of the extremity and, occasionally, pathologic fracture. Most patients present with localized disease. Radiographs commonly demonstrate a mixed sclerotic and lytic lesion arising in the metaphyseal region of the involved bone. Computed tomography and bone scanning are recommended to detect pulmonary and bone metastases, respectively. Before 1970, osteosarcomas were treated with amputation. Survival was poor: 80 percent of patients died from metastatic disease. With the development of induction and adjuvant chemotherapy protocols, advances in surgical techniques and improvements in radiologic staging studies, 90 to 95 percent of patients with osteosarcoma can now be treated with limb-sparing resection and reconstruction. Long-term survival and cure rates have increased to between 60 and 80 percent in patients with localized disease.
ABSTRACT: Sinusitis is one of the most common diseases treated by primary care physicians. Uncomplicated sinusitis does not require radiologic imagery. However, when symptoms are recurrent or refractory despite adequate treatment, further diagnostic evaluations may be indicated. Plain radiography has a limited role in the management of sinusitis. Although air-fluid levels and complete opacification of a sinus are more specific for sinusitis, they are only seen in 60 percent of cases. Noncontrast coronal computed tomographic (CT) images can define the nasal anatomy much more precisely. Mucosal thickening, polyps, and other sinus abnormalities can be seen in 40 percent of symptomatic adults; however, clinical correlation is needed to avoid overdiagnosis of sinusitis because of nonspecific CT findings. Use of CT is typically reserved for difficult cases or to define anatomy prior to sinus surgery. Magnetic resonance imaging (MRI) cannot define bony anatomy as well as CT. MRI is only used to differentiate soft-tissue structures, such as in cases of suspected fungal infection or neoplasm. Referral will occasionally be needed in unusual or complicated cases. Immunocompromised persons and smokers are at increased risk for serious sinusitis complications.
Tarsal Navicular Stress Fractures - Article
ABSTRACT: Stress fractures of the tarsal navicular bone are being recognized with increasing frequency in physically active persons. Diagnosis is commonly delayed, and outcome often suffers because physicians lack familiarity with the condition. Navicular stress fractures typically present in a running athlete who has gradually increasing pain in the dorsal mid-foot with occasional radiation of pain down the medial arch. Because initial plain films are often normal, the next diagnostic test of choice is triple-phase bone scan, which is positive early in the process and localizes the lesion well. After a positive bone scan, a computed tomographic scan should be obtained to provide anatomic detail and guide therapy. Nondisplaced, noncomminuted fractures respond well to six weeks of non-weight-bearing cast immobilization. Displacement, comminution, and delayed or nonunion fractures are indications for surgical open reduction internal fixation.
ABSTRACT: Acute monoarthritis can be the initial manifestation of many joint disorders. The first step in diagnosis is to verify that the source of pain is the joint, not the surrounding soft tissues. The most common causes of monoarthritis are crystals (i.e., gout and pseudogout), trauma, and infection. A careful history and physical examination are important because diagnostic studies frequently are only supportive. Examination of joint fluid often is essential in making a definitive diagnosis. Leukocyte counts vary widely in septic and sterile synovial fluids and should be interpreted cautiously. If the history and diagnostic studies suggest an infection, aggressive treatment can prevent rapid joint destruction. When an infection is suspected, culture and Gram staining should be performed and antibiotics should be started. Light microscopy may be useful to identify gout crystals, but polarized microscopy is preferred. Blood tests alone never confirm a diagnosis, and radiographic studies are diagnostic only in selected conditions. Referral is indicated when patients have septic arthritis or when the initial evaluation does not determine the etiology.
Diagnostic Approach to Tinnitus - Article
ABSTRACT: Tinnitus is a common disorder with many possible causes. Most cases of tinnitus are subjective, but occasionally the tinnitus can be heard by an examiner. Otologic problems, especially hearing loss, are the most common causes of subjective tinnitus. Common causes of conductive hearing loss include external ear infection, cerumen impaction, and middle ear effusion. Sensorineural hearing loss may be caused by exposure to excessive loud noise, presbycusis, ototoxic medications, or Meniere's disease. Unilateral hearing loss plus tinnitus should increase suspicion for acoustic neuroma. Subjective tinnitus also may be caused by neurologic, metabolic, or psychogenic disorders. Objective tinnitus usually is caused by vascular abnormalities of the carotid artery or jugular venous systems. Initial evaluation of tinnitus should include a thorough history, head and neck examination, and audiometric testing to identify an underlying etiology. Unilateral or pulsatile tinnitus may be caused by more serious pathology and typically merits specialized audiometric testing and radiologic studies. In patients who are discomforted by tinnitus and have no remediable cause, auditory masking may provide some relief.
ABSTRACT: Compression fracture of the vertebral body is common, especially in older adults. Vertebral compression fractures usually are caused by osteoporosis, and range from mild to severe. More severe fractures can cause significant pain, leading to inability to perform activities of daily living, and life-threatening decline in the elderly patient who already has decreased reserves. While the diagnosis can be suspected from history and physical examination, plain roentgenography, as well as occasional computed tomography or magnetic resonance imaging, are often helpful in accurate diagnosis and prognosis. Traditional conservative treatment includes bed rest, pain control, and physical therapy. Interventional procedures such as vertebroplasty can be considered in those patients who do not respond to initial treatment. Family physicians can help patients prevent compression fractures by diagnosing and treating predisposing factors, identifying high-risk patients, and educating patients and the public about measures to prevent falls.
ABSTRACT: Gait instability, urinary incontinence, and dementia are the signs and symptoms typically found in patients who have normal pressure hydrocephalus. Estimated to cause no more than 5 percent of cases of dementia, normal pressure hydrocephalus often is treatable, and accurate recognition of the clinical triad coupled with radiographic evidence most commonly identifies likely responders. Magnetic resonance imaging or computed tomography typically demonstrates ventricular dilation with preservation of the surrounding brain tissue. The abnormality in normal pressure hydrocephalus occurs secondary to an abnormality in fluid removal, leading to an increase in ventricular size and encroachment of enlarged ventricles on adjacent brain tissue. The pressure exerted on the cerebral parenchyma by immense fluid-filled cavities deforms white matter tracts, instigating gait abnormalities and incomplete control of the bladder, as well as difficulties in processing incoming stimulation and in producing expeditious responses. Signs and symptoms often occur as sequelae to an imbalance between the expected ongoing production of cerebrospinal fluid and continuous efflux. Ventriculoperitoneal shunting is used to relieve excess ventricular fluid not absorbed by normal physiologic channels. Multiple studies have explored various techniques to identify patients with normal pressure hydrocephalus in an effort to predict likely benefit from shunting. However, the effectiveness of cerebrospinal fluid diversion has never been proven in a randomized controlled trial comparing use of a shunt versus no shunt.
Evaluation of Palpable Breast Masses - Article
ABSTRACT: Palpable breast masses are common and usually benign, but efficient evaluation and prompt diagnosis are necessary to rule out malignancy. A thorough clinical breast examination, imaging, and tissue sampling are needed for a definitive diagnosis. Fine-needle aspiration is fast, inexpensive, and accurate, and it can differentiate solid and cystic masses. However, physicians must have adequate training to perform this procedure. Mammography screens for occult malignancy in the same and contralateral breast and can detect malignant lesions in older women; it is less sensitive in women younger than 40 years. Ultrasonography can detect cystic masses, which are common, and may be used to guide biopsy techniques. Tissue specimens obtained with core-needle biopsy allow histologic diagnosis, hormone-receptor testing, and differentiation between in situ and invasive disease. Core-needle biopsy is more invasive than fine-needle aspiration, requires more training and experience, and frequently requires imaging guidance. After the clinical breast examination is performed, the evaluation depends largely on the patient's age and examination characteristics, and the physician's experience in performing fine-needle aspiration.
ABSTRACT: A detailed history alone may lead to a specific diagnosis in approximately 70 percent of patients who have wrist pain. Patients who present with spontaneous onset of wrist pain, who have a vague or distant history of trauma, or whose activities consist of repetitive loading could be suffering from a carpal bone nonunion or from avascular necrosis. The hand and wrist can be palpated to localize tenderness to a specific anatomic structure. Special tests can help support specific diagnoses (e.g., Finkelstein's test, the grind test, the lunotriquetral shear test, McMurray's test, the supination lift test, Watson's test). When radiography is indicated, the posterior-anterior and lateral views are essential to evaluate the bony architecture and alignment, the width and symmetry of the joint spaces, and the soft tissues. When the diagnosis remains unclear, or when the clinical course does not improve with conservative measures, further imaging modalities are indicated, including ultrasonography, technetium bone scan, computed tomography, and magnetic resonance imaging. If all studies are negative and clinically significant wrist pain continues, the patient may need to be referred to a specialist for further evaluation, which may include cineroentgenography, diagnostic arthrography, or arthroscopy.
ABSTRACT: Scaphoid fracture is a common injury encountered in family medicine. To avoid missing this diagnosis, a high index of suspicion and a thorough history and physical examination are necessary, because early imaging often is unrevealing. Anatomic snuffbox tenderness is a highly sensitive test for scaphoid fracture, whereas scaphoid compression pain and tenderness of the scaphoid tubercle tend to be more specific. Initial radiographs in patients suspected of having a scaphoid fracture should include anteroposterior, lateral, oblique, and scaphoid wrist views. Magnetic resonance imaging or bone scintigraphy may be useful if the diagnosis remains unclear after an initial period of immobilization. Nondisplaced distal fractures generally heal well with a well-molded short arm cast. Although inclusion of the thumb is the standard of care, it may not be necessary. Nondisplaced proximal, medial, and displaced fractures warrant referral to an orthopedic subspecialist.