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Biomedical subjects

V W Wing

Publications and source records attributed to V W Wing.

At least 19 recordsLinked to original sources

Computed tomography and plain film appearance of a bony sequestration: significance and differential diagnosis.

Bony sequestration has been reported in osteomyelitis, eosinophilic granuloma, and fibrosarcoma. Thirty-eight examples of radiographically apparent bony sequestra were collected to examine the validity of this differential diagnosis. Apparent sequestra were found in osteomyelitis (59%), fibrosarcoma or fibrosarcoma-like entities (13%), eosinophilic granuloma (8%), and osteoid osteoma (21%). Although osteoid osteoma does not contain a true bony sequestrum, the partially calcified nidus was radiographically mistaken for a sequestrum in eight (21%) of our cases and, therefore, should be considered when an apparent sequestrum is visualized. Computed tomography enhanced visualization of a sequestrum in 19 of 22 cases and is recommended as an adjunct to conventional radiography when the presence of a sequestrum will alter therapy.

Bone Diseases↗

Improved survival with early CT diagnosis of pancreatic abscess.

Until recently pancreatic abscess was often a lethal complication of acute pancreatitis. A major factor contributing to this high mortality has been delay in diagnosis. When combined with diagnostic needle aspiration, computed tomography (CT) has greatly enhanced the early detection of pancreatic abscesses. In the past 5 years at our institutions 23 patients with proven pancreatic abscesses were evaluated early in their clinical course by CT. In follow-up ranging from 4 months to 4 1/2 years there were only 4 deaths: a mortality rate of 17%. Many of the surviving patients had a long and protracted clinical course (mean length of hospitalization, 58 days) and reoperation for recurrent abscess or gastrointestinal complications was required in 9 patients (39%). Computed tomography proved helpful both in localizing the site of de novo or recurrent pancreatic abscess and in detecting postoperative complications. An aggressive approach to early CT scanning with diagnostic needle aspiration appears to be a factor in the improved survival of these patients.

Abscess↗

Pancreatic abscess: predictive value of early abdominal CT.

The value of a recently reported grading system of early abdominal computed tomography (CT) for predicting development of pancreatic abscess in patients with acute pancreatitis was reassessed. When the previously described CT grading system was used in another patient population, it did not demonstrate the same degree of prognostic value of baseline CT. In this series pancreatic abscess occurred in only eight of 29 patients (28%) with grade E CT scans (with grade E representing the most severe involvement), compared with 60% in the previous series. Of 44 patients with either grade D or E baseline CT scans, abscesses developed in only 30%, with a minimum clinical follow-up of 3 months. A second grading system, which used a semiquantitative analysis of the degree of peripancreatic inflammation (a "CT severity score"), also did not strongly correlate with the future risk of abscess, The authors conclude that early abdominal CT should be performed selectively in patients with acute pancreatitis and reserved for patients who are either diagnostic dilemmas or who fail to respond to supportive treatment and have clinically suspected surgical complications such as pancreatic abscess.

Abscess↗

Deep venous thrombosis of the lower extremity: US evaluation.

The sensitivity of duplex ultrasonography (US) for detecting deep venous thrombosis of the lower extremity was compared with that of venography in a prospective study of 54 patients. Doppler analysis of the common femoral vein and US imaging of the deep venous system from the common femoral vein to the popliteal vein was performed. Common femoral vein response to the Valsalva maneuver was recorded. Sonographically visible thrombi and abnormal vein compressibility were 91% sensitive for the common femoral vein, and 94% sensitive for the superficial femoral or popliteal veins, with no false-positive examinations. Abnormal Doppler flow and abnormal response of the common femoral vein to the Valsalva maneuver enabled thrombi to be detected only in the common femoral and iliac veins. Combined data allowed accurate diagnoses in all patients with deep venous thrombosis proximal to the deep calf veins. US should be the screening examination of choice for evaluating patients with suspected lower extremity deep venous thrombosis.

Adult↗

Uterine adenomyosis. A difficult sonographic diagnosis.

In an effort to distinguish the appearance of generalized uterine adenomyosis from leiomyoma, a retrospective study was performed on 80 patients who had preoperative uterine sonography. A diagnosis of adenomyosis (eight patients) was suggested if the uterus was diffusely enlarged, but the myometrial texture, contour, and central cavity echoes were each normal. Leiomyoma, or other focal uterine pathology (72 patients) was characterized by focal or globular uterine enlargement with abnormal echo texture and contour, as well as nonvisualization or displacement of the central cavity echo complex. Using these criteria, ultrasound was able to suggest adenomyosis with a sensitivity of 63%, a specificity of 97%, and a positive predictive value of 71%. Focal pathology was diagnosed with a sensitivity of 97%, a specificity of 63%, and a positive predictive value of 96%. Although irregular myometrial sonolucent zones have previously been reported as characteristic for adenomyosis, this study did not confirm this finding.

Adult↗

Ultrasound in acute pancreatic trauma.

The ultrasound findings are reviewed in 4 patients with surgically proven acute pancreatic trauma. Despite technically adequate sonograms, pancreatic injuries were not prospectively diagnosed in any of the patients. Computed tomography (CT) performed shortly after ultrasound demonstrated changes of traumatic pancreatitis in each case. Because of the subtlety of the ultrasound findings, CT appears to be the preferred method for evaluating suspected pancreatic trauma.

Abdominal Injuries↗

Extrapancreatic spread of acute pancreatitis: new observations with real-time US.

Real-time ultrasonography (US) was compared with abdominal computed tomography (CT) in 40 patients with moderate to severe acute pancreatitis. Emphasis was placed on the ability of US to disclose peripancreatic involvement of the anterior pararenal spaces, lesser sac, and transverse mesocolon. When a realtime US scanning technique emphasizing semierect patient positioning and coronal views was used, 20 of 26 lesions in the anterior pararenal space (77%) and 14 of 14 abnormalities in the lesser sac (100%) were visualized. Abnormalities in the transverse mesocolon, however, were poorly detected on US scans. Ten patients (25%) in the study had extrapancreatic abnormalities missed by US. CT remains the imaging method of choice in patients with clinically moderate to severe pancreatitis. In patients with mild pancreatitis, the real-time US technique we describe improved extra-pancreatic visualization compared with previous studies using static scanners. A new US observation of perivascular spread of acute pancreatitis around the splenic and portal veins is described.

Acute Disease↗

Biliary dilatation: defining the level and cause by real-time US.

In a 15-month period, 110 patients with subsequently proved biliary dilatation were evaluated with ultrasound (US). The level of dilatation was defined as pancreatic, suprapancreatic, or at the level of the porta hepatis. Causes of dilatation included pancreatitis, choledocholithiasis, neoplasm, and stricture. The distal duct was examined initially on transverse scans obtained with the patient in a semierect right posterior oblique position; the proximal duct was then examined on longitudinal scans obtained with the patient in a supine left posterior oblique position. When this scanning technique was used, US indicated the level of dilatation in 91.8% of cases and suggested the correct cause in 70.9%. Because this approach markedly improves US visualization of the intrapancreatic bile duct, distal obstructing lesions, which are the most common, can be optimally examined.

Bile Duct Diseases↗

Technical factors responsible for "placental migration": sonographic assessment.

Whether placental migration occurs is debatable. To determine the incidence of placenta previa in early pregnancy and the frequency of placental migration, a retrospective analysis was undertaken of 2,087 consecutive obstetrical sonograms obtained during a 23-month period. Among 849 patients scanned between 14 and 26 weeks after conception, placenta previa was diagnosed using ultrasonography (US) in 53 patients (6.2%). This diagnosis was confirmed at surgery in 15 patients (1.8%); there were 12 cases of central previa and three cases of partial previa. Retrospective analysis revealed that in 25 cases, technical factors, such as an overly distended urinary bladder (19 cases) or focal uterine contractions (six cases), were responsible for the false-positive diagnoses. In the 13 remaining patients, however, there were no obvious technical difficulties to account for the diagnosis of previa. Migration did not occur in any of the patients with central previa. It appears that placental migration may occur, although less frequently than has previously been reported. Furthermore, this study suggests that migration does not occur in patients with central previa.

False Positive Reactions↗

Diagnostic and therapeutic percutaneous gallbladder procedures.

The authors report their experience with 24 patients who underwent a variety of percutaneous procedures involving the gallbladder. Twenty diagnostic and 13 therapeutic procedures were performed under sonographic, computed tomographic (CT), or fluoroscopic guidance; these procedures included biopsy of the gallbladder, diagnostic cholecystography, diagnostic aspiration of bile, gallstone dissolution and removal, cholecystostomy for drainage, and gallbladder abscess drainage. The indications for percutaneous cholecystostomy (performed in 11 patients) included relief of hydrops and empyema, gallstone dissolution, mechanical gallstone removal, and drainage for malignant obstruction. Each procedure was successful. There was one complicating episode of cholecystitis and four previously described episodes of vagal hypotension. Bile peritonitis did not occur in any of the patients. The authors discuss the various percutaneous gallbladder procedures and specific technical considerations in performing them.

Adult↗

Plastic wrap for US transducer sterility or sanitization.

Commercially available plastic wrap can be used to encase an ultrasound transducer for sanitization purposes. If sterility is required, an individual piece of plastic wrap can be gas sterilized before the transducer is covered with it. This technique does not degrade or temporally limit the use of the transducer, it is easy to perform, and the materials are readily available.

Acoustics↗

Lymphoceles: imaging characteristics and percutaneous management.

Twenty-five patients who had lymphoceles underwent sectional imaging and interventional radiologic procedures. Viewed using sonography, lymphoceles were hypoechoic to anechoic, occasionally with internal septa and debris. Low numbers (occasionally negative values) were observed using computed tomography (CT); these numbers strongly suggest the diagnosis of lymphocele. Calcification was observed on CT images of one patient. Diagnostic aspiration revealed tan to yellow fluid containing many lymphocytes; pathognomonic fat globules were observed in four cases. Malignant cells were found in two collections, an unusual occurrence. Therapeutic needle aspiration and short-term catheter drainage were usually unsuccessful (only one of five patients [20%] was cured). Long-term (1-5-week) catheter drainage cured 11 of 14 patients (78.6%). Sclerosing agents may have been beneficial for lymphocele obliteration in three of four patients. For most patients, lymphoceles may be diagnosed and treated successfully using radiologic means.

Adult↗

Abdominal CT in acquired immunodeficiency syndrome.

Acquired immunodeficiency syndrome (AIDS) is a lethal infectious disease that has reached epidemic proportions in urban centers of the United States. Intraabdominal opportunistic infections and malignancies are common features of this syndrome. A prodromal phase or possibly milder form of infection is known as the AIDS-related complex. Abdominal computed tomography (CT) in patients with AIDS-related complex often demonstrates a triad of mild retroperitoneal and mesenteric adenopathy, splenomegaly, and perirectal inflammation. Lymph node enlargement greater than 1.5 cm is unusual in the AIDS-related complex and should prompt CT-guided biopsy. Abdominal adenopathy (greater than 1.5 cm) in AIDS, in our experience, is most commonly related to non-Hodgkin lymphoma, Kaposi sarcoma, or infection with Mycobacterium avium-intracellulare. In most instances, CT-guided biopsy with appropriate staining technique can readily distinguish these entities. However, the subtyping of non-Hodgkin lymphoma by fine-needle aspiration biopsy alone remains controversial. Unusual features of abdominal malignancies are common in AIDS. These include a purely lymphadenopathic form of AIDS-related Kaposi sarcoma and a predilection for extranodal sites of lymphoma in AIDS. In general, patients with AIDS-related lymphoma present with advanced stages of disease with highly malignant histologic subtypes. Abdominal CT may be useful clinically for diagnosing intraabdominal complications of AIDS.

Abdominal Neoplasms↗

CT in the management of periappendiceal abscess.

Abdominal CT was the primary diagnostic method used to evaluate 40 patients with suspected periappendiceal abscess. Its subsequent impact on patient management was then analyzed for several categories of clinical presentation, including patients with and without a palpable right-lower-quadrant mass and postoperative patients. CT was reliable in distinguishing periappendiceal abscesses from phlegmons; 17 of 18 patients with phlegmons responded promptly to antibiotic therapy alone without need for surgery. Patients with larger, poorly localized abscesses underwent early surgical drainage. CT was successful in guiding percutaneous catheter drainage (nine patients) or aspiration (one patient) of well-localized periappendiceal abscesses in 10 of 11 patients. One attempted catheter drainage guided by sonography was technically unsuccessful. In patients without a palpable right-lower-quadrant mass, CT was helpful in establishing the diagnosis of periappendiceal inflammation. However, there were three false-positive diagnoses in patients with pericecal fluid collections including a ruptured cecal lymphoma, a ruptured cecal diverticulum, and a ruptured corpus luteum cyst. A diagnostic approach with CT is presented in patients with suspected periappendiceal abscess.

Abscess↗

Pancreatic abscess: impact of computerized tomography on early diagnosis and surgery.

Pancreatic abscess continues to be a lethal complication of acute pancreatitis, with mortality rates of 40 percent in recent surgical series. A major factor contributing to this high mortality has been delay in diagnosis. When combined with diagnostic needle aspiration, computerized tomographic scanning has greatly enhanced the early detection of pancreatic abscesses. In a 4 year period at our institutions, 21 patients with proved pancreatic abscesses were evaluated early in their clinical course by computerized tomography. On follow-up ranging from 7 months to 3 1/2 years, there were only four deaths for a mortality rate of 19 percent. Many of the surviving patients had a long and protracted clinical course (mean length of hospitalization was 56 days) and reoperation for recurrent abscess or gastrointestinal complications was required in eight patients (38 percent). Computerized tomography proved to be of considerable value in localizing the site of de novo or recurrent pancreatic abscess and in detecting postoperative complications. An aggressive approach encompassing early computerized tomographic scanning with diagnostic needle aspiration appears to be a factor in the improved survival rate of these patients.

Abscess↗

Chronic osteomyelitis examined by CT.

CT examination of 25 patients who had acute exacerbations of chronic osteomyelitis allowed for the correct identification of single or multiple sequestra in 14 surgical patients. Plain radiographs were equivocal for sequestra in seven of these patients, because the sequestra were too small or because diffuse bony sclerosis was present. CT also demonstrated a foreign body and five soft tissue abscesses not suspected on the basis of plain radiographs. CT studies, which helped guide the operative approach, were also useful in treating those patients whose plain radiographs were positive for sequestra. We review the potential role of CT in evaluating patients with chronic osteomyelitis.

Adolescent↗