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Biomedical subjects

E vanSonnenberg

Publications and source records attributed to E vanSonnenberg.

At least 109 records · Page 6Linked to original sources

Localization grid for MR-guided biopsy.

A localization grid for use with magnetic resonance (MR)-guided biopsies was designed and evaluated. First, the signal intensities of various concentrations of Gd-DTPA in polyethylene tubes of different sizes and at various pulse sequences were evaluated. The optimal signal intensity on all pulse sequences was obtained with a concentration of 500 microM. A grid was then made with 5-mm-diameter polyethylene tubes filled with 500-microM Gd-DTPA. The grid has provided excellent localization for MR-guided biopsy and fluid aspiration.

Biopsy↗

Sonography of thigh abscess: detection, diagnosis, and drainage.

Sonographic characteristics and percutaneous catheter drainage of thigh abscesses in 18 patients are described. Most of these patients had underlying diseases including osteomyelitis, trauma, diabetes mellitus, rheumatoid arthritis, leukemia, lymphoma, sepsis, bleeding dyscrasia, and autoimmune disease. Previous procedures on these thigh collections included seven operations and 12 nondiagnostic ward aspirations. All collections were shown by sonography to be either anterior or anterolateral. Two cases referred for drainage were posteromedial; sonography showed these to be mycotic pseudoaneurysms. The abscesses were either anechoic or hypoechoic, and occasionally had debris and septations. Abscesses associated with underlying osteomyelitis abutted the femur; those related to other causes generally were more superficial within muscle or fascial layers. Sonographically guided catheter drainage successfully cured all patients, even those in whom ward aspiration or formal surgery had been unsuccessful. Sonography is a simple and inexpensive method of imaging and guiding the drainage of thigh abscesses. Percutaneous catheter drainage is the treatment of choice in cases in which simple emergency room or ward incision and drainage are inadequate.

Abscess↗

[Percutaneous drainage of complicated abscesses and fluid collections].

The original concept of percutaneous, radiological abscess drainage was confined to well circumscribed, solitary abscesses, that could be reached by a short access avoiding transgression of uninvolved organs or compartments. With increasing experience criteria for percutaneous abscess drainage have been expanded to radiological treatment of pancreatic, periappendiceal, diverticular, interloop and mediastinal abscesses and fluid collections. The authors present their experience with percutaneous treatment of such "complicated" abscesses in 140 patients.

Abdomen↗

[Percutaneous gastro-enterostomy].

Percutaneous gastrostomies or gastroenterostomies serve for temporary or permanent enteric feeding in patients with obstruction or functional derangement of the esophagus or hypopharynx. In addition, this radiological procedure may be indicated for small bowel decompression. The authors present their experience in 71 patients. Insufflation of air through a nasogastric tube or catheter is the preferred method for gastric distension. The inferior margin of the left lobe of the liver and the transverse colon are localized sonographically and fluoroscopically prior to puncture. Either Seldinger or Trocar-techniques have proven effective in establishing access to the stomach. The feeding tube is advanced into the proximal jejunum to reduce the likelihood of gastroesophageal reflux and possible aspiration. Complications were encountered in four patients and included catheter dislocation in three and respiratory distress in one patient.

Female↗

Percutaneous cecostomy for decompression of the massively distended cecum.

Massive dilatation of the cecum developed in an elderly man following admission for an acute episode of upper gastrointestinal hemorrhage complicated by myocardial infarction, ventricular fibrillation, and pulmonary edema. A diagnosis of pseudo-obstruction was made. After an unsuccessful attempt at colonoscopy, percutaneous cecostomy was performed under computed tomographic guidance, using trocar technique. The cecal distention resolved and did not recur. Percutaneous cecostomy is an alternative to colonoscopy and to surgical cecostomy in the treatment of massive cecal distention.

Aged↗

Percutaneous drainage access: a simplified coaxial technique.

We describe an access technique that we have used in 150 nephrostomy and biliary drainage procedures and for access to some abscesses and viscera. The system provides safe coaxial access with a 22-gauge removable hub needle, which then acts as a guide wire and is replaced by an 18-gauge cannula. A major advantage is that only one guide wire is used (0.038-inch) for the entire drainage procedure. No significant complications have occurred to date with this method.

Biliary Tract Surgical Procedures↗

Unsuspected pheochromocytoma: risk of blood-pressure alterations during percutaneous adrenal biopsy.

Four unsuspected pheochromocytomas were discovered during percutaneous fine-needle biopsy of the adrenal gland under ultrasound (n = 1) and computed tomographic (n = 3) guidance. One patient suffered an acute episode of alternating hypertension and hypotension during the procedure. A second patient had no alterations in vital signs during the procedure but had a severe hypertensive crisis during induction of anesthesia at surgery. Neither biopsy nor surgery affected the vital signs in the other two patients. During biopsy study of adrenal lesions, the possibility of unsuspected pheochromocytoma should be considered, and the interventional radiologist must be familiar with the emergency treatment of hypotensive or hypertensive crises that may occur.

Adrenal Gland Neoplasms↗

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↗

Unchanged size of a dilated common bile duct after a fatty meal: results and significance.

Sonographic measurement of common bile duct caliber alone is insufficient to ascertain the presence of obstruction. Fatty meal stimulation significantly improves diagnostic accuracy. An increase in caliber of a normal or slightly dilated common duct after the subject has ingested a fatty meal is a strong indicator of biliary obstruction, while a decrease in caliber indicates normal dynamics and virtually excludes obstruction. This study determines the significance of no change in the caliber of the dilated common bile duct of subjects who have eaten a fatty meal. Further imaging studies and clinical/laboratory follow-up of 31 patients showed that in 84% of the cases no obstruction was present. A dilated common duct that does not decrease in size after a fatty meal is not a specific indicator of obstruction. The use of invasive diagnostic procedures in these patients is not advised unless there is other evidence of biliary obstruction.

Adult↗

Biliary stricture dilatation: multicenter review of clinical management in 73 patients.

Eighty-nine biliary strictures in 73 patients who had undergone percutaneous balloon dilatation were reviewed to determine long-term patency rates and clinical management problems. The majority of dilatations were performed in patients with anastomotic strictures (n = 44), iatrogenic strictures (n = 28), and strictures associated with sclerosing cholangitis (n = 17). Patency rates after 36 months or more were 67%, 76%, and 42%, respectively. Complications, mostly minor, occurred in less than 7% of patients. Of patients with significant biliary obstruction, 15% had little or no intrahepatic biliary duct dilatation demonstrated by cross-sectional imaging and/or direct cholangiography. No definite conclusions could be drawn about the utility of long-term internal/external stenting.

Bile Duct Diseases↗

Interventional radiology in the spleen.

Despite the widespread use of interventional radiologic techniques, there has been reluctance to apply these to the spleen. Concern for bleeding and difficulty in negotiating around the colon and pleura have limited its use. The authors report their experience with interventional radiology of the spleen in 35 cases, including percutaneous biopsy (n = 5), diagnostic and therapeutic fluid aspiration (n = 14), and catheter drainage of abscesses (n = 9), hematomas (n = 2), intrasplenic pancreatic pseudocysts (n = 2), and necrotic tumor (n = 1). Transsplenic fluid aspiration and biopsy of the pancreas and adrenal gland were performed as well (n = 2). All procedures were performed under computed tomographic or ultrasound guidance. Biopsies were performed with 22- or 20-gauge needles only; no complications were encountered. Diagnoses included primary and secondary malignancies and an infectious process. Drainages were successful in 11 of 14 patients; pleural effusions occurred in two cases, but neither required specific therapy. Interventional radiologic procedures in the spleen are feasible, and the authors discuss methods to promote their safe application.

Abscess↗

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↗

Oriental cholangiohepatitis: diagnostic imaging and interventional management.

Diagnostic and therapeutic radiologic experience with six patients who had oriental cholangiohepatitis is described. These patients combined had 10 prior operations. Postoperatively each had recurrent cholangitis, numerous stones, concretions, and/or bile duct strictures. Diagnostically, sonography was valuable in the detection of intra- and extrahepatic stones and extrahepatic dilatation of ducts. An important pitfall in sonography was poor visualization of intrahepatic ductal dilatation (due to echogenic sludge filling the ducts) in most patients. CT was helpful diagnostically in all respects. Interventional procedures used postoperatively included percutaneous transhepatic intrahepatic stones, and flushing techniques. Most patients were treated during multiple sessions as outpatients. Cholangitis was the only complication from the procedures. Sectional imaging and interventional radiology perform valuable diagnostic and therapeutic roles in the pre- and postoperative management of patients with oriental cholangiohepatitis.

Adult↗

Percutaneous gastrostomy and gastroenterostomy: 1. Techniques derived from laboratory evaluation.

Various techniques, guidance systems, instruments, and the postmortem effects of percutaneous gastrostomy (PG) and percutaneous gastroenterostomy (PGE) were evaluated in 30 laboratory animals and five human cadavers. Methods to distend the stomach included air, fluid, intragastric balloon, and percutaneous needle inflation; a variety of trocar systems and catheters inserted by Seldinger technique (including those adapted from other uses and several designed specifically) were assessed. Fluoroscopy was the preferred guidance system, though sonography proved valuable (liver position, depth calculation to the stomach, localization of vessels to avoid), and the entire PG procedure was performed under sonographic guidance in four animals. Although the procedure was safe in most cases, several major complications did occur: laceration of a low-lying liver with exsanguination, malpositioned catheters in the lesser sac and adjacent to the spleen, and violation of the backwall of the stomach with laceration of celiac and splenic vessels. The animals and cadavers underwent autopsy. Autopsy revealed that firm gastrocutaneous tracts were formed by 7 days. There were few instances of wound infection, intraperitoneal fluid leakage, or evidence of trauma to the stomach when the catheters were well seated. Injury to the inferior epigastric artery is a potential hazard, and in cadaver dissections was located between the middle third and outer margin of the rectus abdominis muscle. Laboratory experience has been, and continues to be, an important means to improve and use new techniques for PG and PGE.

Animals↗

The bile ducts after a fatty meal: further sonographic observations.

The sonographic appearance of the response of the common hepatic duct to physiologic stimulation by a fatty meal was assessed in 131 patients referred because of right upper quadrant symptoms or abnormal liver chemical studies. In the determination of the presence or absence of biliary obstruction, the sensitivity of the examination was 84%, the accuracy of a positive test was 84%, and the accuracy of a negative test was 93%. This test proved helpful in several circumstances: equivocal duct caliber (6-10 mm); abnormal caliber (6-14 mm) with normal laboratory values; normal caliber duct with abnormal laboratory values; persistent question of cholelithiasis or asymptomatic pancreatic duct dilatation. Measurements of bile duct caliber alone may be insufficient to ascertain the presence of bile duct obstruction and fatty meal stimulation significantly improves diagnostic accuracy.

Bile Ducts↗

Magnetic resonance relaxation times of percutaneously obtained normal and abnormal body fluids.

Seventy-three fluid samples obtained via percutaneous aspiration and drainage were analyzed by proton magnetic resonance spectroscopy. The fluids included abscess contents, bile, ascitic fluid, cyst and pseudocyst fluid, urine, hematomas, pleural fluid, lymphoceles, seromas, cerebrospinal fluid, pancreatic ductal fluid, and necrotic tumor. They were grouped by their clinical etiology and analyzed with respect to their inherent magnetic relaxation properties. In addition, some of the samples were tested for the following chemical parameters which were correlated with T1 and T2 values: total protein content (n = 36), osmolality (n = 24), specific gravity (n = 11), and amylase levels (n = 23). A large overlap was found in the T1 (spin-lattice) and T2 (spin-spin) relaxation times of the fluids; however, the mean T1 values of abscesses and hematomas were significantly lower than those of other fluids. Similar variability was seen in T2 values, though hematomas and abscesses again could be distinguished by shorter relaxation times. The spin-lattice (1/T1) and spin-spin relaxation rates (1/T2) showed a moderate correlation with total protein content, osmolality, and specific gravity. It is concluded that there is some predictability to MR analysis of body fluids, though the overlap in magnetic relaxation times limits specificity.

Body Fluids↗