Abnormal Fluid Collections Research Articles

Natural Course of the Amputee's Residual Limb as Followed by Sequential Ultrasound Examinations

The authors studied 13 amputees (7 below knee, 6 above knee) with sequential ultrasound examinations at weeks 1, 2, 3, and 6 status post amputation to define the natural evolution of stump healing in below- and above-knee amputations. This would permit diagnosis of abnormal conditions such as abscess. In their series, they found striking differences between below- and above-knee amputations. In below-knee amputations the development of fluid collections was rare (2/6) and, when present, small (less than 3 cm) and transient (resolving within two to three weeks). In above-knee amputations, all stumps first developed subcutaneous edema followed by fluid collections (less than 5 cm) all of which resolved within six weeks. They found that ultrasound examinations are a useful technique to define abnormal fluid collections in the amputee's residual limb.

Radiology in the Intensive-Care Unit

Portable chest radiography is an essential component of clinical patient management in the intensive-care unit. With routine use of this procedure, unexpected cardiopulmonary abnormalities are frequently detected, and malposition or complications of intravascular devices and endotracheal, thoracostomy, or nasogastric tubes are also commonly found. The pulmonary parenchyma may be assessed for changes of acute lung injury, cardiogenic edema, areas of pneumonitis, atelectasis, or other abnormal collections of fluid or air. In mechanically ventilated patients, barotrauma occurs frequently and may be manifested by subtle intrathoracic collections of air. Technical factors may limit the resolution of the anteroposterior chest radiograph obtained at the bedside, but crucial clinical information is often gained. Portable chest radiographic findings, the role of computed tomography and ultrasonography, and interventional radiologic procedures pertinent to patients in the intensive-care unit are reviewed.

The etiology and clinical significance of pseudoascites

ASCtTES is an abnormal collection of fluid within the peritoneal cavity. The clinical presence of ascites is suggested by physical signs, including abdominal distention with bulging flanks, a palpable fluid wave, and shifting dullness to percussion. Small amounts of ascitic fluid often are difficult to detect by physical findings, and ultrasonography (US) has become the best procedure to confirm or disprove the presence of ascites in patients who have mild abdominal distent ion) Massive ascites, in contrast, is documented readily by physical examination, and usually the etiology is apparent after a complete history and thorough physical examination. 2 During the evaluation of patients who have obvious ascites, those conditions that produce the physical signs of ascites without actual peritoneal fluid accumulation may not be considered. The term pseudoascites denotes the clinical impression of ascites when, in fact, free fluid is not present within the peritoneal cavity. Our experience with pseudoascites and a literature review prompted us to summarize the reported conditions that may produce pseudoascites. Proper management of these conditions underscores the need to consider imaging studies before invasive diagnostic procedures are performed, especially if the cause of the "ascites" is unclear.

Osteomyelitis: detection with US. Work in progress.

Ten patients with clinically suspected osteomyelitis were studied with ultrasound (US). Five patients had abnormalities detectable on sonograms. An abnormal fluid collection was demonstrated adjacent to the bone in three of these five. US-guided aspiration of the fluid in two of the three patients revealed purulent or infected fluid that was thought to represent an inflammatory exudate dissecting in a subperiosteal or extraperiosteal location. Findings from subsequent radiographic and scintigraphic studies confirmed the diagnosis of osteomyelitis in these three patients. The other two patients with abnormal sonographic results had collections of fluid that were separated from the bone by a variable amount of soft tissue. These collections were confined to the soft tissue and did not appear to arise from the bone. Aspiration revealed a soft-tissue abscess in one patient and a seroma in the second. Findings in this preliminary study suggest that fluid around the bone seen on sonograms may indicate acute osteomyelitis.

Congenital anomalies of the lungs in adults: MR diagnosis.

Over an 18-month period, 11 adults with congenital pulmonary anomalies within the sequestration spectrum, identified either surgically or radiographically by CT and/or angiography, were evaluated with MR. These included seven patients with bronchogenic cysts, two with intralobar pulmonary sequestrations, one with scimitar syndrome, and one with bronchial atresia. In each case, MR showed at least some findings indicative of the correct diagnosis. MR proved especially effective in the detection of abnormal fluid collections (nine cases) and the identification of anomalous vessels (three cases). Fluid collections were easily identified in all cases, including four cases with high-density collections on CT (two with bronchogenic cysts and two with intralobar pulmonary sequestration), especially when single-level, multiecho T2-weighted sequences were obtained. Calculated T2 values ranged from 78 to 439 msec (average, 223 +/- 123 msec). Although T2 values were statistically significant for differentiating fluid from muscle (p = .0012) and fat (p = .0046), they were not sufficiently specific to allow precise fluid characterization. Significant limitations were also apparent, such as an inability to detect alterations in the parenchymal architecture of the lungs (three cases) or intrapulmonary vascularity (one case). Despite this, we conclude that MR may be of considerable value in the assessment of congenital pulmonary anomalies and in select cases obviate more invasive diagnostic procedures.

Pelvic exenteration: role of CT in follow-up.

Fifty-five computed tomography (CT) scans of the pelves and abdomens of 33 patients who had undergone pelvic exenteration were reviewed. There were 27 gynecologic and six colorectal malignancies. The interval between surgery and the first CT scan ranged from 2 weeks to 37 months (median, 8 months). CT findings included abnormal fluid collections (33.3%), abnormalities of the neovagina (30.3%) and presacral soft tissues (36.4%), increased hydronephrosis (54.5%), and lymphocysts (6.1%). Tumors recurred in 17 of 33 patients (51.5%) at a median interval of 9 months after surgery and had several CT manifestations. The most common of these was a soft-tissue mass of variable density and shape, but pelvic fluid collections as well as abnormalities of the neovagina and presacral soft-tissue layer were also associated with tumor recurrence. The surgical indications, methods, and potential post-operative complications of pelvic exenteration were reviewed and the role of CT in the follow-up of these patients was emphasized.

Neuron-glia interactions in CNS myelinogenesis: [formula omitted]. Institute of Morphology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

The presence of pain as a harbinger of bearing-related problems has recently been challenged. Adverse local tissue reactions (ALTRs) have been noted on cross-sectional imaging even in asymptomatic patients. The purpose of this study was to determine the natural history of such lesions in asymptomatic patients.Eighty-three asymptomatic patients with modular metal-on-metal total hip arthroplasties underwent metal ion reports and metal artifact reduction sequence magnetic resonance imaging (MARS MRI). MARS MRI images were reviewed and evaluated for the presence or absence of an ALTR lesion by a musculoskeletal radiologist and the senior author. We defined an ALTR lesion as abnormal fluid collections, solid or semisolid pseudotumors, or muscle or bone damage and was classified according to the MRI Classification System of Hart et al. In addition, serum cobalt and chromium levels were measured and analyzed at the time of MRI.Twenty-six of 83 (31%) asymptomatic patients had cystic lesions identified. All patients with positive MRIs were contacted to have repeat studies a year later. Nineteen of 26 were available for follow-up. Three patients who became symptomatic were revised. Most ALTRs in asymptomatic patients with modular metal-on-metal total hip arthroplasties that underwent repeat MARS MRI decreased in size (15 of 19 [79%]); 3 lesions increased, whereas 1 remained the same. All patients in the series had Co and Cr ion levels below the threshold of 7 ppb.Although most cystic lesions decreased in size, vigilance is still required as 3 patients became symptomatic requiring revision.

Ultrasonic Guidance of Prosthetic Hip Joint Effusion Aspiration

Until recently ultrasound imaging of the orthopedic patient has been limited. A new technique is presented here for the use of ultrasound imaging in guiding prosthetic hip joint effusion aspirations. Previously, x-ray fluoroscopy was used for these procedures. The use of ultrasound allows the examiner to directly visualize the abnormal fluid collection without using contrast injections, provides a three-dimensional orientation of the anatomy, and eliminates the x-ray exposure to the patient and the staff.

Ultrasound-Guided Prenatal Punctures

Ultrasound was used in three cases to assist the physician in performing fetal puncture for decompression of abnormal fluid collections in the fetus. The use of real-time ultrasound guidance can help prevent trauma to the mother and fetus due to such procedures.

Percutaneous feeding gastrostomy

A 77-year-old man initially had hoarseness. During the course of investigations, a barium examination revealed an ulcerated mass in the upper esophagus with definite separation of the tracheoesophageal space and possible narrowing of the trachea. Endoscopic examination with biopsy confirmed the diagnosis of a stenosing, well differentiated, squamous cell carcinoma of the esophagus. Considering the patient’s general condition and his chronic obstrucfive pulmonary disease, radiation therapy was considered to be the appropriate treatment. Three successive nasogastnic feeding tubes on separate occasions were not tolerated by the patient. It was considered that another such tube was not likely to be stable enough for the course of radiation. A percutaneous feeding gastrostomy therefore was suggested. The procedure was explained to the patient and a consent form was signed. He fasted overnight and was premedicated with Buscopan 20 mg, Demerol 50 mg, and Valium 7.5 mg injected intravenously just before the procedure. Under local anesthesia and fluoroscopic control, a 22-gauge spinal needle was aimed at the body of the stomach in the epigastnium. The needle was then slowly withdrawn, with injection of a small amount of Renografin 60 at the same time. Initial extravasation of contrast medium into the penitoneal cavity was noted. The needle was stopped as soon as contrast material outlined the gastric mucosal folds with a collection of contrast medium in the gastric fundus. Then air was introduced through the needle until adequate distension of the stomach was achieved (fig. 1 A). With the spinal needle still in place, the stomach was punctured again using a standard 1 8-gauge needle with stylet. This was in the distal body of the stomach after a small skin incision. There was a tactile sensation of the needle entering the stomach. The position of the needle was confirmed by air returning into the syringe and intraluminal location of injected contrast material (fig. 1 B). An 0.38 inch (0.96 cm) guide wire was introduced through the needle into the stomach, after removal of the stylet (fig. 1 C). The needle was withdrawn. Step dilatation was done to 9 French size. An 8 French pigtail catheter with multiple side holes then was placed over the guide into the stomach, resting in the gastric fundus (fig. 1 0). The catheter was secured with a Molner disk and waterproof tape. The patient did not suffer any discomfort during the entire procedure which took about 20 mm. At the end of the procedure the patient was able to move from the x-ray table to a stretcher by himself. No antibiotic was given before the procedure. However, because of the initial extravasation of injected contrast medium into the peritoneum, Gentamicin 80 mg was given intravenously for 3 days. The patient was fed by the catheter the next day without any complications. Initial radiation therapy was then done. On the seventh day after the percutaneous feeding gastrostomy, computed tomography (CT) was done for planning the radiation treatment field. Additional slices of the upper abdomen demonstrated the satisfactory intraluminal position of the feeding catheter. There was no evidence of any surrounding soft-tissue swelling, hematoma formation, abnormal fluid collection, or ascites (fig. 2).

Nonobstructive hydrocolpos: sonographic appearance and differential diagnosis.

Hydrocolpos in the pediatric patient almost invariably occurs secondary to fluid distending the vaginal canal proximal to an obstructive lesion, usually an imperforate hymen. There are, however, other causes for fluid filling and sometimes markedly distending the vagina; many of these are not pathologic. Sonographically, fluid in the vaginal canal often has a confusing appearance and may be mistaken for a pathologic mass. Ways of differentiating hydrocolpos from other normal and abnormal pelvic fluid collections are described. Five adult patients are presented who showed a varied sonographic spectrum of nonobstructive hydrocolpos.

Percutaneous catheter drainage of intraabdominal fluid collections including infected biliary ducts and gallbladders

Sixty-five abscesses, including 6 infected biliary systems and 15 sterile fluid collections, were treated by percutaneous catheter drainage in 77 febrile patients who were evaluated by computerized tomograhy or ultrasonography for intraabdominal infection. Percutaneous catheter drainage and systemic antibiotic administration without surgery provided satisfactory control of infection in 52 of 65 abscesses (80 percent). Catheter drainage followed by surgical exploration for abscess control was performed in an additional 5 of the 65 abscesses (7 percent). Nine deaths (14 percent) occurred in the abscess group of 64 patients. In 15 patients, aspirations, Gram stain, and culture of the abnormal fluid collection revealed sterile fluid. Drainage with a single catheter allowed complete resolution in 14 of 15 sterile collections. Surgery was performed electively in one patient with a fistula from a pancreatic pseudocyst in the small bowel. No deaths occurred in the noninfected group of 15 patients, 2 of whom underwent drainage of coexisting abscesses.

Sonographic demonstration of air-fluid levels in abdominal abscesses.

Abdominal sonograms were obtained for three patients who had clinically suspected abscesses. There were abnormal fluid collections that, when viewed from a posterior position, demonstrated a horizontal line representing an air-fluid level. Abdominal abscesses containing air were confirmed by both horizontal beam radiography and surgery. Since ultrasound examination is frequently performed before radiography in patients thought to have abscesses, it is important to look for and recognize the sonographic appearance of an air-fluid level.

Sonographic pseudoasymmetry of the prenatal cerebral hemispheres.

The ultrasonographic image of the fetal head at the appropriate level for determination of the biparietal diameter reveals an apparent asymmetry of the cerebral hemispheres. This was confirmed and analyzed in 49 sequential fetuses who had no neurologic deficits at birth and in the autopsy specimen of an 8-month-old infant without any anatomic abnormalities of the head. In the hemisphere farthest from the transducer, a crescent-shaped echo-poor region was visualized abutting the calvarium. This resembles an abnormal fluid collection but represents normal anatomy. High-amplitude reflections were observed on the medial side of the crescent and were produced by the combination of the sylvian fissure and the choroid plexus of the lateral ventricle. The fine echo pattern of the near hemisphere, which appeared to represent normal anatomy, was artifactual. The cerebral asymmetry seen by conventional ultrasonographic imaging after the 15th gestational week should not suggest an underlying pathologic process. The studies suggest that a higher-quality examination of the near hemisphere of the fetal cranium can be performed with properly focused transducers.

Peritransplant fluid collections. Ultrasound evaluation and clinical significance.

Gray-scale ultrasonography was used to detect, localize, and guide percutaneous aspirations of peritransplant fluid collections. Fifty-one (51%) transplant recipients had abnormal fluid collections; 18 of these patients required surgery. Analysis of the 23 proved fluid collections (10 lymphocytes, 7 abscesses, 4 urinomas, and 2 hematomas) revealed certain sonographic and temporal patterns. Lymphoceles were the most common cause of an obstructed transplant and were usually septated. Most of the undiagnosed fluid collections were small and crescentic and were located in the abdominal wall. They usually did not enlarge or resolve on serial ultrasound examinations. A role for ultrasound in the management of peritransplant fluid collections is proposed.

Computed Tomography in Renal Transplant Problems

Nineteen patients were studied with computed tomography immediately after kidney transplantation and subsequently if declining renal function was noted. Abscess formation, hematoma and lymphocele were satisfactorily demonstrated. Of 8 diagnosed abnormal densities, 5 were proved correct (abscess 2; serous collection and old blood 1; lymphocele 1; and hematoma (fresh) 1). Two were not proved but abnormalities resolved on medical therapy. There was one incorrect diagnosis: what was thought to be an abnormal fluid collection was really a markedly enlarged edematous rejected kidney. Computed tomography represents an excellent method of following the course of therapy, whether surgical or conservative.

Gray scale echography of the lung and pleural space: current applications of oncologic interest.

B mode gray scale echography is not useful in evaluation of the normal lung and pleural space. The presence of abnormal fluid collections in the chest change the acoustic properties of the thorax and pleural fluid collections may be detected and localized with precision. Lesions abutting the chest wall may be characterized as cystic or solid. Echography can be used to assess the motion and morphology of the diaphragms. Sonographic examination of the thorax is particularly useful in determining whether a large area of radiographic opacification such as an opaque hemithorax is due to fluid, tumor, or intrinsic pulmonary disease such as atelectasis or consolidation.

Pancreatic pseudocysts: unusual ultrasound features

Three unusual cases of pancreatic pseudocyst are described in which primary renal or splenic pathology was simulated on ultrasound imaging. When an abnormal fluid collection is imaged in a patient with a history of alcoholism, a pancreatic pseudocyst should be considered and an amylase determination should be obtained on any aspirated fluid.

The accuracy of radionuclide imaging in detecting pediatric dural fluid collections.

Twenty-five infants and children with surgically proved abnormal dural fluid collections were examined with radionuc1ide brain imaging. The 60% detection level is significantly lower than the 80% reported in adults. The 72% incidence of bilateral lesions in pediatric patients, as opposed to 16% in adults, contributes to the lower detectability. The triangular head configuration of many normal children and asymmetry of the cranial vault caused by numerous pediatric conditions also contributes to the chance for misinterpretation. Conditions which simulate abnormal dural fluid collections are listed and those which prevail in infants and children are emphasized.

Analyses of Extravascular Fluids

The examination of fluid collections from the pericardial, pleural, and abdominal cavities and the joints remains a frequent adjunct to other diagnostic techniques.1Normally these serous cavities contain only small amounts of fluid for lubrication. A wide variety of pathologic conditions may cause abnormal collections of fluid which are classified according to composition as transudate or exudate. Atransudateis formed by an alteration in the normal mechanisms that regulate the exchange of fluid between the vascular and extravascular compartments. This interchange of fluid between the blood and the tissue spaces is controlled by the balance between the capillary blood pressure forcing fluid into the tissue spaces and the osmotic pressure of the plasma proteins which returns fluid into the vascular compartment. The protein molecules diffuse to a limited extent. The small molecules, such as water, electrolytes, and crystalloids, diffuse back and forth rapidly. The concentration of the small