Ultrasonography of postosteotomy "cysts".

Three patients with postosteotomy "cysts" complicating limb-lengthening procedures are described. In all of the patients serial radiographs after distraction failed to show new bone formation, but the cause of the delay was not obvious from these images. Ultrasonography (US) revealed a well-defined fluid collection as the factor responsible for delayed consolidation. In one of the patients the fluid collection recurred, in spite of several attempts at US-guided percutaneous aspiration. In all three patients compression of the bone ends followed by redistraction failed to yield any new bone at the distraction site. Two of the patients subsequently underwent bone grafting at the site of osteotomy. Postosteotomy "cysts" (which are not true cysts) constitute an avoidable complication of distraction osteotomy resulting from inadequately supervised or too-rapid distraction. US is the imaging modality of choice for early detection of this complication.

Roundworm obstruction: sonographic diagnosis.

We describe the sonographic findings in five pediatric patients with roundworm obstruction. All patients were referred with a clinical diagnosis of acute appendicitis. On ultrasonography (US), an individual worm, when viewed along its longitudinal axis, appeared as a hypoechoic tubular structure with well-defined, echogenic walls. Frequently, the individual body segments could be distinctly visualized. The alimentary canal of the worm was seen either as a single central echogenic line (when in a collapsed state) or as two parallel hyperechoic bands with a hypoechoic center (when distended). When examined transaxially, the individual worm resembled a target with its circular, echogenic body wall and its central dot-like alimentary canal. On prolonged scanning, the worms always showed curling movements. In two patients, a bolus of worms mixed with fecal matter and air produced an unusual appearance of a complex, echogenic mass (helminthoma). Although, an individual worm occasionally resembled an inflamed appendix, visualization of the alimentary canal and individual body segments along with its curling movements helped establish the correct diagnosis. All patients promptly responded to a hypertonic saline enema and no patient was subjected to surgery. Sonographic findings in roundworm obstruction are fairly characteristics to advocate the routine use of sonography for diagnosing this entity.

Exudative v/s transudative ascites: differentiation based on fluid echogenicity on high resolution sonography.

Real time sonography was performed in 52 patients with ascites to evaluate the accuracy of sonography in differentiating an exudative from a transudative collection. The echogenicity of ascites was graded I, II and III using the echogenicity of normal abdominal viscera as comparative standard reference points. Grade I collections (31 patients) were either absolutely anechoic, or showed few internal echoes secondary to particulate matter. Grade II collections (7 patients) were hypoechoic as compared to the liver and spleen. Grade III collections (14 patients) had an echogenicity similar to or greater than that of the liver and spleen. The results of diagnostic aspiration in all patients were then compared to the sonographic grade of the ascitic fluid. All transudates (28 patients) had a Grade I echogenicity. Only 3 patients with an exudative ascites had a Grade I echogenicity. The remaining 21 patients with an exudative collection had an echogenicity equal to or greater than Grade II. Using these results, an ascitic fluid echogenicity of Grade I had a 92.32% sensitivity, 100% specificity, a positive predictive value of 1 and a negative predictive value of 0.875 in diagnosing transudates. An ascitic fluid echogenicity of Grade II or more had a sensitivity of 87.5%, specificity of 100%, a positive predictive value of 1 and a negative predictive value of 0.903 in diagnosing transudates.

Multiple chorioangiomas: ultrasonographic appearance, diagnosis and significance.

Multiple chorioangiomas of the placenta are extremely rare. The authors report one such case diagnosed by ultrasonography. The importance of the diagnosis, possible fetomaternal complications and management of this condition are discussed.

Sonographic detection of pneumoperitoneum: an experimental and clinical study.

The sonographic appearance of intraperitoneal air collection has been studied in 46 patients. In 30 patients (group I), a pneumoperitoneum had been iatrogenically induced either during aspiration of ascitic fluid or during laparoscopy. Three normal volunteers (group II) had been subjected to graded intraperitoneal air injection to quantify the smallest amount of air detectable by ultrasound (US). In eight patients (group III) the sonographic demonstration of free intraperitoneal air led to a diagnosis of hollow visceral perforation; whereas in another five patients (group IV) the sonographic findings reinforced the clinical suspicion of a 'sealed off' perforation in the presence of negative roentgenograms. In all patients intraperitoneal air was seen as an echogenic line with a posterior reverberation or ring down artefact. In patients with free air, this was best seen in the perihepatic spaces with the patient in the supine, left lateral decubitus or prone position. As little as 5 mL of air could be consistently detected in all three volunteers (group II). Artefacts leading to a pseudopneumoperitoneum on US included; (i) the artefacts distal to an overlying rib; (ii) ring-down artefact from air in the adjacent lungs; and (iii) hepatodiaphragmatic interposition of colon. With proper sonographic technique and principles of interpretation these can be distinguished from true intraperitoneal air. Although sonography may be more informative than conventional radiology in patients with hollow visceral perforation, we did not find it more sensitive than conventional roentgenograms in detecting free intraperitoneal air. Sonography, however, is distinctly superior in patients with a sealed off perforation in whom conventional roentgenograms are frequently negative.

Spontaneous perirenal urinoma secondary to cervical carcinoma: diagnosis and management.

Formation of a urinoma secondary to obstruction by a tumour is rare. The authors report a case of perirenal urinoma secondary to cervical carcinoma; the urinoma was drained percutaneously. The diagnosis and management of this problem are reviewed.

Ethanol sclerosis of a mediastinal cyst.

The authors report a mediastinal cyst treated by aspiration and ethanol sclerosis, which were performed under ultrasonographic guidance. Mediastinoscopy and thoracotomy were thus avoided. One year later there had been no recurrence of the cyst or any symptoms.

Isolated gastric varices: ultrasound detection.

Isolated gastric varices (IGV) (resulting from varying etiologies) were diagnosed in six patients using ultrasound examination of the wall of the fluid-filled stomach. Small gastric varices are seen as circular or linear anechoic channels within the gastric wall without a significant intraluminal projection. Large varices are seen as anechoic, lobulated "bulging masses" projecting into the fluid-filled lumen of the stomach. Doppler technique assists in confirming the vascular nature of these lesions and thus avoids confusion with other hypoanechoic lesions of the gastric wall. The technique is simple, noninvasive, and extremely useful in diagnosing IGV in patients investigated for recurrent undiagnosed gastrointestinal bleeding.

Sonographic findings in gastrointestinal and peritoneal tuberculosis.

The various ultrasound (US) findings in 90 patients with abdominal (gastrointestinal, peritoneal, mesenteric and lymph node) tuberculosis (TB) studied in an area of high incidence of TB over a 1 year period were analysed. The lesions encountered were intestinal (n = 31), extraintestinal (n = 39), or a combination (n = 20). The extraintestinal lesions included free and loculated ascites (n = 36), localized ascites ('Club Sandwich sign') (n = 4), adhesions (n = 14), peritoneal thickening (n = 14), peritoneal nodules (n = 3), lymphadenopathy (n = 23) and cold abscesses (n = 10)-of these, the presence of fine fibrinous strands in the ascetic fluid, localized ascites and caseous or calcified lymph nodes were highly suspicious of a diagnosis of TB in appropriate clinical settings. The bowel lesions were characterized by concentric bowel wall thickening (n = 31) with ulceration in six. Bowel thickening, when present in the ileocaecal junction and especially when situated in the subhepatic position, was suggestive of a tuberculous etiology. Complex masses in the abdomen pointed to an advanced stage of the disease. US is a useful imaging modality in patients clinically suspected of having abdominal TB for diagnosis and follow-up, although in a few cases differentiation of it from metastatic disease is difficult. When bowel involvement is suspected, barium studies should be performed.

The role of skeletal sonography in limb lengthening procedures.

Eleven patients (8 males, 3 females) undergoing limb-lengthening procedures were subjected to weekly conventional radiography along with fortnightly skeletal sonography of the distraction site, to assess the rate of new bone production and complications. The radiographs were assessed for: (i) distance between the distracted bone ends, (ii) presence of new bone formation at the distraction site, (iii) regeneration of the cortical outline and (iv) overlaying soft tissue abnormality. The sonographs were assessed for: (i) distance between the distracted bone ends, (ii) rate of new bone formation, (iii) density of the new bone produced, (iv) integrity and continuity of the cortical outline and (v) overlaying soft tissue abnormality. Our results indicate the superiority of sonography over conventional radiographs in: (i) detecting early new bone formation, (ii) establishing cortical and medullary canal remodelling, (iii) detecting soft tissue complications at the distraction site and (iv) determining the presence of fluid collection at the distraction site, in patients with delayed consolidation. Conventional radiographs were more accurate in determining the distance between the two distracted bone ends, and thus the degree of distraction achieved. Ideal assessments of events at the distraction site can be achieved by a combined assessment of conventional radiotherapy and skeletal sonography.

Acute upper extremity deep venous thrombosis: safety and effectiveness of superior vena caval filters.

PURPOSE: To evaluate the safety and effectiveness of percutaneous filter placement in the superior vena cava for prevention of pulmonary embolism (PE) due to acute upper extremity deep venous thrombosis (DVT) in patients with contraindications to or unsuccessful anticoagulation. MATERIALS AND METHODS: Forty-one patients with acute upper extremity DVT and contraindications to or unsuccessful anticoagulation underwent percutaneous placement of a superior vena caval filter for prevention of PE. Four types of filters were used. Follow-up chest radiographs were used to detect filter migration, dislodgment, and fracture. Placements of central venous and Swan-Ganz catheters after filter insertion were recorded. Patients were followed up clinically for evidence of superior vena cava syndrome and PE. Kaplan-Meier survival rates were determined. Follow-up was 1 day to 221 weeks. RESULTS: No complications such as filter migration, dislodgment, or fracture occurred (median follow-up, 12 weeks). No patients developed clinical evidence of PE due to upper extremity thrombosis or superior vena cava syndrome (median follow-up, 15 weeks). Catheters were placed subsequent to filter placement in 23 patients (56%) without complication. CONCLUSION: Percutaneous filter placement in the superior vena cava is a safe and effective method for preventing symptomatic PE due to acute upper extremity DVT in patients in whom therapeutic anticoagulation has failed or is contraindicated.

Solitary retroperitoneal angiofollicular lymph node hyperplasia.

The fine needle aspiration cytology (FNAC) and ultrasound radiologic features of a solitary retroperitoneal angiofollicular lymph node hyperplasia (AFLNH), hyaline vascular type are described. Based on a combination of the two, this diagnosis can be suggested in the differential diagnosis of a retroperitoneal mass.