Sonography of intracranial infection in infants and children

Summary Congenital and acquired infections of the central nervous system (CNS) pose a significant threat to the developing brain, even in the face of appropriate medical treatment. During the past five years, a number of reports have described the ultrasound features of intracranial infection, including echogenic sulci, extra-axial fluid collections, ventricular enlargement, calcifications, abnormal parenchymal echogenicity, abscess formation, cystic degeneration of the brain parenchyma, intraventricular echogenicity, ventricular septations and irregularity and prominence of the ventricular walls. These features permit ultrasound diagnosis of intracranial infection and help to guide decisions affecting patient management.     

Sonography of brain tumors in infants

Cranial sonograms of six children with brain tumors (one newborn, four infants, and one 4-year-old child) are presented. In four, sonography showed a large tumor mass and displacement of adjacent structures. In two, the tumors were demonstrated as areas of abnormal brain parenchymal echogenicity without obvious mass effect. Two of the tumors were diffusely echogenic, one was primarily cystic, and three were of mixed echogenicity. Areas of cystic degeneration and calcification within the tumors were well demonstrated. Correlation was made with cranial computed tomography (CT) in all patients; in each case sonography accurately demonstrated the location and extent of the tumor. Since sonography is used as a screening procedure in infants with a large head or an abnormal neurologic examination, sonography may be the first examination to demonstrate the tumor mass. However, since the sonographic features are not specific for neoplasms, further clarification of the process by CT should be recommended.     

Acute appendicitis in children: value of sonography in detecting perforation.

OBJECTIVE. We determined the sonographic features of perforating appendicitis in children in order to determine the best criteria for establishing the diagnosis. MATERIALS AND METHODS. Sonograms of the right lower quadrants of 71 children with proved appendicitis were reviewed to determine the value of sonography in distinguishing between nonperforating and perforating appendicitis. The sonographic signs evaluated included the presence or absence of an appendix, an echogenic submucosal layer, increased periappendiceal echogenicity, free or loculated periappendiceal or pelvic fluid collections, and appendicoliths. The sonographic findings were correlated with the surgical and pathologic findings. RESULTS. Forty-five patients had nonperforating appendicitis, and 26 had perforating appendicitis. A sonographically visible appendix was present in all patients with nonperforating appendicitis and in 10 (38%) of 26 patients with perforation. An echogenic submucosa was noted in 27 (60%) of 45 patients with uncomplicated appendicitis but in only three (30%) of 10 patients with a visible appendix and perforating appendicitis (p < .05). In 19 of 26 patients with perforating appendicitis, sonography showed loculated periappendiceal or pelvic fluid collections; no patient with nonperforating appendicitis had a loculated fluid collection (p < .05). No statistically significant association was found between the presence or absence of perforation and free pelvic fluid, prominent periappendiceal fat, or an appendicolith. CONCLUSION. Our results indicate that sonography can be helpful in the diagnosis of perforating appendicitis. The best predictors of perforation are absence of the echogenic submucosal layer and the presence of a loculated fluid collection.     

Value of sonography in determining the nature of pleural effusion: analysis of 320 cases.

To assess the value of sonography in determining the nature of pleural effusions, we prospectively analyzed the sonographic findings in 320 patients with pleural effusion of various causes (224 with exudates and 96 with transudates). The nature of the effusions was established on the basis of chemical, bacteriologic, and cytologic examination of pleural fluid; pleural biopsy; and clinical follow-up. All patients had high-frequency, real-time sonography performed by one of three sonographers who had no clinical information concerning the patients. The sonographer evaluated the images for internal echogenicity of the effusion, thickness of the pleura, and associated parenchymal lesions of the lung. The images were also printed out and interpreted a second time by the other two sonographers to reach a consensus. Our results showed that the two types of effusions could be distinguished on the basis of sonographic findings. Transudates were anechoic, whereas an anechoic effusion could be either a transudate or an exudate. Pleural effusions with complex septated, complex nonseptated, or homogeneously echogenic patterns were always exudates (p less than .01). Sonographic findings of thickened pleura and associated parenchymal lesions in the lung also were indicative of an exudate (p less than .01). Homogenous echogenic effusions were due to hemorrhagic effusion or empyema. Sonographic evidence of a pleural nodule was a specific finding in patients with a malignant effusion. We conclude that sonography is useful in determining the nature of pleural effusion.     

Ultrasonography in acute gallbladder perforation

The files of patients with acute cholecystitis from two large university hospitals from the years 1978-1985 were employed to find the cases with acute gallbladder perforation for this study. Only those patients (n = 9) were selected for the analysis of sonographic signs of acute gallbladder perforation who had less than 48 hours of symptoms before sonography, and were operated upon within 24 hours of the sonography. Patients (n = 10) with non-complicated acute cholecystitis and identical in regard to the duration of the symptoms and the timing of the sonography and the operation formed a control group. The sonographic findings in patients with gallbladder perforation were pericholecystic fluid collections, free peritoneal fluid, disappearance of the gallbladder wall echoes, focal highly echogenic areas with acoustic shadows in the gallbladder, and an inhomogeneous, generally echo-poor gallbladder wall.     

Neonatal periventricular leukomalacia: real-time sonographic diagnosis with CT correlation

The utility of real-time sonography in the diagnosis of neonatal periventricular leukomalacia (PVL) has been described only recently. Six cases are reported of PVL diagnosed by serial real-time scanning. The sonographic findings were correlated with the computed tomographic findings and the clinical history. In five of six infants in whom scanning was performed, characteristic multiseptated periventricular cavitations developed 2-3 weeks after birth or later. A transition from normal to increased periventricular echogenicity was often observed before the development of the periventricular cavitations in nonhemorrhagic PVL. The parenchymal abnormality demonstrated by sonography correlated well with an abnormal neurologic outcome. It is suggested that serial real-time scanning be performed in neonates whose history suggests the possibility of hypoxic-ischemic brain injury. Nonspecific predictors of PVL include seizures, apnea, disturbed mental status, abnormal muscle tone, and leg weakness.     

The sonographic appearance of acute focal pyelonephritis 8 years experience

AIM: Acute focal pyelonephritis (AFP) is a variant of pyelonephritis in which single or multiple discrete areas show changes of inflammation. The reported sonographic appearances of AFP are varied but are typically described as being echopoor. The purpose of this study was to review the sonographic appearances of AFP and attempt to explain the range of findings by correlation with clinical details. MATERIALS AND METHODS: We reviewed retrospectively the sonographic findings and medical records of 17 cases of AFP. The study group consisted of 13 women and four men (mean age 20 years). Lesions were designated as echogenic, echopoor or of mixed echogenicity as compared to the adjacent renal cortex, and to the liver or spleen. RESULTS: The abnormal areas were echogenic in 12 patients, echopoor in three and of mixed echogenicity in two. An attempt was made to explain the variation in appearances by correlation with clinical details including the patient's age, the duration of symptoms, the length of antibiotic treatment and the presence of haematuria. CONCLUSION: Areas of acute focal pyelonephritis may be echogenic, echopoor or of mixed echogenicity. Our data would suggest that areas of increased echogenicity are more common. There is no discernible correlation with clinical findings.     

Echogenic periventricular halo: normal sonographic finding or neonatal cerebral hemorrhage

Intracranial sonographic evaluation of the normal neonate frequently reveals an echogenic halo about the lateral ventricles. This periventricular halo is seen to varying degrees when scanning in both semiaxial and parasagittal planes in almost all normal infants. Among 180 consecutive premature neonates scanned serially with real-time sonography, two were prospectively diagnosed as having a form of periventricular echogenicity that was abnormal and represented periventricular hemorrhage. This hemorrhage completely surrounded the lateral ventricles and was intensely echogenic, as echogenic as the choroid plexus. This abnormal periventricular echogenicity was reproducible from multiple scan planes and hemorrhage was confirmed by computed tomography (CT). By contrast, CT scans obtained on another 53 of the 180 premature infants failed to reveal evidence of any abnormality corresponding to the periventricular echogenicity. Both neonates with periventricular hemorrhage developed bilateral multiseptate areas of porencephaly as sequelae to their hemorrhages. The differentiation between normal periventricular echogenicity and periventricular hemorrhage therefore attains great significance to the sonographer.     

Sonographic detection of rotator cuff tears

Thirty-nine consecutive patients referred for shoulder arthrography underwent shoulder sonography to determine the ability of sonography to detect rotator cuff tears. Fifteen patients had arthrographically proven rotator cuff tears. Of these, 14 were detected by sonography, for a sensitivity of 93%. The three sonographic criteria indicative of rotator cuff tear were (1) discontinuity in the normal homogeneous echogenicity of the rotator cuff; (2) replacement of the normal homogeneous echogenicity by a central echogenic band; and (3) nonvisualization of the cuff. Twenty patients had normal sonographic examinations, 19 of which were normal by arthrography. Therefore, the predictive value of a negative sonogram was 95%. On the basis of these findings, sonography can provide a noninvasive means of screening patients with suspected rotator cuff tears.     

Cerebrovascular accidents in neonates treated with extracorporeal membrane oxygenation: sonographic-pathologic correlation

Neonates treated with extracorporeal membrane oxygenation are at high risk for the development of intracranial hemorrhage and infarction. The appearance of these lesions on cranial sonography is often unusual and may be confusing. We compared the findings at autopsy with premorbid cranial sonograms in 17 nonsurviving neonates to define better the anatomic basis for the sonographic appearance of these lesions. Macroscopic abnormalities were identified at autopsy in 13 of the 17 neonates. Five neonates had multifocal hemorrhagic white-matter infarcts, three had large parenchymal hemorrhages with adjacent areas of parenchymal necrosis, three had hemorrhagic infarcts of the cerebellum, one had a germinal matrix and intraventricular hemorrhage, and one had bilateral periventricular cysts with surrounding gliosis. All 17 neonates had abnormalities on microscopic examination. Although sonography was accurate in the detection of macroscopic lesions (11 of 13 lesions detected with sonography), the nature and extent of these abnormalities were difficult to judge because of the variable echogenicity of unclotted blood and the presence of focal areas of abnormal echogenicity associated with microscopic calcification and gliosis. Sonography is excellent for the detection of acute cerebrovascular complications during extracorporeal membrane oxygenation, but the appearance of these lesions is variable and nonspecific.     

Bacterial meningitis in infants: sonographic features

Twenty-three infants with clinically proven bacterial meningitis were studied with real-time cranial sonography at the time of initial diagnosis and in several cases subsequently. A spectrum of sonographic abnormalities was observed, including bright convolutional markings, focal or diffuse increased and/or decreased parenchymal echoes, ventricular debris, and hydrocephalus. In three infants with virulent Gram-negative meningitis serial sonographic studies showed the development of encephalomalacia. Because clinical neurologic assessment of the infant is limited, a diagnostic imaging method that is sensitive to early structural change and suitable for serial observations is advantageous. Transfontanelle real-time sonographic examination of the brain was found to be a reliable, informative, and relatively inexpensive method of documenting and monitoring complicated bacterial meningitis.     

Abdominal sonography after hepatic transplantation: results in 36 patients

Hepatic transplantation was performed in 46 patients over a 2-year period at the University of Minnesota. Thirty-six of these patients subsequently underwent 166 sonographic examinations of the upper abdomen. Forty-three examinations were performed within 2 weeks of transplantation, 47 between 2 and 8 weeks after transplantation, and 76 more than 8 weeks after transplantation. The sonograms were reviewed retrospectively and correlated with the available clinical and histopathologic data. Diffuse, nonspecific parenchymal abnormalities were seen in 27 patients. Focal regions of parenchymal abnormality seen in four patients were associated with abscess and infarction. Moderate to severe biliary dilatation was seen in seven patients with biliary obstruction diagnosed by percutaneous or T-tube cholangiography. Obstruction was seen most commonly in children who had undergone cholecystojejunostomy biliary reconstruction, and it required radiologic or surgical intervention. Routine sonographic assessment of the upper abdominal vasculature showed thrombosis of the portal vein in two cases, thrombosis of the inferior vena cava in one case, thrombosis of the donor aorta in three cases. Focal intraabdominal fluid collections were identified in 14 patients and represented hematomas in all but one. Free peritoneal fluid was detected in 19 patients. Sonography was used to guide percutaneous aspiration of abdominal fluid and to guide fine-needle puncture for percutaneous transhepatic cholangiography. Upper abdominal sonography provides a noninvasive means of evaluating and confirming a wide spectrum of complications that can follow hepatic transplantation. Because clinical and laboratory findings often are nonspecific in these patients, sonographic detection of focal parenchymal abnormalities, biliary dilatation, and vascular compromise is especially valuable.     

Giant subdural empyema in an infant

Summary A giant subdural empyema was found to be the cause of a large head in a two month old female child referred for cranial sonography. The sonographic features of the subdural empyema as illustrated by this case are: (1) The presence of an extra-axial space occupying lesion with mass effect. (2) Its fluid nature with mobile echogenic debris within. (3) Its large extent from frontal to occipital region, and (4) Its thick medial echogenic wall. A total of 250 ml of pus was evacuated from the empyema and the child was doing well on follow up at four months of age.     

The ultrasonographic diagnosis of bacterial meningitis and ventriculitis in infancy: six case reports

Five infants with meningitis and ventriculitis, and a sixth patient with meningitis only are reported. In one hydrocephalic infant, infection of the central nervous system (CNS) was not suspected until cerebral ultrasonography revealed features of ventriculitis. It appears that in non-communicating hydrocephalus managed with a ventriculo-peritoneal (VP) shunt, infection may involve predominantly the "sequestered ventricles" rather than the spinal meninges. In four infants, bacterial meningitis had been proven but ventriculitis was not diagnosed until cerebral ultrasonography was performed. In a sixth neonate, E coli Kl meningitis was diagnosed and treated very early and cerebral ultrasonography showed involvement of the surface of the brain, but not the ventricles. The ultrasonographic features of bacterial ventriculitis and meningitis in infancy are: Increased echogenicity of the ventricular fluid, either in a fine homogeneous pattern, or with strand-like material and coarse particles. Increased echogenicity of the ependymal lining of the ventricles. Loss of definition of the surface of the choroid plexuses. Hydrocephalus, which may be progressive, with or without loculation of fluid. Abnormally wide and prominent cerebral sulci as a sign of meningitis. With treatment, the ventricular fluid became normal in a few days. The other abnormalities resolved more slowly. Hydrocephalus and fluid loculation were slowest to resolve. Ultrasonography has the potential for recognition of other complications such as subdural fluid collections and cerebral abscess.     

Sonographic findings in infants with macrocrania

This study compares the sonographic and CT findings in a group of infants with macrocrania and correlates those findings with neurologic outcome to determine the diagnostic accuracy and prognostic value of sonography. Sonographic findings in 255 infants with macrocrania are described. Of the 195 term infants examined, 130 had normal sonograms, 11 (5.6%) had significant abnormalities, and 54 had increased intra- and/or extraaxial fluid spaces. Of the 60 former preterm infants, 33 had normal sonograms, four (6.7%) had significant abnormalities, and 23 had increased fluid spaces or small resolving germinal matrix hemorrhages. The patients with significant abnormalities usually had head circumferences greater than the 95th percentile and had neurologic abnormalities. There was good correlation between sonography and CT in 30 of the 36 patients evaluated by both. In six there was mild discrepancy in the volume of the extraaxial fluid. No significant abnormality was missed by sonography. CT did not contribute any additional information. Neurologic follow-up was available for 202 patients. Nineteen percent of the term infants and 24% of the former preterm infants were abnormal on neurologic follow-up. Most patients with normal sonograms were normal on follow-up. Twelve of the term and four of the preterm infants with normal sonograms were developmentally delayed on follow-up. Increased CSF in the ventricles and/or extraaxial spaces was a common abnormality, but it usually is associated with a normal neurologic outcome and represents "benign macrocrania." We conclude that an infant with an enlarged or enlarging head should have a neurologic examination and head circumference measurement. If the patient has a head circumference greater than the 95th percentile, particularly if there are abnormal neurologic findings, further evaluation is indicated. Sonography is the initial procedure recommended since it accurately evaluates ventricular size, extraaxial fluid, and congenital malformations. If sonography is normal or shows mildly increased fluid spaces, then follow-up head circumference measurement and clinical evaluation will probably suffice. CT is indicated if there is a significant abnormality on sonography that requires further clarification.     

Uncomplicated acute diverticulitis of the cecum and ascending colon: sonographic findings in 18 patients

To determine the sonographic features of uncomplicated acute diverticulitis of the cecum and ascending colon, the sonographic findings in 534 patients who presented with right lower quadrant pain were reviewed. Of these, 18 patients had uncomplicated acute diverticulitis of the cecum and ascending colon. The diagnosis was confirmed by surgery (one patient), clinical course (17 patients), CT (eight patients), or contrast enema (11 patients). On sonography, a round or oval focus of varying echogenicity, which protruded from a segmentally thickened colonic wall and was surrounded by a hyperechoic area, was seen in all 18 patients. These were hypoechoic foci (12 patients), hypoechoic foci with internal strong echoes (three patients), and echogenic shadowing foci with surrounding hypoechoic bands (three patients). Extraluminal gas (one patient) and thickening of lateroconal fascia (six patients) were seen also. Findings of enlarged appendix, frank abscess, and ascites were absent. All patients, including the one who had laparotomy, were successfully treated medically for diverticulitis. Of 515 patients without diverticulitis, in only one patient with acute appendicitis did sonography show a hypoechoic protruding focus. Our experience indicates that the major sonographic finding in patients with uncomplicated acute diverticulitis of the right colon is a hypoechoic round or oval focus protruding from a segmentally thickened colonic wall.     

Clonorchiasis: sonographic findings in 59 proved cases

Clonorchiasis is a parasitic disease of the bile ducts that occurs in endemic areas after ingestion of the raw flesh of freshwater fish. We analyzed the sonographic findings in 59 patients with clonorchiasis, suspected prospectively from sonographic findings and proved subsequently by demonstration of eggs in their stools. Diffuse dilatation of the small intrahepatic bile ducts with no or minimal dilatation of the large intra- and extrahepatic ducts was observed in all cases. The extrahepatic ducts were patent throughout in all except one case. This characteristic finding reflects diffuse intrahepatic bile duct obstruction and resultant proximal dilatation caused by an adult worm or aggregates of worms, as worms reside diffusely in the medium and small intrahepatic bile ducts. Cholangitis and multifocal periductal fibrosis with proximal dilatation may play an additional role. Increased echogenicity of the intrahepatic bile duct wall was present in 39 cases (66%), reflecting cholangitis and periductal fibrosis. In 17 cases (29%), floating or dependent, discrete, nonshadowing, intraluminal, echogenic foci caused by adult worms in the bile were demonstrated in the gallbladder. These echogenic foci were distinguished from stones because they were fusiform, weak in echogenicity, and floated with a change in position. Clonorchiasis should be considered when sonography discloses the characteristic pattern of bile duct dilatation with increased wall echogenicity and nonshadowing, discrete, echogenic foci in the gallbladder lumen.     

Sonography of the postoperative shoulder

Fifty-three patients with 60 symptomatic shoulders underwent shoulder sonography for recurrent postoperative symptoms after either acromioplasty (10 shoulders) or repair of a full-thickness rotator cuff tear in addition to acromioplasty (50 shoulders). Because surgery distorts landmarks, an understanding of the surgical procedures and their characteristic sonographic appearances is essential. After acromioplasty, the characteristic sharp margination or the acromion was replaced by a less distinct, irregular surface. After repair of a cuff tear, characteristic sonographic appearances included visualization of a reimplantation trough and loss of the echogenic subdeltoid bursa. When the cuff was intact after surgery, echogenicity was abnormal in all cases (17 shoulders). Sonography accurately diagnosed recurrent cuff tears in all 26 shoulders in which surgical proof was available and confirmed an intact cuff in 10 of 11 cases. In one shoulder, a cuff hematoma was incorrectly interpreted as a full-thickness tear. These findings suggest that sonography is an effective procedure for evaluating a postoperative patient with recurrent shoulder symptoms.     

Acute testicular torsion in children: the role of sonography in the diagnostic workup

Acute testicular torsion in children is an emergency and has to be diagnosed urgently. D oppler sonography is increasingly used in imaging the acute scrotum. Nevertheless, in uncertain cases, surgical exploration is required. In this study, we attempted to define the role of Doppler sonography in the diagnostic workup of the acutely painful scrotum. All patients admitted between 1999 and 2005 with acute scrotal pain were included. After clinical assessment, patients were imaged by Doppler sonography with a ‘‘high-end’’ instrument. In cases of absent arterial perfusion of the testis in Doppler sonography, surgical exploration was carried out. Patients with unaffected perfusion were followed clinically by ultrasound for up to 2 years. Sixty-one infants and children aged 1 day to 17 years (median: 7.9 years) were included. In 14 cases, sonography demonstrated absent central perfusion, with abnormal parenchymal echogenicity in six. Absence of venous blood flow together with reduction of central arterial perfusion was found in one infant. In these 15 patients, surgical exploration confirmed testicular torsion. Among the other 46 patients, we found four cases with increased testicular perfusion and 27 with increased perfusion of the epididymis. In one infant, a testicular tumour was found sonographically, and orchiectomy confirmed diagnosis of a teratoma. Follow-up examinations of the conservatively treated patients showed good clinical outcome with physiologic central perfusion as well as normal echogenic pattern of both testes. No case of testicular torsion was missed. By means of Doppler sonography, an unequivocal statement regarding testicular perfusion was possible in all cases. The initial Doppler diagnosis was confirmed by operative evaluation and follow-up ultrasound. Testicular torsion can therefore be excluded by correctly performed ultrasound with modern equipment. Patrick Gunther and Jens-Peter Schenk contributed equally to this work     

Sonography of injury of the ulnar collateral ligament of the elbow—initial experience

Objective The purpose of this study is to describe the sonographic appearance of injuries of the ulnar collateral ligament (UCL) of the elbow.Design and patients Eight non-professional male baseball pitchers, ages 13–35 years, with medial elbow pain and clinical suspicion of ulnar collateral ligament injury, were referred for imaging. All eight underwent sonography of the affected and contralateral asymptomatic elbow, and six also underwent MR imaging. Neither valgus stress nor power Doppler was used during the sonographic examinations. Time from onset of symptoms to imaging was 1.5 weeks to 6 months. Three patients had surgical confirmation of their injuries, with time from imaging to surgery of 2 days to 9 months.Results In four patients, the UCL was ruptured, manifest sonographically in three cases as discontinuity of the normally hyperechoic ligament with anechoic fluid in the gap and in one case as non-visualization of the ligament with heterogeneous echogenicity in the expected location of the ligament. Two adolescent patients had avulsions of the UCL from the medial epicondyle, with sonographic demonstration of the avulsed echogenic bony fragment in both cases. One patient had a mild sprain, manifest as mild thickening and decreased echogenicity of the ligament sonographically compared with the contralateral normal elbow, with mild surrounding hypoechoic edema. The eighth patient had a small partial tear of the deep surface of the distal aspect of the ligament, visualized as a hypoechoic focus between the deep surface of the ligament and its ulnar attachment.Conclusion Tears of the ulnar collateral ligament are manifested sonographically as non-visualization of the ligament or alteration of the normal morphology.