Evaluation of the incidence of nephrogenic systemic fibrosis in patients with moderate renal insufficiency administered gadobenate dimeglumine for MRI.

AIM: To determine the incidence of nephrogenic systemic fibrosis (NSF) in stage 3 chronic kidney disease patients following intravenous exposure to gadobenate dimeglumine. MATERIALS AND METHODS: A prospective study was performed on 168 consecutive patients at a single institution with stage 3 chronic kidney disease who underwent clinically-indicated contrast-enhanced magnetic resonance imaging (MRI) examinations with gadobenate dimeglumine from January 2007 to March 2008. All patients were contacted by phone by investigators 3 months after MRI to verify the presence or absence of NSF signs or symptoms. If signs or symptoms suggestive of NSF developed, dermatologic referral was made and confirmatory skin biopsy performed if indicated. RESULTS: One hundred and eighty contrast-enhanced MRI examinations with gadobenate dimeglumine were performed on the 168 patients. Twenty patients were lost to follow-up, but 160 incidents of contrast medium exposure were followed up for 3-months and 105 incidents were followed up for 6 months. The mean contrast medium dose per weight was 0.093 mmol/kg (range 0.042-0.153 mmol/kg). The mean estimated creatinine clearance was 50.4 ml/min/1.73 m(2) (range from 30-59 ml/min/1.73 m(2)). Ten patients developed skin rashes during the 3-month follow-up period, but none were confirmed to represent NSF (0% prevalence rate). No other signs or symptoms of NSF were reported. CONCLUSION: Based on this limited study, NSF does not appear to occur in patients with stage 3 chronic kidney disease exposed to intravenous gadobenate dimeglumine for MRI at standard dosing of approximately 0.1 mmol/kg.

Diagnosis and management of placenta percreta: a review.

A review of the clinical decisions, diagnostic, and surgical methods in managing patients with placenta percreta was done by conducting a MEDLINE computerized search from January 1991 to January 1997 using the key words "placenta percreta," "placenta previa," "acute normovolemic hemodilution," and "erythropoietin use." Additional sources were identified through cross-referencing. We reviewed all published reports and articles regarding the clinical and surgical management of placenta percreta and nontraditional ways to treat or prevent anemia in these cases (including acute normovolemic hemodilution and erythropoietin use). The diagnosis of placenta percreta using different ultrasonographic criteria is reliable. Clinical and surgical methods of managing placenta previa with a high risk of percreta are all based on prevention of uncontrolled hemorrhage. Ninety percent of these patients will lose more than 3000 ml intraoperatively and will require blood transfusion. To avoid serious maternal morbidity secondary to hypovolemia, several options are available: erythropoietin use, acute normovolemic hemodilution, selective arterial embolization, prophylactic uterine, or hypogastric artery ligation. With the increasing incidence of placenta percreta, the clinician must use all available methods to accurately diagnose this condition. Adequate preparation and good surgical technique will help reduce maternal mortality and morbidity related to this condition.

Postnatal maturation of the sacrum and coccyx: MR imaging, helical CT, and conventional radiography.

OBJECTIVE: The purpose of this paper is to provide a detailed radiologic description of the postnatal developmental anatomy of the sacrum and coccyx as revealed by MR imaging, helical CT, and conventional radiography. MATERIALS AND METHODS: One hundred ten imaging examinations of the sacrococcygeal spine were performed in patients who were newborn to 30 years old. Imaging included conventional radiography (n = 63), three-dimensional gradient-recalled echo MR imaging (n = 10), and helical CT with sagittal and angled coronal reformations (n = 37). A detailed analysis was performed of the ossification and fusion of the primary and secondary ossification centers. RESULTS: The sacrum and coccyx were noted to develop from 58 to 60 sacral ossification centers and eight coccygeal centers, respectively. These centers were noted to ossify and fuse in an organized temporal pattern from the fetal period to the age of 30. CONCLUSION: The sacrum and coccyx are formed by a complex process that fuses primary and secondary ossification centers. Because the maturation process can be asymmetric, an understanding of this process may prove useful for distinguishing physeal plates from fracture lines.

Sonographic analysis of gallbladder findings in Salmonella enteric fever.

The purpose of this study was to analyze gallbladder sonographic findings associated with Salmonella typhi enteric fever. Sixty-two patients with culture positive Salmonella enteric fever were analyzed with serial sonography. The following gallbladder sonographic findings were noted: globular gallbladder distention (33 of 62 patients, 530%), positive sonographic Murphy sign (25 patients, 40%), pericholecystic edema or fluid (25 patients, 40%), gallbladder wall thickening > 4 mm (21 patients, 34%), low-level nonshadowing intraluminal echoes or sludge (nine patients, 15%), intramural linear sonolucency or striation (eight patients, 13%), and mucosal irregularity or sloughed membrane (four patients, 6%). Using the sonographic findings a gallbladder score was devised to assess the severity of gallbladder changes, and the score was correlated with the following clinical parameters--duration of fever, multidrug resistance, and clinical outcome. An abnormal gallbladder score was noted in 37 patients (60%), and multidrug resistance was noted in 35 of these patients (95%). The gallbladder scores showed a strong positive correlation with the duration of fever and the frequency of multidrug resistance. All 62 patients were treated with intensive antibiotic therapy without any deaths.

Improved sonographic visualization of the fetal spine with the mother seated.

OBJECTIVE: Evaluation of the fetal spine is an essential part of obstetric sonography; however, many technical factors may limit this examination. The purpose of our study was to determine if having the mother seated during sonography could significantly improve visualization of the fetal spine when sonography in routine supine and decubitus positions had failed. SUBJECTS AND METHODS: A prospective study was performed on 526 consecutive fetal spines of obstetric patients. The estimated gestational age of the fetuses was 16 weeks or more. Sonography of the spine was considered satisfactory if the spine was seen in its entirety in the posterior sagittal and axial projections. If the spine was not entirely seen, a short (< 3 min) sonogram was obtained with the mother seated to see the remaining spinal segments. Sonograms were assessed for improved visualization of the spine and whether the entire spine could be seen on the routine and seated studies. Hard-copy images of the sonograms were also analyzed independently by two radiologists. Intraobserver agreement (in the prospective and retrospective analyses) and interobserver agreement of the reviewers (in the retrospective analysis) were assessed using Cohen's kappa coefficient. RESULTS: Of the 526 fetal spines initially insonated in the supine or decubitus position, 68 spines (13%) were not satisfactorily seen and required the seated technique. This technique improved the sonographic visualization of the spine in 43 (63%) of 68 cases. The seated technique allowed the previously nonvisualized spinal segments to be completely seen in 37 cases (54%). However, in six cases (9%), improved visualization of the fetal spine fell short of complete visualization. Retrospective analysis showed a high degree of interobserver and intraobserver agreement, with kappa values of .97 and .94, respectively. CONCLUSION: Sonography performed with the seated technique is simple and can significantly improve visualization of the fetal spine when the spine is not satisfactorily seen in routine supine or decubitus positions.

A knee simulating machine for performance evaluation of total knee replacements.

A knee simulating machine is required for the design and evaluation of total knee replacements, the kinematics and the long-term wear being aspects of particular importance. There are no generally agreed design criteria, such that existing designs of simulator have a wide variety of input and constraint conditions. In this study, it was postulated that in order to reproduce physiological wear patterns, the correct kinematics is required, on the basis that the wear will be a direct function of the sliding, rolling and tractive rolling conditions at the joint surfaces. In turn, the correct kinematics would only be achieved by the input of physiological forces, by the appropriate constraints on the fixtures holding the components, and by simulating the soft tissue restraints. A knee simulating machine based on these principles was constructed, and used to test the kinematics of a range of contemporary condylar replacement knees. The displacements and rotations varied over a range of almost two times, even with the soft tissue restraints. Without the restraints, the low constraint designs would have dislocated or moved unrealistically. It was concluded that a simulating machine should be based on the input of forces and moments, rather than on displacements and rotations, in order to provide data of kinematics and wear.

Acute and chronic tears of the anterior cruciate ligament: differential features at MR imaging.

To evaluate the differential features of acute and chronic tears of the anterior cruciate ligament at magnetic resonance (MR) imaging, the authors performed a retrospective evaluation of findings in 81 MR examinations correlated with results at arthroscopy. Intact anterior cruciate ligaments (ACLs) were present in 29 patients; acute complete ACL tears, in 22; and chronic complete ACL tears, in 30. Acute tears were accurately distinguished from intact ligaments and were characterized by the presence of edema. Chronic tears had a more variable appearance: Nine (30%) were depicted at MR as intact bands with low signal intensity that bridged the expected origin and insertion of the ACL. This appearance is likely due to the presence of bridging fibrous scars within the intercondylar notch. Five of these nine cases were correctly characterized as chronically torn because of the presence of focal angulation. In four of these nine cases the scarred fragments produced a relatively straight band that mimicked an intact ligament. Although chronic and acute ACL tears usually have distinct findings at MR, a chronic tear will occasionally be difficult to distinguish from an intact ligament.

Neuroimaging of disseminated germ cell neoplasms.

The purpose of this study was to determine the role of neuroimaging in the management of patients with metastatic germ cell tumors. Retrospective evaluation of 299 patients treated in 1986 and 1987 for initial presentation or recurrence of testicular, retroperitoneal, and mediastinal germ cell tumors was performed to determine indications for neuroimaging, frequency and site of CNS metastases, and occurrence of other CNS abnormalities. Sixty-six patients required CNS imaging with myelography, CT, or MR. Studies were normal in 24 patients. Twenty patients had CNS metastases including 11 with intracranial metastases, eight with spine lesions, and one with both brain and spine involvement. Sixteen had cerebral or cerebellar atrophy of unclear origin and functional significance. Two patients had ventriculomegaly without symptoms of hydrocephalus. Four patients had questionable lesions that were never confirmed. None of the 25 asymptomatic patients with elevated serum tumor markers had brain metastases. Fifteen of 17 patients with focal neurologic deficits and three of six patients with seizures had CNS metastases. CNS imaging to detect germ cell tumor metastases is most useful in the presence of neurologic deficits or seizures but is not useful in patients with unexplained elevation of serum tumor markers in the absence of neurologic deficits.

Neuroimaging of disseminated germ cell neoplasms.

The purpose of this study was to determine the role of neuroimaging in the management of patients with metastatic germ cell tumors. Retrospective evaluation of 299 patients treated in 1986 and 1987 for initial presentation or recurrence of testicular, retroperitoneal, and mediastinal germ cell tumors was performed to determine indications for neuroimaging, frequency and site of CNS metastases, and occurrence of other CNS abnormalities. Sixty-six patients required CNS imaging with myelography, CT, or MR. Studies were normal in 24 patients. Twenty patients had CNS metastases including 11 with intracranial metastases, eight with spine lesions, and one with both brain and spine involvement. Sixteen had cerebral or cerebellar atrophy of unclear origin and functional significance. Two patients had ventriculomegaly without symptoms of hydrocephalus. Four patients had questionable lesions that were never confirmed. None of the 25 asymptomatic patients with elevated serum tumor markers had brain metastases. Fifteen of 17 patients with focal neurologic deficits and three of six patients with seizures had CNS metastases. CNS imaging to detect germ cell tumor metastases is most useful in the presence of neurologic deficits or seizures but is not useful in patients with unexplained elevation of serum tumor markers in the absence of neurologic deficits.