Herma C. Holscher

MR imaging of edema accompanying benign and malignant bone tumors

To evaluate the incidence, quantity, and presentation of intra- and extraosseous edema accompanying benign and malignant primary bone lesions, the magnetic resonance (MR) studies of 63 consecutive patients with histologically proven primary bone tumors were reviewed. MR scans were assessed for the presence and quantity of marrow and soft tissue edema and correlated with peroperative findings, resected specimens and follow-up data. The signal intensity and enhancement of tumor and edema prior to and after intravenous administration (if any) of gadolinium-labled diethylene triamine pentaacetate (Gd-DTPA) was analyzed. Marrow edema was encountered adjacent to 8 of 39 malignant tumors and 14 of 24 benign lesions. Soft tissue edema was found accompanying 28 of 39 malignancies and 10 of 24 benign disorders. On unenhanced T1-weighted MR images tumor and edema were difficult to differentiate. Tumor inhomogeneity made this differentiation easier on T2-weighted sequences. In 36 patients the contrast medium Gd-DTPA was used. Edema was present in 27 of these patients and the respective enhancement of tumor and edema could be compared. Edema always enhanced homogeneously, and in most cases it enhanced to a similar degree as or more than tumor. Marrow and, more specifically, soft tissue edema is a frequent finding adjacent to primary bone tumors. The mere presence and quantity of marrow and soft tissue edema are unreliable indicators of the biologic potential of a lesion. Unenhanced MR scans cannot always differentiate between tumor and edema, but the administration of Gd-DTPA is of assistance in differentiating tumor from edema. Awareness of marrow and/or soft tissue edema adjacent to bone lesions is of importance because edema can be a pitfall in the diagnostic work-up and staging prior to biopsy or surgery.

US examination of the appendix in children with suspected appendicitis: the additional value of secondary signs

This study evaluated the additional value of secondary signs in the diagnosing of appendicitis in children with ultrasound. From May 2005 to June 2006, 212 consecutive paediatric patients with suspected appendicitis were examined. Ultrasonographic depiction of the appendix was classified into four groups: 1, normal appendix; 2, appendix not depicted, no secondary signs of appendicitis; 3, appendix not depicted with one of the following secondary signs: hyperechoic mesenteric fat, fluid collection, local dilated small bowel loop; 4, depiction of inflamed appendix. We classified 96 patients in group 1, 41 in group 2, 13 in group 3, and 62 in group 4. Prevalence of appendicitis was 71/212 (34%). Negative predictive values of groups 1 and 2 were 99% and 100%, respectively. Positive predictive values of groups 3 and 4 were 85% and 95%, respectively. In groups 3 and 4, hyperechoic mesenteric fat was seen in 73/75 (97.3%), fluid collections and dilated bowel loops were seen in 12/75 (16.0%) and 5/75 (6.6%), respectively. This study shows that in case of non-visualization of the appendix without secondary signs, appendicitis can be safely ruled out. Furthermore, secondary signs of appendicitis alone are a strong indicator of acute appendicitis.

The cervical spine in rheumatoid arthritis: relationship between neurologic signs and morphology on MR imaging and radiographs

Abstract Objective. Comparison of clinically observed neurologic long tract signs in a heterogeneous group of patients with rheumatoid arthritis (RA), with morphologic abnormalities of the cervical spine as depicted on radiographs and magnetic resonance (MR) images. Design. The patients were prospectively assigned to one of three classes on the basis of their neurologic status. Lateral cervical spine radiographs and sagittal T1-weighted and gradient echo images were performed. The qualitative MR features evaluated were erosion of the dens and atlas, brain stem compression, subarachnoid space encroachment, pannus around the dens, appearance of the fat body caudal to the clivus, and the signal intensity of the pannus. The quantitative imaging parameters were the cervicomedullary angle and the distance of the dens to the line of McRae. Patients. Sixty-three consecutive patients with RA and subjective symptoms, especially neck or occipital pain, and/or clinical objective signs consistent with a compromised cervical cord were included in this study. Results and conclusions. Damage documented with radiographs and MR imaging in patients with RA is often severe, even in those without neurologic signs (class 1). None of the abnormalities confined to the atlantoaxial level correlated significantly with neurologic classification. Subarachnoid space encroachment anywhere in the entire cervical spine did correlate significantly with neurologic classification.

Neurologic dysfunction in patients with rheumatoid arthritis of the cervical spine. Predictive value of clinical, radiographic and MR imaging parameters

Abstract The aim of this study was to evaluate if subjective symptoms, radiographic and especially MR parameters of cervical spine involvement, can predict neurologic dysfunction in patients with severe rheumatoid arthritis (RA). Sequential radiographs, MR imaging, and neurologic examination were performed yearly in 46 consecutive RA patients with symptoms indicative of cervical spine involvement. Radiographic parameters were erosions of the dens or intervertebral joints, disc-space narrowing, horizontal and vertical atlantoaxial subluxation, subluxations below C2, and the diameter of the spinal canal. The MR features evaluated were presence of dens and atlas erosion, brainstem compression, subarachnoid space encroachment, pannus around the dens, abnormal fat body caudal to the clivus, cervicomedullary angle, and distance of the dens to the line of McRae. Muscle weakness was associated with a tenfold increased risk of neurologic dysfunction. Radiographic parameters were not associated. On MR images atlas erosion and a decreased distance of the dens to the line of McRae showed a fivefold increased risk of neurologic dysfunction. Subarachnoid space encroachment was associated with a 12-fold increased risk. Rheumatoid arthritis patients with muscle weakness and subarachnoid space encroachment of the entire cervical spine have a highly increased risk of developing neurologic dysfunction.

Monitoring the effect of chemotherapy in Ewing's sarcoma of bone with MR imaging

Magnetic resonance (MR) imaging was performed in 26 patients with Ewings sarcoma of bone preceding and following neoadjuvant chemotherapy, to assess tumour response non-invasively prior to surgery. T1- and T2-weighted spin echo images were obtained. Changes including intra- and extramedullary signal intensities, tumour demarcation, tumour volume and the appearance of residual extramedullary tumour were compared with histopathology of the resected specimens. Reduction of tumour volume was significantly higher in good responders. Other single parameters did not correlate with histologic tumour response. However, when several MR parameters summarized in a classification system were combined, a positive correlation with histopathologic response was found. A limited decrease of tumour volume (<25%) and/or residual soft tissue mass following chemotherapy correlated with a poor response. An inhomogeneous, well-defined cuff of abnormal tissue encircling the bone and/or radiological disappearance of the soft tissue tumour component following chemotherapy correlated with good response. Twenty-three out of 26 patients were correctly classified by MR as good or poor responders. Minimal residual disease (<10% of the entire tumour volume), observed histologically, could not be identified with MR imaging. Tumour volume reduction and residual extramedullary tumour, rather than changes of signal intensity, are major features for evaluating the response to chemotherapy in Ewings sarcoma.

Can conventional radiographs be used to monitor the effect of neoadjuvant chemotherapy in patients with osteogenic sarcoma

Abstract Objective. The objective of this study was to assess the effectiveness of conventional radiography in predicting histopathologic response in patients with osteogenic sarcoma who were treated with preoperative chemotherapy. Design and patients. The radiographs of 22 patients with an osteogenic sarcoma, taken before and after neoadjuvant chemotherapy, were reviewed. Tumour location, size, radiographic appearance, margination, cortical destruction and periosteal reaction were evaluated. The findings were correlated with the histopathologic response of the surgical specimen. Results. None of the findings proved to be of predictive value for the histopathologic response. Increase in tumour diameter and increase in ossification and/or calcification, which were seen in more than half of the patients, did not correlate with response. Conclusion. Conventional radiographs do not contribute to the identification of good or poor responders.

Increased echogenicity of renal cortex: a transient feature in acutely ill children.

OBJECTIVE The purpose of our study was to determine the frequency of hyperechogenicity of renal parenchyma in children with acute abdominal illness and to evaluate the assumed transient feature of this hyperechogenicity. MATERIALS AND METHODS Between January 2005 and February 2006, 189 consecutive patients (112 boys and 77 girls; mean age, 10 years) presenting with acute abdominal pain were examined with sonography. Patients with a known history of renal disease and those with acute urinary tract infection were excluded from the study. Echogenicity of the renal cortex in comparison with adjacent liver was recorded. Renal cortex echogenicity was divided into three groups; group 1, renal cortex echogenicity less than liver parenchyma echogenicity; group 2, renal cortex echogenicity similar to that of liver parenchyma; and group 3, renal cortex echogenicity greater than that of liver parenchyma. Patients with hyperechogenicity were reexamined with sonography after 2 weeks or more. The final sonographic diagnosis and clinical outcome were noted. RESULTS Renal cortex echogenicity was equal to or greater than that of the liver parenchyma in 18% (n = 34) of 189 patients. Increased echogenicity of the renal cortex returned to normal in 2 or more weeks in all patients. Three patients had no follow-up. Clinical diagnoses were idiopathic acute abdominal pain (n = 74), appendicitis (n = 83), mesenteric lymphadenitis (n = 15), ileocecitis (n = 7), gastroenteritis (n = 7), Crohns disease (n = 1), intussusception (n = 1), and pneumonia (n = 1). No concurrent renal disease was diagnosed. CONCLUSION Increased echogenicity of renal parenchyma in children with acute illness is a transient feature and does not necessarily indicate renal disease.

Magnetic resonance relaxation times of normal tissue in the course of chemotherapy: a study in patients with bone sarcoma

To study the effect of chemotherapy on normal fat, skeletal muscle, and bone marrow, T1 and T2 relaxation times were measured in 15 patients with bone sarcoma before and after each cycle of preoperative chemotherapy. A section plane containing the tumor and if possible the nonaffected extremity was imaged with combined multiecho spin echo and inversion recovery pulse sequences. T1 and T2 relaxation times were calculated in the normal-appearing tissues. Although some variation was found in the values in the individual patient and between patients, no systematic changes of relaxation times of fat, muscle, or bone marrow occurred in the course of treatment. We conclude that the chemotherapy used in bone sarcoma has no effect on relaxation times of normal fat, muscle, and bone marrow, and that therefore these tissues may serve as a reference for the signal intensity of tumor.