Assessing vascular effects of adding bevacizumab to neoadjuvant chemotherapy in osteosarcoma using DCE-MRI

BACKGROUND

The purpose of this study was to assess the impact of bevacizumab alone and in combination with cytotoxic therapy on tumour vasculature in osteosarcoma (OS) using DCE-MRI.

METHODS

Six DCE-MRI and three (18)F-FDG PET examinations were scheduled in 42 subjects with newly diagnosed OS to monitor the response to antiangiogenic therapy alone and in combination with cytotoxic therapy before definitive surgery (week 10). Serial DCE-MRI parameters (K(trans), v(p), and v(e)) were examined for correlation with FDG-PET (SUV(max)) and association with drug exposure, and evaluated with clinical outcome.

RESULTS

K(trans) (P=0.041) and v(p) (P=0.001) significantly dropped from baseline at 24 h after the first dose of bevacizumab alone, but returned to baseline by 72 h. Greater exposure to bevacizumab was correlated with larger decreases in v(p) at day 5 (P=0.04) and week 10 (P=0.02). A lower K(trans) at week 10 was associated with greater percent necrosis (P=0.024) and longer event-free survival (P=0.034).

CONCLUSIONS

This is the first study to demonstrate significant changes of the plasma volume fraction and vascular leakage in OS with bevacizumab alone. The combination of demonstrated associations between drug exposure and imaging metrics, and imaging metrics and patient survival during neoadjuvant therapy, provides a compelling rationale for larger studies using DCE-MRI to assess vascular effects of therapy in OS.

Development and prevalence of femoroacetabular impingement-associated morphology in a paediatric and adolescent population: a CT study of 225 patients

We investigated the development of CT-based bony radiological parameters associated with femoroacetabular impingement (FAI) in a paediatric and adolescent population with no known orthopaedic hip complaints. We retrospectively reformatted and reoriented 225 abdominal CTs into standardised CT pelvic images with neutral pelvic tilt and inclination (244 female and 206 male hips) in patients ranging from two to 19 years of age (mean 10.4 years). The Tönnis angle, acetabular depth ratio, lateral centre-edge angle, acetabular version and α-angle were assessed. Acetabular measurements demonstrated increased acetabular coverage with age and/or progressive ossification of the acetabulum. The α-angle decreased with age and/or progressive cortical bone development and resultant narrowing of the femoral neck. Cam and pincer morphology occurred as early as ten and 12 years of age, respectively, and their prevalence in the adolescent patient population is similar to that reported in the adult literature. Future aetiological studies of FAI will need to focus on the early adolescent population.

MR arthrography of the glenohumeral joint: a tailored approach

OBJECTIVE

The purpose of this study was to anatomically confirm that anterior shoulder injection could result in penetration of the anterior stabilizing structures of the glenohumeral joint and to advocate the use of a tailored approach to MR arthrography based on presenting symptoms.

CONCLUSION

A tailored approach to MR arthrography may be a useful way to isolate expected pathology in the shoulder and limit confounding findings related to the performance of the procedure.

Recurrent digital fibroma, focal dermal hypoplasia, and limb malformations

Recurrent digital fibroma of infancy generally is considered a sporadic tumor of childhood. We describe the case of a mother with recurrent digital fibroma at a young age who gave birth to a daughter with focal dermal hypoplasia, coloboma of the iris and eyelids, anal atresia, and extensive limb malformations. When the infant was 3 months old, fibromas started to appear at the fingertips. The cases of three additional patients are described, with a similar combination of multiple digital fibromas, pigmented marks on the temporal region, and limb malformations. One of these patients has consanguineous parents. The clinical findings overlap partially with Gorlin-Goltz syndrome, which has been renamed by some authors "microphthalmia with linear skin defects" (MLS). Since the skin signs are clearly different, however-more like those of Setleis syndrome ("forceps mark" temporal dysplasia)-the patients described here seem to have a new combination of congenital malformations. Deletion of distal Xp, known to occur in some MLS patients, was not detected using cosmids in fluorescence in situ hybridization. This pattern of digital fibroma with congenital malformations seems to represent a new syndrome.

Rotator cuff interval: evaluation with MR imaging and MR arthrography of the shoulder in 32 cadavers

PURPOSE

The purpose of this work was to establish the optimal means of evaluation of the rotator cuff interval (RCI) and rotator interval capsule and demonstrate normal anatomy of the RCI using MR imaging and MR arthrography.

METHOD

MR arthrography was performed in 32 cadaveric shoulders. In 20 cases, MR imaging was completed prior to arthrography. Pre- and postarthrography studies included standard imaging planes. Images were evaluated by the consensus of two musculoskeletal radiologists with attention to the RCI, rotator interval capsule (measurements on postarthrographic studies), and crossing structures. In five cases, specialized imaging planes were performed after arthrography.

RESULTS

The RCI, rotator interval capsule, and crossing structures were best evaluated by MR arthrography. The anteroposterior dimension of the rotator interval capsule could be best depicted on postarthrogram images.

CONCLUSION

MR arthrography, with both standard and specialized imaging planes, is a useful way to evaluate the RCI, the rotator interval capsule, and its crossing structures.

Radiography of cervical spine injury in children: are flexion-extension radiographs useful for acute trauma?

OBJECTIVE

We assessed the role of cervical spine flexion-extension radiographs in the acute evaluation of pediatric trauma patients.

MATERIAL AND METHODS

We performed a retrospective review of all pediatric trauma patients who underwent static cervical spine radiography followed by flexion-extension radiography during a 22-month period. We reviewed the mechanism of injury, physical examination findings, and patient age, and tabulated the results of initial and follow-up imaging studies.

RESULTS

Two hundred forty seven children (age range, 1.6-18 years; mean age, 11.5 years) with a history of trauma underwent cervical spine radiography followed by flexion-extension radiography. Static cervical spine radiographs revealed normal findings in 224 patients (91%). Flexion-extension radiographs revealed normal findings for all patients with normal findings on cervical spine radiographs. Of 23 children (9%) with abnormal findings on static cervical spine radiographs, seven (30%) had congenital abnormalities visible on flexion-extension radiographs; 10 (43%) had traumatic injuries including fracture, subluxation, or soft-tissue swelling; two (9%) had instability; and six (26%) had questionable abnormalities that were noted on static cervical spine radiographs. In four patients (66%) with abnormal findings on static cervical spine radiographs, flexion-extension radiographs were helpful in ruling out abnormality.

CONCLUSION

In children with a history of trauma and normal findings on static cervical spine radiographs, additional flexion-extension radiographs are of questionable use.

The duodenal dimple: a specific fluoroscopic correlate to the duodenal web

PURPOSE

We describe a new fluoroscopic sign to aid in the diagnosis of an obstructing duodenal web and its attachment site.

MATERIALS AND METHODS

During an upper GI series of a neonate, a nasogastric tube was passed into an obstructed duodenum and barium injected. The tube, pressing on an obstructing web, caused dimpling of the duodenal contour at the attachment point of the web to the duodenal wall. The same maneuver at surgery caused identical dimpling.

DISCUSSION

While the maneuver is described in surgical textbooks, there has been no radiologic correlate. The "duodenal dimple" is a new fluoroscopic sign of a duodenal web and its attachment point to the duodenal wall.

Normal gadolinium-enhanced MR images of the developing appendicular skeleton: Part 2. Epiphyseal and metaphyseal marrow

OBJECTIVE

We have studied how gadolinium enhancement of T1-weighted MR images affects the expected normal differences in signal intensity between metaphyseal hematopoietic and epiphyseal fatty marrow. We have also analyzed how enhancement affects the expected normal changes in the MR images of the marrow due to fatty conversion.

MATERIALS AND METHODS

We analyzed gadolinium-enhanced MR images of normal distal femurs in 18 immature rabbits that were 5-11 weeks old and of normal proximal femurs in 18 infants, children, and young adults who were 2 months to 21 years old. In all subjects, we studied the change with age in signal intensity and enhancement ratio of the epiphyseal and metaphyseal marrow. In the rabbits, marrow composition and transformation were histologically verified.

RESULTS

On unenhanced T1-weighted MR images of the rabbits and of the infants, children, and young adults, epiphyseal signal intensity always exceeded metaphyseal signal intensity; however, the enhancement ratio was always greater in the metaphysis. The signal intensity in metaphyseal and epiphyseal marrow on unenhanced MR images increased with age. However, enhancement ratios decreased with age in both areas. In the rabbits, histologic studies showed more fatty marrow in the epiphysis than in the corresponding metaphysis and an age-related increase in marrow fat at both sites.

CONCLUSION

In the marrow of the extremities, gadolinium enhancement is greater in the (hematopoietic) metaphysis than in the (fatty) epiphysis. In both areas, enhancement decreases as the marrow becomes more fatty. On T1-weighted images, administration of a gadolinium-containing contrast agent reduces the normal contrast between hematopoietic and fatty marrow and obscures the changes in marrow signal intensity due to fatty conversion.

Gadolinium-enhanced MR imaging demonstrates abduction-caused hip ischemia and its reversal in piglets

PURPOSE

To determine if gadolinium-enhanced MR imaging can detect early reversible ischemia of the capital femoral epiphysis and physis induced by hip hyperabduction in piglets.

MATERIALS AND METHODS

Thirteen 1- to 3-week-old piglets were placed in maximal bilateral hip abduction and then studied with dynamic gadolinium-enhanced MR imaging 1-6 hr later to assess ischemia of the 26 femoral heads. The piglets were then allowed to ambulate freely for 1 or 7 days and reimaged in neutral position to assess reperfusion. We evaluated enhancement on MR images and compared them with histologic findings.

RESULTS

Decreased or absent enhancement, interpreted as ischemia, developed after maximal hip abduction in all 26 cartilaginous epiphyses and 85% of the 26 physes. The most frequently seen abnormality was a sharply marginated, nonenhancing area in the anterior part of the femoral head. A smaller area of decreased enhancement developed in the posterior part of the femoral head adjacent to the acetabular rim. The secondary center of ossification was ischemic in 10 (56%) of the 18 hips after 1 hr of abduction and in all 8 hips after 4 or 6 hr (p = .02). The overall severity of ischemia was greater with longer abduction times (p < .001) and greater degrees of abduction (p < .01). Reperfusion was complete in two (17%) of the 12 hips after 1 day of ambulation and in all 10 (100%) after 1 week of ambulation.

CONCLUSION

Enhanced MR imaging detects early ischemia of the epiphyseal and physeal cartilage and the epiphyseal marrow. In piglets, ischemia due to maximal abduction is reversible if corrected within 6 hr.

Radiologic-Pathologic Conference of Children's Hospital Boston: chest wall mass in an infant with eczema

A 2-month-old infant with fever and a chest mass is presented. Imaging evaluation, differential and final pathological diagnosis are discussed.

Gadolinium-enhanced MR imaging demonstrates abduction-caused hip ischemia and its reversal in piglets

Purpose. To determine whether gadolinium-enhanced MR imaging can detect early reversible ischemia of the capital femoral epiphysis and physis induced by hip hyperabduction in piglets. Materials and methods. Thirteen 1- to 3-week-old piglets were placed in maximal abduction of both hips and studied with dynamic gadolinium-enhanced MR imaging 1-6 h later to assess ischemia of the 26 femoral heads. They were then allowed to ambulate freely for 1 or 7 days, and reimaged in neutral position to assess reperfusion. Enhancement was evaluated on MR images and compared with histologic findings.Results. Ischemia after hyperabduction developed in all 26 cartilaginous epiphyses and in 85 % of the physes. The most frequent abnormality was a sharply marginated nonenhancing area in the anterior part of the femoral head. A smaller area of ischemia developed in the posterior part of the femoral head, adjacent to the acetabular rim. The secondary center of ossification was ischemic in 56 % of the hips after 1 h of abduction and in all hips after 4 or 6 h (p = 0.02). The overall severity of ischemia was greater with increasing abduction time (p < 0.001) and increasing degree of abduction (p < 0.01). There was partial reperfusion in 83 % of the hips after 1 day of ambulation and complete reperfusion in all 26 hips (100 %) after 1 week.Conclusion. Enhanced MRI detects early ischemia of the epiphyseal and physeal cartilage and the epiphyseal marrow. In piglets, ischemia due to hyperabduction is reversible if corrected within 6 h.