Leptomeningeal dissemination of optic pathway gliomas in three children.

We treated three children with optic pathway gliomas who had progressive disease associated with metastatic spread to the leptomeninges. One patient had radiographic resolution of leptomeningeal disease after treatment with intravenous carmustine and oral mercaptopurine but died of progressive pulmonary fibrosis. The second patient was treated with intravenous thiotepa, and the leptomeningeal disease remained stable. The third patient was treated with intravenous vincristine sulfate, cyclophosphamide, cisplatin, and etoposide and had a significant size reduction of the leptomeningeal lesion. Although leptomeningeal dissemination is a seemingly rare event, it is important that all children with optic pathway gliomas be considered for this possibility, particularly after the onset of new, atypical neurologic symptoms.

Imaging of the intensive care unit patient.

Despite advances in "high tech," it is anticipated that plain chest film radiography will continue to play a significant role in the management of patients in the ICU. Digital radiography will most likely displace conventional approaches. As demonstrated throughout this article, CT has played an increasingly important role in the evaluation of the critically ill patient. The results are especially impressive, because most were obtained on earlier-generation CT machines, which are now totally outdated. Newer scanners have many technical improvements, including rapid scanning, which permits breathholding, and thin-section scanning, which has been discussed in great detail throughout this volume. Whether MR imaging will play an important role in ICU care remains to be determined.

Collagenous colitis and pulmonary fibrosis. Manifestations of a single disease?

A 66-year-old man developed chronic watery diarrhea and progressive dyspnea over 1-year. Colonic biopsy revealed a thickened subepithelial collagen layer consistent with collagenous colitis; open lung biopsy revealed pulmonary fibrosis. Only one previous report links extraintestinal manifestations to collagenous colitis. Although the patient had been taking sulfasalazine, the case supports the idea that collagenous colitis, like inflammatory bowel disease, is part of a systemic disorder.

Air in the temporomandibular joint fossa: CT sign of temporal bone fracture.

Temporal bone fractures can be difficult to detect clinically and radiographically. Air is sometimes present in the glenoid fossa of the temporomandibular joint (TMJ) at computed tomography (CT) of acute basilar skull fractures. This study evaluated TMJ fossa air as a sign of temporal bone fracture. Initial CT scans of the head in 114 patients with a diagnosis of basilar skull fracture at discharge were retrospectively reviewed. TMJ fossa air was present in 23 of 114 patients (20.2%) and was bilateral in three patients. Only temporal bone fractures were significantly (P less than .001) associated with TMJ fossa air. Temporal bone fractures were observed at CT in 23 of 26 cases of TMJ fossa air, but in three of 26 cases, TMJ fossa air was the only CT sign of clinically apparent temporal bone fractures. TMJ fossa air is associated with acute temporal bone fracture and may be the only CT sign of an otherwise inconspicuous temporal bone fracture.

Congenital absence of a cervical spine pedicle: clinical and radiologic findings.

Congenital absence of a cervical pedicle is an unusual disorder with potentially confusing clinical and radiologic manifestations. A review of the previously reported 42 cases as well as 13 new cases is presented. Congenital absence of a cervical pedicle was an incidental finding in 10 of the 55 total patients (age range, 3-65 years; mean 31 years). The remainder presented with an array of symptoms; the most common was cervical pain (31 patients), often after trauma (19/31). Neurologic examination was normal in the majority (65%) of patients. The most common neurologic finding, in an additional 19% of patients, was isolated diminished sensation in an upper extremity. Imaging included conventional radiographs, tomograms, myelograms, and CT. The typical radiologic triad of findings included (1) the false appearance of an enlarged neural foramen owing to the absent pedicle; (2) a dysplastic, dorsally displaced ipsilateral articular pillar and lamina; and (3) a dysplastic ipsilateral transverse process. The spectrum of this disorder also included absence of the ipsilateral pillar in four of 55 patients and absence of the entire ipsilateral neural arch in five of 55 patients. Other osseous anomalies were present in 28 (51%) of 55 cases. In 10 of 55 cases, initial misdiagnosis resulted in inappropriate therapy, with a poor clinical outcome after therapy in three cases. Conservative therapy was the only successful management in all cases in which follow-up information was available, with the exception of one patient who had partial improvement after surgery. Careful analysis of radiologic images and knowledge of the specific findings of absent cervical pedicle should decrease the potential for misdiagnosis and inappropriate, potentially harmful therapy.

Sonography of subfascial hematoma after cesarean delivery.

Subfascial hematoma is an important complication of cesarean delivery that has received little attention in the radiologic literature. It results from extraperitoneal hemorrhage within the prevesical space, posterior to the rectus muscles and transversalis fascia but anterior to the peritoneum and umbilicovesical fascia. Subfascial hematomas were found in 12 (38%) of 32 patients referred for sonographic evaluation of a fever or a fall in hemoglobin that occurred after a cesarean delivery. In all cases, sonography revealed cystic or complex masses of various sizes anterior to the bladder. The use of high-frequency, short-focus transducers often was necessary to recognize these superficial abnormalities. Seven of the 12 patients had concomitant bladder-flap hematomas between the lower uterine segment and posterior bladder margin. Of the five remaining patients with isolated subfascial hematomas, the sonograms on four were misinterpreted as showing bladder-flap hematomas. The other was diagnosed correctly. Distinction of subfascial hematomas from bladder-flap hematomas and superficial-wound hematomas must be made if surgical evacuation is contemplated.

Cervical spondylolysis: imaging findings in 12 patients.

Cervical spondylolysis is defined as a corticated cleft between the superior and inferior articular facets of the articular pilar, the cervical equivalent of the pars interarticularis in the lumbar spine. Associated dysplastic changes and spina bifida suggest that the lesion is congenital. It is a rare condition; only 70 cases have been previously reported in the world literature. Recognition of this disorder and differentiation from traumatic articular pilar fracture or dislocation is of paramount importance in patients who have had cervical spine trauma. The present study details radiologic features in 12 patients 20-80 years old with cervical spondylolysis. Plain film radiologic findings were correlated with hypocycloidal high-resolution tomography (nine patients), CT (six patients), and MR imaging (one patient). Seven patients had spondylolysis at C6 (three bilateral) and five had the abnormality at C4 (all unilateral). Nine of 12 patients were initially misdiagnosed. Characteristic radiologic features include (1) a well-marginated cleft between the facets, (2) a triangular configuration of the pilar fragments on either side of the spondylolytic defect, (3) posterior displacement of the dorsal triangular pillar fragment, (4) hypoplasia of the ipsilateral pedicle, (5) spina bifida at the involved level, and (6) compensatory hyper- or hypoplasia of the ipsilateral articular pillars at the level above and/or below the defect. A multistudy approach was often necessary to demonstrate these findings. Heightened awareness of the radiologic features of cervical spondylolysis should allow one to differentiate it from articular pillar fracture or dislocation.

Reversible neurotoxicity following hyperfractionated radiation therapy of brain stem glioma.

Two patients with brain stem gliomas were treated with hyperfractionated radiation therapy (HFR) (7,020 and 7,560 cGy, respectively). Despite initial clinical improvement during irradiation, both patients demonstrated clinical deterioration approximately 3 weeks after completion of radiotherapy. Cranial magnetic resonance imaging (MRI) revealed a progressive increase in distribution of abnormal brain stem signal consistent with either tumor or edema. 18FDG positron emission tomography (PET) was obtained in one patient and demonstrated a hypermetabolic lesion at diagnosis and a hypometabolic lesion at the time of clinical deterioration postirradiation. Management with a tapering dose of dexamethasone alone resulted in marked clinical (both patients) and radiographic (one patient) improvement, allowing reduction or discontinuation of this medication. These results suggest that patients with brain stem tumors demonstrating clinical and radiographic evidence of progressive tumor shortly after completion of HFR should be initially managed conservatively with dexamethasone, since these findings may be manifestations of reversible radiation-related neurotoxicity.