Pseudospread of the atlas: false sign of Jefferson fracture in young children

Jefferson fractures are rare prior to teen-age. Three young children examined after trauma exhibited the characteristic spread appearance of the atlas, but fractures were excluded radiographically and clinically. A retrospective study demonstrated a similar appearance, termed "pseudospread," in most children aged 3 months to 4 years, including over 90% during the second year. Pseudospread results from a discrepancy between the "neural" growth pattern of the atlas and the "somatic" pattern of the axis. An "atlas spread index" is defined and a normal range presented. When an atlas fracture is suggested by apparent lateral spread of the lateral atlas masses, computed tomography is useful to demonstrate an intact atlas ring.     

Intrafracture fluid: a new diagnostic sign of insufficiency fractures of the sacrum and ilium

MRI is generally regarded as being sensitive but non-specific for the detection of insufficiency fractures affecting the sacrum and pelvic ring. The finding of intrafracture fluid is described in two elderly patients with insufficiency fractures. This MR feature is believed to be a new diagnostic sign of these fractures affecting the sacrum and ilium.     

The vacuum phenomenon: a CT sign of nonunited fracture

OBJECTIVE: The purpose of this study was to describe on CT scans the presence of a gas collection within a bone fracture reflecting the vacuum phenomenon as a sign of nonunited fracture. CONCLUSION: A gas collection between fractured bone fragments suggests a nonunited fracture.     

The lollipop sign: a new cross-sectional sign of hepatic epithelioid hemangioendothelioma

In four cases of hepatic epithelioid hemangioendothelioma (HEHE), multiple liver lesions were depicted on enhanced computed tomography (CT) and/or magnetic resonance imaging (MRI) scans. A peculiar sign, a hepatic or portal vein terminating at or just within the periphery of some of the liver lesions, was noted in all four; the images look like a lollipop. Imaging findings of HEHE can suggest other diseases, but this sign buttressed by other radiological findings, seems to be specific for this entity.     

Facet formation sign in sarcoidosis: a new sign in endoscopic ultrasonography

Endoscopic ultrasound was performed in 56 patients with histologically or clinically proven mediastinal or lung diseases. These 56 patients comprised 12 with sarcoidosis, 8 with lymphoma, 20 with lung cancer, 10 with oesophageal cancer, and 6 with other diseases. A 7.5 MHz electronic linear-arrayed ultrasonic endoscope was used. In 38 of the 56 patients lymph nodes were detected by endoscopic ultrasound. Eleven patients with sarcoidosis showed lymph nodes in a facet formation (like stones in an old stone wall), while lymph nodes in the other 27 patients were round in shape and did not form facets. The facet formation sign, evaluated by endoscopic ultrasound, may be a characteristic finding in sarcoidosis. Correspondence to: M. Mori     

The "fat" C2: a sign of fracture

Rotational and lateral bending injuries may cause oblique fractures of the centrum (body) of the second cervical vertebra below the odontoid and plane of the superior articular facets. These fractures are often obscure because the fracture lines are frequently not perpendicular to the plane of the radiograph on either anteroposterior or lateral views. The fracture fragments may shift in relation to one another, causing the body of C2 to appear enlarged or "fat" in relation to C3. We discuss the basis of the "fat" C2 sign and illustrate a variety of fractures that can produce this change.     

The target sign: a new radiologic sign of septic pulmonary emboli.

A new radiographic sign consisting of a pulmonary density suspended in a thin-walled cystic area is described in five patients with hematogenously disseminated infection. A pathogenetic mechanism is suggested to account for this "target sign." The relationship of these findings to pulmonary pneumatoceles is also discussed.     

The venous distension sign: a diagnostic sign of intracranial hypotension at MR imaging of the brain

BACKGROUND AND PURPOSE: Patients with intracranial hypotension (IH) demonstrate intracranial venous enlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weighted sagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires a distended convex appearance; we have termed this the venous distension sign (VDS). This is distinct from the normal appearance of this segment, which usually has a slightly concave or straight lower margin. This sign is introduced, and its performance as a test for the presence of this disease is evaluated. MATERIALS AND METHODS: The transverse sinuses on T1-weighted sagittal imaging of 15 patients with IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for the presence of a VDS. A present or absent VDS was determined for each patient by each reader, and a consensus result for each patient was determined by unanimity or majority rule. RESULTS: Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients and similarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readers for the interpretation of the VDS (multirater kappa = 0.82). The overall sensitivity of the VDS for the diagnosis of intracranial hypotension was 94%. Specificity was also 94%. CONCLUSION: The VDS appears to be an accurate test for the presence or absence of IH and may be helpful in the evaluation of these patients.     

Early myositis ossificans: a new echographic sign

A case of soft tissue swelling of the thigh in which myositis ossificans developed is presented. A series of ultrasound examinations showed previously unreported changes which suggested the diagnosis. The use of ultrasound and other imaging modalities in this condition are discussed and the ultrasound appearances are related to the histology.     

Malformations of the atlas vertebra simulating the Jefferson fracture

Congenital clefts and aplasias of the atlas vertebra, while rare, are often first encountered in the emergency room setting. Thirty-six patients with atlas malformations and 10 with Jefferson fractures were encountered. Sixteen of the patients with congenital malformations showed bilateral atlantoaxial lateral offset, a finding generally considered to be the result of fracture. The diagnosis of these abnormalities is readily made from plain films by noting their characteristic features. Anomalies produce lateral offset of 1-2 mm. Jefferson fractures produce a greater offset (over 3 mm).     

Myelographic features of mucopolysaccharidoses: a new sign.

A new mechanism of myelopathic changes in patients with mucopolysaccharidosis is described. Two similar cases had myelographic evidence of marked concentric impingement of the cervical subarachnoid space and cord compression due to thickening of the dura. Myelography is indicated in the evaluation of these patients because surgical decompression may reverse the progressive neurological deficits.     

Computed tomography of hilar cholangiocarcinoma: a new sign

Thirty-seven patients with histologic proof of cholangiocarcinoma at the confluence were examined by computed tomography (CT) to determine whether this examination is of value in the assessment of these patients for surgery and whether there are any features specific to this type of tumor. Thirty-two patients showed intrahepatic duct dilatation; six of these showed dilatation of ducts in one lobe only. Eighteen patients had intrahepatic low-attenuation areas, while eight had a mass lesion in the porta hepatis. Two of the lesions in the porta hepatis and four of the low-attenuation lesions enhanced. Atrophy of a lobe was noted in seven patients. This feature is not commonly recognized and is suggestive of cholangiocarcinoma rather than other hepatic tumors. The results of this study show that CT provides useful anatomic information preoperatively but that the appearances are nonspecific. Lobar atrophy is highly suggestive of hilar cholangiocarcinoma, either of long-standing or with unilateral portal venous involvement.