Chronic spinal subdural haematoma associated with intracranial subdural haematoma: CT and MRI

Chronic spinal subdural haematoma is a uncommon. We describe the CT and MRI appearances of chronic spinal and intracranial subdural haematomas following minor trauma. The aetiology, pathogenesis and differential diagnosis are discussed.

High-resolution CT findings in Wilson-Mikity syndrome: a case report

Wilson-Mikity syndrome (WMS), an uncommon cause of respiratory distress presenting after birth, is radiologically characterised by varying degrees of interstitial thickening and bilateral cyst-like foci of hyperinflation. Aetiology and pathogenesis are still unknown. There are few reports of WMS in the paediatric literature and none describing the features and value of high-resolution CT. The purpose of this report is to describe the radiographic findings and high-resolution CT appearance of WMS and to correlate them with the histopathological findings.

Multiphasic helical CT in diagnosis and staging of hilar cholangiocarcinoma

OBJECTIVE

The purpose of our study was to assess the potential of thin-section multiphasic helical CT in diagnosis and staging of hilar cholangiocarcinomas.

SUBJECTS AND METHODS

Identically collimated helical CT studies were performed before and during the hepatic artery dominant phase and during the portal vein dominant phase of contrast enhancement in 29 consecutive patients with proven hilar cholangiocarcinomas. Differences in attenuation between the tumor and the liver were calculated in each case by subtracting the average attenuation of the tumor from that of the liver. A four-point scale termed a "lesion conspicuity score" was used to determine rates of tumor detection. CT findings were correlated with surgically assessed extent of tumor, histologic findings, or both in all cases.

RESULTS

Ten (34%) of the 29 hilar cholangiocarcinomas were detected on unenhanced images. All hilar cholangiocarcinomas (100%) were seen on hepatic artery dominant phase scans, and 25 (86%) of 29 hilar cholangiocarcinomas were seen on portal vein dominant phase scans, regardless of the morphologic appearance. An infiltrating stenotic lesion was found in 17 (59%) of 29 patients, an exophytic hilar lesion was found in 11 patients (38%), and one patient (3%) had an intraluminal polypoid lesion. Mean differences in enhancement between infiltrating stenotic lesions and the liver were significantly greater on hepatic artery dominant phase scans (28 +/- 10 H) than on portal vein dominant phase scans (10 +/- 8 H), whereas the mean difference in enhancement between the exophytic lesions and the liver was statistically greater during the portal vein dominant phase (p < .01). Two of the hilar cholangiocarcinomas were resectable at surgery, and 18 were not. The overall accuracy of helical CT for assessing resectability was 60%. In 10 (56%) of 18 patients, unresectable disease was correctly diagnosed with helical CT (sensitivity, 56%). Eight (44%) of 18 patients considered to have resectable tumors with helical CT had unresectable tumors at surgery. A resectable tumor was correctly diagnosed in two patients with helical CT.

CONCLUSION

Multiphasic helical CT can be used to detect and classify hilar cholangiocarcinomas. However, the exact proximal tumor extent along bile ducts tends to be underestimated with helical CT; therefore, helical CT is inaccurate for determining resectability.

Synovial sarcoma of the parapharyngeal space: CT and MRI

We present the CT and MRI findings of a histologically proven synovial sarcoma arising in the left parapharyngeal space of a 21-year-old man. CT was useful for confirming the presence of calcification within the tumour, which may be a favourable prognostic sign, and in excluding involvement of cortical bone. The CT and MRI findings were, however, nonspecific. MRI was superior to CT for assessing the topographical relationships of the tumour to the vessels and the invasion of neighbouring structures.

Detection of pulmonary nodules with helical CT: comparison of cine and film-based viewing

OBJECTIVE

The purpose of our study was to determine whether cine viewing of helical CT scans of the chest improves the detection of pulmonary nodules in patients with known extrathoracic malignancy.

SUBJECTS AND METHODS

Identical helical CT studies of the chest of 60 patients with known extrathoracic malignancy were reviewed for detection of pulmonary nodules. Four radiologists interpreted the helical CT studies. Pulmonary nodules were divided into four groups according to maximum diameter: group 1, nodules smaller than or equal to 5 mm; group 2, nodules larger than 5 mm but smaller than or equal to 10 mm; group 3, nodules larger than 10 mm but smaller than or equal to 20 mm; group 4, nodules larger than 20 mm. Interpreters also assigned a lesion conspicuity score of pulmonary nodules based on a four-point scale: one point for poor visibility, two points for adequate visibility, three points for good visibility, and four points for excellent visibility. Static film-based images printed on a laser printer were viewed on a light box. Cine viewing of helical CT scans from the same examinations was done on a commercially available workstation. The number, diameter, and conspicuity scores of pulmonary nodules detected at lung window settings were documented.

RESULTS

Interpreters saw 266 nodules on cine viewing, whereas 237 nodules were seen with static film-based viewing. A significantly higher percentage of nodules that were smaller than or equal to 5 mm in diameter was found with cine viewing (n = 106) than with static film-based viewing (n = 81) (p < .05). Cine viewing (n = 105) also allowed a slightly but not significantly higher detection rate of nodules that were larger than 5 mm but smaller than or equal to 10 mm in diameter than did static film-based viewing (n = 101). We found no differences between cine (n = 55) and static film-based viewing (n = 55) in the detection of pulmonary nodules that were larger than 10 mm in diameter. The mean conspicuity score of nodules was significantly higher with cine viewing (2.9 +/- 0.2) than with film-based viewing (2.4 +/- 0.2) (p < .05).

CONCLUSION

Cine viewing of helical CT scans significantly increases the detection rate of pulmonary nodules that are smaller than or equal to 5 mm in diameter. However, we found no significant difference between cine and film-based viewing in the detection rate of pulmonary nodules that were larger than 5 mm in diameter. The advantages of cine viewing may be attributed to both the larger image size and the ability to scroll through images for improved differentiation between vessels and nodules.

HRCT features in a 5-year-old child with follicular bronchiolitis

High-resolution CT (HRCT) is the most sensitive radiographic method to image small airways disease. We discuss the HRCT features of follicular bronchiolitis in a 5-year-old boy and correlate them with the histopathological findings. The changes described include centrilobular nodules, bronchiectasis and bronchiolectasis, branching opacities and areas of reduced lung attenuation.

Multiphasic helical CT of the kidney: increased conspicuity for detection and characterization of small (< 3-cm) renal masses

PURPOSE

To evaluate the potential of thin-section multiphasic helical computed tomography (CT) in the detection and characterization of small (< 3.0-cm) renal masses.

MATERIALS AND METHODS

Identically collimated helical CT of the kidney was performed before and after administration of contrast material in 93 patients with small renal masses. Helical CT scans were obtained during the corticomedullary and nephrographic phases. Differences between attenuation of the lesion and that of the kidney were measured quantitatively. The presence of a mass or absence of disease was confirmed with clinical, imaging, and histologic findings.

RESULTS

The number of masses smaller than 3.0 cm detected on corticomedullary-phase scans (n = 211) was statistically significantly fewer than those on nephrographic-phase scans (n = 295) (P < .01). Mean differences in enhancement between the renal cortex and masses were 148 HU +/- 54 and 137 HU +/- 44 during the corticomedullary and nephrographic phases, respectively, and the difference in attenuation of the renal medulla and that of the masses was statistically significantly greater during the nephrographic phase (P < .01). False-positive results (n = 9) occurred only on corticomedullary-phase scans because of lack of enhancement of the renal medulla.

CONCLUSION

Nephrographic-phase scans enabled greater lesion detection and better characterization of small renal masses than corticomedullary-phase scans. Nephrographic-phase scans should be obtained when only monophasic scanning is used to detect small renal masses.