PubMed Health⌕ Search

Biomedical subjects

M Tillich

Publications and source records attributed to M Tillich.

24 records · Page 2Linked to original sources

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.

Bile Duct Neoplasms↗

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.

Biopsy↗

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.

Adult↗

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.

Female↗

Helical CT angiography of stent-grafts in abdominal aortic aneurysms: morphologic changes and complications.

Transfemoral placement of an endovascular stent-graft is increasingly be-ing used as an alternative to surgical repair in the treatment of abdominal aortic aneurysm, especially in high-risk patients. However, complications frequently occur after stent-graft placement. Helical computed tomographic (CT) angiography is a fast, minimally invasive procedure that is quickly becoming the imaging modality of choice for assessment of these complications. Thirty-nine patients who were treated for abdominal aortic aneurysm with stent-graft placement underwent helical CT angiography at routinely scheduled follow-up intervals or whenever complications were suspected. The resulting images were evaluated for the presence, extent, and origin of endovascular leaks. In addition, the position, shape, and patency of the stent-grafts were assessed. Findings included both graft-related (n = 4) and non-graft-related (n = 3) leaks, thrombosis of a graft limb (n = 3), distal migration of the stent-graft (n = 5), angulation of bifurcated stent-grafts distal to the main graft (n = 6), shrinkage of the abdominal aortic aneurysm (n = 7), enlargement of the aneurysm with secondary graft-related leaks (n = 2), and an aortoduodenal fistula (n = 1). Helical CT angiography can depict complications that develop after treatment of abdominal aortic aneurysms with endovascular stent-grafts. Long-term follow-up is required to determine the full spectrum and frequency of complications that may develop after initially successful repair.

Aged↗