Primary localized amyloidosis of the urinary bladder.

We report a rare case of localized form of primary amyloidosis (amyloidoma) of the urinary bladder with CT and MR findings. Clinically, it is difficult to distinguish from invasive transitional cell carcinoma and inflammatory lesion. We think that the MR intensity on T2-weighted images is helpful in making the diagnosis.

Primary localized amyloidosis of the urinary bladder.

We report a rare case of localized form of primary amyloidosis (amyloidoma) of the urinary bladder with CT and MR findings. Clinically, it is difficult to distinguish from invasive transitional cell carcinoma and inflammatory lesion. We think that the MR intensity on T2-weighted images is helpful in making the diagnosis.

Lymph node pathology. Benign proliferative, lymphoma, and metastatic disease.

The evaluation of cervical lymph nodes is one of the main indications for performing CT and MR imaging of the neck. Imaging may be done for evaluation of an unknown neck mass, but more commonly the neck is imaged to evaluate potential metastasis from a known mucosal malignancy. CT and MR imaging characteristics of both malignant and nonmalignant nodal diseases are reviewed and the differential diagnosis of nodal pathologies for specific imaging findings are discussed.

[Reduction of helical artifact using SmartHelical algorithm].

Stair-step artifact is a serious problem in reconstructed images of multiplanar reformation (MPR), surface rendering and maximum-intensity projection (MIP). We developed a new algorithm, SmartHelical Algorithm (SHA), to reduce helical artifacts. SmartHelical Algorithm reduced helical artifacts significantly with slight worsening of longitudinal resolution.

[CT analysis of the anterior mediastinal fat: before and after lobectomy].

CT analysis was performed to evaluate change in the anterior mediastinal fat (AMF) after lobectomy and differences in AMF in the lobectomized region. In 67 carcinoma patients who underwent lobectomy, the area and volume of AMF were measured on CT before and after surgery. Mediastinal deviation after lobectomy was also correlated to the altered fat tissue.

The use of deblurring technique for improving the longitudinal resolution in helical CT of the head and neck region.

We evaluated the use of deblurring technique by digital deconvolution for improving the longitudinal resolution in helical CT in a phantom and CT images of head and neck patients. After performing the helical scanning, overlapped axial images were reconstructed at 1/10 of the actual collimation. Then, the deblurring technique was performed.

Asymmetrical or heterogeneous enhancement of the internal jugular veins in contrast-enhanced CT of the head and neck.

With faster CT scanners, asymmetric/heterogeneous enhancement (ASHE) of the internal jugular veins (IJVs) is frequently encountered in the absence of pathology. We investigated the frequency, side, pattern and significance of ASHE in 200 patients with various head and neck lesions. Non-ionic contrast medium (300 mgI/ml) was infused into a forearm vein (right, n = 100); left, n = 100).

[Improvement of longitudinal resolution by deblurring technique in helical CT of the head and neck].

We assessed the improvement of longitudinal resolution in helical CT by deblurring techniques in a phantom and 8 head and neck patients. After helical scanning with 3- or 5-mm-collimation and 3- or 5 mm/sec table feed, overlapped axial images were reconstructed at every 0.3 or 0.

Computed tomography analysis of the anterior mediastinal fat after left upper lobectomy.

Rationale And Objectives: The authors evaluate changes in the anterior mediastinal fat (AMF) after left upper lobectomy.

Methods: In 36 carcinoma patients undergoing left upper lobectomy, the area and volume of AMF were measured using computed tomography before and after surgery, and their relations to postoperative mediastinal deviation were examined.

Results: The postoperative AMF distribution was changed distinctly, showing marked increase from the aortic arch to the main pulmonary arterial level, with converse decrease at upper and lower slices, but no significant postoperative change was noted in total AMF volume.

Three-dimensional CT imaging of an isolated dissecting aneurysm of the superior mesenteric artery.

A case of an isolated dissecting aneurysm of the superior mesenteric artery is presented with findings of three-dimensional CT imaging. False lumen, intimal flap, entry, and re-entry are clearly identified on three-dimensional CT imaging.

Acinic cell Carcinoma of the parotid gland: CT and MRI.

We report CT and MRI bindings in two cases of acinic cell carcinoma of the parotid glands which behaved differently on T2-weighted images. Differences in signal intensities were considered to reflect the histology of the lesion, although a histological diagnosis could not be made on imaging grounds alone.

[Maximum-intensity-projection CT angiography for evaluating head and neck tumors: usefulness of helical CT and auto bone masking method].

Angiographic images of 10 adult patients with head and neck tumors were obtained by helical computed tomography (CT) using maximum intensity projection (MIP). In all cases, the vasculature of the head and neck region was clearly visualized, and hypervascular lesions were directly demonstrated. In the head and neck, bone masking is a more important problem than in other regions.

CT pixel mapping in the diagnosis of small angiomyolipomas of the kidneys.

In six small renal angiomyolipomas (7-17 mm) the superiority of displaying the CT numbers of pixels within a lesion (pixel mapping) over the usual region of interest (ROI) measurement is described in the detection of small amounts of fat tissue. On precontrast 5 mm CT the ROI measurements were > 0 in four cases whereas pixel maps revealed pixels with values < 0 in six cases.

Obliteration of the descending aortic interface in pectus excavatum: correlation with clockwise rotation of the heart.

Obliteration of the descending aortic interface is a new radiographic finding in pectus excavatum. Seventy frontal and lateral chest radiographs and 33 computed tomographic (CT) scans of patients with pectus excavatum were retrospectively reviewed to evaluate the frequency, possible cause, and clinical significance of this finding, which was detected in 21 of 70 cases (30%) of pectus excavatum. No significant relationship was found between this finding and the extent of the thoracic deformity.

Intraarterial digital subtraction angiography in detection of hepatocellular carcinoma.

To evaluate the usefulness of intraarterial digital subtraction angiography (IADSA) in hepatocellular carcinoma, IADSA was prospectively performed, combined with conventional film-screen angiography, in 40 patients in whom the tumor was histologically proven or highly suspected. Of the 16 main tumors less than 2 cm, IADSA detected 7 that were missed by film-screen angiography; 6 of these were less than 1 cm in size. With other diagnostic modalities including ultrasound, routine CT study, and CT after intraarterial Lipiodol injection, the detection rate of these tumors was low.