Stereotactic body radiation therapy to the spine: contouring the cauda equina instead of the spinal cord is more practical as the organ at risk.

Background: Stereotactic body radiotherapy (SBRT) is recognized as a curative treatment for oligometastasis. The spinal cord becomes the cauda equina at the lumbar level, and the nerves are located dorsally. Recently, a consensus has been reached that the cauda equina should be contoured as an organ at risk (OAR).

Effect of stomach size on organs at risk in pancreatic stereotactic body radiotherapy.

Background: In clinical practice, the organs at risk (OARs) should be carefully determined when performing pancreatic stereotactic body radiotherapy (SBRT). We conducted a simulation study to examine the effect of the stomach size on the radiation dose to the OARs when performing pancreatic SBRT.

Methods: Twenty-five cases were included in this study.

Nonfunctional mediastinal parathyroid cyst: imaging findings in two cases.

The authors describe the computed tomography (CT) and magnetic resonance (MR) imaging findings of a 69-year-old woman and a 69-year-old man with a nonfunctional mediastinal parathyroid cyst. In the described cases, unenhanced CT showed homogeneous areas of water density, and unenhanced MRI showed homogeneous areas that were isointense to cerebrospinal fluid, reflecting their serous fluid contents. Both cysts were located posterior to the left lower pole of the thyroid gland with an extension to the superior mediastinum, either anterior or posterior to the left brachiocephalic vein.

Automated estimation of the upper surface of the diaphragm in 3-D CT images.

This communication describes a fully automated method by which the position of the diaphragm surface can be estimated by deforming a thin-plate model to match the bottom surface of the lung in CT images. This method was applied to 338 X-ray CT scans, and its validity was proved by the experimental results.

Chest wall Castleman's disease: CT and MRI findings.

Castleman's disease is an usually benign lymphoid tumor of uncertain etiology that generally appears as a solitary mediastinal mass. We present a case of Castleman's disease in the right chest wall of a 60-year-old woman. Magnetic resonance imaging showed a well-defined, oval mass that was early enhanced on T1-weighted images.

Automatic segmentation and recognition of anatomical lung structures from high-resolution chest CT images.

This paper describes a fully automated segmentation and recognition scheme, which is designed to recognize lung anatomical structures in the human chest by segmenting the different chest internal organ and tissue regions sequentially from high-resolution chest CT images. A sequential region-splitting process is used to segment lungs, airway of bronchus, lung lobes and fissures based on the anatomical structures and statistical intensity distributions in CT images. The performance of our scheme is evaluated by segmenting lung structures from high-resolution multi-slice chest CT images from 44 patients; the validity of our method was proved by preliminary experimental results.

Neurogenic tumors of the mediastinum and chest wall: MR imaging appearance.

Various histologic types of neurogenic tumors may originate in the mediastinum and chest wall. It is possible to make accurate diagnosis of these tumors by using the multiplanar capability and high contrast resolution of MR imaging because of these characteristic imaging findings. MR and histologic features of these tumors are illustrated and described in this essay.

Solitary mediastinal lymph node metastasis of hepatocellular carcinoma: MR imaging findings.

A 65-year-old man with multiple hepatocellular carcinomas in the liver with type C viral hepatitis had a solitary mediastinal lymph node metastasis in the right paratracheal to tracheobronchial region. Surgical resection for the mediastinal metastasis was undertaken based on magnetic resonance (MR) imaging findings, suggesting its radicality. We assess the MR imaging findings and presumable pathways of lymphatic metastasis from the liver to mediastinal lymph nodes in this report.