[Primary pulmonary cryptococcosis confused with lung cancer by transbronchial biopsy: demonstration by three-dimensional computed tomography].

Routine chest radiographs of a 52-year-old woman displayed abnormal opacities in the right lower lung field. A computed tomographic (CT) scan of the chest disclosed irregular nodular opacities in the peripheral zone of the right S6. Reconstructed three-dimensional images obtained by helical CT displayed the lesions as agglutinated small nodules, with other small nodules near the bronchi appearing as "tree-in-bud" formations. Specimens obtained by transbronchial lung biopsy of the right B6b revealed atypical glandular structures, thus leading to suspected adenocarcinoma of primary lung cancer. A right lower lobectomy was performed; cut-surface specimens of the resected tissues showed multiple lobulate, milky-white nodules near the bronchi. Histopathologic examination found no malignant cells. PAS staining revealed numerous cryptococcal organisms, thus yielding the final diagnosis of primary pulmonary cryptococcosis.

Anomalous systemic arterial supply to the basal segment of the left lung: demonstration using MR angiography.

In a 41-year-old man with an abnormal left lower lobe opacity on a chest radiograph, magnetic resonance (MR) angiography showed a large abnormal vessel extending from the left side of the descending thoracic aorta, supplying the left lower lobe. Furthermore, the lung parenchyma showed no evidence of sequestrated lung. This entity corresponded to type-I of intralobar pulmonary sequestration, as classified by Pryce.

[HR-CT evaluation of lung parenchymal alterations in patients following breast conservation therapy].

Twenty patients with early-stage breast cancer treated with breast conservation surgery and definite radiation, underwent computed tomography (added HR-CT) of the lungs before, immediately after, and at one, six, and twelve months after radiotherapy. During the follow-up period, 17 (85%) of the patients developed parenchymal alterations in the irradiated lung volume. We classified the parenchymal alterations into seven patterns: pattern 1 = septal line, 2 = nodular opacity, 3 = ground-glass opacity, 4 = consolidation, 5 = curvilinear opacity, 6 = aircyst accumulation, and 7 = irregularity of pleural surface. From one to six months after radiotherapy, 14 patients developed nodular opacities and ground glass opacities in the irradiated lung field. At 12 months after radiotherapy, fourteen patients were found to have aircyst accumulation and irregularity of the pleural surface. In this study, none of the patients presented any abnormal findings immediately after irradiation. There was no relationship between central lung distance or boost irradiation and the parenchymal alterations in the lung. On the other hand, there was a close relationship between oral anti-cancer agents and lung lesions. In conclusion, HR-CT was useful to evaluate morphologic changes in the irradiated lung.

Synovial sarcoma arising from the chest wall: MR imaging findings.

We report a case of synovial sarcoma of the chest wall in a 41-year-old man. Chest CT revealed a huge tumor of the left chest wall with heterogeneous enhancement. On MR imaging, the tumor showed the "bowl-of-fruit" mixed-signal appearance with fluid-fluid levels similar to those of synovial sarcoma of the extremities. Synovial sarcoma arising from the chest wall is extremely rare; only four cases have been reported in the English literature. As synovial sarcoma is considered a carcinosarcoma-like tumor with true epithelial differentiation, it is able to originate from various regions. Even if the tumor is found in a region distant from the synovial membrane, the differential diagnosis of a tumor which demonstrates such findings on MR imaging should include synovial sarcoma.

99Tcm tetrofosmin uptake in mediastinal tumours.

We present our experience in visualizing mediastinal tumours using 99Tcm tetrofosmin. Three patients with thymic tumours and two patients with a mediastinal tumour (seminoma and small cell carcinoma) were found to have anterior mediastinal masses on chest radiographs, and subsequently underwent computed tomography and magnetic resonance imaging. In addition, the patients underwent single photon emission computed tomography (SPECT) with 99Tcm tetrofosmin and 201Tl. Intense uptake was seen on early 99Tcm tetrofosmin images in three patients with thymoma, invasive thymoma and mediastinal tumour (small cell carcinoma). In the remaining two patients with thymic carcinoma and mediastinal seminoma, there was intense 99Tcm tetrofosmin uptake on early images which reduced on delayed images. 201Tl uptake was intense on both early and delayed images. These findings suggest that different 99Tcm tetrofosmin uptake in early and delayed imaging may offer new information on these mediastinal tumours.

[Evaluation of the retrosternal space and the retrocardiac space on normal left lateral radiographs of the chest].

Left lateral chest radiographs with normal studies were evaluated in 100 Japanese (50 females and 50 males) to compare the radiolucency of the retrosternal space (RSS) with that of the retrocardiac space (RCS) and to measure the RSS. In 56 (56%) cases, the RSS was equally radiolucent to the RCS. In 40 (40%) cases, the RSS was less radiolucent than the RCS (33 of 50 females and 7 of 50 males). The difference between the sexes was statistically significant (p = 0.0001). The RSS was more radiolucent than the RCS in only 4 (4%) males. Frontal chest radiographs of 50 females were classified into one of three groups (Small, Medium, or Large) depending on the size of soft tissue opacity of the breast. The differences between the radiolucency of the RSS and RCS were statistically significant between the Small and Medium and the Small and Large groups (both p < 0.0001). The strength of the relationship between the radiolucency and body-to-fat ratio was statistically significant (p = 0.0028). Results of data comparison between females and males remained significant when adjusted for differences in body-to-fat ratio (p < 0.0001). The distance on the chest radiograph from the sternum to the most anterior aortic border (the distance of RSS) could be measured on only 37 (37%) lateral chest radiographs, and the averages and standard deviations were as follows: 2.2 +/- 0.5 in all cases, 2.0 +/- 0.5 in females, and 2.4 +/- 0.5 in males. The difference between the sexes was statistically significant (p < 0.05). In conclusion, an RSS that is more opaque (less radiolucent) than the RCS is a frequent normal finding because of the opacity of the breast and fat tissue, especially in females, and the length of the RSS is shorter in females than in males.

[MR diagnosis for metastasis or non-metastasis of mediastinal and hilar lymph nodes in cases of primary lung cancer: detectability, signal intensity, and MR-pathologic correlation].

The detectability and signal intensity on MR imaging of mediastinal and hilar lymph nodes were studied in cases of lung cancer. Additionally, short inversion time inversion recovery (STIR) images and pathologic findings were compared. In the detection of resected metastatic mediastinal and hilar lymph nodes (n = 146), the STIR image (82%) was superior to the T1-weighted image (71%) and the T2-weighted image (60%). On STIR imaging, 212 (60%) of 412 resected non-metastatic mediastinal nodes and 38 (33%) of 116 resected non-metastatic hilar lymph nodes were detected. Characteristics of signal intensities of metastatic nodes were mainly low on T1-weighted images, high on T2-weighted images, and very high on STIR images. The rate of these characteristics of signal intensity of metastatic nodes was 59%. However, the rate of very high signal intensity of metastatic nodes on STIR imaging was 81%. Pathologically, lymph nodes with high or very high signal intensities on STIR images were metastatic, reactive and hyperplastic, or non-metastatic. Lymph nodes with slightly high signal intensity or high intensity with a low focus on STIR images were anthracotic, anthrasilicotic, caseous necrotic, calcified, or fibrotic. Thus, when the signal intensity of a lymph node was decreased on the STIR image, there was no definite evidence of metastasis excluding micro-metastasis or coagulation necrosis of a metastatic tumor. We conclude that the signal characteristics on STIR imaging are useful for distinguishing between macro-metastatic and non-metastatic lymph nodes when enlarged nodes are detected by various other types of medical imaging.

[A study of the utility of the MR image for the diagnosis of thymic tumors--imaging and pathologic correlation].

MR imaging was performed in 25 patients with thymic tumors (five with non-invasive thymomas, 15 with invasive thymomas, and five with thymic carcinomas), and the MR imaging appearance was compared with the pathological findings. Non-invasive thymomas showed generally oval or round masses with well-defined margins and homogeneous intensity on T1- and T2-weighted images. Invasive thymomas showed a multinodular appearance in 79% (11/15) of cases, and an internodular difference in signal intensity (IDSI) in 64% (7/11) on T2-weighted images. It was considered that the IDSI on T2-weighted images correlated pathologically with the hemorrhagic and/or necrotic areas and hyalinization. The IDSI seemed to be a characteristic finding of invasive thymomas. The histological findings and MR imaging appearance of thymomas were compared. The predominantly epithelial type showed a low incidence of nodular appearance but showed marked IDSI on T2-weighted images. Therefore, it is more likely that the predominantly epithelial type induced more varied intratumoral changes than other types. Extension of thymic carcinomas was similar to that of invasive thymomas on MR imaging, but thymic carcinomas showed no definite nodular appearance. In conclusion, MR images in thymic tumors were useful for not only determining the morphology of the tumor but also the tissue characteristics. Therefore, MR imaging can be a useful modality to correlate with the histological findings and biological behavior of thymic tumors.

[Evaluation of the invasion of esophageal cancer to the aorta by cine-MR imaging].

We examined the usefulness of cine-MR imaging for evaluation of the invasion of esophageal cancer to the aorta in 12 cases. We used the technique of field echo pulse sequence. When the low intensity stripe was recognized between the tumor and the wall of aorta, we interpreted it as negative finding of the direct tumor invasion. By using this criteria, 11 of the 12 cases (92%) of the esophageal cancer for aortic wall invasion were correctly diagnosed as compared with 75% correct diagnosis by conventional MR imaging.