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Helical Scan CT (HS-CT) for Detection of Peripheral

Kouzo Yamada ), Hldeo Kumtoul) Koshiro Watanabel), Pulmonary Nodules (PPN)

Kiyoshi Moriz) Mlchizo Sasa awai), Masahiro Kanekos), Kenji Eguchis), Noriyukl ’ I&rirmas), 1) Yokohama Munici al Citizen Hosp., 2) Tot igi Prefectural Cancer Center !Iosp 3) National Cancer Center Hosp. Japan 1) Address: 36 Okazawa-thou, Hodogaya-ku, kokohama, 240 Ja

? an

o facilitate early detection of PPN, we studied the feasibility of HS-CT as a routine screenm modahty. Fifteen patients (pts.), a

g *%

malignant pulmonary es over 50~0, wit *advanced umors entered this study.

Informed consent was taken from all pts. HS-CT were taken with Toshiba TCT-SOOS, using continuous exposure system on the movable table at the speed of 10,20, 25, 30 and 50mm/sec (8-25sec. from the apex to the dlaphra At each level of s different levels oft g

eed, 2-3 pts. were enrolled. !Z: e exposure doses (mA) were taken to

evaluate the quality of images when HS-CT was taken with low mA. The reconstructed images were shown op film (one image/set) and on VTR using tine-mode multi-

lanar reconstruction. PPN shown in conventional 8 T(lOmm thickness) were compared to those of HS-CT as a control. At the apex ortion, artifact of bone was maJor obstacle in detectmg ! PN in HS-CT taken with faster table-speed. Ima es taken at the speed of 25mm/sec were enough to find P & of >3mm in diameter. With the level of 50 mA the location of PPN could be detected but i_t was difficult to get differential diagnosis due to quahty of images. _

In conclusion, HS-CT with 5OmA could take whole images of the chest within 10 seconds and the quahty of i~;zt was feasible to detect mlnlmal peripheral lung

232

Transesophageal Color Doppler Echogram for

K.Kaneko, M.Matsumura, M.Ogiwara, M.Sukigara, S.Kyo, the Assessments of Thoracic Neoplasms

Y.Yokote and R.Omoto. First Dept.of Surgery, Saitama Medical School, Moroyama,Saitama,350-04, Japan

Fifty five patients with thoracic neoplasms (38: primary lung cancer; 13:mediastinal tumor; 4:other tuner) were examined with transesophageal color doppler echogram (TEE). In all cases, left atrium, pulmonary veins, pulmonary arteries and aorta were well visualized.In six cases with direct invasion to the pulmonary vein, Pulsed-Doppler spectrum showed a turbulent flow pattern in the pulmonary veins. In four cases, tumor was seen to be very close to pulmonary vein. However, Doppler spectrum showed the laminar flow pattern. The tumor didn't invade the pulmonary vein and was successfully resected. In two cases with the tumorous invasion to the aorta, movement of the wall of aorta disappeared. In four cases whose tumors were adjacent to the aorta without invasion,aortic wall moved well. Two' cases with superior vena caval syndrome, Doppler spectrum showed very small blood flow in superior vena tava.

By using TEE we can know the mode of mediastinal movement, the blood flow and the flow pattern. Regarding the detail information of the posterior mediastinal organs such as left atrium and pulmonary veins, TEE is superior to the conventional angiogram and computed tomogram.TEE will be a useful diagnostic tool for the evaluation of tumorous invasion to the mediastinal large vessels and heart.

Evaluation of Dynamic - Table Sliding Rapid Sequence - Thin Slice Computed Tomography Scan in Diagnosis of Lymph Node Metastasis in Lung Cancer

Hideaki Miyamoto, Yfisuke Mitoma, Enj6 Hata, Yoshihiro Inoue, Mitsui Memorial Hospital, Tokyo, Japan

The accuracy of CT diagnosis for lymph node metastasis of lung cancer is limited, because the diagnosis is based on the size of lymph node image alone.

For more qualitative diagnosis of lymph node metastasis of lung cancer, we devised a new CT image by combining dynamic CT with thin slice CT and by employing table sliding rapid sequence scans.

In 80 cases, preoperative a new CT image could be compared with the findings from histological confir- mation of surgically removed lymph nodes, for the purpose of morphological characterization of histolo- gically metastatic lymph nodes on the new CT image.

This new CT image allowed more distinct visuali- zation of hilar and mediastinal lymph nodes by suppressing the partial volume effect of large vessels as compared to the conventional CT scan.

Furthermore, it provided detailed images of the internal structure and marginal morphology of lymph nodes. Metastatic lymph nodes were enhanced later than normal lymph nodes, and presented with unhomogenous internal image.

In the diagnosis of N factor of lung cancer, the sensitivity, specificity and accuracy of this new CT image were 84.6, 83.3 and 84.0X.

233

ULTRASONOGRAF’HICAL FINDINGS OF CHEST WALL TUMOR IN PATIENTS WITH

PRIMARY AND METASTATIC LUNG CANCER Hiroyuki Saito’. Takashi Dambara’. Masashi Muramatsu’, Kenichi Obatal, Toshihiro Nukiwa’ and Shire Kira’ ‘Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo. Bunkyo-ku, Tokyo 113, Japan

Chest wall tumor(CWT) is uncommonly observable in patienu with lung cancer accompanied with metastasis to thoracic cage or maliguant pleurisy. We analyzed ultrasonographical findings of CWT in patients with lung cancer. Subjects were 38 patients with CWT who were consisted 26 in primary lung cancer and 12 in metastatic lung cancer. CWT of these patients were visualized with ultrasonography(US), among 1700 patients who were performed US for recent 5 years. US could visualize CWT distinctly, because it is not difficult to find out ultrasonic window to see CWT directly or indirectly through thoracic wall. US is very convenient clinically to figure out CWT at real time dynamically during respiratory movement and statically during breath holding. Equipment and ultrasonic probes used in this study were SSA-90A ultrasonic unit(Toshiba. Japan) and 5 and/or 7.5 MHz linear array transducers. On the basis of US findings, distribution of CWT were devided into 3 types as follows: (i)CWT extended from intrapulmonary lesion, (ii)CWT lacking of communication with intrapulmonary lesion and (iii)multiple tumors on parietal pleural surface with or without malignant pleurisy. US findings of the three types corresponded to direct invasion to chest wall, distant metastasis to chest wall and cancerous dissemination on parietal pleural surface or haemotogenous metastasis to the pleura. In primary lung cancer, US findings (i), (ii) and (iii) were seen in 18 cases(704b). in 4(15%) and in 4(15%). In contrast, in metastatic lung cancer, these three were recognized in 2(17%), in 5(42%) and in 5(42%),respectively. These result suggested that US is valid modality to analysis CWT in relation with the lesion within the thoracic space and the lung.