Evaluation of chest wall invasion by lung cancer using respiratory dynamic MRI.

Conventional CT or MRI has low accuracy in assessing chest wall invasion in patients with peripheral lung cancer. For preoperative evaluation of chest wall invasion by peripheral lung cancer, respiratory dynamic (RD) MRI was carried out in 98 patients in whom conventional CT scan showed that the tumour was abutting the pleural surface, but there was no evidence of definite tumour invasion. We used 1.5-T MR equipment. RD MR images were acquired by snapshot fast field echo sequence (repetition time = 8, echo time = 3, flip angle = 100) and 25 consecutive images were taken while the patient took deep breaths. These images were evaluated in cine mode to assess tumour movement along the chest wall. Sixty-one patients underwent surgical resection of the tumour and RD MR findings were compared with those in pathological specimens. RD MR showed free tumour movement along the chest wall in 34 patients. At pathological examination, the RD MR findings were proved correct in all patients. Pathologically, 20 patients had chest wall invasion and their RD MR was positive (sensitivity 100%). There were seven false-positive results among the 41 patients without chest wall invasion (specificity 82.9%). RD MR may improve the accuracy of conventional CT scan or MRI in the prediction of chest wall invasion of lung cancer, especially in patients in whom the results of conventional CT scan or MRI appear equivocal in the presence of a peripheral mass abutting the chest wall surface without obvious chest wall invasion.

Barium aspiration showing crazy-paving appearance on high-resolution computed tomography.

We encountered a case showing a crazy-paving appearance on high-resolution computed tomography (HRCT), which mimicked various pulmonary diseases, e.g. pulmonary alveolar proteinosis, or non-specific interstitial pneumonia, but which we ultimately determined to be due to barium aspiration. The initial radiological findings were considered to be most likely due to pulmonary alveolar microlithiasis, because the crazy-paving appearance had high density, resembling calcification. However, distribution was limited to the area of dependent drainage of the right lung. Since a barium swallowing study had been performed 2 weeks before the CT examination, and since the follow-up HRCT showed improvement we reached a diagnosis of barium aspiration. Although barium aspiration may yield findings similar to other diseases with crazy-paving appearance, it is possible to identify it because of the limited distribution and high density.

Multiplanar reconstruction MR image of primary adenoid cystic carcinoma of the central airway: (MPR of central airway adenoid cystic carcinoma).

Multiplanar reconstruction (MPR) is a method that allows free selection of computerized reconstruction images. We reviewed a total of six MPR magnetic resonance (MR) examinations in five cases of adenoid cystic carcinoma of the central airway, which is a rare low-grade malignant tumor. MPR MR provides images either longitudinally or at right angles to the longitudinal axis of the trachea and main bronchi, so it was useful to diagnose tumor extent along airways more precisely and to evaluate therapeutic effects. MPR MR may help in planning therapeutic strategy and in posttherapeutic follow-up.

Venous hemangioma of the mediastinum.

Mediastinal hemangiomas are rare tumors. We present a case of venous hemangioma of the mediastinum. Computed tomography shows anterior mediastinal solid mass without enhancement effects. We believe that it is necessary to include a mediastinal hemangioma for differential diagnosis, when little or no enhancement effects are noted at early and delayed CT examination.

MR features of a case of chronic expanding hematoma.

We describe a patient with chronic expanding hematoma that was pathologically confirmed by examination of the resected specimen. It has increased gradually in the right lower lung field during a period of 10 years without symptoms. The MR T2-weighted image was useful to establish a diagnosis of chronic expanding hematoma, because of the mosaic of various signal intensities we named the "mosaic sign".

[A case of choroidal malignant melanoma in which 123I-IMP scintigraphy was useful for diagnosis].

A case of choroidal malignant melanoma in which N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) scintigraphy was useful for diagnosis is reported. A 62-year-old man first visited our hospital 3 years ago complaining of decreases in left eyesight. CT showed a tumor with an arcuate high attenuation area on the aural side of the optic disk in the left eye. A crescent high attenuation area, evidence of retinal detachment, was also observed on the nasal side of the optic disk. T1-weighted MR images showed low signal intensity in most of the tumor and a high signal intensity area was seen in the center, T2-weighted MR images showed homogeneous and marked low signal intensity area. Differentiation from a hematoma or a vascular tumor associated with bleeding was impossible based on CT and MRI. However, because late-phase images obtained on 123I-IMP scintigraphy showed marked high accumulation in an area corresponding to almost the entire left eye, left eye enucleation was undertaken under a diagnosis of malignant melanoma. Histopathologic examinations showed tumor growth mainly in the subretinal area. The melanin content of the tumor was high in the periphery and relatively low in the center. Infiltration was observed into the sclera and around the vortex vein outside the eyeball, but this change could not be detected by CT or MRI. 123I-IMP scintigraphy was useful not only for qualitative diagnosis of choroidal malignant melanoma, but for the determination of the extent of the lesion as well.

CT scanning of bronchioloalveolar carcinoma: specific appearances.

We reviewed CT scans in 38 cases with pathologically proved bronchioloalveolar carcinoma. CT revealed three CT patterns: solitary, pneumonic and diffuse forms. The solitary pattern (22 patients) had a high percentage of air bronchograms (95%), pleural indentation (77%) and spiculation (68%). The pneumonia-like pattern (16 lesions in 10 patients) had air bronchograms in all cases (100%), low attenuation (88%) and protrusion of interlobar fissures (63%). The diffuse form (six patients) had 2 or 3 mm diffuse small nodules scattered throughout the entire lung. CT of bronchioloalveolar carcinoma revealed many findings and was useful in recognizing the tumor distribution and extent. We conclude that CT is helpful for the diagnosis and evaluation of bronchioloalveolar carcinoma.

[Ovarian cancer--a comparison between CT diagnosis and serum tumor markers].

In 40 patients undergoing pre-treatment for an ovarian tumor, a CT scan of the pelvis and measurements of their CA 125, CA 19-9, IAP (immunosuppressive acidic antigen), and TPA (tissue polypeptide antigen were performed. The specificity and sensitivity of the CT diagnosis was found to be better than any of other tumor markers measurements. Comparison of the 4 markers showed that the CA 125 testing had the greatest sensitivity in detecting an ovarian cancer. Moreover, the sensitivity of CA 125, was better than a combination of the 4 markers. Thus, a CT scan still remains necessary for the diagnosis of an ovarian cancer.