Fumiyoshi Takayama

Discrimination of subtypes of small adenocarcinoma in the lung with thin-section CT.

We studied the usefulness of thin-section CT in discriminating two categories of adenocarcinoma in the lung. Thin-section CT findings, such as, lesion size, ground-glass opacity (GGO) areas of lesion and presence or absence of lobulation, coarse spiculation, air bronchogram, small air space, or pleural tag of lesion in 62 consecutive patients with 62 adenocarcinomas (35 type A or B tumors (Noguchis classification) and 27 type C tumors) of < or =20 mm, including 36 women and 26 men with a mean age of 64 years were analyzed. We performed stepwise logistic modeling using all the CT findings as independent variables to estimate the significant factors for discriminating type C from type A or B tumor. Lesion size in type C tumors was significantly (P<0.001) greater than that in type A or B tumors. GGO areas in type C tumors were significantly (P<0.001) smaller than that in type A or B tumors. The prevalence of coarse spiculation, air bronchogram, and pleural tag in type C tumors was significantly greater (P=0.001, 0.010, and <0.001, respectively) than that in type A or B tumors. Logistic modeling revealed that the GGO area was the only significant factor for discriminating two categories (P<0.001). Using the percentage of GGO areas for predicting type C tumor, 40% or less showed the highest accuracy of 85% with 70% sensitivity and 97% specificity. GGO areas of 30% or less had no false-positive diagnosis (100% specificity) with 81% accuracy but its sensitivity was low (56%). Thin-section CT was useful in discriminating two categories of adenocarcinoma in the lung.

Esophageal Invasion by Thyroid Carcinomas: Prediction Using Magnetic Resonance Imaging

Purpose We evaluated the accuracy of magnetic resonance imaging (MRI) in predicting esophageal invasion by thyroid carcinomas and established an optimal criterion for diagnosing esophageal invasion. Method The MRI findings (size and margins of tumor, ratio of tumor contact to the esophagus, shape and displacement of the esophagus, and tumor invasion to the outer and inner layers of the esophagus) in 67 patients with thyroid carcinomas were retrospectively reviewed and correlated with surgical and pathologic findings. Logistic modeling was used to determine the significant factors for predicting esophageal invasion. Results Seventeen (34%) of the 67 patients had pathologically or surgically verified esophageal invasion. The logistic modeling revealed that outer layer invasion (P < 0.001) and poorly defined margins (P = 0.001) were the significant factors. The outer layer invasion showed the highest accuracy of 91%, with 82% sensitivity and 94% specificity. The addition of poorly defined margins to this criterion did not improve its accuracy. Conclusion Esophageal invasion by thyroid carcinoma was accurately predicted with MRI, and an MRI finding of outer layer invasion was optimal for diagnosing esophageal invasion.

Parotid gland lesions: Diagnosis of malignancy with MRI and flow cytometric DNA analysis and cytology in fine‐needle aspiration biopsy

The purpose of this study was to assess the capability of magnetic resonance imaging (MRI) and cytology and flow cytometric (FCM) deoxyribonucleic acid (DNA) analysis in fine‐needle aspiration biopsy (FNAB)–derived materials for diagnosing malignancy of the parotid lesions and the efficacy of FCM analysis in FNAB.

MR IMAGING OF THE LINGUAL THYROID: Comparison to other submucosal lesions

Purpose: To study MR findings for clues to the diagnosis of lingual thyroid. Material and Methods: MR findings and clinical and scintigraphic data of 5 cases of lingual thyroid were reviewed and the MR findings were compared to those of 16 cases of other submucosal lesions in the base of the tongue. Results: Four of the 5 patients with lingual thyroid were women and all had hypothyroidism. MR imaging depicted lingual thyroid in the midline in the base of the tongue (n=5) and additional ectopic thyroid glands in the floor of the mouth (n=2) or between the right and left sternohyoid muscles (n=1). Ectopic thyroid glands appeared isointense or hyperintense relative to muscle tissue on T1-weighted images and showed slight or fair contrast enhancement. All glands had low to intermediate T2 signal, which was also seen in 1 case of non-Hodgkins lymphoma and 1 case of adenoid cystic carcinoma. All ectopic thyroid glands had well-defined margins, whereas malignant tumors tended to have ill-defined margins and to invade the surrounding structures. All but the 5 cases of lingual thyroid had an MR-demonstrable thyroid gland in the normal cervical position. Conclusion: A well-defined mass of low-intermediate T2 signal in the midline base of the tongue, neither with invasive tendency nor with a cervical thyroid gland in the normal site on MR imaging, may strongly indicate lingual thyroid.

Spontaneous extensive necrosis in non-Hodgkin lymphoma : Prevalence and clinical significance

Purpose We studied the prevalence of spontaneous extensive necrosis in the nodes of patients with non-Hodgkin lymphomas and assessed the clinical significance of this finding. Method CT and MRI performed before initiation of radiation or chemotherapy were reviewed in 60 consecutive patients with non-Hodgkin lymphomas to evaluate the presence or absence of spontaneous extensive necrosis in the lymphomatous nodes. The results were correlated with histopathologic grading, stages of lymphomas, maximal axial diameters of the lesions, International Prognostic Index (IPI), age, and serum lactate dehydrogenase (LDH) levels. We then performed Kaplan-Meier analysis of disease-free survival using each factor. Results Extensive necrotic nodes that appeared as rim-enhanced masses on enhanced CT or MR images were found in 15 patients (25%), of whom 10 patients had pathologic verification. The patients with necrosis had significantly higher stages (Stage II or higher), greater IPI (IPI of ≥2), and higher serum LDH levels than those without necrosis (p = 0.001, p = 0.005, and p = 0.005, respectively). With the Kaplan-Meier method, a statistically significant difference was noted for serum LDH levels (p = 0.015) and IPI (p = 0.021) but not for extensive necrosis (p = 0.600). Conclusion Spontaneous extensive necrosis in lymphomatous nodes is not a rare event. This finding may have a prognostic significance for patients with non-Hodgkin lymphomas.

Radiologic assessment of metastases to the thyroid gland.

Purpose We reviewed the radiologic and clinical data in patients with metastatic disease to the thyroid gland and assessed the role of radiologic techniques in this disorder. Method The findings on US (n = 11), CT (n = 7), MRI (n = 6), palpation or US-guided fine needle aspiration (FNA) biopsy, and clinical records were reviewed in 11 cases of pathologically verified metastatic tumors of the thyroid gland. Results Five patients had palpable thyroid nodules and six had nonpalpable nodules discovered incidentally with imaging procedures. Three patients had no known malignancies at the time of diagnosis of thyroid tumors. Correct diagnosis was obtained in 10 of the 11 cases with FNA biopsy. Thyroid metastases were detected in all of the cases with US and MRI and six of the seven cases with CT. Thyroid metastases were solitary (n = 5) or multiple (n = 6), and about half of them measured <2 cm in diameter. These tumors typically had well defined margins and no calcification and sometimes had cystic portions. Multiple nodules within the same patient were radiologically quite similar to each other. On US, metastases appeared as hypoechoic or markedly hypoechoic areas without halo, on CT as low density areas, and on MRI as areas of varying signal intensities. Half of the metastases showed hypointensity on either T2-weighted images or gadolinium-enhanced T1-weighted images. The tumors involved lymph nodes in 10 cases and other remote organs in 5. Level I or II or parotid nodes were involved in six cases. Conclusion These radiologic features may alert clinicians to a possibility of metastatic thyroid cancer. US combined with US-guided FNA biopsy is suitable for early diagnosis of metastases to the thyroid gland.

Thyroid metastasis from rectal carcinoma coexisting with hashimoto's thyroiditis: Gray-scale and power Doppler sonographic findings

We present the gray‐scale and power Doppler sonographic findings in a case of rectal carcinoma metastasis to the thyroid that mimicked a primary thyroid neoplasm and coexisted with Hashimotos thyroiditis in a 67‐year‐old man. Gray‐scale sonography revealed a hypoechoic mass with ill‐defined borders in the left lobe of the thyroid; the mass extended through the isthmus to the right lobe. Sonography also showed multiple enlarged cervical lymph nodes. Power Doppler sonography showed increased flow in the nontumorous thyroid gland and decreased flow in the tumor. This contributed to the differentiation between the tumor and the remainder of the thyroid, which was involved with Hashimotos thyroiditis.

Assessment of parotid masses: which MR pulse sequences are optimal?

The objective of this paper is to determine which MR pulse sequences are optimal for delineation of lesion and predicting pathologic nature of lesion with signal intensity. A prospective study was performed in 53 parotid masses (39 benign and 14 malignant lesions) in 53 patients. Signal intensity of lesion was visually assessed and lesion/parotid contrast-to-noise ratios were measured. On visual assessment, detection sensitivity was 100% for nonenhanced nonfat-suppressed T1-weighted images, 91% for nonfat-suppressed fast spin-echo (FSE) T2-weighted images, 83% for gadolinium-enhanced fat-suppressed T1-weighted images, and 75% for fat-suppressed FSE T2-weighted images. The highest contrast-to-noise ratios were obtained with nonenhanced T1-weighted images. Hypointensity of lesion relative to the parotid gland on nonfat-suppressed FSE T2-weighted images was seen in 11 of 14 malignancies, 12 of 15 Warthin tumors, and two of 18 pleomorphic adenomas. Cystic portion of hyperintensity on nonenhanced T1-weighted images was solely seen in benign tumors (n = 11). Thus, the highest accuracy (81%) (79% sensitivity and 82% specificity) for predicting malignancy was obtained with a criterion of hypointensity on nonfat-suppressed FSE T2-weighted images plus absence of cystic portion of hyperintensity on nonenhanced T1-weighted images. Nonenhanced T1-weighted images combined with nonfat-suppressed FSE T2-weighted images is optimal for delineation of lesion and prediction of pathologic nature of parotid masses.

MR imaging of primary leiomyosarcoma of the thyroid gland

Primary leiomyosarcoma of the thyroid gland is extremely rare and radiological information on this tumor is scant. We presented radiological findings on primary thyroid leiomyosarcoma in a 66-year-old woman in which anaplastic carcinoma was suspected based on clinical and cytological features and discussed the radiological clues to distinguish between the two diseases. Ultrasonography showed an ill-defined hypoechoic mass without halo in the left lobe and the isthmus of the thyroid gland. Computed tomography depicted a low-density mass with calcification and necrosis, which invaded the thyroid cartilage. No lymphadenopathy was seen. The tumor was demonstrated as an isointense mass on T1-weighted MR images and a mass of intermediate signal on T2-weighted images. The tumor showed a fair enhancement on gadolinium-enhanced T1-weighted images. Although the radiological picture was nonspecific, primary thyroid leiomyosarcoma appeared less invasive and far less frequent in developing nodal metastasis than anaplastic carcinoma in light of the literature.

Prognostic Significance of Magnetic Resonance Findings in Advanced Papillary Thyroid Cancer

We assessed the prognostic importance of magnetic resonance (MR) findings in locally advanced papillary thyroid cancer. MR findings, clinical data, and pathologic (and surgical) data for 66 patients, including 51 women and 15 men with a mean age of 57 years, who had primary surgery for papillary thyroid cancers were correlated with prognosis. Mean follow-up was 27.5 months (range, 5-117 months). Recurrence was seen in 18 patients (27%). In univariate analyses, age of 60 years or more (p = 0.0066), male gender (p = 0.0373), six MR findings (tumor size of > or = 4 cm ([p = 0.0002], ill-defined margins ([p < 0.0001], tumor extension of the trachea [p = 0.0337], carotoid artery [p = 0.0028]), esophagus [p < 0.0001], and lymph nodes [p = 0.0005]), and three pathologic findings (tumor extension of soft tissues [p = 0.0288], carotid artery [p = 0.0013], and esophagus [p < 0.0001]) had a significant adverse effect on disease-free survival. In multivariate analyses, tumor size (p = 0.0169) and nodal metastasis (p = 0.0393) determined on MR imaging and pathologic esophageal invasion (p = 0.0016) were the only significant independent variables. Esophageal invasion was accurately diagnosed with MR imaging (94% accuracy). MR findings may contain prognostic importance of locally advanced papillary thyroid cancer.