Ken Motoori

Diffusion-weighted imaging of prostate cancer.

Objective: The purpose of this study was to assess whether T2-weighted (T2W) imaging with diffusion-weighted (DW) imaging could improve prostate cancer detection as compared with T2W imaging alone. Methods: The subjects consisted of 37 patients with prostate cancer and 23 without cancer undergoing magnetic resonance (MR) imaging. Using a 1.5-T superconducting magnet, all patients underwent T2W and DW imaging with parallel imaging. Images were independently reviewed by 3 readers to determine the detectability of prostate cancer. The detectability of T2W imaging without and with DW imaging was assessed by means of receiver operating characteristic analysis. Results: Mean areas under the receiver operating characteristic curve for T2W imaging alone and for T2W imaging with DW imaging were 0.87 and 0.93, respectively. The receiver operating characteristic analysis showed that the addition of DW imaging to conventional T2W imaging significantly improved tumor detection (P = 0.0468) compared with T2W imaging alone. Conclusions: The addition of DW imaging to conventional T2W imaging provides better detection of prostate cancer.

Inter- and intratumoral variability in magnetic resonance imaging of pleomorphic adenoma: an attempt to interpret the variable magnetic resonance findings.

Objectives: The purpose of our study was to describe the various magnetic resonance (MR) findings of pleomorphic adenoma and to interpret these findings. Methods: MR studies of 33 pleomorphic adenomas and 13 malignant tumors in the major salivary glands were reviewed. Results: High signal intensity on short-inversion-time inversion recovery (STIR) and T2-weighted (T2W) images, progressive enhancement on dynamic MR images, and high apparent diffusion coefficient (ADC) values on diffusion-weighted (DW) images reflected myxoid-dominant components in pleomorphic adenomas. Hypercellularity with less-myxoid stroma showed reduced signal intensity on STIR and T2W images and also reduced ADC values on DW images, and the peak of time versus signal intensity curves (TICs) was reached earlier on dynamic MR images. Conclusions: The MR images of hypercellularity components in pleomorphic adenoma overlap with those of malignant parotid tumors. Detecting myxoid components by STIR, T2W, DW, and dynamic MR images is useful for predicting whether salivary gland tumors are pleomorphic adenoma or not.

Diagnostic value of FDG PET and salivary gland scintigraphy for parotid tumors

Purpose: The purpose of this study was to examine the diagnostic value of the combination of F-18 fluorodeoxyglucose (FDG) PET and Tc-99m pertechnetate salivary gland scintigraphy in parotid tumors. Materials and Methods: Seventy-two patients with benign parotid gland tumors (n = 52), malignant parotid tumors (n = 12), and inflammation (n = 8) underwent both FDG PET and salivary gland scintigraphy within 1 week, and 66 of the patients also underwent gallium scintigraphy. All patients were negative on their first fine-needle aspiration (FNA). Results: Malignant parotid tumors showed significantly higher FDG uptake (standard uptake values [SUVs]) than both benign tumors and inflammation, except in Warthins tumor (5.82 ± 3.95 vs. 2.07 ± 1.33; P <0.01). Although the SUV values of Warthins tumor and malignant parotid tumors overlapped somewhat, Warthins tumor did demonstrate increased radiotracer uptake, and it was reliably distinguished from other parotid gland tumors by the use of salivary gland scintigraphy. Considering a SUV value >3 as being positive for malignancy and excluding Warthins tumor on the basis of salivary gland scintigraphy, sensitivity and specificity of FDG PET were 75% and 80%, respectively. These results were superior to those of gallium scintigraphy (58% and 72%, respectively). Conclusions: Although the diagnostic value of FDG PET in the differentiation of malignant from benign parotid gland tumors was limited because of the high FDG uptake in some benign tumors, and particularly pleomorphic adenomas, combining salivary gland scintigraphy with FDG PET may help to negate this drawback, and this combination may be a more promising approach for differentiation of various parotid gland tumors in patients compared with nondiagnostic needle aspiration.

Chronic obstructive pulmonary disease and interstitial lung disease in patients with lung cancer

Background and objective:  Although lung cancer is frequently accompanied by COPD and interstitial lung disease (ILD), the precise coincidence of these diseases with lung cancer is not well understood. The objectives of this study were to determine the prevalence of abnormal CT and spirometric findings suggestive of COPD or ILD in a population of patients with untreated lung cancer, and to estimate the lung cancer risk in this population.

Chondrosarcoma of the nasal septum

Abstract. The nasal septum is a particularly rare site of origin of chondrosarcoma. Cranial base invasion may be at hand, with such lesions making complete tumor removal difficult. MRI techniques allow precise definition of tumor extent. In the described case, CT and Dynamic MR imaging were performed in a case of chondrosarcoma of the nasal septum. Imaging clearly illustrated size and extent of the mass with central regions of internal calcification. Dynamic MRI was additionally performed, which helped to define the presumed origin of the lesion from the nasal septum.

Identification of Warthin tumor : magnetic resonance imaging versus salivary scintigraphy with technetium-99m pertechnetate

Objective: The aim of this study was to evaluate the accuracy of technetium-99m (Tc-99m) pertechnetate scintigraphy and magnetic resonance (MR) imaging in the diagnosis of Warthin tumor. Methods: Sixteen cases of Warthin tumor and 17 cases of non-Warthin tumor were examined by Tc-99m pertechnetate scintigraphy with lemon juice stimulation and MR imaging, including T1-weighted, T2-weighted, short inversion time inversion recovery, diffusion-weighted, and contrast-enhanced dynamic images. We used the receiver operating characteristic (ROC) curve to evaluate diagnostic accuracy. Results: The mean area under the ROC curves of MR imaging in the diagnosis of Warthin tumor (0.97) was higher than that of Tc-99m pertechnetate scintigraphy (0.88). Conclusion: Magnetic resonance imaging is more useful in the evaluation of Warthin tumor than Tc-99m pertechnetate scintigraphy.

Diffuse Pulmonary Involvement by Mycosis Fungoides: High-resolution Computed Tomography and Pathologic Findings

The authors report the high-resolution computed tomography (HRCT) appearance of diffuse pulmonary involvement by mycosis fungoides in a 74-year-old woman whose clinical and radiographic manifestations simulated pneumonia. The HRCT showed multiple, dense, peribronchovascular nodules with surrounding ground-glass opacity and several wedge-shape peripheral opacities. The autopsy specimen revealed angiocentric and peribronchovascular involvement of mycosis fungoides and pulmonary infarctions distal to angiocentric infiltration of the tumor cells.

Trends in oncological CT imaging: clinical application of multidetector-row CT and 3D-CT imaging.

Computed tomography (CT) plays an essential role in oncological imaging as the modality of screening for malignancies, mapping out the treatment strategy at staging, assessing response to the treatment, and following up patient outcome after the treatment. The advent of multidetector-row CT (MDCT) has brought about dramatic changes in clinical oncological imaging. The very superior temporal and spatial resolution of MDCT has transformed CT imaging from a transaxial cross-sectional technique into an isotropic volume-imaging technique. MDCT facilitates multiphasic contrast-enhanced study for a wide range of body scanning in a single examination, as well as providing flexibility of multidirectional reconstruction and high-quality three-dimensional imaging. With increases in the number of detector rows year by year, systems with 64-detector rows have become commercially available in 2006. The purpose of this article is to review the status of CT imaging in oncological imaging: (1) to outline the impact of MDCT, focusing on oncological imaging and (2) to review the clinical applications of oncological CT imaging with MDCT.

Dual-time point scanning of integrated FDG PET/CT for the evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT

PURPOSE To evaluate whether dual-time point scanning with integrated fluorine-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography and computed tomography (PET/CT) is useful for evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT. MATERIALS AND METHODS PET/CT data and pathological findings of 560 nodal stations in 129 patients with pathologically proven non-small cell lung cancer diagnosed as operable by contrast-enhanced CT were reviewed retrospectively. Standardized uptake values (SUVs) on early scans (SUVe) 1h, and on delayed scans (SUVd) 2h after FDG injection of each nodal station were measured. Retention index (RI) (%) was calculated by subtracting SUVe from SUVd and dividing by SUVe. Logistic regression analysis was performed with seven kinds of models, consisting of (1) SUVe, (2) SUVd, (3) RI, (4) SUVe and SUVd, (5) SUVe and RI, (6) SUVd and RI, and (7) SUVe, SUVd and RI. The seven derived models were compared by receiver-operating characteristic (ROC) analysis. k-Fold cross-validation was performed with k values of 5 and 10. p<0.05 was considered statistically significant. RESULTS Model (1) including the term of SUVe showed the largest area under the ROC curve among the seven models. The cut-off probability of metastasis of 3.5% with SUVe of 2.5 revealed a sensitivity of 78% and a specificity of 81% on ROC analysis, and approximately 60% and 80% on k-fold cross-validation. CONCLUSION Single scanning of PET/CT is sufficiently useful for evaluating mediastinal and hilar nodes for metastasis.

Selective intra-arterial 3-dimensional computed tomography angiography for preoperative evaluation of nephron-sparing surgery.

Objective: To evaluate selective intra-arterial 3-dimensional computed tomography (3D-CT) angiography as a tool for the preoperative evaluation of nephron-sparing surgery (NSS). Methods: Twenty-three patients with renal cell carcinoma indicating NSS underwent selective intrarenal 3D-CT angiography. The time-lapse dual-phase technique was used for simultaneous vascular and urographic visualization. The 3D images were created by the shaded volume-rendering method. The CT attenuation of target structures was measured for quantitative evaluation. The 3D images were visually evaluated for the renal artery, vein, and collecting system using a grading system. Results were statistically analyzed. Results: The 3D-CT angiography depicted the intrarenal branches of the renal artery and vein and the whole collecting system in most patients. Visualization of the renal artery was significantly correlated to its CT attenuation. Visualization of the renal vein was correlated to its CT attenuation adjusted by the surrounding renal parenchyma. Conclusion: Selective intra-arterial 3D-CT angiography allows the detailed visualization of intrarenal structures.