Effect of Gd-EOB-DTPA on T2-weighted and diffusion-weighted images for the diagnosis of hepatocellular carcinoma.

PURPOSE: To evaluate the effect of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) for the diagnosis of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The phantom signal intensity was measured. We also evaluated 72 patients including 30 patients with HCC. T2WI and DWI were obtained before and then 4 and 20 min after injecting the contrast medium. The signal to noise ratio (SNR), contrast to noise ratio (CNR), and apparent diffusion coefficient (ADC) were calculated in the tumor and liver parenchyma. RESULTS: The phantom signal intensity increased on T2WI at a concentration of contrast medium less than 0.2 mmol/L but decreased when the concentration exceeded 0.4 mmol/L. SNR of the liver parenchyma on T2WI was significantly different between before and 4 min after injecting the contrast medium, while there were no significant differences between before and 4 and 20 min after injection. On T2WI, SNR, and CNR of HCC showed no significant differences at any time. SNR, CNR, and ADC of the liver parenchyma and tumor on DWI also showed no significant differences at any time. CONCLUSION: It is acceptable to perform T2WI and DWI after injection of Gd-EOB-DTPA for the diagnosis of HCC.

Perfusion study of liver lesions with superparamagnetic iron oxide: distinguishing hepatocellular carcinoma from focal nodular hyperplasia.

We performed a perfusion study with superparamagnetic iron oxide (SPIO) and evaluated the possibility of acquiring hemodynamic imaging in hypervascular hepatocellular nodules. Single-slice computed tomography during arteriography (SCTA) and an SPIO perfusion study were performed and compared. The findings of the direction of blood flow in the lesion and the findings corresponding to the corona enhancement on the SPIO perfusion study agreed well with the findings of SCTA. In conclusion, SPIO perfusion is useful in evaluating the hemodynamics of hypervascular hepatocellular nodules.

Evaluation of cardiac iron overload in transfusion-dependent adult marrow failure patients by magnetic resonance imaging.

We investigated magnetic resonance imaging T2-star (MRI-T2*) values and left ventricular ejection fraction (LVEF) in 7 adult patients with bone marrow failure with heavy transfusion to elucidate the correlation between cardiac iron overload and dysfunction. We demonstrated a positive correlation between the total volume of red blood cells (RBC) transfusion and ejection fraction. The normal T2* limit value, which represents cardiac siderosis, is probably 200 mL/kg RBC transfusion. Patients with serum ferritin levels of under 5000 ng/mL and who received 200-400 mL/kg RBC transfusion showed mild but progressive decrease of the T2* value without obvious reduction of the ejection fraction, indicating that the T2* value of MRI could be a predictor for cardiac iron deposition before the appearance of myocardial dysfunction. Transfused RBC amount of >400 mL/kg or rapid elevation of ferritin level of >5000 ng/mL might be warning sign for critical cardiac dysfunction. Since iron overload of the heart is a major factor affecting co-morbidity of bone marrow failure, MRI evaluation of cardiac iron overload and functional disturbance in adult non-thalassemic patients is essential.

High-resolution computed tomographic findings of small peripherally located squamous cell carcinoma.

With the spread of high-resolution computed tomography (HRCT) screening for lung cancer, we are increasingly faced with the need to determine whether certain small lesions are benign or malignant. The features of small adenocarcinomas have been clarified but not those of squamous cell carcinoma. The objective of our study was therefore to clarify the HRCT findings of peripherally located squamous cell carcinomas less than 2 cm in maximum dimension. Subjects consisted of 27 consecutive pathologically proven cases of peripherally located squamous cell carcinoma that were less than 2 cm in maximum dimension. HRCT findings of all 27 cases were analyzed retrospectively and independently by three radiologists who were unaware of the pathological diagnosis, and decisions were reached by consensus with special attention to 10 review points. Internal characteristic features included calcification, cavity formation, and air bronchogram. Tumor margin features included spiculation, notching, irregularity, and ground-glass opacity. Surrounding structural features consisted of pleural indentation, pulmonary emphysema, and satellite lesions. The presence of irregularity (70.4%), surrounding pulmonary emphysema (70.4%), and pleural indentation (51.9%) was observed frequently. No mass was accompanied by calcification. HRCT images of peripherally located squamous cell carcinoma suggested that the demonstration of irregularity, surrounding pulmonary emphysema, pleural indentation, and absence of calcification may contribute to the accurate CT diagnosis of small peripheral squamous cell carcinoma.

Glomus tumor of the left main bronchus.

We report a case of left main bronchial glomus tumor in a 39-year-old man who presented with a cough he had had for 1 month. A computed tomography (CT) scan revealed a polypoid tumor in the membranous portion of the left main bronchus. The tumor showed marked enhancement on the early phase of dynamic contrast-enhanced CT, and it was thought to be a hypervascular tumor. The tumor was carefully resected by a rigid bronchoscope, and the pathological and immunohistochemical findings yielded a diagnosis of glomus tumor. Marked enhancement of early phase dynamic contrast-enhanced CT may be useful for a diagnosis of bronchial glomus tumor.

Computed tomographic findings of large cell neuroendocrine carcinoma of the lung.

The purpose of our study was to describe the computed tomography (CT) findings of large cell neuroendocrine carcinoma (LCNEC) and to correlate radiological and pathological findings. We reviewed the CT findings of 36 patients [including the high-resolution computed tomography (HRCT) findings of 29 patients] with resected LCNEC specimens. There were 33 men (92%), and 30 patients had a smoking history (83%). Only one case was of the central type. Mediastinal or hilar lymphadenopathy was seen in 12 (33%), but only one showed bulky lymphadenopathy. The HRCT findings of LCNEC consisted of irregular margins (66%), surrounding emphysema (41%), notching (38%), calcifications (21%), and pleural indentation (24%). Our study indicates that the CT image of LCNEC generally shows a peripherally located, expansively growing, irregularly margined pulmonary mass, with or without calcification, and without bulky lymphadenopathy. While the CT image of LCNEC resembles that of squamous cell carcinoma, cavitation is infrequent. LCNEC cannot be differentiated from poorly differentiated adenocarcinoma or atypical carcinoid on the basis of CT findings.

Clinical application of virtual hysteroscopy by CO(2)-multidetector-row computed tomography to submucosal myomas.

STUDY OBJECTIVE: We produced virtual hysteroscopy (VH) images from the images obtained after expanding the uterine cavity of patients with submucosal myomas and performing multidetector-row computed tomography scans, and assessed them in comparison with hysteroscopic imaging and in relation to the advantages of VH. DESIGN: Cohort-control study (Canadian Task Force classification II-2). SETTING: Tokyo Medical University Hospital department of obstetrics and gynecology. PATIENTS: Thirty-one patients with submucosal myomas treated by endoscopic surgery. MEASUREMENTS AND MAIN RESULTS: The expandability of the uterine cavity by CO(2) gas was favorable in all 31 patients in whom imaging was performed, and it was possible to obtain clear VH images. The sites of origin of the submucosal myomas were clearly visualized; their imaging was consistent with imaging by hysteroscopy; and as a method of establishing the orientation of the uterine cavity, it was possible to obtain a greater amount of information than by hysteroscopy. CONCLUSION: Although the invasiveness of radiation exposure and contrast medium cannot be denied, the possibilities of and indications for VH, which by expanding and visualizing the uterine cavity enables the acquisition of navigation images of the uterine cavity that varies in morphology from patient to patient, are expected to continue to expand.

Myometrial invasion and cervical invasion by endometrial carcinoma: evaluation by CO2-volumetric interpolated breathhold examination (VIBE).

PURPOSE: To assess myometrial invasion and cervical invasion by endometrial carcinoma, using CO2-volumetric interpolated breathhold examination (VIBE) enabling more precise evaluation of depth of tumor invasion. MATERIALS AND METHODS: CO2-VIBE was performed in 21 cases of endometrial carcinoma (Stage Ia-IIb) prior to treatment. The images were interpreted by performing multiplanar reconstruction (MPR), and the findings obtained from the images (degree of myometrial invasion and presence or absence of cervical invasion) were assessed in comparison with the histopathological diagnosis. RESULTS: The sites of the endometrial carcinoma lesions were clearly visualized by the CO2-VIBE method. Evaluation of the degree of myometrial invasion enabled a high correct diagnosis rate of 90.5%, and evaluation for the presence of cervical invasion also allowed a high correct diagnosis rate of 90.5%. CONCLUSION: VIBE permits evaluation of any plane desired by means of thin slices, and it is a truly revolutionary method for preoperative evaluation of depth of invasion of endometrial carcinoma that enables highly accurate determination of the extent of lesion sites and degree of invasion before treatment.

Differential diagnosis of hepatic nodules using delayed parenchymal phase imaging of levovist contrast ultrasound: comparative study with SPIO-MRI.

T2-weighted fast spin echo images and T2*-weighted gradient-echo images of superparamagnetic iron oxide magnetic resonance imaging (SPIO-MRI) have been reported to reflect the number and function of macrophages in reticuloendothelial organs and be useful to differentiate malignant tumors from benign nodules of liver. We tried to prove that contrast-enhanced ultrasound can diagnose hepatocellular carcinoma (HCC) by comparing the findings of SPIO-MRI and the findings of the liver parenchyma on the delayed parenchymal phase of ultrasound imaging using the intravenous contrast agent Levovist, not through the evaluation of vascular imaging. Forty-six patients (52 nodules) with histopathological diagnosis of hepatic tumors were studied. They consisted of 11 non-malignant nodules (six regenerative nodules and five dysplastic nodules) and 41 HCC. All the patients were examined by Levovist contrast-enhanced ultrasonography and SPIO-MRI. The delayed liver parenchymal images of contrast-enhanced ultrasound using the intravenous contrast agent Levovist were similar to those observed on SPIO-MRI. The similarity of both findings suggests that delayed phase imaging by Levovist is closely related to the number and function of Kupffer cells in liver tumors. The diagnostic accuracy of contrast-enhanced ultrasound for HCC was high (90.4%) demonstrating that it is as reliable as SPIO-MRI.

[Three-dimentional volumetric interpolated breath-hold magnetic resonance imaging for the diagnosis of breast tumors].

PURPOSE: Three dimensional volumetric interpolated breath-hold examination magnetic resonance imaging(3D-VIBE MRI) has the advantage of improving z-axis resolution, which makes it possible to obtain high quality multi-planar reconstruction (MPR) and 3-D reconstruction images. Using these capabilities of 3D-VIBE MRI, we have attempted to diagnose and evaluate breast tumors for preoperative planning. MATERIALS AND METHODS: One hundred patients with breast cancer and 5 patients with benign breast tumors were scanned by 1.5-T MR imaging, and the findings were compared with pathological findings. Triple-phase contrast-enhanced 3D-VIBE MRI was performed at 20 seconds (early arterial phase), 50 seconds (late arterial phase) and 180 seconds (equilibrium phase) after the beginning of injection of contrast material. Dynamic imaging was performed with 20 ml Gd-DOTA injected at a rate of 3.0 ml/sec. We also attempted to diagnose breast tumor for the detection of the primary lesion, estimation of histologic type, prediction of extensive intraductal components (EIC) and axillary lymph node metastases from breast cancer. RESULTS: (1) The diagnostic accuracy for breast cancer was 96.0% and it was 100.0% for benign disease. (2) The accuracy of the histologic estimation for breast cancer was 56.4%, and it was 83.3% for benign disease. (3) The accuracy of evaluation of ductal spread of breast cancer was 52.4%. (4) The accuracy was 72.4% for lymph node metastasis from breast cancer. CONCLUSION: This method provides useful information about the location of the primary tumor and lymph nodes. 3D-VIBE method is considered especially important for the preoperative evaluation of axillary lymph node status.

Gallium-67 accumulation to the tumor thrombus in anaplastic thyroid cancer.

A sixty-five-year-old woman was hospitalized for examination of swelling in the left arm. Gallium-67 scintigraphy showed the same radioactivity in the left lobe of the thyroid gland and the junction of the internal jugular vein and the subclavian vein. Operation then proved obstruction of the left internal jugular vein and subclavian vein due to tumor thrombus accompanied by anaplastic thyroid cancer. Gallium-67 scintigraphy was extremely useful in grasping the extent and feature of the tumor.

Evaluation of endometrial cancer with 3D-VIBE (volume interpolated breath-hold examination) using intrauterine CO2 gas.

To evaluate the myometrial infiltration of the endometrial cancer prior to aggressive treatment, dynamic MRI (magnetic resonance imaging) has attracted attention. However, it has also been found that in a number of cases, MRI exhibits inconsistent results with regards to the extent of the infiltration into this component of the uterine body. To overcome this limitation, the authors designed a method to delineate the tumor morphology more clearly by injecting CO2 gas into the uterine cavity. This procedure was combined with VIBE (volumetric interpolated breath-hold examination) to determine more precisely the depth of the tumor invasion. From our clinical results, the efficacy of the method was evaluated. On four patients with endometrial cancers (stage Ia-Ic), CO2 was injected to dilate the intra-uterine space through a catheter equipped with a balloon that had been introduced into the uterine cavity, after which VIBE was conducted. The images were interpreted by MPR (multiplanar reconstruction) and the findings from these images were compared against the histopathological findings. By employing this method, it was possible to delineate clearly the tumorous lesion in the uterine body, and three-dimensional images of the tumor invasion was acquired. The site and extent of tumor invasion in the myometrium were generally consistent with the histopathological findings. This method allows one to observe multiple planes by using thin slices. By dilating the uterine cavity, the site of involvement and the extent of invasion can be more precisely defined before treatment. It is truly a revolutionary procedure for determining-prior to surgery-the depth of invasion of a cancer located in the uterine body.