Tumor staging of advanced esophageal cancer: combination of double-contrast esophagography and contrast-enhanced CT.

OBJECTIVE: The objective of this study was to compare the diagnostic accuracy of tumor staging in patients with advanced esophageal cancer based on contrast-enhanced CT findings alone with that based on a combination of CT and double-contrast esophagography and to evaluate the relevance of tumor stage to survival rate. MATERIALS AND METHODS: In 94 patients who underwent surgery as the primary treatment for esophageal cancer and had a diagnosis of postoperative T stage 3 (pT3) or pT4 disease based on pathologic examination, T stage was evaluated using CT alone and using a combination of CT and double-contrast esophagography. The diagnostic criterion for T4 disease using CT alone was tumor strongly displacing or deforming adjacent organs. The diagnostic criterion for T4 disease using the combined method was tumor displacing or deforming adjacent organs in the direction that corresponded to the direction of the location of the tumor or the deepest ulcer as diagnosed by barium esophagography. Concordance of T staging based on imaging with postoperative T staging based on pathology results, the gold standard, and survival rate were assessed for CT alone and for the combined method. RESULTS: The concordance rate with postoperative T staging pathology results was 78% for CT alone and 84% for CT and double-contrast esophagography combined, with a significant difference between the two diagnostic methods. For patients with a diagnosis of T3 and those with a diagnosis of T4 using CT alone, the 3-year survival rate was 42% and 26%, respectively, with no significant difference between the two. For patients with a diagnosis of T3 and those with a diagnosis of T4 using the combined method, the 3-year survival rate was 42% and 21%, respectively, with a significant difference between the two. CONCLUSION: The diagnostic performance of contrast-enhanced CT and double-contrast esophagography combined in staging advanced esophageal tumors is better than that of CT alone and thus has potential for estimating prognosis.

Hepatic metastases: diffusion-weighted sensitivity-encoding versus SPIO-enhanced MR imaging.

PURPOSE: To retrospectively compare accuracy of diffusion-weighted (DW) single-shot echo-planar imaging with sensitivity encoding (SENSE) with that of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the evaluation of hepatic metastases due to extrahepatic malignancies. MATERIALS AND METHODS: Patients provided informed consent; ethics committee approval was not required. The data of 24 patients (16 men, eight women; age range, 41-68 years; mean age, 61.9 years) with 40 resected hepatic metastases were retrospectively reviewed. Before SPIO administration, DW SENSE imaging and T2-weighted fast spin-echo (SE) and T1-weighted dual-echo fast field-echo (FFE) MR imaging were performed. After SPIO administration, T2-weighted fast SE, T1-weighted dual-echo, and T2*-weighted FFE MR examinations were performed. Images were divided into two sets: The SPIO-enhanced MR image set consisted of pre- and postcontrast T2-weighted fast SE and dual-echo T1-weighted FFE images and postcontrast T2*-weighted FFE images. The DW SENSE image set included DW SENSE images and precontrast T2-weighted fast SE and dual-echo T1-weighted FFE images. Three radiologists individually interpreted these images and sorted the confidence levels for presence of hepatic metastasis in each section into five grades. Area under the receiver operating characteristic (ROC) curve (A(z)) was calculated for each image set. RESULTS: Hepatic metastases showed higher signal intensity on DW SENSE images than on T2-weighted fast SE images. Conversely, signals from vessels and cysts were suppressed with DW SENSE imaging. ROC analysis showed higher A(z) values when the DW SENSE image set was interpreted (0.90) than when the SPIO-enhanced MR image set was interpreted (0.81). The sensitivity and specificity, respectively, of total cases were 0.66 and 0.90, for the SPIO-enhanced MR image set and 0.82 and 0.94 for the DW SENSE image set. During SPIO-enhanced MR image interpretation, lesions 1 cm in diameter or smaller showed significantly lower sensitivity than lesions larger than 1 cm in diameter. During both interpretation sessions, left lobe lesions showed significantly lower sensitivity than right lobe lesions. CONCLUSION: Combined reading of DW SENSE images and T2-weighted fast SE and dual-echo T1-weighted FFE MR images showed higher accuracy in the detection of hepatic metastases than did reading of SPIO-enhanced MR images.

Diffusion-weighted single shot echo planar imaging of colorectal cancer using a sensitivity-encoding technique.

BACKGROUND: We wanted to determine the feasibility of diffusion-weighted single shot echo planar imaging using a sensitivity-encoding technique (SENSE-DWI) in depicting colorectal cancer. METHODS: Forty-two patients with sigmoid colon cancer and rectal cancer, all proven pathologically, were examined on T2-turbo spin echo (TSE) and SENSE-DWI. No bowel preparation was performed before examination. The b-factors used in SENSE-DWI were zero and 1000 s/mm(2). In 10 randomly selected cases, the images whose b-factors were 250 and 500 s/mm(2) were also obtained. The reduction factor of SENSE was 2.0 in all sequences. Two radiologists evaluated the obtained images from the viewpoints of tumor detectability, image distortion and misregistration of the tumors. The apparent diffusion coefficients (ADCs) of the tumors and urine in the urinary bladders in each patient were measured to evaluate the correlation between ADC and pathological classification of each tumor. RESULTS: All tumors were depicted hyperintensely on SENSE-DWI. Even though single shot echo planar imaging (EPI) was used, the image distortion and misregistration was quite pronounced because of simultaneous use of SENSE. On SENSE-DWI whose b-factor was 1000 s/mm(2), the normal colon wall and feces were always hypointense and easily differentiated from the tumors. The mean ADC value of each tumor was 1.02 +/- 0.1 (x 10(-3)) mm(2)/s. No overt correlation can be pointed out between ADC and pathological classification of each tumor. CONCLUSION: SENSE-DWI is a feasible method for depicting colorectal cancer. SENSE-DWI provides strong contrast among colorectal cancers, normal rectal wall and feces.

Thymic MALT lymphoma: MR imaging findings and their correlation with histopathological findings on four cases.

There has been no report on the MRI findings of primary thymic MALT lymphoma. We report the correlation between MRI findings and histopathology in four cases of this entity. While primary thymic MALT lymphomas exhibited diverse characteristics, the cystic components inside, which were clearly depicted on T2-weighted images, were considered to be pathognomonic. Primary thymic MALT lymphoma should be considered as one of the differential diagnoses of anterior mediastinal tumors having multilocular cysts that arise in patients with immunological abnormalities.

[Evaluation of pancreatic cancer extent using balanced turbo field echo (bTFE)].

PURPOSE: Recent advances in MR system technology have allowed for the development of new imaging techniques. Balanced turbo field echo (bTFE) is one such example. The purpose of this study was to evaluate the usefulness of bTFE for evaluating pancreatic cancer extent. MATERIALS AND METHODS: 45 patients with pathologically proven pancreatic cancer were examined with bTFE. The images obtained were evaluated by the consensus of two radiologists, from the following viewpoints: tumor detection and vascular invasion, e.g., celiac axis (CA); superior mesenteric artery (SMA); portal vein (PV); and splenic artery (SA). The results of vascular evaluation were compared with those of dynamic CT. RESULTS: All tumors were demonstrated on bTFE images, however, tumors in the pancreatic head were less clear than those in the pancreatic body. Vascular evaluation on bTFE images was in good agreement with that on dynamic CT scan. CONCLUSION: bTFE is a useful method for evaluating pancreatic cancer extent. Because image quality does not show overt changes in this sequence as time passes, unlike so-called dynamic study, not only are divided scans or respiration-trigered scans available, but repeated scans and multi-directional image acquisition can be performed as well.

Optimization of Gd-DTPA-enhanced balanced turbo field echo sequence in abdominal imaging: a basic study.

PURPOSE: To determine the optimum imaging conditions for the balanced turbo field echo (bTFE) sequence in abdominal imaging, we performed phantom experiments and scanning of a normal volunteer while noting the correlation among signal intensity, k-space ordering, flow velocity and Gd-DTPA concentration. MATERIALS AND METHODS: Initially, the abdomen of a healthy volunteer and some samples (water, blood and bovine albumin solutions with various Gd-DTPA concentrations, and olive oil) were examined with the bTFE sequence under various conditions to define the correlation among signal intensity, k-space ordering and Gd-DTPA concentration. Another experiment was performed to assess the correlation between the flow velocity and Gd-DTPA concentration. With the centric-bTFE sequence, we measured the signal intensity of water samples having various Gd-DTPA concentrations flowing in a long tube with an internal diameter of 4 mm. RESULTS: The experiments revealed the following issues: (i) The contrast of bTFE images was much influenced by k-space ordering; (ii) Gd-DTPA did not exhibit an overt enhancement effect in water and blood under stable conditions; (iii) The signal intensity of moving water decreased in centric-bTFE images, and this signal drop became more significant as the fluid speed increased; and (iv) Gd-DTPA decreased the range of signal loss in the moving fluid; however, this effect had no correlation with Gd-DTPA concentration. CONCLUSION: When the bTFE sequence was employed for abdominal imaging, centric view ordering, fat suppression and Gd-DTPA contrast enhancement were assumed to be necessary.

Optimization of Gd-DTPA-enhanced balanced turbo field echo sequence in abdominal imaging: clinical application.

PURPOSE: We performed MRI examinations of patients in order to confirm the enhancement effect of the balanced turbo field echo (bTFE) sequence with centric view ordering and SPIR (SPIR-centric-bTFE) as mentioned in the prior paper, and to evaluate the actual image quality of this sequence. MATERIALS AND METHODS: The upper abdomens of 30 patients with various abdominal disorders were examined with the SPIR-centric-bTFE sequence before and after Gd-DTPA administration. To assess the enhancement effect of Gd-DTPA, ROI measurements were taken in the aorta, superior mesenteric artery, portal vein, liver and bile juice in the common bile duct in each patient both in pre- and postcontrast images. Visual evaluations were also carried out in order to depict the peripheral vessels in the peritoneal fat and the apparent brightness of the soft-tissue organs. RESULTS: In all patients, the signal of the arteries after Gd-DTPA administration increased by about 50% compared with precontrast images. On the other hand, the veins and the liver showed a signal gain of less than 20% in postcontrast images. Consequently, only the signal of the arteries appeared enhanced in the postcontrast images. The visual evaluation revealed that postcontrast SPIR-centric-bTFE acquisition can depict the thin vessels clearly and the abdominal soft-tissue organs brightly. CONCLUSION: The balanced turbo field echo sequence with centric view ordering and SPIR after Gd-DTPA injection was considered the most appropriate protocol when this sequence was employed for abdominal imaging.

Diffusion-weighted imaging of breast cancer with the sensitivity encoding technique: analysis of the apparent diffusion coefficient value.

PURPOSE: The usefulness of diffusion-weighted imaging (DWI) in the field of neuroradiology has been established. Despite its high contrast resolution, DWI has the disadvantages of susceptibility artifact and chemical shift artifact. We performed DWI of breast cancer with the sensitivity encoding (SENSE) technique. METHODS: The subjects were 60 female patients with breast mass. All patients underwent MRI including SENSE-DWI and were diagnosed histologically. Of these patients, 55 were diagnosed with breast cancer and the remaining five were diagnosed with benign mass. The histological diagnoses of breast cancer were as follows: 39 cases of invasive ductal carcinoma (IDC); 11 cases of IDC with a predominant intraductal component and non IDC (pure or predominant NIDC); and five cases of special types of cancer. The MR system used was a Gyroscan Intera 1.5T (Philips Medical Systems). In addition to routine MRI for breast cancer, including contrast-enhanced dynamic, SENSE-DWI was obtained. The accuracy of the positional information of SENSE-DWI was visually compared with that of conventional images. The apparent diffusion coefficient (ADC) values of breast mass were analyzed with SENSE-DWI. RESULTS: The accuracy of positional information was adequate for diagnosing of all patients. The mean ADC value of breast cancer was 1.021x10(-3) mm2/s and that of benign mass was 1.488x10(-3) mm2/s (p=0.0002). The mean ADC value of IDC was 0.968x10(-3) mm2/s and that of pure or predominant NIDC was 1.218x10(-3) mm2/s (p=0.0011). CONCLUSION: SENSE-DWI was of sufficient quality to support diagnosis of breast mass. SENSE-DWI may permit the acquisition of more detailed information about lesions, including tumor cellularity, that is difficult to obtain with conventional techniques.