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Purpose: The aim of this study was to determine if any correlation exists between tumor cell density and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET)/CT) for pure or predominant ductal carcinoma in situ (DCIS)., Materials and Methods: Subjects in this retrospective review comprised 11 patients who underwent FDG-PET/CT for DCIS. Pathological tumor cell density and FDG-PET/CT images were compared. A tumor background count density ratio of >1.5 was defined as the detectable range for DCIS., Results: Pathological density of disease was high in eight patients, intermediate in one, and low in two. In all eight patients with a detectable intraductal component on PET/CT, the density of disease was classified as high. In three patients undetected by PET/CT, the density of disease was classified as intermediate or low. On statistical analysis, the correlation between the density of disease and tumor background count density ratio (TBCDR) on PET/CT was significant (<0.05), whereas the nuclear grade and Van Nuys grade were not significant. In the eight patients detected by PET/CT, the discrepancy between histopathological mapping and FDG-PET/CT mapping was >20 mm in four patients and represented underestimation in four patients who showed low density of disease in the peripheral area., Conclusions: Tumor cell density of intraductal carcinoma appears strongly correlated to detection by FDG-PET/CT.

Purpose: The aim of this study was to determine any difference in hepatic enhancement values on dynamic multidetector row computed tomography (MDCT) among three groups: noncirrhotic patients and cirrhotic patients with and without a large portosystemic shunt., Materials and Methods: A group of 20 noncirrhotic patients (group A), 43 cirrhotic patients without a large shunt (group B), and 20 cirrhotic patients with a large shunt (group C) underwent dynamic MDCT of the liver using a standard concentration (300 mg I/ml) and volume (100 ml) of contrast material. The attenuation values of the liver were measured during arterial, portal, and late phases., Results: The hepatic enhancement value during the portal phase was significantly higher in group A (56.2 +/- 13.7 HU) than in the other two groups (group B 39.8 +/- 11.9 HU, group C 41.3 +/- 8.3 HU) (P < 0.01). No significant difference was present between group B and group C. The regression line of the scattergram, which shows the relation between the hepatic enhancement value during the portal phase and the iodine dose per the patients' body weight was more gently sloping in group C than in the other two groups., Conclusion: In cirrhotic patients without a large shunt, injection of a larger amount of total iodine is necessary to optimize hypovascular tumor visualization. However, in cirrhotic patients with a large shunt, further investigation is needed concerning the effectiveness of administering a larger amount of total iodine.

Purpose: To evaluate the effect of aortic and hepatic enhancement in patients with chronic liver disease who underwent dynamic MDCT using a higher concentration of contrast material within the same total iodine dose (80 mL of 370 mgI/mL), compared with a standard iodine concentration (100 mL of 300 mgI/mL)., Materials and Methods: Dynamic MDCT of the liver was performed in 35 patients using different prefilled syringes (300 mgI/mL = group A, 370 mgI/mL = group B) during follow-up periods. The bolus-tracking program was used to automatically start the arterial phase scan. The attenuation values for the abdominal aorta, the hepatic parenchyma, and portal veins were measured., Results: Attenuation values of the aorta and hepatic artery in group B were significantly higher than those in group A (p<0.001). Attenuation values of the splenic vein (SV) in group A were higher than those in group B (p=0.045). The relative hepatic enhancement (RHE) values during the portal phase in group B were significantly higher than those in group A (p=0.014)., Conclusion: Administration of a higher iodine concentration in the contrast materials is advantageous for the detection of both hyper- and hypo-vascular hepatocellular carcinomas (HCCs).

Purpose: To assess a new interpretation model combining kinetic pattern and morphologic characteristics using high-spatial-resolution MR imaging., Materials and Methods: Breast MR imaging was performed in 58 patients with 63 pathologically proved focal breast masses (49 malignant and 14 benign). MR imaging was performed on a 1.5-Tesla system using the volumetric interpolated breath-hold examination (VIBE) sequence. Morphological parameters were lesion shape, mass margin, rim enhancement (RE), enhancing internal septations, and internal signal on T2-weighted images. Lesion shape/margin was classified into four categories as follows: smooth (smooth/round or smooth/oval), lobulated (lobular shape), irregular (irregular margin or irregular shape), and spiculated (spiculated margin). RE was sub-classified as early RE at 60 sec and delayed RE at 4 min. Strongly high signal and the presence of internal black septations were evaluated over the entire lesion on T2-weighted images. The kinetic parameter was visually assessed as follows: washout, plateau, and progressive., Results: The most frequent types of lesion shape/margin in the malignant lesions were irregular (47%) and spiculated (43%), whereas 13 of the benign lesions had smooth or lobular margins (93%). The most frequent characteristics in breast cancers with lobulated configuration were washout pattern (80%), whereas 78% of the lobulated benign lesions were negative for visual washout. The positive predictive value (PPV) was 98% (49/50)., Conclusion: "Washout with enhancing septations" is thought be specific for carcinoma with a lobulated configuration (80%). A combination of morphological criteria (including lesion shape/margins, strongly high signal on T2-weighted images) and visual washout is useful for differentiating between benign and malignant lesions.

Purpose: To evaluate the efficacy of dynamic multidetector-row CT (MDCT) in assessing residual cancer extent after neoadjuvant chemotherapy (NAC), and to compare MDCT results with those derived from dynamic three-dimensional MRI using the volumetric interpolated breath-hold examination (VIBE) sequence., Materials and Methods: MDCT before and after NAC was performed in 19 consecutive patients with breast cancer. MRI was also performed before surgery. The early phase of MDCT and MRI was started 60 sec after commencing contrast injection. The late phase was started at a 4-min delay from the injection. The injection rate was 3 mL/sec. The distribution pattern of contrast enhancement (CE) by CT before NAC was classified into two groups: replaced lesion (diffuse CE in whole quadrants) and non-replaced lesion (localized CE)., Results: Pathological complete response (pCR) was obtained in one case. In replaced lesions, accuracy for the detection of tumor extent with a deviation of less than 2 cm in length was 0% (0/7) with early-phase CT/MRI and 100% (7/7) with late-phase CT/MRI. In non-replaced lesions, accuracy was 55% (6/11) with early-phase CT/MRI and 82% (9/11) with late-phase CT/MRI. One case of ductal carcinoma in situ (DCIS) could be detected only with late phase MRI., Conclusion: Late-phase images obtained by MDCT and MRI may be accurate in the diagnosis of residual cancer extent after NAC. The tumor distribution determined by MDCT before NAC is thought to be useful in the evaluation of shrinkage pattern following NAC.

Purpose: To evaluate the clinical usefulness of multislice helical CT (MSCT) for assessing breast cancer extent., Materials and Methods: MSCT was performed in 70 patients with Tis/T1 breast cancer [12 ductal carcinoma in situ (DCIS) and 58 invasive carcinoma]. The distribution pattern of contrast enhancement (CE) was classified into five categories: solitary lesion (localized area of CE), grouped lesion (satellite: localized CE with linear and/or spotty enhancement; crowded: clustered spotty enhancement), separated lesion (multifocal foci of CE), mixed lesion (grouped lesion with multifocal foci), and diffuse lesion (diffuse CE)., Results: Solitary lesion was seen in five cases of DCIS, 27 invasive carcinomas without intraductal spread (IDS), six invasive carcinomas with IDS, and one multicentric cancer. Grouped lesion was seen in six DCIS and 15 invasive carcinomas with IDS. Separated lesion was seen in one case of invasive carcinoma and fibroadenoma, and three multifocal/multicentric cancers. Mixed lesion was seen in two multicentric cancers. Diffuse lesion was seen in one case of DCIS and three invasive carcinomas. The coincident rate between MSCT pattern and histologic distribution was 85.7% (60/70). In solitary and grouped lesions, accuracy for the detection of tumor extent with a deviation of less than 2 cm in length was 91.7% (55/60)., Conclusion: MSCT is extremely accurate in the diagnosis of IDS and the multicentricity of breast cancer.

Purpose: To evaluate the clinical usefulness of dynamic multislice helical CT in differentiating ameloblastoma from other cystic lesions in cases of maxillomandibular cystic lesions., Materials and Methods: The study included 32 patients with maxillomandibular cystic lesions (ameloblastoma [n=6], myxofibroma [n=1], odontogenic keratocyst [n=3], dentigerous cyst [n=11], radicular cyst [n=11], and paradental cyst [n=2]). Dynamic study was performed before and 30 sec, and 90 sec after intravenous contrast medium administration. CT density values and percentage of density increase were calculated at 30 and 90 sec., Results: In five cases of ameloblastoma, a rapidly enhancing area was detected within the cystic lesions at 30 sec, while no apparent rapid enhancement was seen in the other cystic lesions. Three cysts showed gradual enhancement in the marginal area at 90 sec. Comparing ameloblastoma and other kinds of cysts, we found significant differences in the percentage of density increase at 30 sec (p<0.01) and 90 sec (p<0.05)., Conclusion: Dynamic multislice helical CT is useful in the diagnosis of cystic lesions of the maxillomandibular region, especially in the detection of neovascularities in ameloblastoma.