Nami Kodaira

Torsion of the Wandering Spleen: CT and Angiographic Appearance.

Objective To seek CT and angiographic appearances that characterize torsion of the wandering spleen. Materials and Methods The CT and angiographic findings of two cases of preoperatively diagnosed torsion of the wandering spleen were reviewed, and the findings were closely compared with intraoperative and histopathological findings. Results Characteristic CT appearance seemed to be a whirled appearance formed at the medial side of the displaced spleen. The angiographic finding that was characteristic of the disease was a tapered and abruptly twisted distal splenic artery. Conclusion These findings were useful in making the early and correct diagnosis of this rare but fulminant condition.

Assessment of a potential tumor-seeking manganese metalloporphyrin contrast agent in a mouse model.

The performance of a newly developed potential tumor‐seeking magnetic resonance (MR) contrast agent α‐Aqua‐13,17‐bis(1‐carboxypropionyl) carbamoylethyl‐3,8‐bis(1‐phenethyloxyethyl)‐β‐hydroxy‐2,7,12,18‐tetramethyl‐porphyrinato manganese (III) (HOP‐8P) was tested using a mouse model. Tumor‐bearing (SCC‐VII) mice were imaged using a 1.5T MR imager before and after intravenous administration of 0.1 mmol/kg of HOP‐8P. A biodistribution analysis was performed using an optical emission spectrometer. Significant enhancement of the transplanted tumor was observed in MR images 24 h after intravenous injection of HOP‐8P. The biodistribution assessment of manganese also correlated with the results of the imaging study. During the 24‐h period following contrast administration, HOP‐8P was consistently cleared from the circulation, liver, kidneys, and muscle; however, it was progressively accumulated within the tumor. HOP‐8P is a promising tumor‐seeking metalloporphyrin MR contrast agent with a wide imaging window. Magn Reson Med 47:549–553, 2002.

Tumour enhancement with newly developed Mn-metalloporphyrin (HOP-9P) in magnetic resonance imaging of mice.

The purpose of the study is to evaluate the tumour enhancing characteristics and biodistribution of a newly developed metalloporphyrin derivative, HOP-9P (13, 17-bis (1-carboxypropionyl) carbamoylethyl-3, 8-bis (1-phenylpropyloxyethyl)-2,7,12,18-tetra- methyl-porphynato manganese (III)). Seven mice bearing SCC VII tumours were imaged using T1-weighted conventional spin echo magnetic resonance images before and 5 min, 2 h and 24 h after intravenous injection of 0.1 mmol/kg of HOP-9P. For the acquired images, signal intensities of the tumour, muscle and oil-phantom were measured. Then, tumor/oil and tumor/muscle signal intensity ratios were calculated. Nineteen mice were sacrificed before or after the administration of HOP-9P (at 5 min, 2 h and 24 h), and the biodistribution of manganese in the tumour, muscle, liver, blood and kidneys was measured using optical emission spectrometers and was expressed as micrograms of manganese per gram of tissue. The tumour/muscle signal intensity ratio at 24 h (3.18 ± 0.34) was significantly higher than precontrast ratio (1.77 ± 0.20) (P < 0.05). The biodistribution assessment of manganese demonstrated that HOP-9P gradually and consistently accumulated in the tumour to reach the highest concentration at 24 h (3.49 ± 1.22 μ gMn/g). It is concluded that HOP-9P is a potential tumour-specific MR contrast agent.

Anterior extension of acute pancreatitis: CT findings.

Objective The purpose of this study is threefold: (a) to specify the pathway of the extension of pancreatitis to the anterior abdominal wall, which is clinically famous as the Cullen sign; (b) to assess if this pattern of involvement affects a patients prognosis; and (c) to seek its association with the inflammatory processes that take place in the vicinity of the pancreatic head. Materials and Methods The CT findings of 277 patients with acute pancreatitis were retrospectively reviewed. Results Inflammatory changes involved the anterior abdominal wall in 5 of 277 cases (1.8%) with acute pancreatitis. Inflammatory processes seemed to have been delivered to the anterior abdominal wall from the pancreatic head and the hepatoduodenal ligament and along the falciform ligament. The probable triggers of acute pancreatitis in such cases were endoscopic retrograde cholangiopancreatography in two cases, alcohol intake in one case, and one case unknown. Three of five cases had proven or suspected choledocholithiasis or cholelithiasis. All five patients got well after proper treatments for acute pancreatitis. Conclusion The results of our review suggest that the anterior extension of acute pancreatitis does not directly mean extensive retroperitoneal involvement of the phlegmon or pseudocysts nor fatal prognosis either and that this style of extension might be associated with inflammatory processes that occur around the pancreatic head.

Tumor enhancement using Mn-metalloporphyrin in mice: Magnetic resonance imaging and histopathologic correlation

To determine the signal enhancement characteristics of tumors after administration of a metalloporphyrin derivative, HOP‐9P (13, 17‐bis (1‐carboxypropionyl) carbamoylethyl‐3, 8‐bis (1‐phenylpropyloxyethyl)‐2, 7, 12, 18‐tetramethyl‐porphyrinato manganese (III)) and to determine whether HOP‐9P is tumor‐necrosis specific.