PubMed Health⌕ Search

Biomedical subjects

Kengo Yoshimitsu

Publications and source records attributed to Kengo Yoshimitsu.

At least 37 records · Page 2Linked to original sources
PubMed2005

Detection of combined hepatocellular and cholangiocarcinomas on enhanced CT: comparison with histologic findings.

OBJECTIVE: The purpose of this study was to evaluate the performance of enhanced CT in making a diagnosis of combined hepatocellular and cholangiocarcinomas (HCC-CCs) by comparing CT findings with histologic findings. CONCLUSION: One third (nine of 27 cases) of the combined HCC-CCs were correctly diagnosed on enhanced CT by detailed analysis of the enhancing pattern around or within the mass. Various factors such as an atypical enhancing pattern, the size of each component, and the presence of a mass composed of intermediate tumor cells-that is, cells with intermediate characteristics between HCC and CC-were found to be the causes of misdiagnosis of combined HCC-CC on enhanced CT.

Adult↗
PubMed2005

Periappendiceal hyperechoic structure on sonography: a sign of severe appendicitis.

OBJECTIVE: We retrospectively investigated the clinical importance of the periappendiceal hyperechoic structure (PHS) using sonography in patients with appendicitis, which may reflect the omentum encapsulating the inflammation or spread of inflammation over the omental and adjacent mesenteric fat. METHODS: We defined the positive finding of a PHS as a noncompressible and enlarged (>6 mm in its maximal outer diameter) appendix surrounded by the hyperechoic structure that was not visualized in the right lower quadrant on sonography. We compared this finding with surgical records and pathologic diagnosis in 25 patients who underwent an appendectomy for appendicitis. RESULTS: Of 25 patients, there were 7 patients with positive PHS findings. The positive PHS rates were 100% (2 of 2), 29% (5 of 17), and 0% (0 of 6) for gangrenous, phlegmonous, and early appendicitis, respectively. There was a statistically significant difference by the Spearman rank test. The incidence rates of perforation (57% versus 6%), macroscopic purulent exudate or abscess (57% versus 6%), and prominent adhesion to the periappendiceal tissue (100% versus 22%) were higher in the patients with positive PHS findings. CONCLUSIONS: The PHS may indicate the possibility of serious inflammation, and accurate diagnosis and appropriate treatment should be decided.

Adolescent↗
PubMed2005

Percutaneous vertebroplasty in the treatment of pain caused by metastatic tumor.

Percutaneous vertebroplasty is a radiologically guided therapeutic procedure that consists of percutaneous injection of polymethylmetacrylate (PMMA) into pathologic vertebral bodies. It is a minimally invasive procedure that is effective in the treatment of pain resulting from bone metastasis. This procedure has the advantage of providing rapid pain relief and spinal stabilization. A patient with severe, aggressive pain from metastatic lumbar spinal tumor of thyroid follicular carcinoma is presented herein. Despite treatment with analgesic agents, external beam radiation therapy, radioiodine therapy, and posterior fusion surgery, the pain reemerged and progressed. After percutaneous vertebroplasty, definite pain relief was achieved. Vertebroplasty would be useful as an additional or alternative pain relief method in patients with metastatic vertebral tumors.

Adenocarcinoma, Follicular↗
PubMed2004

Well-differentiated adenocarcinoma of the gallbladder with intratumoral cystic components due to abundant mucin production: a mimicker of adenomyomatosis.

The prevalence and etiology of the cystic components within gallbladder carcinomas as seen on MR images were evaluated. A retrospective review of MR images was performed for 35 proven gallbladder carcinomas in search of radiologically detectable intratumoral cystic components. The pathologic specimens were meticulously reviewed to determine the etiology. MR images of 31 adenomyomatoses were also reviewed for comparison to clarify the difference in MR features between these two entities. Three cases out of 35 proven gallbladder carcinomas were found to have intratumoral cystic components. They were all well-differentiated adenocarcinomas, and the cystic components consisted of dilated neoplastic glands filled with abundant mucin pool. Adenomyomatosis tended to have more and rounded cystic components (Rokitansky-Aschoff sinuses) lined in a linear fashion and were flat-elevated in shape, smaller in size and had a regular surface, as compared to the three carcinomas. Although rare, radiologists need to be aware that well-differentiated gallbladder carcinoma with mucin production can have cystic components, which may mimic adenomyomatosis. Careful interpretation of MR images may provide useful information in the differentiation of these two entities.

Adenocarcinoma, Mucinous↗
PubMed2004

In vivo MR detection of vascular endothelial injury using a new class of MRI contrast agent.

A new class of dye-based MRI contrast agents, EB-DTPA-Gd, was designed and synthesized. The contrast agent was found to accumulate at the site of endothelial injury when the reagent was applied to isolated porcine blood vessels or in an ex vivo experiment using rat. In vivo MR detection of vascular endothelial injury was also successful in rat with its common carotid artery injured by balloon treatment. These results indicate that EB-DTPA-Gd is potentially useful for the diagnosis of vascular diseases.

Animals↗
PubMed2004

Transient uterine myometrial contraction associated with moles.

PURPOSE: To examine the incidence of transient distortion of uterine central tissue and myometrial hypointense areas observed on MR images in women with clinically suspicious moles. MATERIALS AND METHODS: The study population consisted of six women aged 15-47 years with clinically suspicious moles (hydatidiform mole in four, invasive mole in one, and microscopic mole in one). The control study population was 105 reproductive-age women (18-52 years) without uterine malignancy, gestational trophoblastic disease, or pregnancy. MR images were analyzed to check for discrepancies of the uterine central tissue configuration. If a discrepancy was observed, the myometrial hypointense area, its diameter, and changes in its shape and location were analyzed. RESULTS: Differences in uterine central tissue configuration and hypointense areas were observed in all six patients. In the control study, only seven cases showed uterine endometrial distortion, and five exhibited hypointense areas. These areas disappeared, changed in shape, or other hypointense areas appeared on subsequent MR images. Significant differences (P < 0.01) in the incidence of uterine central tissue distortion and hypointense areas, and in their maximum diameter between the study and the control groups were observed. CONCLUSION: Uterine myometrial hypointense areas with central tissue distortion, most likely due to transient myometrial contraction, are frequently seen in women with clinically suspicious moles.

Adolescent↗
PubMed2004

Usefulness of the calculated apparent diffusion coefficient value in the differential diagnosis of retroperitoneal masses.

PURPOSE: To elucidate whether or not the apparent diffusion coefficient (ADC) values calculated from echo-planar diffusion-weighted (EPDW) MR images are useful in the differential diagnosis of retroperitoneal masses. MATERIALS AND METHODS: In 50 patients with known retroperitoneal masses, EPDW images were performed with b-factors of 0-1100 seconds/mm2. The final histologic diagnoses of these lesions were as follows: 12 malignant lymphomas, four other malignant mesenchymal neoplasms, 25 malignant epithelial neoplasms, seven benign mesenchymal neoplasms, and two nonneoplastic lesions. The ADC values obtained for the solid portion of the lesions were used to represent each lesion, and the values of the histologic groups were compared. RESULTS: The respective value of ADC for 12 malignant lymphomas, four other mesenchymal neoplasms, seven benign mesenchymal neoplasms, and two nonneoplastic lesions were as follows: 0.66 +/- 0.26, 1.26 +/- 0.50, 0.90 +/- 0.20, 1.87 +/- 0.48, 1.32 +/- 0.20 x 10(-3) mm2/second. The ADC value of the malignant lymphoma was significantly lower than that of the other malignant mesenchymal lesions, and was also lower than the ADC of the benign lesions. The ADC value of the malignant epithelial neoplasms was lower than that of the benign mesenchymal tumors. The ADC values of the malignant and benign lesions were 0.94 +/- 0.30 and 1.75 +/- 0.49 x 10(-3) mm2/second, respectively, which also demonstrated a significant difference. CONCLUSION: ADC values calculated from EPDW MR images may provide useful information in the differential diagnosis of retroperitoneal masses.

Adolescent↗
PubMed2004

Pitfalls in the imaging diagnosis of hepatocellular nodules in the cirrhotic and noncirrhotic liver.

Contrast-enhanced CT and MR are the most commonly used modalities for objective evaluation of hepatocellular nodules. Various types of pseudolesions as seen on CT or MR have been reported, which are attributable to either focal alteration in hemodynamics or parenchymal metabolism, or to both. Pseudolesions specifically seen in cirrhotic liver include arterio-portal shunt, regenerating or hyperplastic nodules, and confluent fibrosis. In noncirrhotic liver, transient focal compression to the liver, third inflow other than normal hepatic arterial and portal venous flow, and vessel compromise are the causes of pseudolesions. To understand the characteristic features of these pseudolesions, and their underlying mechanism as well, is important for proper diagnosis of true hepatocellular lesions.

Carcinoma, Hepatocellular↗
PubMed2004

First functionalized MRI contrast agent recognizing vascular lesions.

A new MRI-contrast agent, EB-DTPA-Gd, that has an Evans Blue analogue as a sensing unit for endothelium lesions, was designed and synthesized. The agent also has diethylenetriamine-N,N,N',N",N"-pentaacetic acid-Gd complex (Gadolinium-DTPA) units, which have been used as detection units for T1-weighted MRI. The EB-DTPA-Gd was able to recognize and adsorb to the vascular endothelium-denuded region of porcine aorta, and to decrease the relaxation time of circumferential water's protons, making possible MR imaging of the endothelium-denuded region. The compound can be employed as a contrast agent for the imaging of vascular lesions using MRI.

Contrast Media↗
PubMed2003

Radiologic features of Castleman's disease occupying the renal sinus.

OBJECTIVE: Our purpose was to describe the radiologic findings in five abnormalities in three patients with Castleman's disease occupying the renal sinus. CONCLUSION: Common findings such as mild homogeneous enhancement passing through the mass of the collecting system with mild hydronephrosis on contrast-enhanced CT and hypointense signal on T2-weighted images were obtained. Castleman's disease may be considered in a differential diagnosis of a mass occupying the renal sinus, although it is difficult to differentiate from malignant lymphoma.

Aged↗
PubMed2003

[A case of Fitz-Hugh-Curtis Syndrome representing hepatic capsular enhancement].

We present CT findings of a 22-year-old woman diagnosed as Fitz-Hugh-Curtis syndrome. The patient was admitted to our hospital with right upper abdominal pain. Abdominal enhanced CT showed hepatic capsular enhancement over the medial segment and the right lobe on the early phase. This capsular enhancement completely disappeared after treatment. Abdominal enhanced CT may serve as a non-invasive modality for the diagnosis of Fitz-Hugh-Curtis syndrome.

Abdominal Pain↗
PubMed2003

[Fitz-Hugh-Curtis syndrome: analysis of CT findings].

Fitz-Hugh-Curtis syndrome (FHCS) is a condition with right upper quadrant pain in association with pelvic inflammatory disease. Invasive procedures such as laparoscopy or laparotomy were indispensable to definite diagnosis of FHCS, and no more useful methods in radiological diagnosis of FHCS has been reported until now. In this present study abdominal enhanced-CT findings were analysed retrospectively in eight cases diagnosed clinically as FHCS. We focused on hepatic capsular enhancement, which was identified on early phase in all cases and on delayed phase in five. Moreover, hepatic capsular enhancement was detected at the anterior surface of medial segment and the lateral aspect of right lobe in all cases, while at the anterior surface of lateral segment in five cases. These findings, which disappeared on follow-up CT after treatment, were thought to reflect "acute" peri-hepatitis. Abdominal enhanced CT, especially on early phase, is suggested to be a non-invasive, useful modality for the diagnosis of FHCS. When hepatic capsular enhancement is identified in the interpretation of abdominal enhanced CT images in sexually active women who have right upper abdominal pain, we should suspect the possibility of FHCS and examine gynecological findings or the value of IgA and IgG antibodies for Chlamydia trachomatis.

Abdominal Pain↗
PubMed2003

[A case of isolated hepatic malignant lymphoma representing characteristic findings on radiological imaging].

We present an 80-year-old-man who showed characteristic radiological findings of secondary hepatic malignant lymphoma. The patient was first admitted to our hospital 6 months before with left cervical mass, which was diagnosed as malignant lymphoma by biopsy. After complete response to chemotherapy, a large hepatic mass appeared, as the serum value of lactic dehydrogenase elevated. CT/MRI showed a well-demarcated hypovascular mass, which was penetrated by the right hepatic vein. The apparent diffusion coefficient of the mass was 0.70 x 10(-3) mm2/s. The patient was diagnosed as relapse of malignant lymphoma, mainly based on these radiological findings reflecting the mass with high cellularity which grows without destruction of existing vascular structure, and additional chemotherapy was given. The hepatic mass disappeared almost all and the serum value of lactic dehydrogenase decreased with in normal range. The patient was discharged in a good condition 2 months later.

Aged↗
PubMed2002

Sequential hemodynamic change in hepatocellular carcinoma and dysplastic nodules: CT angiography and pathologic correlation.

OBJECTIVE: The purpose of this study was to clarify the hemodynamic changes associated with hepatocarcinogenesis using CT angiography. MATERIALS AND METHODS: Eighty-six hepatocellular lesions were confirmed at pathology in 49 patients who underwent CT with both hepatic arteriography and arterioportography. These images were compared with lesion-to-liver vascular ratios of cumulative arteries, preexisting hepatic arteries, and portal veins in resected specimens. Lesions were classified in five groups according to intranodular hemodynamics determined by CT hepatic arteriography and CT during arterioportography: group 1, isoattenuating on both procedures; group 2, hypoattenuating on CT hepatic arteriography and isoattenuating on CT during arterioportography; group 3, hypoattenuating on both procedures; group 4, isoattenuating on CT hepatic arteriography and hypoattenuating on CT during arterioportography; and group 5, hyperattenuating on CT hepatic arteriography and hypoattenuating on CT during arterioportography. RESULTS: Among 86 lesions, we identified seven low-grade dysplastic nodules, eight high-grade dysplastic nodules, 14 well-differentiated hepatocellular carcinomas, 45 moderately differentiated hepatocellular carcinomas, and 12 poorly differentiated hepatocellular carcinomas. The lesions were classified as group 1 (n = 5), group 2 (n = 13), group 3 (n = 6), group 4 (n = 2), or group 5 (n = 60). Intranodular hemodynamics was significantly correlated with pathologic grading (p < 0.001). For correlations between combinations of the groups and pathologic gradings, the order "groups 1-2-3-4-5" was the most significant (p < 0.001). CONCLUSION: During hepatocarcinogenesis, most hepatocellular nodules show deterioration of arterial blood flow before loss of portal blood flow. Vascular imaging of hepatic nodules may predict malignant abnormality via the early loss of hepatic arterial flow seen before portal flow changes.

Aged↗
PubMed2002

Helical CT of the local spread of carcinoma of the gallbladder: evaluation according to the TNM system in patients who underwent surgical resection.

OBJECTIVE: Our aim was to evaluate the performance of helical CT as an aid in the preoperative diagnosis of the spread of carcinomas of the gallbladder. MATERIALS AND METHODS: Two radiologists retrospectively reviewed both hard-copy and soft-copy (on a monitor with multiplanar reconstruction capability) versions of helical CT scans (3-mm collimation and 3-mm reconstruction) of 21 patients who had undergone surgical resection for carcinomas of the gallbladder. The local spread of the disease was evaluated according to the TNM system, and the results were correlated to the pathologic findings. Inter- and intraobserver differences were checked with kappa statistics. Results of the consensus interpretations were used to calculate sensitivity, specificity, and accuracy of helical CT. RESULTS: No significant inter- or intraobserver differences were found in any T category evaluation. The sensitivities of the hard-copy consensus interpretations in the diagnosis of T1, T2, T3, and T4 lesions were 33%, 64%, 80%, and 100%, respectively; specificities of hard-copy interpretations were 94%, 80%, 81%, and 95%, respectively. For soft-copy (monitor) consensus interpretations, the sensitivities for the diagnosis of T1, T2, T3, and T4 lesions were 33%, 73%, 80%, and 100%, respectively; the specificities of soft-copy interpretations were 94%, 80%, 88%, and 95%, respectively. Overall accuracy of the hard-copy interpretation was 83%; the overall accuracy of the soft-copy interpretation was not significantly different-86%. CONCLUSION: Helical CT provided 83-86% accuracy in the diagnosis of the local extent of carcinomas of the gallbladder, showing acceptable sensitivity and specificity for the T2 and more advanced lesions but poor sensitivity for the T1 lesions. Use of a monitor with multiplanar reconstructions of the CT data did not significantly improve the diagnostic accuracy.

Adult↗
PubMedDate not supplied

A case of pulmonary synovial sarcoma diagnosed with detection of chimera gene: imaging findings.

Pulmonary synovial sarcoma is a rare disease, and reports detailing clinicians' radiological findings are few. We report a case of a primary pulmonary synovial sarcoma in a 68-year-old woman. Chest CT revealed a well-defined and homogeneous oval mass measuring 3x2.5 cm in the left lower lobe in contact with the visceral pleura. No pleural effusion was evident. No calcification or fat component was detected. The tumor showed homogeneous hypointensity on both T1- and T2-weighted MR imaging. In this case, a lung metastasis could be excluded with fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), and the final diagnosis was histopathologically confirmed by the chimeric gene detection.

Aged↗
PubMedDate not supplied

Presacral dermoid cyst with scanty fat component: usefulness of chemical shift and diffusion-weighted MR imaging.

We present a case of a dermoid cyst located at the presacral space. Although CT and conventional MR (T1- and T2-weighted images) demonstrated a non-specific cystic mass with little evidence of calcification or fat, chemical shift and diffusion-weighted MR imaging suggested the presence of small amount of fat and abundant keratinoid substance within the tumor, respectively. Pre-operative diagnosis of dermoid cyst was made. The tumor was surgically resected and the diagnosis was confirmed. Chemical shift and diffusion-weighted MR imaging are useful in the diagnosis of dermoid cyst with little evidence of calcification and fat.

Abdominal Neoplasms↗