Biomedical subjects
Publications and source records attributed to Hitoshi Aibe.
A 36-year-old man fell from his bicycle and struck his lower abdomen on the end of the handlebar. Computed tomography (CT) showed a small bowel loop protruding into the subcutaneous fat layer of the abdominal wall. We present this case of handlebar hernia, a rare type of traumatic abdominal wall hernia, and the usefulness of CT in diagnosing such injuries.
OBJECTIVE: The objective of our study was to determine the usefulness of recognizing the continuity of the gonadal veins to the pelvic mass to differentiate ovarian versus uterine origin on MDCT in females with a large pelvic mass. MATERIALS AND METHODS: Two radiologists interpreted the MDCT images obtained on a monitor, using paging methods, in 86 female patients with a large pelvic mass (> 8 cm) and 40 patients without an abdominopelvic mass as control subjects. The following issues were recorded using a 5-point scale: visualization of gonadal veins and origin determination based on anatomic continuity. Receiver operating characteristic (ROC) curve analysis was performed, and the interobserver differences were checked with kappa statistics. The maximum diameters of the gonadal veins were also measured. With consensus interpretations, the sensitivity, specificity, and accuracy of ovarian origin determination were calculated. RESULTS: Gonadal veins were shown in more than 70% of the subjects in both the control group and the patients with a mass (hereafter referred to as the "mass group"). There was no significant difference in the diameter of the gonadal veins between the control and mass groups and between patients with an ovarian mass and those with a uterine mass. The values for the area under the ROC curve (A(z)) of the two observers for ovarian origin determination were 0.90 and 0.92. The kappa value was 0.48. The sensitivity, specificity, and accuracy were 83.3%, 87.5%, and 84.9%, respectively. CONCLUSION: Gonadal veins can be shown on MDCT with high consistency; MDCT provides useful information for determining the origin of relatively large pelvic tumors arising in females.
OBJECTIVE: To determine whether the incidence of pseudolesions of the liver caused by rib compression is correlated with liver function. MATERIALS AND METHODS: Multidetector row CT images of 150 consecutive cases were evaluated for the presence of pseudolesions caused by rib compression. Liver function was categorized into two groups mainly using the Child-Pugh classification: Group I-normal liver function and Grade A; Group II-Grades B and C. The number of focal deformities of the liver caused by rib compression was also counted. The incidence of pseudolesions based on number of patients or focal deformities of liver parenchyma by rib compression were compared between the two groups. RESULTS: There were 108 and 42 patients in Groups I and II, respectively. 169 and 41 focal deformities of the liver caused by rib compression were found in Groups I and II, respectively. Patient-based and deformity-based incidences of pseudolesions were 10.7% (16/150) and 7.6% (16/210), respectively. All pseudolesions were seen in patients of Group I. Both patient-based and deformity-based incidences of pseudolesions were significantly higher in Group I as compared with those in Group II. CONCLUSION: Pseudolesions of the liver caused by focal rib compression may be seen more frequently in patients with preserved liver function than in those with impaired function.
PURPOSE: To elucidate whether apparent diffusion coefficient (ADC) values calculated from echo-planar diffusion-weighted MR imaging (EPDWI) are useful in the differential diagnosis of ovarian cystic masses. MATERIALS AND METHODS: EPDWI was performed in 131 patients with ovarian cystic masses (54 mature cystic teratomas, 35 endometrial cysts, four other benign cysts, 14 benign neoplasms, and 24 malignant neoplasms). The areas of the highest signal intensity on EPDWI (b = 1000 seconds/mm(2)) and the lowest ADC values within the cystic component were evaluated. RESULTS: On qualitative and quantitative analyses, mature cystic teratomas tended to show higher signal intensity and had areas of lower ADC values than endometrial cysts and other benign and malignant neoplasms (P < .005). In vitro scanning of the cystic contents of mature cystic teratomas confirmed that high signal on DWI or low ADC value was attributable to the keratinoid substance within the tumors. The difference in ADC between malignant and benign lesions were significant when mature cystic teratomas and endometrial cysts were included, but was not significant when they were excluded. CONCLUSION: The ADC value may add useful information to the differential diagnosis of ovarian cystic masses in limited populations, such as those with mature cystic teratomas with a small amount of fat.
OBJECTIVE: The purpose of our study was to evaluate the feasibility and usefulness of using a port-catheter system equipped with a W-spiral catheter for hepatic chemotherapy; this novel catheter does not require fixation by pericatheter embolization and can be safely withdrawn when not needed. SUBJECTS AND METHODS: Sixty-one patients (40 men and 2l women; mean age, 59 years) with advanced liver cancers (primary hepatic or biliary cancer [n = 31] and metastatic liver cancer [n = 30]) underwent percutaneous port-catheter placement with the tip of W-spiral catheter inserted into the right gastroepiploic artery and the side-hole opened at the common hepatic artery after embolization of the right gastric artery, pancreaticoduodenal arteries, or aberrant hepatic arteries. Pericatheter embolization for preventing catheter dislodgement was not performed. The technical success of port-catheter placement, clinical patency of the port-catheter system, and technical success of port-catheter removal were evaluated. RESULTS: Percutaneous port-catheter placement using this method was successfully performed in 59 (97%) of 61 patients. Subsequently, chemotherapy was successfully performed through the port in 57 (93%) of 61 patients. Complications during and after the procedure were observed in two (3%) of 61 patients and 12 (20.7%) of 58 patients. Hepatic artery thrombosis occurred in two (3.4%) of 58 patients. The port-catheter removal and the catheter replacement were performed in eight and four patients, respectively, who wanted the procedure. It was completed successfully without any complications. CONCLUSION: This method of implantation of a port-catheter system appeared to offer clinical advantages of safe catheter removal, femoral artery access, and an acceptable complication rate.
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.
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.
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.
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.
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.
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.
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.
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.
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PURPOSE: The purpose of this study was to determine the frequency, patterns of disease, and risk factors for development of pulmonary complications after liver chemoembolization via the inferior phrenic artery (IPA). MATERIALS AND METHODS: Forty-four selective transcatheter hepatic chemoembolization (THCE) procedures via the IPA were performed in patients with primary liver cancers with use of a mixture of anticancer agents and iodized oil (Lipiodol) with or without transcatheter arterial embolization. The grades of pulmonary complications were assessed on triphasic helical computed tomographic (CT) images after THCE and were correlated with angiographic findings of the IPA, infused dosages of Adriamycin and Lipiodol, and hepatic venous tumor thrombus on triphasic CT images before THCE. RESULTS: THCE via the IPA frequently resulted in lung CT changes: Lipiodol accumulation in the lung field (52%), consolidation (68%), and pleural effusion (41%). Among 44 patients, two (5%) developed respiratory symptoms. An excellent correlation was shown between Lipiodol accumulation and the presence of angiographic abnormalities of the IPA (P <.005). A significant correlation was also shown between the grades of pulmonary complications and the numbers of angiographic abnormalities (P <.01). The grades of pulmonary complications increased according to the infused dosage of Adriamycin and Lipiodol (P <.05). CONCLUSIONS: Angiographic abnormalities such as arteriovenous shunts, dilated anastomotic branches, and dense pleural staining are important risk factors for pulmonary complications of THCE via the IPA. Embolization for shunts may be required to prevent such complications, especially in cases with shunts to pulmonary vessels or hepatic veins.
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.
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.
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.