Biomedical subjects
Publications and source records attributed to H Onitsuka.
We describe a case of retroaortic left renal vein with hematuria. In this case, pullback pressure from the retroaortic left renal vein to the inferior vena cava revealed left renal vein hypertension according to criteria of the "nutcracker phenomenon." We stress that left renal vein anomaly including retroaortic left renal vein can cause clinical symptoms such as hematuria.
A case of ileoileocolic intussusception caused by an ileal lipoma is presented, in which CT revealed the characteristic double layer of mesenteric fat and a lipoma as the leading mass.
The CT and clinical features of six patients with congenital renal arteriovenous malformation (RAVM) were reviewed to determine the characteristics of this condition. The most common symptom was hematuria. The CT images were characterized by masses of vascular density located in the renal sinus and surrounding the pelvicaliceal system with or without dilated renal veins. The exact size of the RAVM and the relation to the pelvicaliceal system were well demonstrated by delayed images or drip infusion technique, whereas the bolus injection technique was essential to document the vascular nature. The potential pitfalls in diagnosis that can occur if only an infusion study is performed are discussed.
A case of splenic angiosarcoma with siderotic nodules is reported. The tumor was hyperechoic on ultrasound and had high density on CT and very low intensity on MR. Gandy-Gamna nodules (siderotic nodules) were demonstrated histopathogically.
The MR appearance of eight bronchogenic cysts is reported. All the cysts appeared homogeneous and were of very high signal intensity, approximating that of CSF on spin-echo T2-weighted imaging, and of relatively high intensity, between that of muscle and subcutaneous fat on T1-weighted imaging. The cysts were round or ovoid and were well demarcated. These findings are consistent with the fluid-containing properties of cysts.
OBJECTIVE: The "CT angiogram sign" in dynamic pulmonary CT consists of enhanced branching pulmonary vessels in a homogeneous hypoattenuating consolidation of lung parenchyma and is reportedly useful for diagnosing lobar bronchioloalveolar cell carcinomas. MATERIALS AND METHODS: To identify cases exhibiting the CT angiogram sign, we retrospectively reviewed the reports of 5,500 dynamic incremental CT examinations of the chest. RESULTS: We identified the CT angiogram sign in five patients with obstructive pneumonitis due to lung tumors and four patients with pneumonias. CONCLUSION: The CT angiogram sign can be observed in pulmonary consolidation of varying etiologies.
A case of leiomyosarcoma of the kidney is reported here with its CT and MRI manifestations correlated to the pathologic findings. The leiomyosarcoma appeared as a well-defined multinodular mass of varying density and signal intensity on CT and MRI, respectively. The low signal-intensity regions on T2-weighted MRI exhibited delayed enhancement on CT and contained more fibrous tissues than did other sites that had more spindle-shaped muscle cells. Knowledge of the MR and CT characteristics may permit radiologists to refine the diagnosis of renal leiomyosarcoma considerably.
To correlate the signal intensity of uterine leiomyoma with its pathologic characteristics, with particular emphasis on the fibrous component, 33 magnetic resonance (MR) examinations that revealed 93 leiomyomas were prospectively studied. All patients were imaged in axial and sagittal planes with different spin-echo pulse sequences to obtain T1-, T2-weighted, and proton density images. Nondegenerative leiomyomas (n = 62) showing a homogeneous signal of low intensity, and degenerative leiomyomas (n = 31) with a heterogeneous signal of variable intensity on T2-weighted images could be correlated. Histopathological assessment of fiber constitution and degeneration, and MR intensity were interpreted by independent observers. There was excellent accord between the averages for MR intensity, T2 relaxation time and fiber content, although the intensity values in each fiber grade showed a wide range. The greater the fiber content the lower the MR intensity on T2-weighted images, and the shorter the T2 relaxation time (p < 0.0001). In addition, the manner in which fiber distribution affected MR appearance was also elucidated. These data contribute guidelines for precise tissue differentiation of myogenic tumors on MR images, and for MR imaging tissue diagnosis of any lesion with a considerable fibrous element.
Calcifications of renal masses are common. They are usually dense, partial, small, punctate, and linear opacities. Diffuse calcification is an extremely rare feature of renal masses. Generally, calcified renal cell carcinomas are hypovascular, with calcifications in the interstitium, and they also contain fibrotic capsules, necrotic areas, or hyalinization. We recently observed a renal neoplasm with diffuse calcification on CT and intermediate vascularity on angiography, which was diagnosed histologically as renal cell carcinoma, clear cell type. Interestingly, there were numerous calcific deposits within the tumor cells.
Volumetric comparisons of portions of liver and spleen were performed in patients with chronic liver diseases to determine their diagnostic value. Volumetric ratios of liver and spleen were determined by CT examination in 34 normal subjects and 125 consecutive patients with histologically proved liver cirrhosis, chronic active hepatitis, chronic persistent hepatitis, acute hepatitis, or fatty liver. Ratios of caudate lobe, spleen, and lateral segment of the left lobe of the liver to the remainder of the liver, right lobe and medial segment of the left lobe (RL+LM), were calculated. The product of caudate lobe/RL+LM and spleen/RL+LM was of value in differentiating liver cirrhosis from other liver disease, with a sensitivity of 60%, specificity of 98%, and accuracy of 86%. The same ratios differentiated liver cirrhosis and chronic active hepatitis from other liver diseases with a sensitivity of 79%, specificity of 100%, and accuracy of 90%. Volumetric ratio measurements are useful in the diagnosis of cirrhosis and chronic active hepatitis.
One hundred thirty-four patients with histo-pathologically proven bronchogenic carcinoma underwent computed tomography (CT) of the thorax and adrenal glands. Prospectively, 23 of the 134 patients had adrenal metastasis, based on CT criteria for enlargement of the gland. Retrospectively, however, some proved to be false positives. In addition, the diagnosis of adrenal metastasis frequently altered the initial staging and the treatment modality. We suggest that valid diagnoses of adrenal metastases on CT scan be made on the basis of altered shape as well as on altered size of the gland.
Computed tomography's (CT) ability to detect accessory spleens was assessed using histopathologically proven cases. CT proved to be a sensitive procedure for detecting accessory spleens that were 10 mm or larger in diameter and located in the left upper quadrant.
In order to grade pathologic factors that influence CT findings in hepatocellular carcinomas (HCCs), the CT-pathologic correlation was assessed statistically using univariate and multivariate analyses of 75 lesions. CT findings of early and delayed phase scans using two-phase dynamic incremental CT (TDICT) were compared with pathologic findings in resected specimens to calculate a category score for each pathologic finding. According to category scores, histopathologic differentiation and growth pattern were the major determinants of tumor density. Determinants of the internal structure of tumors were cytological variants, histologic differentiation, and macroscopic classification, in that order. Macroscopic classification, histologic differentiation, fibrous capsule characteristics, and growth pattern were important in descending order for tumor margins. Histologic differentiation was the most important factor for determining TDICT findings in HCCs. The CT findings were modified by parenchymal liver disease and cytologic variants.
To elucidate the characteristic CT findings of intrahepatic peripheral cholangiocarcinoma, two-phased dynamic incremental CT scans of 20 cholangiocarcinomas in 16 patients were carefully analyzed. Dynamic incremental CT scanning was performed after intravenous administration of 100 ml iodinated contrast medium at a rate of 2 ml/s using a power injector. The CT scans (8-16 sections) were obtained during 45-110 s (early phase) and 6-7 min (delayed phase) after commencement of the injection of the contrast medium. On CT, 55% (11 of 20) of intrahepatic peripheral cholangiocarcinomas appeared hypodense in both phases. Most of the tumors (80%) appeared hypodense in the early phase and had increased CT numbers in their delayed images. Lymphadenopathy was observed in 69% (11 of 16) of patients whose main tumors exceeded 3 cm in diameter. All tumors appeared irregular or indistinct. Twenty percent (4 of 20) of the cholangiocarcinomas were difficult to distinguish from hepatocellular carcinomas or hemangiomas.