Evaluation of the elimination and safety of gadodiamide injection in patients with hemodialysis

We performed this study to evaluate the safety and elimination of gadodiamide injection in patients with hemodialysis (HD). The subjects were 10 patients on maintenance HD therapy, after receiving gadodiamide injection for magnetic resonance imaging (MRI) examination. The patients' mean age was 59.4 +/- 3.5 years, and their mean hemodialysis period was 70.6 +/- 20.4 months. Diseases for MRI examination were liver tumor (n=2), gallbladder tumor (n=1), renal tumor (n=3), pancreas tumor (n=1), abdominal aortic aneurysm (n=1), and arteriosclerosis obliterans (n=2). HD was performed routinely three times a week for 4 hours. Cellulose triacetate (CTA) membranes were used for 5 patients, polysulphone (PS) for 3 patients and polyester-polymer alloy (PEPA) for 2 patients. Serum levels of gadodiamide were analyzed before and after the first and second HD, and before the third and fourth HD. At the first HD, the concentration of gadodiamide in dialysate was analyzed every hour. Gadodiamide was eventually eliminated over time; 74.1% of the gadodiamide was dialyzed after the first HD and 98.8% after the third HD. There were no significant changes in the removal rate and laboratory parameters between each membrane. The present study suggests that gadodiamide could be removed by HD therapy efficiently thereby indicating that gadodiamide injection is possible in patients with HD.     

Three-dimensional dynamic MR imaging with a volumetric interpolated breath-hold examination for solitary pulmonary lesions: correlation of contrast enhancement pattern with pathological features

PURPOSE: To evaluate the clinical feasibility of dynamic MR imaging of solitary pulmonary lesions (SPLs) using a fat-suppressed three-dimensional gradient-echo technique with a volumetric interpolated breath-hold examination (VIBE). Correlation between the enhancement pattern and the histological characteristics of the nodules was also assessed. MATERIALS AND METHODS: Dynamic 3D-VIBE was performed in 16 patients with pathologically proven SPLs. Each lesion was analyzed for its internal enhancement pattern, dynamic enhancement pattern, and peripheral enhancement (PE). RESULTS: A heterogeneous pattern of internal enhancement was well correlated with histological observation of necrosis, cystic changes, and variously sized air spaces. The washout pattern was seen in the medullary parts of the nodules with little fibrous stroma. The progressive pattern was seen at foci of collapse in the alveolar structure, central scars, and prominent fibrosis. PE was also seen in 6 malignant lesions (43%), and was well correlated with the medullary growth of adenocarcinoma and marginal fibrosis with lymphocytic infiltration of squamous cell carcinoma. The presence of PE was statistically significantly related with tumor size (p < 0.05). CONCLUSION: Dynamic 3D-VIBE allows assessment of the histological characteristics of SPLs. It is also thought that this technique may be a promising method for differentiation between benign and malignant lesions.     

A Case of Aorto-Bronchial Fistula After Insertion of Left Main Bronchial Self-Expanding Metallic Stent in a Patient with Recurrent Esophageal Cancer

We report a case of aorto-bronchial fistula (ABF) caused by a self-expanding metallic stent (EMS) 51 days after insertion into the left main bronchus. The patient presented with left main bronchial stenosis caused by post-operative local recurrence of esophageal cancer. Post-operative radio therapy totaling 40 Gy and post-recurrence radiotherapy totaling 34 Gy were administered, with daily fractions of 2 Gy. Stenosis of the left main bronchus improved slightly, and was followed with insertion of EMS to prevent re-stenosis. The patient experienced massive hemoptysis for 3 days before sudden death. Autopsy revealed the EMS edge perforating the descending aortic lumen. Tumor infiltration and bacterial infection were observed on the wall of the left bronchus, and atherosclerosis was present on the aortic wall around the fistula. It should be noted that the left main bronchus was at considerable risk of ABF after insertion of EMS for malignant stenosis, and prophylactic stent insertion into the bronchus without imperative need must be avoided.     

Acute Korsakoff syndrome following mammillothalamic tract infarction

There are limited case reports of structural lesions causing Korsakoff syndrome. This report describes acute Korsakoff syndrome following localized, bilateral infarction of the mammillothalamic tracts (MTTs). Axial T2-weighted imaging revealed the lesions at the lateral wall level of the third ventricle and diffusion-weighted imaging confirmed that the left lesion was new and the right old. Korsakoff syndrome persisted 6 months after the onset. This case suggests that bilateral MTT dysfunction can lead to Korsakoff syndrome.     

Contrast-enhanced high-resolution MRI of invasive breast cancer: correlation with histopathologic subtypes

OBJECTIVE: We sought to determine whether contrast-enhanced MRI could aid in the identification of the histopathologic subtypes of invasive ductal carcinoma. MATERIALS AND METHODS: We evaluated the contrast-enhanced MR images obtained in 62 women with invasive ductal carcinoma of no special type. The presence or absence of three distinct MRI findings-linear enhancement, a serrated border, and delayed rim enhancement-was evaluated. Classification and regression tree analyses were performed to construct the most efficient algorithm for predicting histopathologic subtype on the basis of dynamic MRI features. RESULTS: Histopathologic subtypes of the invasive ductal carcinomas were scirrhous carcinoma in 22 patients, solid tubular carcinoma in 14, and papillotubular carcinoma in 26. A lesion with a serrated border was observed in 28 (45.2%) of the 62 patients. Delayed rim enhancement was seen in 23 (37.1%) and linear enhancement in 20 (32.3%). Scirrhous carcinomas were closely associated with a serrated border (20/22 or 90.9%, p < 0.0001). Delayed rim enhancement was frequently observed in solid tubular carcinomas (12/14 or 85.7%, p < 0.0001) but was not typically seen in scirrhous carcinomas (1/22 or 4.5%, p < 0.0001). Linear enhancement showed relatively high prevalence in papillotubular carcinomas (13/26 or 50%) and low prevalence in solid tubular carcinomas (1/22 or 7%, p < 0.02). Histopathologic subtypes of invasive breast carcinoma of no special type could be correctly identified in 47 (75.8%) of 62 lesions using the diagnostic algorithm generated by the classification and regression tree analyses. CONCLUSION: MRI features showed a close relationship with histopathologic subtypes of invasive ductal carcinoma of no special type. Contrast-enhanced MRI can be a noninvasive diagnostic tool for histopathologic subtypes of invasive breast cancer.     

Pulmonary dirofilariasis: computed tomography findings and correlation with pathologic features

OBJECTIVE: The purpose of this study was to describe the computed tomography (CT) and pathologic features of 5 nodules of pulmonary dirofilariasis in 4 patients. METHODS: Four patients with 5 nodules of pathologically confirmed pulmonary dirofilariasis who under went CT were enrolled, and the imaging interpretations were retrospectively compared with the histopathologic characteristics. RESULTS: Three of the 4 patients had a solitary nodule, and the remaining patient had 2 nodules. All the nodules were distributed in the right lower lobe and were attached to the pleura. They were all round or oval in shape and ranged in size from 11 to 22 mm in largest diameter (mean=17 mm). On thinner section CT, the nodules had a well-defined smooth margin with or without a shallow notch; they were connected to the arterial branch and, occasionally, to the venous branch. On contrast-enhanced CT, all the nodules contained a homogeneous low-attenuation area, which corresponded to areas of coagulative necrosis on histopathologic examination. CONCLUSION: Although the CT findings of a pulmonary dirofilariasis nodule are nonspecific, awareness of the findings on contrast-enhanced CT and the pathologic appearance of this rare benign condition may facilitate its differentiation from a malignant nodule.     

Single photon emission computed tomography and statistical parametric mapping analysis in cirrhotic patients with and without minimal hepatic encephalopathy

OBJECTIVE: The early diagnosis and treatment of cognitive impairment in cirrhotic patients is needed to improve the patients' daily living. In this study, alterations of regional cerebral blood flow (rCBF) were evaluated in cirrhotic patients using statistical parametric mapping (SPM). The relationships between rCBF and neuropsychological test, severity of disease and biochemical data were also assessed. METHODS: 99mTc-ethyl cysteinate dimer single photon emission computed tomography was performed in 20 patients with non-alcoholic liver cirrhosis without overt hepatic encephalopathy (HE) and in 20 age-matched healthy subjects. Neuropsychological tests were performed in 16 patients; of these 7 had minimal HE. Regional CBF images were also analyzed in these groups using SPM. RESULTS: On SPM analysis, cirrhotic patients showed regions of significant hypoperfusion in the superior and middle frontal gyri, and inferior parietal lobules compared with the control group. These areas included parts of the premotor and parietal associated areas of the cortex. Among the cirrhotic patients, those with minimal HE had regions of significant hypoperfusion in the cingulate gyri bilaterally as compared with those without minimal HE. CONCLUSIONS: Abnormal function in the above regions may account for the relatively selective neuropsychological deficits in the cognitive status of patients with cirrhosis. These findings may be important in the identification and management of cirrhotic patients with minimal HE.     

Endovascular stent-graft treatment for thoracic aortic aneurysms: short- to midterm results

PURPOSE: To evaluate short- and midterm results of the endovascular repair of thoracic aortic aneurysm (TAA) with the use of custom-made stent-grafts. MATERIALS AND METHODS: Between May 1997 and May 2003, 40 patients with TAA (26 degenerative/atherosclerotic, seven dissection-related, three traumatic, two mycotic, one anastomotic, and one penetrating ulcer) underwent endovascular stent-graft placement. The mean age of the patients (29 male and 11 female) was 67.2 years. Twenty-four of the 40 patients (60%) were judged not to be good candidates for conventional open repair. Stent-graft placement was performed in the angiography suite with general anesthesia and transient cardiac arrest or induced hypotension. Custom-made stent-grafts were used in all patients. Four of the 40 patients (10%) underwent preliminary extra-anatomic bypass surgery to provide a sufficiently long landing zone. The mean follow-up period was 16.7 months (range, 1-65 months). RESULTS: The technical success rate was 97.5% and the early mortality rate was 2.5% (one out of 40 patients). There were four late deaths (two procedure-related). Survival rates were 84.2%+/-6.6% at 1 year and 84.2%+/-6.6% at 2 years. Survival rates were not significantly different between surgical candidates and non-surgical candidates (P =.423). Intraprocedural complications included access artery complications in nine patients and bleeding in three patients. Postoperative complications included early aneurysmal expansion in one patient, pneumonia in one patient, wound infection in one patient, stroke in three patients, paraplegia in one patient, respiratory insufficiency in two patients, aortoesophageal fistula in one patient, and late aneurysmal expansion in three patients. The rates of freedom from first additional intervention were 91.0%+/-6.7% at 1 year and 74.5%+/-11.9% at 2 years. The rates of freedom from second additional intervention was 100% at 2 years. The rates of freedom from treatment failure were 84.7%+/-7.6% at 1 year and 69.3%+/-11.6% at 2 years. CONCLUSION: Endovascular repair of TAA with a custom-made stent-graft is a safe and effective alternative to open repair and continues to play an important role. However, careful follow-up is mandatory to manage complications.