Kidney R2* Mapping for Noninvasive Evaluation of Iron Overload in Paroxysmal Nocturnal Hemoglobinuria.

PURPOSE: The kidney iron deposition can cause kidney damage and renal insufficiency in paroxysmal nocturnal hemoglobinuria (PNH) patients. Assessment of iron deposition in the kidney is essential for the early diagnosis of renal damage in PNH patients. The purpose of this study was to evaluate kidney R2* (T2* reciprocals) values in PNH patients using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ). METHODS: Two radiologists measured the R2* values of the renal cortex in 14 PNH patients and 13 healthy volunteers using IDEAL-IQ. Lactate dehydrogenase (LDH), a reliable marker of intravascular hemolysis, was also measured in all participants. RESULTS: The kidney R2* values were significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). High inter-operator reproducibility of the measurements was also acquired using IDEAL-IQ. LDH levels were also significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). Kidney R2* values strongly correlated with LDH levels in PNH patients. CONCLUSION: IDEAL-IQ has a possibility of becoming a useful method for the noninvasive evaluation of renal iron overload in PNH patients.

Multiparametric magnetic resonance imaging of plasmacytoid urothelial carcinoma with histopathological correlation: A case report.

Plasmacytoid urothelial carcinomas of the bladder are rare, aggressive variants with a poor prognosis. Few reports have described the correlation of histopathological features with multiparametric magnetic resonance imaging findings in the local staging of plasmacytoid urothelial carcinoma. An 82-year-old woman with hematuria was referred to our hospital. Magnetic resonance imaging showed diffuse bladder wall thickening, with different signal intensities in the 2 layers-inner and outer. This case suggests that the presence of diffuse bladder wall thickening and varying signal intensities in the 2 layers could aid in the local staging of plasmacytoid urothelial carcinoma. A thickened bladder wall with restricted diffusion suggests tumor invasion, indicating that the tumor can invade the organ in contact with the thickened bladder wall.

Histological analysis of vasculopathy associated with pulmonary hypertension in combined pulmonary fibrosis and emphysema: comparison with idiopathic pulmonary fibrosis or emphysema alone.

AIMS: To evaluate pulmonary vasculopathy in an autopsy series of patients with combined pulmonary fibrosis and emphysema (CPFE), and compare these findings with those of patients with idiopathic pulmonary fibrosis (IPF) alone and emphysema alone. METHODS AND RESULTS: We retrospectively analysed the clinical, radiological and pathological features of 26 patients with CPFE, 11 with IPF, and 23 with emphysema. We evaluated pulmonary vascular, venous-venular and arteriolar tissue changes in the fibrotic, emphysematous and relatively unaffected (preserved) areas by using the Heath-Edwards scoring system. We found moderate-to-severe vasculopathy in the CPFE group, but no significant differences in the fibrotic and emphysematous areas among the three groups. However, in the preserved area, the grading was significantly different among the three groups (P < 0.001), and vasculopathy in the CPFE group was the most severe. Although venous-venular and arteriolar changes in almost all fibrotic and emphysematous areas in the three groups showed no significant differences, there were significant differences in venous-venular (P = 0.004) and arteriolar (P < 0.001) changes in the preserved area among the three groups, which were most prevalent in the CPFE group. In the CPFE group, venous-venular changes and vasculopathy by Heath-Edwards grading were highest in the fibrotic area and lowest in the preserved area. CONCLUSIONS: These results imply that pulmonary vasculopathy in patients with CPFE could occur in the whole lung tissue. This may explain the tendency for it to lead to the development of pulmonary hypertension in CPFE cases.

Chronic expanding hematoma in the retroperitoneal space: a case report.

A case of retroperitoneal chronic expanding hematoma complicated with hydronephrosis, which was difficult to diagnose preoperatively, is reported. The patient was a 70-year-old man. An 18 cm mass was detected in the right retroperitoneal space on abdominal CT screening. There were small calcifications in the periphery of the mass that were strongly enhanced in the delayed phase of dynamic CT. The mass involved the right ureter and iliopsoas muscle, resulting in severe hydronephrosis. The histological diagnosis was chronic expanding hematoma.

[Contrast-enhanced MR venography of the head using magnetization prepared rapid gradient echo imaging: comparison between head and body radiofrequency transmitter coil systems].

PURPOSE: To evaluate the image quality and vascular selectivity of MR venography of the head using an MP-RAGE technique when obtained with a body radiofrequency transmitter coil system. MATERIALS AND METHODS: A total of 24 patients were imaged with a head or body RF transmission system. Subtraction MRA was processed with 0.1 mmol Gd-DTPA administration, and signal-to-noise ratios of the vascular system were measured. Venous demonstration and selectivity were also assessed. RESULTS: MP-RAGE MR venography with a body transmission system showed almost the same signal intensity for the venous and arterial systems, resulting in nonspecific vascular demonstration, while the head transmission system showed semi-selective venograms owing to inflow-induced high signal on precontrast images. However, MRA with a body transmission system provided a 1.5- to 2.5-fold higher signal-to-noise ratios based on higher gradient performance and excellent demonstration of the head veins, especially those below the skull base. CONCLUSION: Although selective venography was difficult, MRA with a body transmission coil provided excellent vascular images of the brain.

[Feasibility of CT attenuation values in the diagnosis of anemia].

PURPOSE: To verify the possible correlation between CT attenuation value and hemoglobin (Hb). MATERIALS AND METHODS: CT attenuation was evaluated in 113 CT studies. Anemia was defined as an Hb level less than 14 g/dl in males and less than 12 g/dl in females. Hb was compared visually by grading (Grade 1: cardiac muscle density much higher than lumen, Grade 2: cardiac muscle density higher than lumen, Grade 3: cardiac muscle density equal to lumen), and with HU of CT attenuation on unpaired t-test (p<0.01). Correlations were calculated using the linear regression method. RESULTS: Hb of less than 6 g/dl was found to be Grade 1, while that over 12 g/dl was considered Grade 3 on visual grading. The attenuation numbers of subjects with anemia yielded low values, whereas those of normal subjects were higher. There were significant differences between subjects with anemia and normal subjects (p<0.01). HU versus hemoglobin showed a linear increase, with a correlation coefficient of 0.76. CONCLUSIONS: This simple, readily available information may provide a valuable adjunct in the interpretation of CT examinations.

Usefulness of early-phase helical CT for detecting recurrent rectal cancer.

PURPOSE: To evaluate the usefulness of dynamic enhancement of helical CT in the detection of local recurrence of resected rectal cancer. MATERIALS AND METHODS: In 142 patients with a history of curatively resected T2 or T3 rectal cancer, follow-up plain CT indicated that they had a loco-regional recurrent tumor; consequently, they underwent follow-up pelvic helical CT providing accurate early-phase contrast enhancement in the lower pelvic region. The patients were divided into four groups according to the grade of contrast enhancement of the suspected mass-like lesion before and after contrast enhancement, and the correlation between groups and results obtained by biopsy and/or surgery were assessed. If no correlation was found, patients were followed up for a period lasting from 400 days to two years. As of June 2002, results had been obtained for 80 patients, and correlation between these results and grouping by contrast enhancement ratio was analyzed. RESULTS: All patients in the highest-grade group (n=10) had local recurrence. When only the highest-grade group was considered positive, there were no false positives and only one false negative. CONCLUSION: Our results suggest that early-phase contrast enhancement is useful for accurately detecting recurrent rectal cancer. This can be easily achieved using the SmartPrep function, and should be used to distinguish recurrent tumors from postsurgical scar tissue, because these two tissue types do not exhibit similar enhancement patterns.

Detection of lung nodules on digital chest radiographs: potential usefulness of a new contralateral subtraction technique.

PURPOSE: To evaluate the potential usefulness of a contralateral subtraction technique developed for radiologists' performance in the detection of subtle lung nodules on chest radiographs. MATERIALS AND METHODS: Fifty chest radiographs (25 normal and 25 abnormal with a subtle lung nodule) that were digitized with a 0.175-mm pixel size and 4,096 gray levels were used. Twelve radiologists (10 attending and two residents) participated in observer tests and read both original and contralateral subtraction images with a sequential testing method. Radiologists' performance was evaluated by means of receiver operating characteristic analysis with use of a continuous rating scale. The beneficial and detrimental effects of the contralateral subtraction technique on the radiologists' performance were also evaluated. RESULTS: The area under the receiver operating characteristic curve values obtained without and with contralateral subtraction images were 0.926 and 0.962, respectively. Results indicated that the contralateral subtraction images significantly (P <.05) improved diagnostic accuracy, particularly for radiologists with limited experience. CONCLUSION: The contralateral subtraction technique can assist radiologists in the correct identification of subtle lung nodules on chest radiographs.