Apparent diffusion coefficient on magnetic resonance imaging (MRI) in bladder cancer: relations with recurrence/progression risk.

AIMS: To evaluate the relationship between the apparent diffusion coefficient (ADC) value for bladder cancer and the recurrence/progression risk of post-transurethral resection (TUR). METHODS: Forty-one patients with initial and non-muscle-invasive bladder cancer underwent MRI from 2009 to 2012. Two radiologists measured ADC values. A pathologist calculated the recurrence/progression scores, and risk was classified based on the scores. Pearson's correlation was used to analyze the correlations of ADC value with each score and with each risk group, and the optimal cut-off value was established based on receiver operating characteristic (ROC) curve analysis. Furthermore, the relationship between actual recurrence / progression of cases and ADC values was examined by Unpaird U test. RESULTS: There were significant correlations between ADC value and the recurrence score as well as the progression score (P<0.01, P<0.01, respectively). There were also significant correlations between ADC value and the recurrence risk group as well as progression risk group (P=0.042, P<0.01, respectively). The ADC cut-off value on ROC analysis was 1.365 (sensitivity 100%; specificity 97.4%) for the low and intermediate recurrence risk groups, 1.024 (sensitivity 47.4%; specificity 100%) for the intermediate and high recurrence risk groups, 1.252 (sensitivity 83.3%; specificity 81.3%) for the low and intermediate progression risk groups, and 0.955 (sensitivity 87.5%; specificity 63.2%) between the intermediate and high progression risk groups. The difference between the ADC values of the recurrence and nonrecurrence group in Unpaired t test was significant (P<0.05). CONCLUSION: ADC on MRI in bladder cancer could potentially be useful, non-invasive measurement for estimating the risks of recurrence and progression.

Placental recess accompanied by a T2 dark band: a new finding for diagnosing placental invasion.

PURPOSE: Our aim was to assess the usefulness of a new magnetic resonance imaging (MRI) finding, the placental recess, for diagnosing placental invasion. METHODS: This retrospective study included 51 patients (mean age 34.1 years, range 26-43 years) with suspected placental invasion who underwent cesarean section. Preoperative MRI was performed using a 1.5-T unit and included axial, sagittal, and coronal T2-weighted imaging (T2WI) with half-Fourier fast spin-echo sequences. Overall, 9 patients showed placental invasion, and 42 did not. Placental recess was defined as a placental deformity with contraction of the placental surface and outer rim of the uterus accompanied by a T2 dark band. Two radiologists independently assessed the presence of the placental recess and conventional findings including uterine bulging, abnormal placental vascularity, placental heterogeneous intensity on T2-weighted imaging (T2WI), and the T2 dark band. Fisher's two-sided exact test was used to compare findings between patients with and without placental invasion. Interobserver reliability was assessed using the kappa statistic. RESULTS: MRI features had interobserver reliability of >0.40. Placental recess yielded the highest kappa value (0.898). Significant differences were identified between patients with and without placental invasion regarding abnormal placental vascularity, placental heterogeneous intensity, a T2 dark band, and the placental recess on T2WI (p = 0.0282, 0.0003, 0.0003, <0.0001, respectively). The placental recess had sensitivity, specificity, positive and negative predictive values, and accuracy of 56, 100, 100, 91, and 92%, respectively. CONCLUSION: The placental recess was useful for diagnosing placental invasion, with high interobserver variability and accuracy.

A phase II study of radiofrequency ablation therapy for thoracic malignancies with evaluation by FDG-PET.

PURPOSE: Computed tomography (CT)-guided radiofrequency ablation (RFA) is safe and effective for patients with unresectable primary, recurrent, or metastatic thoracic malignancies. Several studies have shown the benefit of employing 18-fluoro-deoxyglucose positron-emission tomography (FDG-PET) to follow thoracic malignancies treated with RFA. In this prospective study, we show the safety and therapeutic efficacy of RFA and the utility of FDG-PET as tool for early detection of local recurrence. METHODS: Twenty patients were enrolled in this study, and 24 lesions were ablated. Seven lesions were primary lung cancer, and 17 lesions were recurrent tumors or metastases from extrathoracic sites. Tumor size was in the range of 0.4-3.3 cm in diameter (mean: 1.5 cm). CT and FDG-PET scans were scheduled 7-14 days and 3-6 months after RFA treatment. RESULTS: There were 17 adverse events (70.8 %) in 24 ablations included 13 pneumothoraces, two cases of chest pain, and two episodes of fever. With a median follow-up of 35.9 months (range 1-62 months), the overall 2-year survival rate was 84.2 %. Local recurrence occurred at four sites (2-year local control rate was 74.3 %). The FDG-PET results 7-14 days after RFA did not predict recurrence, whereas positive findings 3-6 months after RFA significantly correlated with local recurrence (p = 0.0016). CONCLUSIONS: We confirmed the effectiveness of RFA for unresectable primary and secondary thoracic malignancies. FDG-PET analysis 3-6 months after ablation is a useful tool to assess local control.

Tc-99m MAA findings in dilated cardiomyopathy with partial anomalous venous connections.

Tc-99m MAA showed asymmetric uptake in the lung field in a 21-year-old man with dilated cardiomyopathy. CT revealed partial anomalous venous connections in the left upper lobe. Angiogram of the left pulmonary upper lobe showed all the contrast material drained into the left vertical vein. The possible cause of relative increase in the left upper lobe blood flow is that right pulmonary blood flow is slowed by the high pressure in the left atrium due to dilated cardiomyopathy, whereas the flow from the left upper lobe drains into the superior vena cava which has less pressure than left atrium.

Whole-body gallium-67 scintigraphic findings in IgG4-related disease.

PURPOSE: To clarify the features of gallium-67 (Ga-67) imaging typical of IgG4-related disease. METHODS: We retrospectively investigated 14 patients diagnosed with IgG4-related disease who underwent Ga-67 scintigraphy in our hospital between January 2005 and May 2010. Of these, 13 patients who underwent gallium scintigraphy before steroid therapy were enrolled in this study. The patient population comprised 11 men and 2 women with age ranging from 47 to 76 years (mean age, 61.9 years). RESULTS: Among the 13 patients, significant accumulation of Ga-67 was detected in the bilateral pulmonary hila in 10 patients (77%), pancreas in 10 (77%), salivary glands in 7 (54%), lacrimal glands in 7 (54%), periaortic lesions in 2 (15%), and lung parenchyma in 1 (8%) patient. High accumulation of Ga-67 in the salivary glands was observed in the parotid glands in 3 cases and in the submandibular glands in 6 cases, with the following pattern: normal parotid gland uptake and symmetrical submandibular gland uptake in 2 cases; symmetrical high accumulation in both parotid and submandibular glands in 1 case; symmetrical high accumulation in parotid glands and normal submandibular gland uptake in 1 case; symmetrical uptake by parotid glands and asymmetric uptake by submandibular glands in 1 case; normal parotid gland uptake and asymmetric submandibular gland uptake in 1 case; and asymmetric parotid gland uptake and symmetrical parotid gland uptake in 1 case. CONCLUSION: Characteristic patterns of gallium uptake would be helpful for diagnosis, detection of involved lesions, and differential diagnosis in patients with IgG4-related disease to avoid unnecessary surgery.

Causes of photopenic defects in the lower sternum on bone scintigraphy and correlation with multidetector CT.

PURPOSE: To determine the cause of this photopenia in the lower sternum on bone scintigraphy and its correlation with sternal foramen on multidetector computed tomography (MDCT). METHODS: Between January and December 2008, we studied 1053 patients who underwent bone scintigraphy and CT scanning that included the chest. Bone scintigraphy showed photopenic areas in the lower sternum in 58 of these 1053 patients. The study population consisted of 19 men and 37 women, aged from 15 to 87 years (mean: 60.4 years). RESULTS: Of the 58 patients with photopenic areas in the lower sternum, 25 (43%) showed a sternal foramen by MDCT, whereas 33 patients (57%) showed no sternal foramen. However, of the total study population of 1053 patients, MDCT showed sternal foramen in 33 patients (3.1%). In 7 of the 33 patients with sternal foramen by MDCT, bone scintigraphy showed no photopenic areas. On the basis of CT morphometry of the sternum, the possible causes of photopenia in the lower sternum in patients without sternal foramen are as follows: thin middle portion of sternum bone marrow, a focal defect or notch in the posterior sternal cortex, high accumulation of peripheral lesions, and bone metastasis. CONCLUSION: This study revealed that not all patients showing photopenic areas in the lower sternum have sternal foramen and not all patients with sternal foramen show photopenic areas by bone scintigraphy. It is important to exclude metastasis when photopenic areas are detected, and inform the clinician to avoid the serious complication of cardiac tamponade.

Imaging findings at the donor site after iliac crest bone harvesting.

OBJECTIVE: Postoperative imaging after iliac crest bone harvesting is commonly performed, but has not been extensively reported in the literature. The objective of this analysis was to investigate the donor site after iliac crest graft harvesting. MATERIALS AND METHODS: Between January and December 2008, 3,450 patients underwent CT, which included the pelvis. Eighty-four patients were found whose iliac crests were harvested. The patient population consisted of 47 male and 37 female subjects ranging from 10 to 80 years old (mean 52.6 years) at the time of iliac bone harvesting. With the inclusion of prior examinations, 188 CT examinations, 17 MR imaging studies, and 19 bone scintigrams were analyzed at various time points after surgery. RESULTS: Computed tomography images demonstrated fluid collections, hematoma, and air at the donor site up to 1 month after bone harvesting. The air then disappeared. Fluid collection decreased in size by 4 months. Scar-like changes at the harvest site and irregular thick cortical bone were observed after 4 months. Later, CT and MR imaging demonstrated small scar-like lesions and cortical irregularities. CONCLUSION: The appearance of harvest site abnormalities depends on the time elapsed after surgery.

Comparison of Alzheimer's disease with vascular dementia and non-dementia using specific voxel-based Z score maps.

OBJECTIVE: We investigated the ability to discriminate between Alzheimer's disease (AD) and vascular dementia (VaD), and between AD and non-dementia using the program "easy Z score imaging system" (eZIS) developed by Matsuda et al., for the diagnosis of very early AD. METHODS: Of 201 patients, we investigated 12 patients with AD, 10 with VaD, and 9 with non-dementia, who underwent brain perfusion single-photon emission computed tomography by technetium-99m ethyl cysteinate dimer (99mTc-ECD) between February 2005 and September 2006. The sensitivity and specificity of the indicators of specific volume of interest (VOI) analysis, namely, severity, extent, and ratio were evaluated for the distinction of AD from VaD and non-dementia. RESULTS: There was a significant difference in all the criteria for severity, extent, and ratio between AD and non-dementia cases and in the ratio between AD and VaD. Between AD and non-dementia, the sensitivity and specificity of severity were 100% and 45%, respectively, using the cutoff value of 1.19. When using the cutoff value of 14.2 for extent, the sensitivity and specificity were both 100%. Using the cutoff value of 2.22 for ratio, the sensitivity of 42% and specificity of 100% were demonstrated. When comparing AD with VaD, using the cutoff value of 2.22 for ratio, the sensitivity and specificity were 42% and 100%, respectively. Using the cutoff value of 1.5 for ratio, the sensitivity and specificity between AD and VaD were 92% and 80%, respectively, thereby showing the best results. CONCLUSIONS: The specific VOI analysis program of AD using specific voxel-based Z score maps is not influenced by interobserver differences among radiologists and is useful to discriminate AD from VaD and non-dementia. However, the setting of the cutoff value at each institution and comparison with original and eZIS images are suggested to distinguish better AD from VaD.