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.

Analysis of chromosome translocation frequency after a single CT scan in adults.

We recently reported an increase in dicentric chromosome (DIC) formation after a single computed tomography (CT) scan (5.78-60.27 mSv: mean 24.24 mSv) and we recommended analysis of 2000 metaphase cells stained with Giemsa and centromere-FISH for dicentric chromosome assay (DCA) in cases of low-dose radiation exposure. In the present study, we analyzed the frequency of chromosome translocations using stored Carnoy's-fixed lymphocyte specimens from the previous study; these specimens were from 12 patients who were subject to chromosome painting of Chromosomes 1, 2 and 4. Chromosomes 1, 2 and 4 were analyzed in ∼5000 cells, which is equivalent to the whole-genome analysis of almost 2000 cells. The frequency of chromosome translocation was higher than the number of DICs formed, both before and after CT scanning. The frequency of chromosome translocations tended to be higher, but not significantly higher, in patients with a treatment history compared with patients without such a history. However, in contrast to the results for DIC formation, the frequency of translocations detected before and after the CT scan did not differ significantly. Therefore, analysis of chromosome translocation may not be a suitable assay for detecting chromosome aberrations in cases of low-dose radiation exposure from a CT scan. A significant increase in the frequency of chromosome translocations was not likely to be detected due to the high baseline before the CT scan; the high and variable frequency of translocations was probably due to multiple confounding factors in adults.

Comparison of integrated whole-body PET/MR and PET/CT: Is PET/MR alternative to PET/CT in routine clinical oncology?

PURPOSE: To compare the diagnostic accuracy of whole-body PET/CT and integrated PET/MR in relation to the total scan time durations. METHODS: One hundred and twenty-three (123) patients (40 males and 83 females; mean age 59.6 years; range 20-83 years) with confirmed primary cancer and clinical suspicion of metastatic disease underwent whole-body 18F-FDG-PET/CT and 18F-FDG-PET/MR. Data acquisition was done after intravenous administration of 110-301 MBq radioactivity of 18F-FDG, and PET/MR data were acquired after the PET/CT data acquisition. The mean uptake times for PET/CT and PET/MR acquisition were 68.0 ± 8.0 and 98.0 ± 14 min, respectively. Total scan time was 20.0 and 25.0 min for whole-body PET/CT and PET/MR imaging. RESULTS: The reconstructed PET/CT and PET/MR data detected 333/355 (93.8 %) common lesions in 111/123 (90.2 %) patients. PET/CT and PET/MR alone detected 348/355 and 340/355 lesions, respectively. No significant (p = 0.08) difference was observed for the overall detection efficiency between the two techniques. On the other hand, a significant difference was observed between the two techniques for the detection of lung (p = 0.003) and cerebrospinal (p = 0.007) lesions. The 15 lesions identified by PET/CT only included 8 lung, 3 lymph nodes, 2 bone, and 1 each of peritoneal and adrenal gland lesions. On the other hand, 7 (6 brain metastatic lesions and 1 bone lesion) were identified by PET/MR only. CONCLUSION: Integrated PET/MR is a feasible whole-body imaging modality and may score better than PET/CT for the detection of brain metastases. To further prove diagnostic utility, this technique requires further clinical validation.

Increase in dicentric chromosome formation after a single CT scan in adults.

Excess risk of leukemia and brain tumors after CT scans in children has been reported. We performed dicentric chromosome assay (DCAs) before and after CT scan to assess effects of low-dose ionizing radiation on chromosomes. Peripheral blood (PB) lymphocytes were collected from 10 patients before and after a CT scan. DCA was performed by analyzing either 1,000 or 2,000 metaphases using both Giemsa staining and centromere-fluorescence in situ hybridization (Centromere-FISH). The increment of DIC formation was compared with effective radiation dose calculated using the computational dosimetry system, WAZA-ARI and dose length product (DLP) in a CT scan. Dicentric chromosome (DIC) formation increased significantly after a single CT scan, and increased DIC formation was found in all patients. A good correlation between the increment of DIC formation determined by analysis of 2,000 metaphases using Giemsa staining and those by 2,000 metaphases using Centromere-FISH was observed. However, no correlation was observed between the increment of DIC formation and the effective radiation dose. Therefore, these results suggest that chromosome cleavage may be induced by one CT scan, and we recommend 2,000 or more metaphases be analyzed in Giemsa staining or Centromere-FISH for DCAs in cases of low-dose radiation exposure.

Changes in radiological imaging frequencies in children before and after the accident at the Fukushima Daiichi Nuclear Power Plant in Fukushima Prefecture, Japan.

PURPOSE: The accident at the Fukushima Daiichi Nuclear Power Plant has raised concerns about radiation exposure, including medical radiation exposure such as X-ray and CT, in residents of Fukushima. MATERIALS AND METHODS: We compared the numbers and the ratio of outpatients less than 10 years old who underwent imaging examinations [e.g., CT, X-ray, MRI, ultrasonography (US), etc.] at Fukushima Medical University hospital in Fukushima, Japan before (April 1, 2008-March 31, 2011) and after (April 1, 2011-March 31, 2014) the accident. RESULTS: The number of outpatients less than 10 years old decreased after the accident. The number of outpatients less than 10 years old who underwent CT and X-ray examinations also significantly decreased after the accident (p < 0.001, p < 0.01, respectively). CONCLUSION: Our results suggest that the number of pediatric radiological examinations decreased after the accident in Fukushima. We should continue to communicate with patients and their families to ensure that they understand the risks and benefits of radiological imaging in order to overcome their concerns about the nuclear disaster.

VALIDATION OF THERAPEUTIC RESPONSE ASSESSMENT BY BONE SCINTIGRAPHY IN PATIENTS WITH BONE-ONLY METASTATIC BREAST CANCERS DURING ZOLEDRONIC ACID TREATMENT: COMPARISON WITH COMPUTED TOMOGRAPHY ASSESSMENT.

PURPOSE: To validate the use of bone scintigraphy (BS) versus computed tomography (CT) for therapeutic monitoring in patients during treatment with zoledronic acid. MATERIALS AND METHODS: Eleven patients with bone-only metastatic disease and being treated with zoledronic acid were included. The effects of therapies including chemotherapy and hormone therapy were evaluated in 25 separate examinations in total as follows: complete response (CR), when no bone metastasis was visible; partial response (PR), when a decrease in the lesion area was detected; stable disease (SD), when no or slight change was observed; and progressive disease (PD), when new or enlarged lesion areas were observed. RESULTS: The accuracies of examination by Readers 1, 2, and 3 respectively were 76%, 80% and 76% for BS, 52%, 48%, and 40% for CT, and 64%, 52% and 60% for BS and CT combined with Readers 2 and 3 observing significant differences between CT and BS results. The rates of interobserver agreement between Readers 1 and 2, between Readers 1 and 3, and between Reader 2 and 3 respectively, were 84%, 80% and 88% (κ = 0.648, 0.561 and 0.766) for BS, 52%, 56%, and 60% (κ = 0.180, 0.278 and 0.282) for CT, and 52%, 60%, and 56% (κ = 0.215, 0.282 and 0.232) for CT and BS combined. CONCLUSION: BS is effective for assessing the response of bone metastasis to therapy in patients during zoledronic acid treatment.

Factors Contributing to Early Recovery of Urinary Continence Analyzed by Pre- and Postoperative Pelvic Anatomical Features at Robot-Assisted Laparoscopic Radical Prostatectomy.

OBJECTIVE: The aim of the present study is to elucidate factors contributing to early recovery of urinary continence after robot-assisted laparoscopic radical prostatectomy (RARP) from the perspective of urethral and vesical anatomical features after RARP. PATIENTS AND METHODS: Sixty consecutive patients undergoing RARP also underwent pre- and postoperative urethrovesicography (UVG). Both pre- and postoperative UVG evaluated the posterior-urethral vesical angle and position of the urethrovesical junction. Postoperative UVG was performed 7 days after RARP and also evaluated postoperative membranous urethral length (MUL) and the postoperative degree of atony of the external urethral sphincter. Associations were analyzed between pre- or postoperative UVG variables and urinary incontinence as well as between UVG variables significantly correlating with urinary incontinence and neurovascular bundle-preservation procedures. RESULTS: Postoperative MUL was the only factor significantly associated with the state of continence in the early postoperative period according to multivariate logistic regression analysis (odds ratio, 1.94; 95% confidence interval, 1.22-3.12; p<0.005). A cutoff value of 17 mm offered the best accuracy in receiver operating characteristics analysis. Postoperative MUL was significantly increased in the group with preservation of the neurovascular bundle (p=0.01). CONCLUSIONS: Postoperative MUL is the most important factor for recovery of urinary continence in the early postoperative period after RARP. Postoperative MUL >17 mm as measured on UVG can be expected to predict early recovery of urinary continence. Postoperative MUL was greater with preservation of the neurovascular bundle, thus allowing early recovery of urinary continence.

Association between postoperative pelvic anatomic features on magnetic resonance imaging and lower tract urinary symptoms after radical prostatectomy.

OBJECTIVE: To elucidate the etiology of lower urinary tract symptoms (LUTS) after radical prostatectomy, the present study investigated associations between postoperative urethral and vesical anatomic features on magnetic resonance imaging (MRI) and LUTS. PATIENTS AND METHODS: Fifty consecutive patients undergoing radical prostatectomy also underwent preoperative and postoperative MRI. Preoperative MRI only evaluated preoperative membranous urethral length (MUL). Postoperative MRI evaluated postoperative MUL, posterior-urethral vesical angle, depth of the urethrovesical junction (UVJ), and urinary pooling inside the urethra and bladder neck configuration. At the same time as postoperative MRI, International Prostate Symptom Score (IPSS), quality of life index, continence grade, and uroflowmetry parameters were investigated. Associations between preoperative or postoperative MRI variables and questionnaire results or uroflowmetry were analyzed to examine the relationships between the morphology of urethral and vesical anatomic features and LUTS. RESULTS: Preoperative and postoperative MRI variables were not significantly associated with IPSS total score or uroflowmetry results. Urinary pooling inside the urethra was significantly associated with urgency score in the IPSS (P = .005). Postoperative MUL (P <.001), depth of the UVJ (P = .002), and urinary pooling inside the urethra (P = .04) were significantly associated with continence grade. CONCLUSION: Urinary pooling inside the urethra might induce urgency, and postoperative MUL and depth of UVJ were related to urinary incontinence. Avoiding damage to the nerves involved in continence to prevent inflow of urine into the urethra, preservation of MUL, and development of procedures to prevent descent of the bladder neck during surgery are therefore recommended.

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.

A strategy for a rapid radiological screening survey in large scale radiation accidents: a lesson from an individual survey after the Fukushima Daiichi nuclear power plant accidents.

To establish a strategy for a rapid screening survey of surface contamination among a large number of people after nuclear power plant (NPP) accidents, the authors analyzed the measured surface contamination of subjects. From 12 March through 25 March 2011, a screening survey was conducted in a hospital on 336 subjects who had stayed within a 50-km radius of the Fukushima Daiichi NPPs. The count rates from measuring points of each subject were measured and compared in association with individual characteristics such as survey timing, gender, age, and distance between their location and the Fukushima Daiichi NPPs. The count rates from the head, hands, and clothes of subjects were correlated to the survey timing and distance by multiple regression analyses. When subjects were divided into two-by-two groups of survey timing and distance, the count rates from hands were not significantly different from those of the head and clothes. However, the count rates from the shoes of the subjects, excluding one group, were significantly higher than those of the other points. In addition, the count rate from a married couple showed a significant correlation. These findings suggest that measurement of at least two regions, such as one hand and one shoe, can be used as representative survey data in order to save surveillance time for a large number of people.

[Abnormal lung uptake of 123I-BMIPP].

An eighty-one-year-old male patient with a feeling of chest pressure was admitted to our hospital for investigation of the heart. 201T1/123I-BMIPP dual scintigraphy was performed and multiple uptakes of 123I-BMIPP were detected in the lung, but not of 201T1. His chest X-ray and chest CT showed no abnormal lesions in the corresponding regions. There have been no reports that 123I-BMIPP accumulate in the lung. The possible cause of the lung uptake was embolism from aggregated 123I-BMIPP due to cold tempetatures.

Comparison between sarcoidosis and IgG4-related disease by whole-body 67Ga scintigraphy.

PURPOSE: The aim of this study was to compare uptake lesions in sarcoidosis and IgG4-related disease through gallium-67 ((67)Ga) scintigraphy to differentiate between the two diseases. MATERIALS AND METHODS: Whole-body (67)Ga scintigraphy findings of 27 patients with sarcoidosis and 16 with IgG4-related disease were reviewed between 2005 and 2011 at our hospital. RESULTS: In the case of patients with sarcoidosis, significant accumulation of (67)Ga was observed in the lacrimal gland in the case of 26 patients (96%), in mediastinal lymph nodes (LNs) in 23 (85%), in pulmonary hilar LNs in 21 (78%), in the parotid gland in 10 (38%), in supraclavicular LNs in eight (30%), in muscles in seven (26%), in the lung in five (18%), in inguinal LNs in four (15%), in submandibular LNs in two (7%), and in the heart, spleen, kidney and para-aorta in one patient (4%). In patients with IgG4-related disease, abnormal uptake was detected in the pulmonary hilar LNs in 12 patients (75%), in the lacrimal gland in 10 (62%), in the pancreas in 10 (62%), in the parotid gland in six (37%), in the submandibular gland in six (37%), in the para-aorta in three (19%), in the lung in three (19%), in mediastinal LNs in two (12%), and in the kidney in the case of two patients (12%). Asymmetrical accumulation in the submandibular gland was observed in three of six patients (50%) with IgG4-related disease and in none of the two patients (0%) with sarcoidosis. Significant differences were observed in the uptake ratio of the lacrimal gland, the submandibular gland, supraclavicular LNs, mediastinal LNs, pancreas, and muscle between the two groups (P<0.05). CONCLUSION: (67)Ga scintigraphy was useful in differentiating between the two diseases. Uptake in mediastinal LNs, in supraclavicular LNs, and in the muscle was specific to sarcoidosis, whereas uptake in the pancreas and in the submandibular gland indicated IgG4-related disease.

Incidence of leukoencephalopathy after whole-brain radiation therapy for brain metastases.

PURPOSE: To evaluate the incidence of leukoencephalopathy after whole-brain radiation therapy (WBRT) in patients with brain metastases. METHODS AND MATERIALS: We retrospectively reviewed 111 patients who underwent WBRT for brain metastases from April 2001 through March 2008 and had evaluable computed tomography (CT) and/or magnetic resonance imaging (MRI) at least 1 month after completion of WBRT. We evaluated the leukoencephalopathy according to the Common Terminology Criteria for Adverse Events, version 3.0. The patients who had brain tumor recurrence after WBRT were censored at the last follow-up CT or MRI without recurrence. To evaluate the risk factors for leukoencephalopathy, bivariate analysis was performed using a logistic regression analysis adjusted for follow-up time. Factors included in the analysis were age, gender, dose fractionation, 5-fluorouracil, methotrexate, cisplatin, and other chemotherapeutic agents. RESULTS: The median age of the 111 patients was 60.0 years (range, 23-89 years). The median follow-up was 3.8 months (range, 1.0-38.1 months). Leukoencephalopathy developed in 23 of the 111 patients. Grades 1, 2, and 3 were observed in 8, 7, and 8 patients, respectively. The incidence was 34.4% (11 of 32), 42.9% (6 of 14), 66.7% (2 of 3), and 100% (2 of 2) of the patients who were followed up for ≥6, ≥12, ≥24, and ≥36 months, respectively. In the bivariate analysis, older age (≥65 years) was significantly correlated with higher risk of leukoencephalopathy (odds ratio 3.31; 95% confidence interval 1.15-9.50; P=.03). CONCLUSIONS: The incidence of leukoencephalopathy after WBRT was 34.4% with ≥6 months follow-up, and increased with longer follow-up. Older age was a significant risk factor. The schedule of WBRT for patients with brain metastases should be carefully determined, especially for favorable patients.

Pheochromocytoma in multiple endocrine neoplasia type 2A: positive 123I MIBG with negative CT and equivocal 131I MIBG imaging.

An 123I metaiodobenzylguanidine (MIBG) planar image showed abnormal uptake in the left adrenal gland and thyroid in a 24-year-old woman with multiple endocrine neoplasia type 2A. 131I MIBG showed abnormal uptake in the thyroid but not in the adrenal gland. Abdominal CT with 2-mm thin slices demonstrated a normal adrenal gland. Postoperative pathologic findings were consistent with medullary carcinoma in both thyroid lobes and a small 1-mm pheochromocytoma in the left adrenal gland. 123I MIBG could clearly show the small pheochromocytoma, which was negative in thin-slice CT and equivocal in 131I MIBG.

Hematoma after femoral arterial blood sampling: incidence, imaging features, and course of hematoma.

OBJECTIVE: This study evaluated the incidence and course of a hematoma occurring after femoral arterial sampling. MATERIALS AND METHODS: We studied 270 patients who underwent computed tomography (CT) including the pelvis and blood gas sampling from femoral artery using a 22-gauge needle during 2010. This population comprised 176 men and 94 women with a mean (SD) age of 54.9 (24.3) years (range, 0-97 years). We evaluated whether hematoma was present at the femoral artery. Size and location of the hematoma, the short-axial luminal diameter of artery contact with the hematoma was also assessed. RESULTS: The CT images showed hematoma around the femoral artery in 128 patients (47.4%); this group comprised 84 men and 44 women with a mean (SD) age of 51.1 (24.1) years (range, 0-92 years). Hematoma was not observed in 142 patients (52.6%; 92 men and 50 women; mean [SD] age, 58.3 [24.2] years; range, 0-97 years). There was no significant difference in age, sex, altered hemostasis, or time between arterial puncture and CT between the 2 groups with or without hematoma. Arterial stenosis of 50% or greater was observed in 7 patients (mean [SD] age, 17.1 [8.97] years; range, 6-31 years; 4 males and 3 females). CONCLUSIONS: Our data revealed a high frequency of small hematoma around the femoral artery is following arterial blood sampling that was independent of bleeding diathesis. No patient progressed to a severe condition, although temporary arterial stenosis did occur.

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.