Accuracy of non-contact semiconductor X-ray analyzer for quality assurance in intraoral radiography: a comparison with ionization chamber dosimeter

OBJECTIVES

The aim of the present study was to evaluate the accuracy of a non-contact semiconductor X-ray analyzer for quality assurance in intraoral radiography, especially a comparison with an ionization chamber dosimeter.

METHODS

Intraoral radiography was performed with intraoral X-ray unit using the dental protocol at our hospital: tube voltage, 70 kV; tube current, 7 mA. Accuracy of dose and half-value layer (HVL) measurements was analyzed with a non-contact semiconductor X-ray analyzer and an ionization chamber dosimeter. Stability of the semiconductor sensor, effect of scattered radiation, and comparison of measured HVL between the ionization chamber and the semiconductor sensor were analyzed in this study.

RESULTS

The values with the semiconductor sensor were tube voltage: 70.3 ± 0.2 kVp (degree of variability: 0.28%), dose: 454.1 ± 12.3 μGy (degree of variability: 2.7%), and HVL: 1.91 ± 0.02 mmAl (degree of variability: 1.0%). With collimator, the dose with the semiconductor sensor and the ionization chamber decreased by 2.3 μ Gy and 5.2 μ Gy, respectively. The measured HVL of the semiconductor dosimeter was more than that of ionization chamber, and the semiconductor dosimeter was less than ionization chamber in variation of between without and with collimator.

CONCLUSION

This study indicated the accuracy of a non-contact semiconductor X-ray analyzer for quality assurance in intraoral radiography, especially a comparison with an ionization chamber dosimeter. The semiconductor sensor can be useful for quality assurance in intraoral radiography.

A pilot study of half-value layer measurements using a semiconductor dosimeter for intraoral radiography

Purpose

This pilot study was conducted to evaluate half-value layer (HVL) measurements obtained using a semiconductor dosimeter for intraoral radiography.

Materials and Methods

This study included 8 aluminum plates, 4 of which were low-purity (less than 99.9%) and 4 high-purity (greater than 99.9%). Intraoral radiography was performed using an intraoral X-ray unit in accordance with the dental protocol at the authors' affiliated hospital: tube voltage, 60 kVp and 70 kVp; tube current, 7 mA; and exposure time, 0.10 s. The accuracy of HVL measurements for intraoral radiography was assessed using a semiconductor dosimeter. A simple regression analysis was performed to compare the aluminum plate thickness and HVL in relation to the tube voltage (60 kVp and 70 kVp) and aluminum purity (low and high).

Results

For the low-purity aluminum plates, the HVL at 60 kVp (Y) and 70 kVp (Y) was significantly correlated with the thickness of the aluminum plate (X), with Y = 1.708 + 0.415X (r=0.999, P<0.05) and Y = 1.980 + 0.484X (r=0.999, P<0.05), respectively. Similarly, for the high-purity aluminum plates, the HVL at 60 kVp (Y) and 70 kVp (Y) was significantly correlated with the plate thickness (X), with Y = 1.696 + 0.454X (r=0.999, P<0.05) and Y = 1.968 + 0.515X (r=0.998, P<0.05), respectively.

Conclusion

This pilot study examined the relationship between aluminum plate thickness and HVL measurements using a semiconductor dosimeter for intraoral radiography. Semiconductor dosimeters may prove useful in HVL measurement for purposes such as quality assurance in dental X-ray imaging.

Incidental findings on computed tomography for preoperative assessment before transcatheter aortic valve implantation in japanese patients

Background

Extra-cardiovascular incidental findings (IFs) on preoperative computed tomography (CT) are frequently observed in transcatheter aortic valve implantation (TAVI) candidates. However, the backgrounds of TAVI candidates and comorbidities differ based on the race and/or country, and data on IFs in a specific population are not always applicable to another.

Objective

To assess the prevalence, type, and clinical impact of IFs in Japanese TAVI candidates.

Methods

This was a retrospective, single-center, observational study. CT reports of 257 TAVI candidates were reviewed, and IFs were classified as (a) insignificant: findings that did not require further investigation, treatment, or follow-up; (b) intermediate: findings that needed to be followed up or were considered for further investigation but did not affect the planning of TAVI; and (c) significant: findings that required further investigation immediately or affected the planning of TAVI.

Results

At least one IF was found in 254 patients (98.8%). Insignificant, intermediate, and significant IFs were found in 253 (98.4%), 153 (59.5%), and 34 (13.2%) patients, respectively. Newly indicated significant IFs were found in 19 patients (7.4%). In 2 patients (0.8%), TAVI was canceled because of significant IFs. In patients who consequently underwent TAVI, the presence of significant IFs was not associated with the duration from CT performance to TAVI [28 (19–40) days vs. 27 (19–43) days, p=0.74] and all-cause mortality during the median follow-up period of 413 (223–805) days (p=0.44).

Conclusion

Almost all Japanese TAVI candidates had at least one IF, and the prevalence of significant IFs was not negligible. Although the presence of significant IFs was not associated with mid-term mortality, appropriate management of IFs was considered important.

Funding Acknowledgement

Type of funding sources: None.

Regression of electrocardiographic left ventricular hypertrophy after transcatheter aortic valve replacement for aortic stenosis

Background

The changes in electrocardiographic left ventricular hypertrophy (ECG-LVH) after transcatheter aortic valve replacement (TAVR) are not fully elucidated.

Methods

This retrospective single-center study investigated 156 patients who underwent TAVR for severe aortic stenosis. Twelve-leads ECGs obtained before and at 2 days and 1, 6 and 12 months after TAVR were analyzed. Patients with an implanted pacemaker, with a bundle branch block before or after TAVR or whose electrocardiogram at any measuring point was not available were excluded. As an assessment of ECG-LVH, Sokolow-Lyon voltage, Cornell voltage, Cornell product and Peguero–Lo Presti voltage were evaluated.

Results

Finally, 64 patients were included. Sokolow-Lyon voltage, Cornell voltage, Cornell product and Peguero–Lo Presti voltage significantly decreased between 1 and 6 months after TAVR compared to baseline. The prevalence of ECG-LVH criteria for each parameter decreased as well. QRS duration significantly decreased at 6 months after TAVR and the number of patients with strain pattern decreased significantly at 1 month when compared to baseline. When the patients were divided into two groups, those with and without ECG-LVH at baseline, ECG-LVH parameter values decreased significantly, especially in patients with ECG-LVH at baseline.

Conclusion

Regression of ECG-LVH after TAVR was demonstrated as per various criteria of ECG-LVH. The voltages and prevalence of ECG-LVH decreased significantly between 1 and 6 months after TAVR.

Funding Acknowledgement

Type of funding sources: None.

Imaging Differences between Neuromyelitis Optica Spectrum Disorders and Multiple Sclerosis: A Multi-Institutional Study in Japan

BACKGROUND AND PURPOSE

Both clinical and imaging criteria must be met to diagnose neuromyelitis optica spectrum disorders and multiple sclerosis. However, neuromyelitis optica spectrum disorders are often misdiagnosed as MS because of an overlap in MR imaging features. The purpose of this study was to confirm imaging differences between neuromyelitis optica spectrum disorders and MS with visually detailed quantitative analyses of large-sample data.

MATERIALS AND METHODS

We retrospectively examined 89 consecutive patients with neuromyelitis optica spectrum disorders (median age, 51 years; range, 16-85 years; females, 77; aquaporin 4 immunoglobulin G-positive, 93%) and 89 with MS (median age, 36 years; range, 18-67 years; females, 68; relapsing-remitting MS, 89%; primary-progressive MS, 7%; secondary-progressive MS, 2%) from 9 institutions across Japan (April 2008 to December 2012). Two neuroradiologists visually evaluated the number, location, and size of all lesions using the Mann-Whitney U test or the Fisher exact test.

RESULTS

We enrolled 79 patients with neuromyelitis optica spectrum disorders and 87 with MS for brain analysis, 57 with neuromyelitis optica spectrum disorders and 55 with MS for spinal cord analysis, and 42 with neuromyelitis optica spectrum disorders and 14 with MS for optic nerve analysis. We identified 911 brain lesions in neuromyelitis optica spectrum disorders, 1659 brain lesions in MS, 86 spinal cord lesions in neuromyelitis optica spectrum disorders, and 102 spinal cord lesions in MS. The frequencies of periventricular white matter and deep white matter lesions were 17% and 68% in neuromyelitis optica spectrum disorders versus 41% and 42% in MS, respectively (location of brain lesions, P < .001). We found a significant difference in the distribution of spinal cord lesions between these 2 diseases (P = .024): More thoracic lesions than cervical lesions were present in neuromyelitis optica spectrum disorders (cervical versus thoracic, 29% versus 71%), whereas they were equally distributed in MS (46% versus 54%). Furthermore, thoracic lesions were significantly longer than cervical lesions in neuromyelitis optica spectrum disorders (P = .001), but not in MS (P = .80).

CONCLUSIONS

Visually detailed quantitative analyses confirmed imaging differences, especially in brain and spinal cord lesions, between neuromyelitis optica spectrum disorders and MS. These observations may have clinical implications.

Application of The Paris System to atypical urine cytology samples: correlation with histology and UroVysion® FISH

OBJECTIVES

To evaluate whether atypical urine cytology cases may be stratified more objectively using The Paris System (TPS) and whether reclassified cases correlate with histology and UroVysion^® results.

METHODS

Atypical urine cytology cases subjected to UroVysion^® testing over a period of 6 years were reviewed. Each case was reclassified according to TPS and correlated with histology and UroVysion^® results.

RESULTS

A total of 91 cases were identified; 70.3% were reclassified as 'negative for high-grade urothelial carcinoma (HGUC)' and 14.3% as 'atypical urothelial cells (AUC)'. The histological correlation was available in 45 cases. In the 'negative for HGUC' category, 67.9% had no histological evidence of malignancy, but 17.9% were diagnosed as HGUC. In the 'AUC' category, histology revealed urothelial carcinoma in 70% of the cases (of these, 71.4% were high grade). There was no histological evidence of malignancy in 30% of cases; notably, all of which were from patients under surveillance. The sensitivity and specificity of UroVysion^® were 85.7% and 33.3% in the 'AUC' group and 62.5% and 100% in the 'negative for HGUC' group.

CONCLUSIONS

The Paris System is an objective template for reporting urine cytology specimens, and is particularly useful in identifying HGUC cases and refining the category of 'AUC'.

The Roles of the Secreted Phospholipase A2 Gene Family in Immunology

Within the phospholipase A₂ (PLA₂) family that hydrolyzes phospholipids to yield fatty acids and lysophospholipids, secreted PLA₂ (sPLA₂) enzymes comprise the largest group containing 11 isoforms in mammals. Individual sPLA₂s exhibit unique tissue or cellular distributions and enzymatic properties, suggesting their distinct biological roles. Although PLA₂ enzymes, particularly cytosolic PLA₂ (cPLA₂α), have long been implicated in inflammation by driving arachidonic acid metabolism, the precise biological roles of sPLA₂s have remained a mystery over the last few decades. Recent studies employing mice gene-manipulated for individual sPLA₂s, in combination with mass spectrometric lipidomics to identify their target substrates and products in vivo, have revealed their roles in diverse biological events, including immunity and associated disorders, through lipid mediator-dependent or -independent processes in given microenvironments. In this review, we summarize our current knowledge of the roles of sPLA₂s in various immune responses and associated diseases.

Simultaneous immunostaining with anti-S100P and anti-SV40 antibodies revealed the origin of BK virus-infected decoy cells in voided urine samples

BACKGROUND

Methods for determining the origin of BK virus (BKV)-infected cells (decoy cells) in clinical urine samples have not been established although they could enhance the diagnosis of BKV infection in immunocompromised patients.

METHODS

We performed simultaneous immunostaining with anti-S100P (a urothelial marker) and anti-SV40 antibodies in 66 clinical urine samples exhibiting SV40 positivity and a decoy-cell appearance on Papanicolaou staining. The clinical voided urine samples included seven cases of renal transplantation, 47 cases of cancer therapy and 12 cases of non-neoplastic disease. SurePath(™) liquid-based cytology was used for the urine samples.

RESULTS

BKV-infected cells were categorized as SV40(+)/S100P(+) and SV40 (+)/S100p(-). SV40(+)/S100P(-) cells were found in 55 cases (83.4%); nine cases (13.6%) carried both SV40(+)/S100P(-) and SV40(+)/S100P(+) cells. The former were identified as BKV infection in renal tubules and the latter in both the renal tubules and urothelial epithelia. The remaining two cases (3.0%) had only SV40(+)/S100P(+) cells of urothelial origin.

CONCLUSION

Simultaneous immunostaining with anti-S100P and anti-SV40 is a useful method for determining the origin of BKV-infected cells in clinical urine samples from immunocompromised patients such as renal transplantation recipients.

Squamous-lined cyst of the pancreas: Radiological-pathological correlation

Pancreatic cystic lesions are increasingly being detected incidentally because of the increased use of cross-sectional imaging. Squamous-lined cysts of the pancreas (lymphoepithelial cyst, epidermoid cyst, and dermoid cyst) are rare cystic lesions lined with squamous epithelium. Distinguishing squamous-lined cysts from other cystic lesions of the pancreas is important to avoid unnecessary surgery, because squamous-lined cysts of the pancreas have no malignant potential. The purpose of this review is to describe findings on computed tomography and magnetic resonance imaging and the histopathological characteristics of squamous-lined cysts, and to summarize the key points of differential diagnosis for pancreatic cystic lesions.

Single institutional experience of the treatment of angiosarcoma of the face and scalp

OBJECTIVE

Angiosarcoma is a rare malignant neoplasm with a poor prognosis. A retrospective study was performed to accumulate radiotherapy (RT) data.

METHODS

Data from 17 patients with angiosarcoma of the face and scalp (AFS) who were treated with definitive RT between January 1999 and July 2011 were retrospectively analysed. The total radiation dose was 70 Gy, and the fractional doses were 2.0-2.5 Gy. Combined with RT, chemotherapy using docetaxel alone, recombinant interleukin-2 immunotherapy alone and both of these was performed in 10, 4 and 2 patients, respectively. Three patients underwent limited surgery before RT.

RESULTS

The response rate was 82%, and the median overall survival (OS) rate was 26 months. Locoregional relapse alone, distant metastasis alone and both of these were confirmed in 4, 5 and 4 patients, respectively. Patients treated with docetaxel showed a better prognosis (p=0.0477), a distant metastasis-free rate (p=0.0063) and a better in-field control rate, although the last was not statistically significant (p=0.1645).

CONCLUSION

Definitive RT combined with docetaxel chemotherapy provided an effective approach for treating AFS.

ADVANCES IN KNOWLEDGE

Since patients treated with chemoradiotherpy using docetaxel showed better OS and distant metastasis-free rates than those who did not receive docetaxel, it was warranted to continue use of docetaxel. In chemoradiotherapy at a dose of 70 Gy using docetaxel, 2-year in-field control rate was 67%.

LMTK3 is implicated in endocrine resistance via multiple signaling pathways

Resistance to endocrine therapy in breast cancer is common. With the aim of discovering new molecular targets for breast cancer therapy, we have recently identified LMTK3 as a regulator of the estrogen receptor-alpha (ERα) and wished to understand its role in endocrine resistance. We find that inhibition of LMTK3 in a xenograft tamoxifen (Tam)-resistant (BT474) breast cancer mouse model results in re-sensitization to Tam as demonstrated by a reduction in tumor volume. A whole genome microarray analysis, using a BT474 cell line, reveals genes significantly modulated (positively or negatively) after LMTK3 silencing, including some that are known to be implicated in Tam resistance, notably c-MYC, HSPB8 and SIAH2. We show that LMTK3 is able to increase the levels of HSPB8 at a transcriptional and translational level thereby protecting MCF7 cells from Tam-induced cell death, by reducing autophagy. Finally, high LMTK3 levels at baseline in tumors are predictive for endocrine resistance; therapy does not lead to alteration in levels, whereas in patient's plasma samples, acquired LMTK3 gene amplification (copy number variation) was associated with relapse while receiving Tam. In aggregate, these data support a role for LMTK3 in both innate (intrinsic) and acquired (adaptive) endocrine resistance in breast cancer.

Intratumoral concentration of estrogens and clinicopathological changes in ductal carcinoma in situ following aromatase inhibitor letrozole treatment

Background:

Estrogens have important roles in ductal carcinoma in situ (DCIS) of the breast. However, the significance of presurgical aromatase inhibitor treatment remains unclear. Therefore, we examined intratumoral concentration of estrogens and changes of clinicopathological factors in DCIS after letrozole treatment.

Methods:

Ten cases of postmenopausal oestrogen receptor (ER)-positive DCIS were examined. They received oral letrozole before the surgery, and the tumour size was evaluated by ultrasonography. Surgical specimens and corresponding biopsy samples were used for immunohistochemistry. Snap-frozen specimens were also available in a subset of cases, and used for hormone assays and microarray analysis.

Results:

Intratumoral oestrogen levels were significantly lower in DCIS treated with letrozole compared with that in those without the therapy. A great majority of oestrogen-induced genes showed low expression levels in DCIS treated with letrozole by microarray analysis. Moreover, letrozole treatment reduced the greatest dimension of DCIS, and significantly decreased Ki-67 and progesterone receptor immunoreactivity in DCIS tissues.

Conclusion:

These results suggest that estrogens are mainly produced by aromatase in DCIS tissues, and aromatase inhibitors potently inhibit oestrogen actions in postmenopausal ER-positive DCIS through rapid deprivation of intratumoral estrogens.

Androgen receptor in triple negative breast cancer

The clinical management of triple negative breast cancer (TNBC) is challenging due to the relatively aggressive biological behaviour and paucity of specific targeted therapy. A subset of TNBC patients has been reported to express androgen receptor (AR) in carcinoma cells and the manipulation of androgen signalling or AR targeted therapies have been proposed. However, the biological significance of AR in TNBC has remained relatively unknown. Therefore, this review aims to summarise the reported studies assessing the rates of AR positivity in TNBC patients and androgenic effects in TNBC cell lines. The rates of AR positivity among TNBC cases varied depending on the study population (0-53% of all TNBC patients). This difference among the reported studies may be largely due to the methodological differences of analysing AR. While the majority of cell line studies suggest that androgen increase proliferation and preliminary clinical studies suggest that AR antagonists improve the prognosis of AR positive TNBC patients, cell line transfection experiments and survival analyses of histological samples suggest that the presence of AR in tumour is either benign or predicts better survival. Therefore further translational investigations regarding the mechanisms of androgen action in TNBC are required to explain this discrepancy between clinical and basic studies.

Abstract P6-05-14: Estrogen-induced genes in ductal carcinoma in situ(DCIS): their comparison with invasive ductal carcinoma

It is well known that estrogens play important roles in both the pathogenesis and development of invasive ductal carcinoma (IDC) of human breast. However, molecular features of estrogen actions have remained largely unclear in pure ductal carcinoma in situ (pDCIS), regarded as a precursor lesion of many IDCs. This is partly due to the fact that gene expression profiles of estrogen-responsive genes have not been examined in pDCIS. Therefore, we first examined the profiles of estrogen-induced genes in estrogen receptor (ER)-positive pDCIS and DCIS (DCIS-c) and IDC (IDC-c) components of IDC cases (n = 4, respectively) by microarray analysis. Estrogen-induced genes identified in this study were tentatively classified into three different groups in the hierarchical clustering analysis, and 33% of the genes were predominantly expressed in pDCIS rather than DCIS-c or IDC-c cases. Among these genes, the status of MYB (c-MYB), RBBP7 (RbAp46) and BIRC5 (survivin) expression in carcinoma cells was significantly higher in ER-positive pDCIS(n = 53) than that in ER-positive DCIS-c (n = 27) or IDC-c (n = 27) by subsequent immunohistochemical analysis of the corresponding genes (P &lt; 0.0001, P = 0.03 and P = 0.0003, respectively). In particular, the status of c-MYB immunoreactivity was inversely (P = 0.006) correlated with Ki-67 in the pDCIS cases. These results suggest that expression profiles of estrogen-induced genes in pDCIS may be different from those in IDC, and c-MYB, RbAp46 and survivin may play particularly important roles among estrogen induced genes in ER-positive pDCIS.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-05-14.

Carcinoembryonic antigen-related cell adhesion molecules as surrogate markers for EGFR inhibitor sensitivity in human lung adenocarcinoma

Background:

Lung adenocarcinoma (LADCA) patients with epidermal growth factor receptor (EGFR) mutations are in general associated with relatively high clinical response rate to EGFR-tyrosine kinase inhibitors (TKIs) but not all responded to TKI. It has therefore become important to identify the additional surrogate markers regarding EGFR-TKI sensitivity.

Methods:

We first examined the effects of EGFR-TKIs, gefitinib and erlotinib, upon cell proliferation of lung adenocarcinoma cell lines. We then evaluated the gene profiles related to EGFR-TKI sensitivity using a microarray analysis. Results of microarray analysis led us to focus on carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family, CEACAM 3, 5, 6, 7, and 19, as potential further surrogate markers of EGFR-TKI sensitivity. We then examined the correlation between the status of CEACAM 3, 5, 6, 7, and 19 immunoreactivity in LADCA and clinicopathological parameters of individual cases.

Results:

In the cases with EGFR mutations, the status of all CEACAMs examined was significantly higher than that in EGFR wild-type patients, but there were no significant differences in the status of CEACAMs between TKI responder and nonresponder among 22 patients who received gefitinib therapy. However, among 115 EGFR mutation-negative LADCA patients, both CEACAM6 and CEACAM3 were significantly associated with adverse clinical outcome (CEACAM6) and better clinical outcome (CEACAM3).

Conclusion:

CEACAMs examined in this study could be related to the presence of EGFR mutation in adenocarcinoma cells but not represent the effective surrogate marker of EGFR-TKI in LADCA patients. However, immunohistochemical evaluation of CEACAM3/6 in LADCA patients could provide important information on their clinical outcome.

Immunohistochemical analysis of gastrin-releasing peptide receptor (GRPR) and possible regulation by estrogen receptor βcx in human prostate carcinoma

Gastrin-releasing peptide (GRP) belongs to the family of bombesin-like peptides. GRP was demonstrated to stimulate the proliferation and invasiveness of androgen-independent prostate carcinoma. GRP mediates its action through the membrane-bound receptor, GRP receptor (GRPR), which is characterized by a high-affinity binding for both GRP and bombesin. In human prostate cancer tissue, GRPR mRNA was reported to be detectable in more than 90% but its immunolocalizaition has not been reported. Therefore, in this study we immunolocalized GRPR in 51 human prostate cancer cases and correlated the findings with several clinicopathological parameters in order to better understand the function and regulation of GRPR in human prostate cancer. GRPR was immnolocalized in carcinoma cells and their values were significantly associated with Gleason score and immunoreactivity of estrogen receptor βcx (ERβcx) that is one of splicing variants of ligand dependent transcription factor, ERβ, and considered to be prognostic factor of prostate cancer patients. The amounts of GRPR and ERβcx mRNA in three prostate cancer cell lines PC-3, DU-145 and LNCaP evaluated by quantitative RT-PCR (qPCR) analysis were also significantly correlated. In addition, we established stable transformants of prostate carcinoma cell line PC-3 introduced with ERβcx, and confirmed that GRPR mRNA was induced in ERβcx over-expressing PC-3 cells by qPCR analysis. These results also suggest that ERβcx contributes to prostate cancer development possibly through mediating GRPR expression in carcinoma cells.

Experimental venous thrombi: MRI characteristics with histopathological correlation

OBJECTIVES

The purpose of this study was to evaluate the MRI characteristics of venous thrombus over set time thresholds with histopathological correlation in a porcine model.

METHODS

Inferior vena cava thrombi were induced in 12 pigs. MRI was performed in three pigs 2 h, 1 day, 3 days and 2 weeks after thrombus induction.

RESULTS

The MRI characteristics were analysed in correlation with histopathological findings. The thrombi after 2 hours, which consisted of red blood cells (RBCs), showed isointensity on T(1 )weighted images (T(1)WIs) and hyperintensity on both T(2 )weighted images (T(2)WIs) and diffusion-weighted images (DWIs). The mean apparent diffusion coefficient (ADC) value was 1.93 × 10(-3) mm(2) s(-1). The thrombi after Day 1, which consisted of RBCs and migrating neutrophils at the periphery, showed isointensity on T(1)WIs, slight hyperintensity on T(2)WIs and hypointensity on DWIs. The mean ADC value was 1.62 × 10(-3) mm(2) s(-1) [corrected]. The thrombi after Day 3, which consisted of RBCs and peripheral inflammatory cells including macrophages, showed isointensity with peripheral hyperintense regions on T(1)WIs and hypointensity on both T(2)WIs and DWIs. The mean ADC value was 1.67 × 10(-3) mm(2) s(-1). After 2 weeks, the thrombi, which revealed RBC lysis surrounded by granulation tissues, showed isointensity on T(1)WIs and hyperintensity on T(2)WIs and DWIs. The mean ADC value was 2.48 × 10(-3) mm(2) s(-1).

CONCLUSION

The temporal MRI characteristics seemed to be related to chemical and physical changes in RBC and organisation of granulation tissues. Free radicals generated by macrophages might also be related to some extent.

Development of a highly efficient implanted thermal ablation device: in vivo experiment in rat liver

OBJECTIVES

To evaluate an implanted thermal ablation device that can be heated with high efficiency using a resonant circuit as the implant.

METHODS

16 rats were used. The implants, adjusted at a resonance frequency of 4 MHz, were fixed on the surface of the liver of rats under laparotomy. In 14 of 16 rats, an alternating magnetic field (AMF) was applied for 6 min with an output of 300 W from outside the body using a ferrite core applicator. The implant temperature during AMF exposure was measured. The 14 rats were divided into 5 groups, depending on time from AMF application until they were sacrificed (1 h, 1 day, 3 days, 7 days and 1 month after application). Two rats not exposed to AMF were used as controls. Livers were removed and evaluated; the cross-sectional area and width of the ablated region were measured.

RESULTS

During AMF exposure, the implant temperature rose to 127.8±39.3 °C (mean±standard deviation). The cross-sectional area of the ablated region was largest after 1 day and tended to decrease with time. The widths of the ablated region were 4.87±0.22 mm, 4.15±0.36 mm, 3.67±0.58 mm and 3.24±0.16 mm in the 1 day, 3 day, 7 day and 1 month groups, respectively. No significant differences (p<0.05) were seen in either cross-sectional area or width of the ablated region.

CONCLUSION

Sufficient heat for ablation was obtained in vivo using a newly developed implanted thermal ablation device. This device may be a new option for thermal ablation therapy.

The non-vascularised fibular graft: a simple and successful method of reconstruction of the pelvic ring after internal hemipelvectomy

Internal hemipelvectomy is a standard treatment for malignant tumours of the pelvis. Reconstruction using a non-vascularised fibular graft is relatively straightforward compared to other techniques. We describe the surgical and functional outcomes for a series of ten patients who underwent an internal hemipelvectomy (type I or I/IV) with reconstruction by a non-vascularised fibular graft between 1996 and 2009. A key prerequisite for this procedure was a preserved sciatic notch, confirmed pre-operatively on MRI. Graft-host union was achieved in all patients with a single fibular graft, and in the lower graft where two grafts had been used. The mean time to union was 7.3 months (3 to 12). The upper graft did not unite in four of six cases where two grafts had been used. Seven patients were eventually able to walk without a stick. The mean post-operative Musculoskeletal Tumour Society score was 75.4% (16.7 to 96.7). There were no cases of deep post-operative infection. The mean pelvic shortening was 0.9 cm (0.2 to 3.4). Recurrent tumour occurred in three cases, and death from tumour-related disease occured in one. Patients who need an internal hemipelvectomy will do well if their pelvic ring is reconstructed with a non-vascularised fibular graft. The complication rate is low, and they attain a good functional outcome.

The significance of size change of soft tissue sarcoma during preoperative radiotherapy

AIM

To assess the significance of change in tumour size during preoperative radiotherapy in patients with soft tissue sarcoma (STS).

METHODS

A retrospective review of 91 cases with STS was performed. Inclusion criteria were localised extremity and truncal STS with measurable disease, older than 18 years, treated with preoperative radiotherapy and wide local excision, in the period between January 1966 and December 2005. Patients with head and neck STS, or who received neoadjuvant chemotherapy were excluded. A difference in excess of 10% of the greatest tumour diameter of the pre-radiotherapy and the post-radiotherapy MRI scans was considered as change in tumour size.

RESULTS

Increase in tumour size was noted in 28 patients (31%) (Group 1). No change or decrease in size was observed in 63 patients (Group 2). There were no significance differences in local control or overall survival rates between the 2 groups. The estimated overall actuarial local recurrence free, event-free and overall survival rates were 90.5%, 64.4%, 62.9% in Group 1, and 85.7%, 60.8%, 68.9% in Group 2 respectively.

CONCLUSION

Increase in tumour size during preoperative radiotherapy for soft tissue sarcoma does not seem to associate with inferior local tumour control or compromise survival. Lack of reduction in tumour size is not necessarily a sign of lack of response to preoperative radiotherapy.

Pim-1 controls NF-kappaB signalling by stabilizing RelA/p65

Post-translational modification and degradation of proteins by the ubiquitin-proteasome system are key regulatory mechanisms in cellular responses to various stimuli. The NF-kappaB signaling pathway is controlled by the ubiquitin-mediated proteolysis. RelA/p65, which is a main subunit of NF-kappaB, is ubiquitinated for degradation by SOCS-1, but the functional mechanism of its ubiquitination remains poorly understood. In this study we show that phosphorylation of RelA/p65 at Ser276 prevents its degradation by ubiquitin-mediated proteolysis. In contrast, impairment of Ser276 phosphorylation affects constitutive degradation of RelA/p65. Importantly, we identify Pim-1 as a further kinase responsible for the phosphorylation of RelA/p65 at Ser276. Depletion of Pim-1 hinders not only Ser276 phosphorylation but also transactivation of RelA/p65 target genes. We also show that Pim-1 contributes to recruitment of RelA/p65 to kappaB-elements to activate NF-kappaB signalling after TNF-alpha stimulation. In concert with these results, the knockdown of Pim-1 impairs IL-6 production and augments apoptosis by interfering RelA/p65 activation. These findings provide a model in which Pim-1 phosphorylation of RelA/p65 at Ser276 allows defense against ubiquitin-mediated degradation and whereby exerts activation of NF-kappaB signalling.

Normal pituitary stalk: high-resolution MR imaging at 3T

BACKGROUND AND PURPOSE

Knowing the normal imaging appearance of the pituitary stalk is important for the diagnosis of pituitary infundibular lesions, and more accurate assessment of the stalk may be possible at 3T than at 1.5T. Our purpose was to evaluate the normal pituitary stalk by use of high-resolution MR imaging at 3T.

MATERIALS AND METHODS

Sagittal MPRAGE images and high-resolution oblique-axial T2-weighted images of the pituitary stalk were acquired in 29 healthy volunteers (16 men and 13 women; mean age, 28 years; age range, 21-43 years) at 3T. The diameter and length of the pituitary stalk and the depth of the infundibular recess were measured. Signal intensity of the stalk was visually evaluated on T2-weighted images.

RESULTS

The AP and transverse diameters of the pituitary stalk were 2.32 +/- 0.39 mm and 2.16 +/- 0.37 mm at the pituitary insertion, respectively, and 3.25 +/- 0.43 mm and 3.35 +/- 0.44 mm at the level of the optic chiasm. No significant differences were observed between the AP and transverse diameters at each level. The length of the stalk was 5.91 +/- 1.24 mm, and the depth of the infundibular recess was 4.69 +/- 0.87 mm. The stalk showed central hyperintensity with a peripheral rim of isointensity in 20 subjects (69%) and homogeneous isointensity in 9 subjects (31%).

CONCLUSIONS

The data of the current study can serve as standard measurements of the normal pituitary stalk. The central hyperintensity and peripheral rim may represent the infundibular stem and pars tuberalis, respectively.

Three-dimensional double-echo steady-state (3D-DESS) magnetic resonance imaging of the knee: contrast optimization by adjusting flip angle

BACKGROUND

The three-dimensional double-echo steady-state (3D-DESS) sequence is being used to investigate sequence parameters for the assessment of knee cartilage by magnetic resonance imaging (MRI). With the flip angle (FA) values that are commonly used, contrast between cartilage and synovial fluid may be too low to delineate minor lesions of the cartilage surface.

PURPOSE

To investigate the value of FA maximizing contrast between cartilage and synovial fluid using the 3D-DESS sequence.

MATERIAL AND METHODS

In 10 healthy volunteers (five men, five women; age range 23-48 years), 3D-DESS imaging was performed to capture median sagittal sections of the knee by adjusting FA from 10 degrees to 90 degrees. Cartilage-synovial fluid contrast-to-noise ratio (CNR) was measured to determine the value of FA maximizing CNR. Water-excitation pulse was used to suppress fat signals. MRI was performed at 1.0 T using a circular polarization flex coil.

RESULTS

Cartilage-synovial fluid CNR was highest with 90 degrees FA, yielding images with good contrast between cartilage and synovial fluid.

CONCLUSION

Simply by increasing FA to 90 degrees in 3D-DESS imaging, the contrast between cartilage and synovial fluid increased substantially. Subtle cartilage lesions may thus be detectable using 3D-DESS sequences.

Hemispheric asymmetry of the arcuate fasciculus: a preliminary diffusion tensor tractography study in patients with unilateral language dominance defined by Wada test

OBJECTIVE

Lateralization of language function is a prominent feature of human brain function, and its underlying structural asymmetry has been recently reported in normal right-handed subjects. By means of diffusion tensor tractography (DTT), we investigated the asymmetry of the language network, namely, the arcuate fasciculus in patients in whom the unilateral language dominance was defined by Wada test.

METHODS

DTT was performed in 24 patients with a focal lesion or an epileptic focus outside the C-shaped segment of the arcuate fasciculus. The arcuate fasciculus was reconstructed by placing two regions-of-interest in the deep white matter lateral to the corona radiata. The pathway was then divided into one terminating in the temporal lobe (FT tract) and the other in the parietal lobe (FP tract). The relative number and volume of the FT and FP tracts in each hemisphere were submitted to repeated measure ANOVA separately, with the hemisphere as a within-subject factor and with the side of pathology as a between subject factor.

RESULTS

The FT tract showed a significantly larger number and volume in the language dominant hemisphere than in the non-dominant hemisphere, while, for the FP tract, no significant hemispheric difference was observed in the relative number or volume. There was a tendency that the FT tract was less lateralized when the pathology was located in the dominant hemisphere than in the non-dominant hemisphere.

CONCLUSION

Dominance of the FT tract in the language dominant hemisphere was demonstrated for the first time in a patient population and implicated a clinical utility of DTT for non-invasive evaluation of language lateralization. Our preliminary study might indicate reorganization of the language network in conjunction with pathology.