Prognosis prediction of uterine cervical cancer using changes in the histogram and texture features of apparent diffusion coefficient during definitive chemoradiotherapy

OBJECTIVES

We investigated prospectively whether, in cervical cancer (CC) treated with concurrent chemoradiotherapy (CCRT), the Apparent diffusion coefficient (ADC) histogram and texture parameters and their change rates during treatment could predict prognosis.

METHODS

Fifty-seven CC patients treated with CCRT at our institution were included. They underwent MRI scans up to four times during the treatment course (1st, before treatment [n = 41], 2nd, at the start of image-guided brachytherapy (IGBT) [n = 41], 3rd, in the middle of IGBT [n = 27], 4th, after treatment [n = 53]). The entire tumor was manually set as the volume of interest (VOI) manually in the axial images of the ADC map by two radiologists. A total of 107 image features (morphology features 14, histogram features 18, texture features 75) were extracted from the VOI. The recurrence prediction values of the features and their change rates were evaluated by Receiver operating characteristics (ROC) analysis. The presence or absence of local and distant recurrence within two years was set as an outcome. The intraclass correlation coefficient (ICC) was also calculated.

RESULTS

The change rates in kurtosis between the 1st and 3rd, and 1st and 2nd MRIs, and the change rate in grey level co-occurrence matrix_cluster shade between the 2nd and 3rd MRIs showed particularly high predictive powers (area under the ROC curve = 0.785, 0.759, and 0.750, respectively), which exceeded the predictive abilities of the parameters obtained from pre- or post-treatment MRI only. The change rate in kurtosis between the 1st and 2nd MRIs had good reliability (ICC = 0.765).

CONCLUSIONS

The change rate in ADC kurtosis between the 1st and 2nd MRIs was the most reliable parameter, enabling us to predict prognosis early in the treatment course.

MR Imaging Findings of Carcinoma Ex Pleomorphic Adenoma Related to Extracapsular Invasion and Prognosis

BACKGROUND AND PURPOSE

MR imaging can reflect the pathologic progression of carcinoma ex pleomorphic adenoma (CXPA). This study aimed to identify the imaging findings related to extracapsular invasion of CXPA. Additionally, the pathologic background of these findings was investigated.

MATERIALS AND METHODS

This retrospective study included 37 patients with histologically confirmed CXPA. Three radiologists independently evaluated whether the CXPA showed the following characteristic MR imaging findings: border, capsule, the corona sign on fat-saturated T2WI and contrast-enhanced fat-saturated T1WI, and the black ring sign. The corona sign appeared larger on fat-saturated and/or contrast-enhanced fat-saturated T1WI than on T1WI. The black ring sign was defined as an intratumoral nodule with a thick low-intensity rim on T2WI. Interreader agreement of the visual assessment was performed using κ analysis, and MR imaging and histopathologic findings were also correlated. Kaplan-Meier survival and the log-rank test were used to estimate the 3-year disease-free survival.

RESULTS

MR imaging findings, especially peritumoral findings, showed a significant difference between invasive and noninvasive CXPA. The reliability was poor for the border and capsule. In contrast, it was good for the corona sign on fat-saturated and contrast-enhanced fat-saturated T1WI and the black ring sign. Pathologically, the corona sign reflected the invasiveness of the tumor and inflammatory cells, while the black ring sign reflected hyalinization or fibrosis. The corona sign also showed a significant difference in the 3-year disease-free survival.

CONCLUSIONS

MR imaging findings, including the corona and black ring signs, reliably differentiated invasive and noninvasive CXPA. The corona sign can be used as a prognostic factor for CXPA.

Mass-forming hepatic cryptococcosis: a mimicker of metastatic tumors

This report provides the first imaging report of isolated intrahepatic cryptococcosis. An 83-year-old man was incidentally pointed out of hepatic nodules. CT revealed four well-defined nodules of 21 mm, 15 mm, 7 mm, and 5 mm in diameter without contrast enhancement. Two nodules displayed central hyperattenuation and the others were totally hyperattenuating. MRI showed that the nodules were hypointense relative to normal liver parenchyma on T1- and T2-weighted images. 18F-FDG PET imaging revealed no obvious increased uptake of nuclear species into the liver nodules. Partial resection of the three largest hepatic nodules was performed based on a preoperative diagnosis of hepatic metastasis from known sigmoid colon cancer. All three resected nodules were composed mainly of necrotic tissue with peripheral histiocytic aggregates and numerous yeast-like cells. The final diagnosis was hepatic cryptococcosis.

Impaired lesion detectability on gadoxetic acid-enhanced MR imaging in indocyanine green excretory defect: case series of three patients

Indocyanine green (ICG) excretory defect is characterized by an ICG retention rate of more than 50% at 15 min without any other abnormal liver functions. The incidence of ICG excretory defect is 0.007% in the Japanese population. Due to its rarity, the imaging characteristics associated with ICG excretory defect remain unclear. Herein, we present three cases of ICG excretory defect, which showed impaired lesion detectability on gadoxetic acid-enhanced MR imaging (EOB-MRI). In the hepatobiliary phase (HBP) of EOB-MRI, diminished enhancement of the liver parenchyma, prolonged intravascular enhancement, and attenuated gadoxetic acid excretion to the bile duct were observed. Our study also investigated the expression level of organic anion transporting polypeptide (OATP) 1B3 and OATP1B1/1B3, which is related to the uptake of ICG and gadoxetic acid into hepatocytes. All cases showed decreased expression of OATP1B3, which was assumed to be characteristic of ICG excretory defect. The present study indicates that, when patients with ICG excretory defect are evaluated using EOB-MRI, attention should be paid to the impaired lesion detectability in the HBP due to the attenuated gadoxetic acid uptake into the liver parenchyma.

Indicator for local recurrence of hepatocellular carcinoma after proton beam therapy: analysis of attenuation difference between the irradiated tumor and liver parenchyma on contrast enhancement CT

OBJECTIVES

We aimed to identify dynamic CT features that can be used for prediction of local recurrence of hepatocellular carcinoma (HCC) after proton beam therapy (PBT).

METHODS

We retrospectively retrieved CT scans of patients with PBT-treated HCC, taken between January 2004 and December 2016. 17 recurrent lesions and 34 non-recurrent lesions were retrieved. The attenuation difference between irradiated tumor and irradiated parenchyma (AD_HCC-IP) was compared in the two groups by using the Mann-Whitney U test. Cut-off value of AD_HCC-IP was estimated by using the Youden index.

RESULTS

The follow-up time after PBT initiation ranged from 374 to 2402 days (median, 1069 days) in recurrent lesions, and 418 to 2923 days (median, 1091.5 days) in non-recurrent lesions (p = 0.892). The time until appearance of local recurrence after PBT initiation ranged from 189 to 2270 days (median, 497 days). AD_HCC-IP of recurrent lesions [mean, -21.8 Hounsfield units (HU); from -95 to -31 HU] was significantly greater than that of non-recurrent lesions (mean, -51.7 HU; from -117 to -12 HU) at 1-2 years in portal venous phase (p = 0.039). 5-year local tumor control rates were 0.93 and 0.56 in lesions with AD_HCC-IP at 1-2 years in PVP < -55 and ≥ -55 HU, respectively.

CONCLUSION

The attenuation difference between irradiated HCC and irradiated liver parenchyma in portal venous phase at 1-2 years after PBT can predict long-term local recurrence of HCC after treatment.

ADVANCES IN KNOWLEDGE

We identified a cut-off value for contrast enhancement of HCC after PBT that could predict future local recurrence.

P974Efficacy of plaque debulking for bifurcated or ostial lesion by directional coronary atherectomy before 2nd generation drug eluting stent (PERFECT2)

Objectives

We sought to evaluate the efficacy of plaque debulking by directional coronary atherectomy (DCA) before 2nd generation drug-eluting stent (DES) implantation for bifurcated coronary lesions.

Background

Percutaneous coronary intervention (PCI) for bifurcated lesions still remains complex and challenging in terms of restenosis or stent thrombosis regardless of whether simple or complex stenting used.

Methods

Patients with bifurcated lesions were enrolled in this prospective multicenter registry. Pre-2nd generation DES plaque debulking with a novel DCA was conducted. All patients were scheduled to perform a follow up (9–12 months) angiography (coronary angiography or coronary computed tomography). The primary end point was the target vessel failure (TVF) at follow-up. Secondary end points were procedure-related events and major adverse cardiac events at 1 year.

Results

A total of 77 patients with bifurcated lesions were enrolled. PCI with DCA was performed successfully in all without any major procedure-related event and only 1 case needed complex stenting. TVF rate at 9–12 months follow up was 3.9% (3 of 77) and those were all associated with revascularization of the target vessel. Restenosis was only observed at ostial of main-branch in 3cases. No death, no coronary artery bypass grafting, and no myocardial infarction were reported in the patients within the first year.

Figure1

Conclusion

DCA before 2nd generation DES implantation can possibly avoid complex stenting and provide a good mid-term outcome in patients with bifurcated lesions.

Acknowledgement/Funding

None

124Impact of intimal tracking for recanalization of CTO lesions on long-term clinical outcomes

Background

For recanalization of coronary chronic total occlusion (CTO) lesions, subintimal guidewire tracking in both antegrade and retrograde approaches are commonly used.

Purpose

This study aimed to assess the impact of subintimal tracking on long-term clinical outcomes after recanalization of CTO lesions.

Methods

Between January 2009 and December 2016, 474 CTO lesions (434patients) were successfully recanalized in our center. After guidewire crossing in a CTO lesion, those lesions were divided into intimal tracking group (84.6%, n=401) and subintimal tracking group (15.4%, n=73) according to intravascular ultrasound (IVUS) findings. Long-term clinical outcomes including death, target lesion revascularization (TLR), target vessel revascularization (TVR) were compared between the two groups. In addition, the rate of re-occlusion after successful revascularization was also evaluated.

Results

The median follow-up period was 4.7 years (interquartile range, 2.8–6.1). There was no significant difference of the rate of cardiac death between the two groups (intimal tracking vs. subintimal tracking: 7.0% vs. 4.1%; hazard ratio, 0.61; 95% confidence interval [CI], 0.19 to 2.00; p=0.41), TLR (14.3% vs. 16.2%; hazard ratio, 1.34; 95% CI, 0.71 to 2.53; p=0.37), and TVR (17.5% vs. 20.3%; hazard ratio, 1.27; 95% CI, 0.72 to 2.23; p=0.42). However, the rate of re-occlusion was significantly higher in the subintimal tracking group than intimal tracking group at 3-years re-occlusion (4.2% vs. 14.5%; log-rank test, p=0.002, Figure). In the multivariate COX regression, subintimal guidewire tracking was an independent predictor of re-occlusion after CTO recanalization (HR: 5.40; 95% CI: 2.11–13.80; p<0.001).

Figure 1

Conclusions

Subintimal guidewire tracking for recanalization of coronary CTO was associated with significantly higher incidence of target lesion re-occlusion during long-term follow-up period.

Organo-axial volvulus of the small intestine: radiological case report and consideration for its mechanism

Gastrointestinal volvulus is mainly classified into two subtypes, mesentero-axial volvulus and organo-axial volvulus. The detailed imaging findings of organo-axial volvulus of the small intestine have never been reported as far as we know. In this article, we report a case of organo-axial volvulus of the small intestine, focusing on the computed tomography (CT) findings. An 80-year-old man was radiologically diagnosed as having organo-axial volvulus of the terminal ileum and it was confirmed by open surgery without adhesion or any other anatomical abnormalities. CT showed two specific findings, split-bowel sign and rotating-C sign, which we think reflect pathophysiologic features of organo-axial volvulus. We think the pathogenic mechanism of organo-axial volvulus can be explained by the convergence of the reversed-rotational twist following the formation of a twisted but non-obstructive circular loop, even if there is no adhesion. Radiologists should be aware that organo-axial volvulus can occur even in the small intestine, and in the case of small bowel obstruction with single transition point, the two pathophysiologic signs mentioned above must be looked for to diagnose the possibility of organo-axial volvulus.

Organ Atrophy Induced by Sorafenib and Sunitinib - Quantitative Computed Tomography (CT) Evaluation of the Pancreas, Thyroid Gland and Spleen

Background

To evaluate organ atrophy induced by sorafenib and sunitinib, we retrospectively reviewed the CT scans of renal cell carcinoma (RCC) patients receiving molecular targeted therapy (MTT) using sorafenib or sunitinib, and performed volumetric analysis of the pancreas, thyroid gland, and spleen.

Material/Methods

Thirteen RCC patients receiving MTT were assigned as the evaluation cases (MTT group), while thirteen additional RCC patients not receiving MTT were retrieved as the Control group. We evaluated the baseline and follow-up CT studies. The volume of the three organs estimated by CT volumetry was compared between the baseline and follow-up CTs. The atrophic ratio of the organ volume in the follow-up CT to that in the baseline CT was calculated, and compared between the MTT and Control groups.

Results

All measured organs in the MTT group showed statistically significant volume loss, while no significant change was observed in the Control group. Mean atrophic ratio in the MTT group was 0.74, 0.58, and 0.82 for the pancreas, thyroid and spleen, respectively. The differences in atrophic ratios between both groups were all statistically significant (P<0.05).

Conclusions

Single-agent sorafenib or sunitinib therapy induced statistically significant atrophy in the pancreas, thyroid, and spleen.

Endoleak detection after endovascular aneurysm repair using unenhanced MRI with flow suppression technique: Feasibility study in comparison with contrast-enhanced CT

OBJECTIVES

To evaluate the feasibility of unenhanced motion-sensitized-driven equilibrium (MSDE)-prepared balanced turbo field echo (BTFE) sequences for detecting endoleaks after endovascular aneurysm repair (EVAR).

METHODS

Forty-six patients treated with EVAR for aortic and/or iliac arterial aneurysms underwent contrast-enhanced CT and MSDE-prepared BTFE sequences with and without flow suppression. Two independent observers reviewed these sequences and their subtraction images and assigned confidence levels for detecting endoleaks. Relative contrast values were calculated by dividing signal intensities by those of paraspinal muscles. CT provided the reference standard.

RESULTS

CT showed types I and II endoleaks in one and ten patients, respectively. Areas under receiver operating characteristic curves were 0.92 and 0.97 for observers 1 and 2, respectively. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of both observers were 91 (10/11), 91(32/35), 91 (42/46), 77 (10/13) and 97 % (32/33), respectively. Relative contrast values of endoleaks and flowing blood significantly decreased by flow suppression on MSDE-prepared BTFE images (P = 0.002 and P < 0.0001 respectively), and were significantly higher than those of the excluded aneurysms on subtraction images (P = 0.003 and P = 0.001, respectively).

CONCLUSIONS

Unenhanced MSDE-prepared BTFE sequences are feasible for detecting endoleaks.

KEY POINTS

• Flow suppression significantly reduces endoleak signals on MSDE-prepared BTFE images. • Subtraction images of MSDE-prepared BTFE sequences ± flow suppression demonstrate endoleaks. • MSDE-prepared BTFE sequences indicate high diagnostic values (>90 %) except PPV (77 %). • MSDE-prepared BTFE sequences need further refinement to reduce false positives. • Endoleaks can be detected without contrast injection using MSDE-prepared BTFE sequences.

Enhanced miR-210 expression promotes the pathogenesis of endometriosis through activation of signal transducer and activator of transcription 3

STUDY QUESTION

What are the roles of the microRNA miR-210-an miRNA that is up-regulated in endometriotic cyst stromal cells (ECSCs)-in the pathogenesis of endometriosis?

SUMMARY ANSWER

Up-regulated miR-210 expression in ECSCs is involved in their proliferation, resistance to apoptosis and angiogenesis through signal transducer and activator of transcription (STAT) 3.

WHAT IS KNOWN ALREADY

In the pathogenesis of endometriosis, a number of roles for microRNAs (miRNAs) are becoming apparent.

STUDY DESIGN, SIZE, DURATION

ECSCs and normal endometrial stromal cells (NESCs) were isolated from ovarian endometriotic tissues (patients aged 24-40 years undergoing salpingo-oophorectomy or evisceration for the treatment of ovarian endometriotic cysts, n = 10) and the eutopic endometrial tissues without endometriosis (premenopausal patients aged 35-45 years undergoing hysterectomies for subserousal leiomyoma, n = 13), respectively.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We used a global gene expression microarray technique to identify downstream targets of miR-210, and we assessed the functions of miR-210 in the pathogenesis of endometriosis by using the miR-210-transfected NESCs.

MAIN RESULTS AND THE ROLE OF CHANCE

Gene expression microarray analysis revealed that one of the key target molecules of miR-210 is STAT3. In the NESCs, in comparison to the control, miR-210 transfection resulted in the induction of cell proliferation (P < 0.0005), the production of vascular endothelial cell growth factor (VEGF) (P < 0.0005) and the inhibition of apoptosis (P < 0.05) through STAT3 activation [increased levels of mRNA (P < 0.0005), and protein (P < 0.005)]. In the ECSCs, inhibitors of STAT3 inhibited the cell proliferation and VEGF production (P < 0.05), and induced the apoptosis of these cells (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

The roles of aberrant miR-210 expression were investigated only in the stromal component of ectopic and eutopic endometrium. Control endometrial tissues were obtained from premenopausal patients who had subserosal leiomyoma and NESC gene expression patterns may be altered in these women. Furthermore, the effects of STAT3 inhibitors were evaluated only in ECSCs and not in NESCs.

WIDER IMPLICATIONS OF THE FINDINGS

The present findings indicate that miR-210 induces NESCs to differentiate into the endometriotic phenotype and we speculate that up-regulated miR-210 expression in ECSCs is involved in the creation of the endometriosis-specific cellular dysfunctions through epigenetic mechanisms. The data indicate that STAT3 inhibitors may be promising candidates for the treatment of endometriosis.

STUDY FUNDING/COMPETING INTERESTS

This work was supported in part by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (no. 13237327 to K.N., no. 25861500 to Y.K. and no. 23592407 to H.N.). There are no conflicts of interest to declare.

[A case of incidentally diagnosed retroperitoneal lymphangioleiomyomatosis with no respiratory symptoms]

A 39-year-old woman presented with a large retroperitoneal tumor found incidentally in a routine examination. The 138×37×26 mm mass was located in the left paraaortic region. Blood tests and urinalyses including endocrinological examinations revealed no abnormalities. A chest computed tomography revealed multiple thin-walled pulmonary cysts, which is a characteristic of lymphangioleiomyomatosis (LAM). Because the findings strongly suggested that the retroperitoneal tumor was an extrapulmonary manifestion of LAM, we performed laparoscopic resection of the tumor for diagnosis and treatment. The pathological diagnosis was LAM. The tumor cells were immunohistochemically positive for α -smooth muscle actin and weakly positive for HMB45, which is consistent with LAM. The cells were also positive for estrogen receptor (ER) and progesterone receptor (PgR). LAM is a rare progressive disease that affects mainly the lung, and leads to chronic respiratory failure. Extrapulmonary LAM without respiratory symptoms, is extremely rare. In the past, the prognosis of LAM was poor, with a median survival of 8-10 years, but now 85% survive more than 10 years. In the present case, deterioration of pulmonary lesions was not observed during the 10 months follow-up. Because ERand PgRfindings were positive, we will consider hormonal therapy as a treatment option, when the pulmonary lesions progress in the present case.

A novel preoperative fusion analysis using three-dimensional MDCT combined with three-dimensional MRI for patients with hilar cholangiocarcinoma

The purpose of the present study was to evaluate the anatomical relationship between the tumor, portal veins, hepatic arteries, and hilar hepatic ducts at the hepatic hilum using a novel preoperative fusion analysis for patients with hilar cholangiocarcinoma. This involved combining three-dimensional multidetector-row computed tomography with three-dimensional magnetic resonance imaging. This novel fusion imaging technique can play an important clinical role for patients undergoing surgery for hilar cholangiocarcinoma.

Noninvasive visualization of endoleaks after endovascular aortic aneurysm repair through unenhanced MRI with motion-sensitized driven equilibrium preparation: Phantom experiments

PURPOSE

To optimize imaging parameters for balanced turbo field echo (BTFE) sequence combined with motion-sensitized driven equilibrium (MSDE) preparation for endoleak detection and type classification in phantom experiments.

MATERIALS AND METHODS

We prepared four phantoms: a pulsatile flow generator with an aortic aneurysm model simulating no endoleak, and a type-1, type-2, and type-3 endoleak. Throughout the experiments, MSDE-BTFE images with and without flow suppression were obtained at 1.5 T and subtraction images were used for image evaluation. The no-endoleak phantom was imaged using different MSDE-BTFE sequences to optimize the k-space trajectory and evaluate the use of electrocardiogram gating. The relative contrast between flowing saline and background was calculated. Then all phantoms were imaged to determine the optimal velocity encoding (VENC) for endoleak detection and type classification. Three independent observers performed the image evaluation. Consistencies between the interpreted and true results were analyzed using kappa statistics.

RESULTS

The 3D low-high k-space trajectory with electrocardiogram gating provided the highest relative contrast. Low VENCs of 2-10 cm/s and high VENCs of 20 cm/s showed perfect consistency in endoleaks detection and type classification, respectively.

CONCLUSION

MSDE-BTFE sequences of appropriate VENCs has potential for endoleak detection and type classification, without contrast material.

Depression and pregnancy-associated death by suicide after spinal cord injury: a case report

PURPOSE OF INVESTIGATION

To report a case of a pregnant woman with traumatic spinal cord injury complicated with a psychiatric disorder.

CASE REPORT

A 24-year-old woman at 18 weeks of gestation was transferred to our hospital with a history of having jumped from a third-floor apartment patio.

RESULT

A trauma survey showed no life-threatening hemorrhage, and fetal wellbeing was confirmed. Neurological examination showed complete loss of motor and sensory function in her lower extremities. Termination of pregnancy was advised and was achieved medically. Surgical intervention was performed to achieve stabilization of the spine and decompression of neural elements. After the operation, she was referred to a psychiatrist, and the administration of paroxetine, etizolam and flunitrazepam was begun. Four months after undergoing the abortion, she choked herself to death on her ward bed.

CONCLUSION

Although it is rare, we should pay special attention to the substantial suicide risk of women who face severe spinal cord injury.

Diffusion-weighted imaging findings of mucinous carcinoma arising in the ano-rectal region: comparison of apparent diffusion coefficient with that of tubular adenocarcinoma

PURPOSE

To determine the diffusion-weighted imaging (DWI) characteristics of ano-rectal mucinous carcinoma. Apparent diffusion coefficient (ADC) and DWI findings for mucinous and tubular adenocarcinomas were retrospectively compared.

MATERIALS AND METHODS

Eight-one consecutive surgically resected ano-rectal adenocarcinomas were evaluated. The patient group consisted of 15 mucinous and 66 tubular adenocarcinomas. The DWI signal intensity (SI) pattern of each tumor was visually classified into one of three groups. Differences in the proportions in each group were statistically compared for the two types of tumor. The ADCs of each tumor, calculated from two different b-factors (0 and 1500 s/mm(2)) were compared statistically.

RESULTS

Visual evaluation revealed ten mucinous carcinomas as predominantly hypointense lesions, and the remaining five as mixed SI lesions. Sixty-one of 66 tubular adenocarcinomas had hyperintensities; the remaining five had mixed SI. The different proportions in each group were statistically significant. The mean ADC for mucinous carcinomas was 1.49 ± 0.34 × 10(-3) mm(2)/s whereas that for tubular adenocarcinomas was 0.80 ± 0.15 × 10(-3) mm(2)/s. The difference between those figures was statistically significant.

CONCLUSION

In DWI, mucinous carcinomas had higher ADCs and lower SI than tubular adenocarcinomas. DWI and ADC measurements were useful for differentiating these two tumors.

Pancreatic cancer screening employing noncontrast magnetic resonance imaging combined with ultrasonography

PURPOSE

We have conducted an initial evaluation on the potential of combining noncontrast magnetic resonance imaging (MRI) and ultrasonography (US) to screen for pancreatic cancer.

MATERIALS AND METHODS

An independent ethics committee approved this study. A total of 2511 patients who underwent US were enrolled. Among them, noncontrast MRI was performed in patients in whom the entire pancreas was difficult to depict or in those with US-suspected pancreatic lesions. In total, using 1.5-T MRI, T1- and T2-weighted imaging, magnetic resonance cholangiopancreatography, and diffusion-weighted imaging, we acquired a variety of images. The efficacy of US and MRI in screening for pancreatic lesions, including pancreatic cancer, was evaluated.

RESULTS

Of 2511 patients, 184 underwent MRI, and the pancreas was demonstrated in all of them. Among the 2511, five pancreatic cancers were detected by MRI combined with US (detection rate 0.20%). Of the five pancreatic cancers, three were detected by US (detection rate 0.12%) and two by MRI. Four of the five pancreatic cancers were resectable.

CONCLUSION

By combining noncontrast MRI with US, pancreatic cancer can be detected with high accuracy. Other pancreatic lesions that require follow-up, including intraductal papillary mucinous neoplasms, can also be detected. Thus, pancreatic cancer screening with a combination of US and MRI is suggested.

Primary mucinous adenocarcinoma of the vagina

PURPOSE

Primary mucinous adenocarcinoma of the vagina is a rare disease which is characterized by aggressiveness and poor prognosis because of its rapid growth and recurrence, its frequent distant metastases, and its relative resistance to conventional treatment modalities including surgery, radiotherapy, and chemotherapy. We report a case of advanced stage primary mucinous adenocarcinoma of the vagina that showed a highly aggressive course and resistance to combination chemotherapy with paclitaxel and carboplatin.

CASE

A 46-year-old multigravid Japanese woman was admitted to our hospital to be treated for Stage IVb primary mucinous adenocarcinoma of the vagina. She had no history of in utero exposure to diethylstilbestrol. She was treated by two courses of neoadjuvant chemotherapy with tri-weekly paclitaxel and carboplatin, which were not effective. Subsequently, total pelvic exenteration with pelvic lymphadenectomy was performed. However, the disease progressed rapidly and the patient died five months after the initial treatment.

CONCLUSION

Because of its rarity, little is known about the behavior of primary mucinous adenocarcinoma of the vagina. Additional data about patients with this rare tumor should be collected and analyzed in an attempt to elucidate its prognostic factors, characteristics, optimal treatment, and outcome.

Role of diffusion-weighted magnetic resonance imaging in the differential diagnosis of focal hepatic lesions

AIM: To evaluate the utility of diffusion-weighted imaging (DWI) in screening and differential diagnosis of benign and malignant focal hepatic lesions.

METHODS: Magnetic resonance imaging (MRI) examinations were performed using the Signa Excite Xl Twin Speed 1.5T system (GE Healthcare, Milwaukee, WI, USA). Seventy patients who had undergone MRI of the liver [29 hepatocellular carcinomas (HCC), four cholangiocarcinomas, 34 metastatic liver cancers, 10 hemangiomas, and eight cysts] between April 2004 and August 2008 were retrospectively evaluated. Visualization of lesions, relative contrast ratio (RCR), and apparent diffusion coefficient (ADC) were compared between benign and malignant lesions on DWI. Superparamagnetic iron oxide (SPIO) was administered to 59 patients, and RCR was compared pre- and post-administration.

RESULTS: DWI showed higher contrast between malignant lesions (especially in multiple small metastatic cancers) and surrounding liver parenchyma than did contrast-enhanced computed tomography. ADCs (mean ± SD × 10^-3 mm²/s) were significantly lower (P < 0.05) in malignant lesions (HCC: 1.31 ± 0.28 and liver metastasis: 1.11 ± 0.22) and were significantly higher in benign lesions (hemangioma: 1.84 ± 0.37 and cyst: 2.61 ± 0.45) than in the surrounding hepatic tissues. RCR between malignant lesions and surrounding hepatic tissues significantly improved after SPIO administration, but RCRs in benign lesions were not improved.

CONCLUSION: DWI is a simple and sensitive method for screening focal hepatic lesions and is useful for differential diagnosis.

Direct observation of the critical relaxation of polarization clusters in BaTiO3 using a pulsed x-ray laser technique

We have developed a new method to investigate the relaxation time of the dipole moment in polarization clusters in BaTiO3. Time correlation of speckle intensities was measured by the use of a double pulsed soft x-ray laser. The evolution of the relaxation time of the dipole moment near the Curie temperature (T(C)) was investigated. The maximum relaxation time (approximately 90 ps) is shown to appear at a temperature of 4.5 K above the T(C), being coincident with the one where the maximum polarization takes place. This method is widely applicable to any other critical decay processes at phase transitions.

Involvement of resistance to apoptosis in the pathogenesis of endometriosis

Endometriosis, a disease affecting 3-10% of women of reproductive age, is characterized by the ectopic growth of endometrial tissue. Increasingly, endometriosis is also becoming recognized as a condition in which ectopic endometrial cells exhibit abnormal proliferative and apoptotic regulation in response to appropriate stimuli. Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that, in healthy women, endometrial cells expelled during menstruation do not survive in ectopic locations because of programmed cell death, while decreased apoptosis may lead to the ectopic survival and implantation of these cells, resulting in the development of endometriosis. Both the inability of endometrial cells to transmit a 'death' signal and the ability of endometrial cells to avoid cell death have been associated with increased expression of anti-apoptotic factors and decreased expression of pre-apoptotic factors. This paper is a review of the recent literature focused on the differential expression of apoptosis-associated molecules in the normal endometria of women without endometriosis, and in the eutopic and ectopic endometria of women with endometriosis. The role of apoptosis in the pathogenesis of endometriosis and the basic and clinical research on the current medical treatment for endometriosis from the view of apoptosis will be discussed.

Radiofrequency ablation of the liver: determination of ablative margin at MR imaging with impaired clearance of ferucarbotran--feasibility study

Institutional review board approval and informed consent were obtained. The feasibility of magnetic resonance (MR) imaging with impaired clearance of ferucarbotran to visualize ablated liver parenchyma surrounding a tumor (ablative margin [AM]) was evaluated after radiofrequency (RF) ablation of the liver. Twenty-one patients with hepatocellular carcinomas underwent RF ablation 2-7 hours after ferucarbotran-enhanced MR imaging. On unenhanced T2*-weighted images acquired after 3-5 days, AMs appeared as hypointense rims. The AM status was related to incidence of residual or recurrent tumors. This technique is feasible for visualization of AM and prediction of residual or recurrent tumors after RF ablation of the liver.

Formation of sp3-bonded carbon nanostructures by femtosecond laser excitation of graphite

A scanning tunneling microscopy study and ab initio total energy calculations have identified the atomic-level structure of novel sp;{3}-bonded carbon nanoscale domains formed dynamically from graphite by femtosecond-laser excitation. The structure is characterized by a pseudo sp;{3}-bonding configuration that results in inward displacement of surface carbon atoms by 0.5 A in every third row along the [11[over ]00] orientation. This structural periodicity is unique and differs from conventional phases of diamond.

Advances in breast MRI: diffusion-weighted imaging of the breast

DWI, which is less affected by the state of the background mammary gland, has sufficient capability to diagnose invasive, noninvasive, and invasive lobular carcinoma. DWI is different from conventional methods based on blood flow data and has the potential to provide useful information for the evaluation of NAC, which is considered to be insufficient at present. Having the ability to provide steady, high-resolution tissue images, DWI is expected to play an important role in future breast cancer diagnosis. DWI, however, is not a complete method of diagnosis. Limits exist in spatial resolution and problems with ADC. In consideration of these shortcomings, we need to apply DWI to clinical practice while taking advantage of its high contrast resolution.

Bowel obstruction due to endometriosis in the rectovaginal septum

It is very rare that endometriotic lesions in the rectovaginal septum cause ileus. We report a case of bowel obstruction due to endometriotic lesions in the rectovaginal septum in a 22-year-old woman whose barium enema presented with apple-core-like findings. Diagnostic and treatment modalities were discussed. Preoperative and postoperative gonadotropin-releasing hormone analog and aromatase inhibitor therapy promote relief of clinical symptoms, a reduction of tumor volume and a better approach to radical surgery.

Hepatic pseudo-anisotropy: a specific artifact in hepatic diffusion-weighted images obtained with respiratory triggering

PURPOSE

Hepatic pseudo-anisotropy is an artifact observed in hepatic diffusion-weighted imaging under respiratory triggering (RT-DWI). To determine the clinical significance of this phenomenon, hepatic RT-DW images were reviewed.

METHODS

One hundred and five MR examinations, including RT-DWI, were assessed. The patient group included 62 non-cirrhotic and 43 cirrhotic individuals. All images were evaluated by mutual agreement of two radiologists from the viewpoints of incidence of pseudo-anisotropy and correlation between pseudo-anisotropy and the quality of trace images. The ADC of normal hepatic parenchyma of non-cirrhotic livers were measured in both areas with and without pseudo-anisotropy.

RESULTS

Pseudo-anisotropy was observed in 60% of non-cirrhotic (37/62) and 30% of cirrhotic (13/43) images. The difference between the two groups was statistically significant (P < 0.001). The quality of trace images showed a tendency to worsen as pseudo-anisotropy became significant. However, the quality of trace images was generally satisfactory, with only two patients whose trace images were difficult to interpret due to pseudo-anisotropy. The areas with pseudo-anisotropy showed higher ADC than those without pseudo-anisotropy (P < 0.001).

CONCLUSION

Pseudo-anisotropy is a type of artifact that originates from respiratory movement. Even though respiratory triggering is employed, ADC measurement of the liver is inaccurate because of pseudo-anisotropy, especially in non-cirrhotic patients.

Influence of delayed tumor clearance on reliability of complete response rate in chemoradiotherapy for head and neck cancer

OBJECTIVE

The relationship was studied between the timing of assessment of complete response and ultimate cure rate in the chemoradiotherapy of advanced head and neck cancer.

METHODS

A retrospective review was conducted regarding tumor responses at 4 weeks, 3 months, and 6 months after concomitant chemoradiotherapy using cisplatin and 5-FU for 70 patients with stage III/IV squamous cell carcinoma of the oropharynx, hypopharynx and supraglottic larynx. Predictive values of tumor responses at these three time points for survival and tumor control at 2 years were tested using the chi-square test.

RESULTS

Twelve (17%) patients achieved complete response (CR) at 4 weeks. Because of late regression or early recurrence, the CR rate changed to 18/70 (26%) and 24/70 (34%) at 3 and 6 months, respectively. CR or not at 6 months was significantly correlated with all survival endpoints (P < 0.001), but not those at 4 weeks and 3 months (P > 0.100). Kaplan-Meier estimate of overall survival at 5 years was 63% (95% CI 43-84%) for 24 CR patients at 6 months.

CONCLUSION

CR rate at 6 months was a better surrogate endpoint than that at 4 weeks or 3 months in this series of patients.