Combination of leucine-rich alpha-2 glycoprotein and fecal markers detect Crohn's disease activity confirmed by balloon-assisted enteroscopy

BACKGROUND/AIMS

Endoscopic activity confirmed by enteroscopy is associated with poor clinical outcome in Crohn's disease (CD). We investigated which of the existing biomarkers best reflects endoscopic activity in CD patients including the small bowel, and whether their combined use can improve accuracy.

METHODS

One hundred and four consecutive patients with ileal and ileocolonic type CD who underwent balloon-assisted enteroscopy (BAE) from October 2021 to August 2022 were enrolled, with clinical and laboratory data prospectively collected and analyzed.

RESULTS

Hemoglobin, platelet count, C-reactive protein, leucine-rich alpha-2 glycoprotein (LRG), fecal calprotectin, and fecal hemoglobin all showed significant difference in those with ulcers found on BAE. LRG and fecal calprotectin showed the highest areas under the curve (0.841 and 0.853) for detecting ulcers. LRG showed a sensitivity of 78% and specificity of 80% at a cutoff value of 13 μg/mL, whereas fecal calprotectin showed a sensitivity of 91% and specificity of 67% at a cutoff value of 151 μg/g. Dual positivity for LRG and fecal calprotectin, as well as LRG and fecal hemoglobin, both predicted ulcers with an improved specificity of 92% and 100%. A positive LRG or fecal calprotectin/hemoglobin showed an improved sensitivity of 96% and 91%. Positivity for LRG and either of the fecal biomarkers was associated with increased risk of hospitalization, surgery, and relapse.

CONCLUSIONS

The biomarkers LRG, fecal calprotectin, and fecal hemoglobin can serve as noninvasive and accurate tools for assessing activity in CD patients confirmed by BAE, especially when used in combination.

Association of AI-determined Kellgren-Lawrence grade with medial meniscus extrusion and cartilage thickness by AI-based 3D MRI analysis in early knee osteoarthritis

The associations among Kellgren-Lawrence (KL) grade, medial meniscus extrusion (MME), and cartilage thickness in knee osteoarthritis (OA) remain insufficiently understood. Our aim was to determine these associations in early to moderate medial tibiofemoral knee OA. We included 469 subjects with no lateral OA from the Kanagawa Knee Study. KL grade was assessed using artificial intelligence (AI) software. The MME was measured by MRI, and the cartilage thickness was evaluated in 18 subregions of the medial femorotibial joint by another AI system. The median MME width was 1.4 mm in KL0, 1.5 mm in KL1, 2.4 mm in KL2, and 6.0 mm in KL3. Cartilage thinning in the medial femur occurred in the anterior central subregion in KL1, expanded inwardly in KL2, and further expanded in KL3. Cartilage thinning in the medial tibia occurred in the anterior and middle external subregions in KL1, expanded into the anterior and middle central subregions in KL2, and further expanded in KL3. The absolute correlation coefficient between MME width and cartilage thickness increased as the KL grade increased in some subregions. This study provides novel insights into the early stages of knee OA and potentially has implications for the development of early intervention strategies.

Novel utility of Vesical Imaging-Reporting and Data System in multimodal treatment for muscle-invasive bladder cancer

OBJECTIVES

To examine the clinical significance of the Vesical Imaging-Reporting and Data System (VI-RADS) in predicting outcome of multimodal treatment (MMT) in muscle-invasive bladder cancer (MIBC) patients.

METHODS

We reviewed 78 pathologically proven MIBC patients who underwent MMT including transurethral resection and chemoradiotherapy, followed by partial or radical cystectomy. Treatment response was assessed through histologic evaluation of cystectomy specimens. Two radiologists categorized the index lesions of pretherapeutic MRI according to the 5-point VI-RADS score. The associations of VI-RADS score with the therapeutic effect of MMT were analyzed. The diagnostic performance of VI-RADS scores with a cut-off VI-RADS scores  ≤ 2 or ≤ 3 for predicting pathologic complete response to MMT (MMT-CR) was evaluated.

RESULTS

MMT-CR was achieved in 2 (100%) of VI-RADS score 1 (n = 2), 16 (84%) of score 2 (n = 19), 12 (86%) of score 3 (n = 14), 7 (64%) of score 4 (n = 11), and 14 (44%) of score 5 (n = 32). VI-RADS score was inversely associated with the incidence of MMT-CR (p = 0.00049). The cut-off VI-RADS score  ≤ 2 and  ≤ 3 could predict the favorable therapeutic outcome of MMT with high specificity (0.89 with 95% confidence interval [CI]: 0.71-0.98 and 0.82 with 95% CI: 0.62-0.94, respectively) and high positive predictive value (0.86 with 95% CI: 0.64-0.97 and 0.86 with 95% CI: 0.70-0.95, respectively).

CONCLUSION

VI-RADS score may serve as an imaging marker in MIBC patients for predicting the therapeutic outcome of MMT.

CLINICAL RELEVANCE STATEMENT

Muscle-invasive bladder cancer patients with a lower Vesical Imaging-Reporting and Data System score can be a good candidate for bladder-sparing treatment incorporating multimodal treatment.

KEY POINTS

• Vesical Imaging-Reporting and Data System (VI-RADS) score was potentially valuable for classifying pathologic tumor response in patients with muscle-invasive bladder cancer. • The likelihood of achieving complete response of multimodal treatment (MMT) decreased with increasing VI-RADS score. • VI-RADS score could serve as an imaging marker that optimizes patient selection for MMT.

Motility Mapping Quantification Using the Classical Optical Flow Algorithm for Small Bowel Crohn's Disease: Comparison with Balloon-assisted Enteroscopy Findings

PURPOSE

To quantify bowel motility shown on cine MRI using the classical optical flow algorithm and compare it with balloon-assisted enteroscopy (BAE) findings in patients with Crohn's disease (CD).

METHODS

This retrospective study included 29 consecutive patients with CD who had undergone MR enterocolonography (MREC) and BAE between March and May 2017. We developed computer software to present motion vector magnitudes between consecutive cine MR images as bowel motility maps via a classical optical flow algorithm using the Horn-Schunck method. Cine MR images were acquired with a balanced steady-state free precession sequence in the coronal direction to capture small bowel motility. The small bowels were divided into three segments. In total, 63 bowel segments were assessed via BAE and MREC. Motility scores on the maps, simplified MR index of activity (sMaRIA), and MREC score derived from a 5-point MR classification were assessed independently by two radiologists and compared with the CD endoscopic index of severity (CDEIS). Correlations were assessed using Spearman's rank coefficient. The areas under the receiver-operating characteristic curve (AUCs) of motility score for differentiating CDEIS was calculated; a P value < 0.05 was considered statistically significant.

RESULTS

Motility score was negatively correlated with CDEIS (r = -0.59 [P < 0.001] and -0.54 [P < 0.001]), and the AUCs of motility scores for detecting CDEIS ≥ 3 were 88.2% and 78.6% for observers 1 and 2, respectively. There were no significant differences in the AUC for detecting CDEIS ≥ 3 and CDEIS ≥ 12 between motility and sMaRIA or MREC score.

CONCLUSION

The motility map was feasible for locally quantifying the bowel motility. In addition, the motility score on the map reflected the endoscopic inflammatory activity of each small bowel segment in patients with CD; hence, it could be used as a tool in objectively interpreting cine MREC to predict inflammatory activity in CD.

Transmural remission characterized by high biologic concentrations demonstrates better prognosis in Crohn's disease

BACKGROUND

The importance and pathophysiology of transmural healing in patients with Crohn's disease (CD) remains to be verified. We aimed to examine the association between serum concentrations of biologics and transmural remission evaluated via magnetic resonance enterography (MRE).

METHODS

We enrolled patients with CD who received maintenance biologics 1 year after induction and prospectively followed up for at least 1 year after baseline laboratory, endoscopic and MRE examination. We evaluated the relationship between baseline factors including the presence of transmural remission and patient prognosis, as well as between serum concentrations and transmural remission.

RESULTS

We included 134 patients. Of them, 65, 31, 27, and 11 patients received infliximab, adalimumab, ustekinumab, and vedolizumab, respectively. Those who achieved transmural remission showed a lower risk of hospitalization and surgery than those who did not achieve remission (P < 0.01). Adjusted hazard ratios of transmural remission for predicting hospitalization and surgery was 0.11 and 0.02, respectively, which was lower than that of clinical remission, biochemical remission, and endoscopic remission. Regarding serum concentrations, the median concentration was higher in patients with transmural remission than in patients with transmural activity for all agents (P < 0.01 for infliximab, P = 0.04 for adalimumab, P < 0.01 for ustekinumab, P = 0.08 for vedolizumab).

CONCLUSIONS

Transmural remission was the best predictor for prognosis in CD patients who received maintenance biologic therapy. High drug concentration levels were associated with transmural remission confirmed via MRE.

Virtual Interpolation Images of Tumor Development and Growth on Breast Ultrasound Image Synthesis With Deep Convolutional Generative Adversarial Networks

OBJECTIVES

We sought to generate realistic synthetic breast ultrasound images and express virtual interpolation images of tumors using a deep convolutional generative adversarial network (DCGAN).

METHODS

After retrospective selection of breast ultrasound images of 528 benign masses, 529 malignant masses, and 583 normal breasts, 20 synthesized images of each were generated by the DCGAN. Fifteen virtual interpolation images of tumors were generated by changing the value of the input vector. A total of 60 synthesized images and 20 virtual interpolation images were evaluated by 2 readers, who scored them on a 5-point scale (1, very good; to 5, very poor) and then answered whether the synthesized image was benign, malignant, or normal.

RESULTS

The mean score of overall quality for synthesized images was 3.05, and that of the reality of virtual interpolation images was 2.53. The readers classified the generated images with a correct answer rate of 92.5%.

CONCLUSIONS

A DCGAN can generate high-quality synthetic breast ultrasound images of each pathologic tissue and has the potential to create realistic virtual interpolation images of tumor development.

The Utility of Deep Learning in Breast Ultrasonic Imaging: A Review

Breast cancer is the most frequently diagnosed cancer in women; it poses a serious threat to women's health. Thus, early detection and proper treatment can improve patient prognosis. Breast ultrasound is one of the most commonly used modalities for diagnosing and detecting breast cancer in clinical practice. Deep learning technology has made significant progress in data extraction and analysis for medical images in recent years. Therefore, the use of deep learning for breast ultrasonic imaging in clinical practice is extremely important, as it saves time, reduces radiologist fatigue, and compensates for a lack of experience and skills in some cases. This review article discusses the basic technical knowledge and algorithms of deep learning for breast ultrasound and the application of deep learning technology in image classification, object detection, segmentation, and image synthesis. Finally, we discuss the current issues and future perspectives of deep learning technology in breast ultrasound.

Dynamic Enhancement Pattern on CT for Predicting Pancreatic Neuroendocrine Neoplasms with Low PAX6 Expression: A Retrospective Observational Study

Paired box 6 (PAX6) is a transcription factor that plays a critical role in tumor suppression, implying that the downregulation of PAX6 promotes tumor growth and invasiveness. This study aimed to examine dynamic computed tomography (CT) features for predicting pancreatic neuroendocrine neoplasms (Pan-NENs) with low PAX6 expression. We retrospectively evaluated 51 patients with Pan-NENs without synchronous liver metastasis to assess the pathological expression of PAX6. Two radiologists analyzed preoperative dynamic CT images to determine morphological features and enhancement patterns. We compared the CT findings between low and high PAX6 expression groups. Pathological analysis identified 11 and 40 patients with low and high PAX6 expression, respectively. Iso- or hypoenhancement types in the arterial and portal phases were significantly associated with low PAX6 expression (p = 0.009; p = 0.001, respectively). Low PAX6 Pan-NENs showed a lower portal enhancement ratio than high PAX6 Pan-NENs (p = 0.044). The combination based on enhancement types (iso- or hypoenhancement during arterial and portal phases) and portal enhancement ratio (≤1.22) had 54.5% sensitivity, 92.5% specificity, and 84.3% accuracy in identifying low PAX6 Pan-NENs. Dynamic CT features, including iso- or hypoenhancement types in the arterial and portal phases and lower portal enhancement ratio may help predict Pan-NENs with low PAX6 expression.

High b-value computed diffusion-weighted imaging for differentiating bowel inflammation in Crohn's disease

Purpose This study evaluated whether high b-value computed diffusion-weighted imaging (cDWI) can improve detection and differentiation of bowel inflammation in patients with Crohn's disease (CD). Methods Fifty-four consecutive CD patients who had undergone magnetic resonance enterography (MRE) and ileocolonoscopy (ICS) or balloon-assisted enteroscopy (BAE) were retrospectively studied; cDWI with a b-value = 1500s/mm² (cDWI1500) was generated using DWI acquired with b-values of 0 and 800 s/mm² (aDWI800). Overall, 366 bowel segments were evaluated. The signal intensities (SIs) of the bowel lumina were visually assessed on DWI. Bowel wall-to-iliopsoas muscle SI ratios on aDWI800 and cDWI1500 images and apparent diffusion coefficient (ADC) values were measured; visual assessments for lesion detection were performed using a 5-point Likert-like scale on plain MRE with aDWI800, plain MRE with cDWI1500, and contrast-enhanced (CE)-MRE without DWI. The area under the receiver-operating characteristic curve (AUC) was calculated to compare quantitative and qualitative assessments. Results SIs of the intraluminal fluid were shown as comparable to, or lower than background SIs on 157 (44.7 %) and 345 (98.3 %) of 351 segments on aDWI800 and cDWI1500, respectively. AUCs of SI ratios on cDWI1500 images (82.0 %, [95 % confidence interval: 76.6-87.3 %]) were greater than on aDWI800 (75.2 %, [68.2-82.3 %]; p < 0.001), and were close to the ADC values (81.5 % [76.3-86.7 %]; p = 0.76). The AUCs of CE-MRE images were largest, followed by plain MRE with cDWI1500, and plain MRE with aDWI800. Conclusions As it suppresses the SIs of intraluminal fluid and improves contrast between severe and non-severe inflammation, cDWI1500 helps with CD evaluation.

Deep-learning approach with convolutional neural network for classification of maximum intensity projections of dynamic contrast-enhanced breast magnetic resonance imaging

PURPOSE

We aimed to evaluate deep learning approach with convolutional neural networks (CNNs) to discriminate between benign and malignant lesions on maximum intensity projections of dynamic contrast-enhanced breast magnetic resonance imaging (MRI).

METHODS

We retrospectively gathered maximum intensity projections of dynamic contrast-enhanced breast MRI of 106 benign (including 22 normal) and 180 malignant cases for training and validation data. CNN models were constructed to calculate the probability of malignancy using CNN architectures (DenseNet121, DenseNet169, InceptionResNetV2, InceptionV3, NasNetMobile, and Xception) with 500 epochs and analyzed that of 25 benign (including 12 normal) and 47 malignant cases for test data. Two human readers also interpreted these test data and scored the probability of malignancy for each case using Breast Imaging Reporting and Data System. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) were calculated.

RESULTS

The CNN models showed a mean AUC of 0.830 (range, 0.750-0.895). The best model was InceptionResNetV2. This model, Reader 1, and Reader 2 had sensitivities of 74.5%, 72.3%, and 78.7%; specificities of 96.0%, 88.0%, and 80.0%; and AUCs of 0.895, 0.823, and 0.849, respectively. No significant difference arose between the CNN models and human readers (p > 0.125).

CONCLUSION

Our CNN models showed comparable diagnostic performance in differentiating between benign and malignant lesions to human readers on maximum intensity projection of dynamic contrast-enhanced breast MRI.

Evaluation of the Usefulness of CO-RADS for Chest CT in Patients Suspected of Having COVID-19

The purpose of this study was to use the Coronavirus Disease 2019 (COVID-19) Reporting and Data System (CO-RADS) to evaluate the chest computed tomography (CT) images of patients suspected of having COVID-19, and to investigate its diagnostic performance and interobserver agreement. The Dutch Radiological Society developed CO-RADS as a diagnostic indicator for assessing suspicion of lung involvement of COVID-19 on a scale of 1 (very low) to 5 (very high). We investigated retrospectively 154 adult patients with clinically suspected COVID-19, between April and June 2020, who underwent chest CT and reverse transcription-polymerase chain reaction (RT-PCR). The patients' average age was 61.3 years (range, 21-93), 101 were male, and 76 were RT-PCR positive. Using CO-RADS, four radiologists evaluated the chest CT images. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated. Interobserver agreement was calculated using the intraclass correlation coefficient (ICC) by comparing the individual reader's score to the median of the remaining three radiologists. The average sensitivity was 87.8% (range, 80.2-93.4%), specificity was 66.4% (range, 51.3-84.5%), and AUC was 0.859 (range, 0.847-0.881); there was no significant difference between the readers (p > 0.200). In 325 (52.8%) of 616 observations, there was absolute agreement among observers. The average ICC of readers was 0.840 (range, 0.800-0.874; p < 0.001). CO-RADS is a categorical taxonomic evaluation scheme for COVID-19 pneumonia, using chest CT images, that provides outstanding performance and from substantial to almost perfect interobserver agreement for predicting COVID-19.

Efficient Anomaly Detection with Generative Adversarial Network for Breast Ultrasound Imaging

We aimed to use generative adversarial network (GAN)-based anomaly detection to diagnose images of normal tissue, benign masses, or malignant masses on breast ultrasound. We retrospectively collected 531 normal breast ultrasound images from 69 patients. Data augmentation was performed and 6372 (531 × 12) images were available for training. Efficient GAN-based anomaly detection was used to construct a computational model to detect anomalous lesions in images and calculate abnormalities as an anomaly score. Images of 51 normal tissues, 48 benign masses, and 72 malignant masses were analyzed for the test data. The sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of this anomaly detection model were calculated. Malignant masses had significantly higher anomaly scores than benign masses (p < 0.001), and benign masses had significantly higher scores than normal tissues (p < 0.001). Our anomaly detection model had high sensitivities, specificities, and AUC values for distinguishing normal tissues from benign and malignant masses, with even greater values for distinguishing normal tissues from malignant masses. GAN-based anomaly detection shows high performance for the detection and diagnosis of anomalous lesions in breast ultrasound images.

Classification of Breast Masses on Ultrasound Shear Wave Elastography using Convolutional Neural Networks

We aimed to use deep learning with convolutional neural networks (CNNs) to discriminate images of benign and malignant breast masses on ultrasound shear wave elastography (SWE). We retrospectively gathered 158 images of benign masses and 146 images of malignant masses as training data for SWE. A deep learning model was constructed using several CNN architectures (Xception, InceptionV3, InceptionResNetV2, DenseNet121, DenseNet169, and NASNetMobile) with 50, 100, and 200 epochs. We analyzed SWE images of 38 benign masses and 35 malignant masses as test data. Two radiologists interpreted these test data through a consensus reading using a 5-point visual color assessment (SWEc) and the mean elasticity value (in kPa) (SWEe). Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated. The best CNN model (which was DenseNet169 with 100 epochs), SWEc, and SWEe had a sensitivity of 0.857, 0.829, and 0.914 and a specificity of 0.789, 0.737, and 0.763 respectively. The CNNs exhibited a mean AUC of 0.870 (range, 0.844-0.898), and SWEc and SWEe had an AUC of 0.821 and 0.855. The CNNs had an equal or better diagnostic performance compared with radiologist readings. DenseNet169 with 100 epochs, Xception with 50 epochs, and Xception with 100 epochs had a better diagnostic performance compared with SWEc (P = 0.018-0.037). Deep learning with CNNs exhibited equal or higher AUC compared with radiologists when discriminating benign from malignant breast masses on ultrasound SWE.

Prognostic implications of 62Cu-diacetyl-bis (N4-methylthiosemicarbazone) PET/CT in patients with glioma

OBJECTIVE

The potential of positron emission tomography/computed tomography using ⁶²Cu-diacetyl-bis (N⁴-methylthiosemicarbazone) (⁶²Cu-ATSM PET/CT), which was originally developed as a hypoxic tracer, to predict therapeutic resistance and prognosis has been reported in various cancers. Our purpose was to investigate prognostic value of ⁶²Cu-ATSM PET/CT in patients with glioma, compared to PET/CT using 2-deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F-FDG).

METHOD

56 patients with glioma of World Health Organization grade 2-4 were enrolled. All participants had undergone both ⁶²Cu-ATSM PET/CT and ¹⁸F-FDG PET/CT within mean 33.5 days prior to treatment. Maximum standardized uptake value and tumor/background ratio were calculated within areas of increased radiotracer uptake. The prognostic significance for progression-free survival and overall survival were assessed by log-rank test and Cox's proportional hazards model.

RESULTS

Disease progression and death were confirmed in 37 and 27 patients in follow-up periods, respectively. In univariate analysis, there was significant difference of both progression-free survival and overall survival in age, tumor grade, history of chemoradiotherapy, maximum standardized uptake value and tumor/background ratio calculated using ⁶²Cu-ATSM PET/CT. Multivariate analysis revealed that maximum standardized uptake value calculated using ⁶²Cu-ATSM PET/CT was an independent predictor of both progression-free survival and overall survival (p < 0.05). In a subgroup analysis including patients of grade 4 glioma, only the maximum standardized uptake values calculated using ⁶²Cu-ATSM PET/CT showed significant difference of progression-free survival (p < 0.05).

CONCLUSIONS

⁶²Cu-ATSM PET/CT is a more promising imaging method to predict prognosis of patients with glioma compared to ¹⁸F-FDG PET/CT.

Prediction of histological grade of hepatocellular carcinoma using quantitative diffusion-weighted MRI: a retrospective multivendor study

OBJECTIVE

To evaluate the usefulness of quantitative diffusion-weighted (DW) imaging acquired by multivendor magnetic resonance units for predicting grade of hepatocellular carcinoma (HCC).

METHODS

83 patients with 100 histologically diagnosed HCCs who underwent pre-operative liver DW imaging with b = 0 and1000 s mm^-2 or b = 0 and800 s mm^-2 at any of six institutions were included. Two radiologists independently measured the apparent diffusion coefficient (ADC) of the lesion as well as non-ADC parameters, such as the relative contrast ratio and the contrast-to-noise ratio (CNR) between the lesion and the liver parenchyma on high b-value DW images. The diagnostic performance of the DW parameters in discriminating poorly-differentiated HCCs was compared using receiver operating characteristic (ROC) analysis.

RESULTS

The areas under the receiver operating characteristic curves for the CNR (86.4% [95% confidence interval (CI) (77.2-95.6] and 83.9% [95% CI 71.2-96.6] for b = 1000 and 800 s mm^-2, respectively] and the relative contrast ratio (85.3% [95% CI 75.5-94.8] and 83.5% [95% CI 70.5-96.4]) tended to be superior to the ADC [71.1% [95% CI (56.9-85.2)] and 75.7% [95% CI (55.1-96.2)]; p < 0.05 for CNR vs ADC for b = 1000 s mm^-2, but not significant for other parameters) for discrimination of poorly-differentiated HCCs.

CONCLUSION

All DW parameters could discriminate HCC grade. Non-ADC parameters might be more useful than the ADC for predicting poorly-differentiated HCCs. Advances in knowledge: The utility of quantitative DW parameters for predicting HCC grade was demonstrated by using multivendor MR units.

Utility of Magnetic Resonance Enterography For Small Bowel Endoscopic Healing in Patients With Crohn's Disease

OBJECTIVES

Small bowel (SB) endoscopic healing has not been well studied in patients with Crohn's disease (CD). This study aims to evaluate the utility of magnetic resonance (MR) enterography (MRE) for SB lesions in comparison with balloon-assisted enteroscopy (BAE) findings.

METHODS

In total, 139 patients with CD in clinical-serological remission were prospectively followed after BAE and MRE procedures. We applied a modified version of the Simple Endoscopic Score for CD (SES-CD) for an endoscopic evaluation of the SB, called the Simple Endoscopic Active Score for CD (SES-CDa). We also used the MR index of activity (MaRIA) for MR evaluations. The primary end points were time to clinical relapse (CD activity index of >150 with an increase of >70 points) and serological relapse (abnormal elevation of C-reactive protein).

RESULTS

Clinical and serological relapses occurred in 30 (21.6%) and 62 (44.6%) patients, respectively. SB endoscopic healing (SES-CDa<5) was observed in 76 (54.7%) patients. A multiple regression analysis showed that the lack of SB endoscopic healing was an independent risk factor for clinical relapses (hazard ratio (HR): 5.34; 95% confidence interval (CI): 2.06-13.81) and serological relapses (HR: 3.02; 95% CI: 1.65-5.51), respectively. MR ulcer healing (MaRIA score <11) demonstrated a high diagnostic accuracy (90.9%; 95% CI: 87.9-93.2%) for endoscopic healing. The kappa coefficient between BAE and MRE for longitudinal responsiveness was 0.754 (95% CI: 0.658-0.850) for clinical relapse and 0.783 (95% CI: 0.701-0.865) for serological relapse.

CONCLUSIONS

SB inflammation was associated with a poor prognosis in patients with clinical-serological remission. MRE is a valid and reliable examination for SB inflammatory activity both for cross-sectional evaluations and prognostic prediction.

Magnetic resonance evaluation for small bowel strictures in Crohn's disease: comparison with balloon enteroscopy

BACKGROUND

Magnetic resonance (MR) imaging is the recommended technique for detection of small bowel lesions in Crohn's disease. We aimed to evaluate the impact of stricture findings obtained by MR imaging on patient outcomes using balloon-assisted enteroscopy (BAE) as a reference.

METHODS

Two hundred Crohn's disease patients undergoing both MR enterocolonography and BAE were prospectively followed up for at least 1 year. The presence of strictures detected by MR enterocolonography was compared with endoscopic findings. Moreover, the relationship between MR findings and surgery was evaluated.

RESULTS

The accuracy of MR imaging for detection of small bowel strictures was defined by a sensitivity of 60.6% and a specificity of 93.4%. Major strictures (diameter less than 10 mm or with internal fistula), long strictures (length 10 mm or greater), and prestenotic dilatation were predictors of stricture detection by MR imaging (P = 0.001, 0.017, and 0.002 respectively). Surgery was performed in 31.6% of patients (18 of 57) in the MR-positive-BAE-positive stricture group and in 10.8% of patients (4 of 37) in the MR-negative-BAE-positive stricture group. Multiple regression analysis showed MR-positive-BAE-positive strictures were an independent risk factor for surgery (P = 0.002 at 6 months and P < 0.001 at 1 year). The surgery-free rate in the MR-negative-BAE-positive stricture group was significantly lower than that in nonstricture group at 1 year (P = 0.001).

CONCLUSIONS

The specificity of MR imaging for detection of small bowel strictures was clinically sufficient, and the MR procedure could detect critical strictures, which was a predictive factor for surgery. But MR-negative-BAE-positive strictures were also associated with an increased risk compared with no strictures after 1 year of follow-up.

Magnetic resonance enterography for the evaluation of the deep small intestine in Crohn's disease

For the control of Crohn's disease (CD) a thorough assessment of the small intestine is essential; several modalities may be utilized, with cross-sectional imaging being important. Magnetic resonance (MR) enterography, i.e., MRE is recommended as a modality with the highest accuracy for CD lesions. MRE and MR enteroclysis are the two methods performed following distension of the small intestine. MRE has sensitivity and specificity comparable to computed tomography enterography (CTE); although images obtained using MRE are less clear compared with CTE, MRE does not expose the patient to radiation and is superior for soft-tissue contrast. Furthermore, it can assess not only static but also dynamic and functional imaging and reveals signs of CD, such as abscess, comb sign, fat edema, fistula, lymph node enhancement, less motility, mucosal lesions, stricture, and wall enhancement. Several indices of inflammatory changes and intestinal damage have been proposed for objective evaluation. Recently, diffusion-weighted imaging has been proposed, which does not need bowel preparation and contrast enhancement. Comprehension of the characteristics of MRE and other modalities is important for better management of CD.

Vanishing intravenous leiomyomatosis after hysterectomy: Assessment of the need to perform complete resection

Intravenous leiomyomatosis (IVL) is a rare smooth muscle tumor that may extend into extrauterine veins. A high IVL recurrence rate has been reported after hysterectomy. A 44-year-old woman underwent total hysterectomy as a result of uterine leiomyoma, and IVL within the left uterine vein was incidentally found during the surgery. A residual tumor within the right ovarian vein was detected on contrast-enhanced computed tomography (CT) two days postoperatively. The tumor was diagnosed as IVL because it showed contrast enhancement on preoperative magnetic resonance imaging by retrospective re-interpretation. However, the tumor completely disappeared on contrast-enhanced CT without any medical treatment five months postoperatively. This is the first report of spontaneous regression of IVL. Postsurgical imaging was important to determine the residual extrauterine extension of IVL when it was incidentally found during gynecologic surgery. A hysterectomy alone may be adequate in selected cases, but long-term follow-up imaging is strongly recommended in all cases.

Diffusion-weighted magnetic resonance imaging to differentiate malignant from benign gallbladder disorders

PURPOSE

To retrospectively evaluate the utility of apparent diffusion coefficient (ADC) and lesion to spinal cord ratio (LSR) in diffusion-weighted magnetic resonance (MR) imaging (DWI) as compared with morphological assessment alone, for differentiating malignant from benign gallbladder disorders.

METHODS

This study was approved by the ethics committee, and written informed consent was waived. Ninety-one patients (13 malignancy and 78 benignancy) were reviewed. ADC was calculated using two DW images with different motion-probing gradient strengths (b=0, 1000s/mm(2)). LSR was measured by dividing the signal intensity of a thickened gallbladder wall by the maximum signal intensity of the lumbar enlargement of the spinal cord. In addition, the morphology of the gallbladders was assessed with conventional MR imaging.

RESULTS

In receiver operating characteristic curve analysis, the areas under the curves for ADC and LSR were 0.861 and 0.906, respectively. Three morphological findings were considered: a massive formation, a disrupted mucosal line, and the absence of a two-layered pattern. When a combination of two or more of these morphological findings was positive for malignancy, the sensitivity, specificity, and accuracy were 76.9%, 84.0%, and 83.0%, respectively. When a combination of three or more of the above morphological findings together with ADC of less than 1.2 × 10(-3)mm(2)/s or LSR of more than 0.48 were positive for malignancy, these values were 73.0%, 96.2%, and 92.9%, respectively. There were significant differences in specificity and accuracy.

CONCLUSION

Use of ADC and LSR in DWI can improve diagnostic performance for differentiating malignant from benign gallbladder disorders.

Comparison of FDG-PET/CT images between chronic renal failure patients on hemodialysis and controls

The whole-body 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) distribution in chronic renal failure (CRF) patients on hemodialysis would be different from that in subjects with normal renal function, because they lack urinary FDG excretion and remain in a constant volume overload. We evaluated the difference in the physiological uptake pattern of FDG between chronic renal failure patients on hemodialysis and control subjects. The subjects for this retrospective study consisted of 24 chronic renal failure patients on hemodialysis (HD group) and 24 age- and sex-matched control subjects (NC group). Standardized uptake values normalized by the body weight (SUVbw), ideal body weight (SUVibw), lean body mass (SUVlbm), and body surface area (SUVbsa) in the cerebellum, lungs, liver, gluteal muscles and subcutaneous fat, spleen, thoracolumbar spine, thoracic and abdominal aorta, and right atrium were calculated in positron emission tomography/computed tomography (PET/CT) images. SUVbw in the gluteal muscles, subcutaneous fat, spleen and right atrium was significantly higher in the HD group as compared to that in the NC group (p < 0.05; unpaired t test). In addition, SUVibm, SUVlbm, as well as SUVbsa in the abdominal aorta were significantly higher in the HD group as compared to those in the NC group (p < 0.05; unpaired t test). In conclusion, as compared to normal subjects, chronic renal failure patients on hemodialysis show significantly higher physiological FDG uptake in the soft tissues, spleen and blood pool.

Advancing magnetic resonance imaging in Crohn's disease

Crohn's disease (CD) is a lifelong chronic inflammatory bowel disease associated with diarrhea, abdominal pain, bloody stool and often perianal fistulae. Inflammation in CD involves the entire gastrointestinal tract, especially including the small and large bowels, causing irreversible bowel damage. Frequent imaging examinations are necessary to monitor disease activity and to evaluate response to therapeutic interventions, and, furthermore, to predict recurrence in order to provide appropriate treatment. The suitable imaging modality should be reproducible, well tolerated, safe and free of ionizing radiation. In recent years, imaging used in CD has dramatically changed. Cross-sectional imaging techniques such as computed tomography and magnetic resonance imaging (MRI) are used to investigate not only extraluminal abnormalities, but also intraluminal changes. Recently, new techniques such as MR enteroclysis, enterography, colonography and enterocolonography have been developed. These recent advances enable the use of MRI to assess bowel disorders with high sensitivity, specificity and accuracy. MRI can evaluate simultaneously the bowel surface, bowel wall, abdominal abscesses and perianal lesions, such as perianal fistulae and perianal abscesses, without the problem of overlapping bowel loops. Therefore, MRI has the potential for evaluation of the overall disease activity of CD without radiation exposure. We believe that MRI is a suitable first choice imaging modality in the assessment of CD.

Comparison of magnetic resonance and balloon enteroscopic examination of the small intestine in patients with Crohn's disease

BACKGROUND & AIMS

Magnetic resonance (MR) enterography is a recommended imaging technique for detecting intestinal involvement in Crohn's disease (CD). However, the diagnostic accuracy of MR enterography has not been compared directly what that of enteroscopy of the jejunum and proximal ileum. We evaluated the usefulness of MR enterocolonography (MREC) by comparing its findings with those from balloon-assisted enteroscopy.

METHODS

In a prospective study, MREC and enteroscopy were performed within 3 days of each other on 100 patients. Ulcerative lesions and all mucosal lesions were evaluated. Physicians and radiologists were blinded to results from other studies. Findings from MREC were compared directly with those from enteroscopy; the sensitivity and specificity with which MREC detected CD lesions were assessed.

RESULTS

MREC detected ulcerative lesions and all mucosal lesions in the small intestine with 82.4% sensitivity (95% confidence interval [CI], 75.4%-87.7%) and 67.5% sensitivity (95% CI, 63.1%-70.0%); specificity values were 87.6% (95% CI, 83.7%-90.6%) and 94.8% (95% CI, 90.1%-97.5%). MREC detected major stenosis with 58.8% sensitivity (95% CI, 37.6%-77.2%) and 90.0% specificity (95% CI, 88.4%-91.5%) and all stenoses with 40.8% sensitivity (95% CI, 30.8%-49.4%) and 93.7% specificity (95% CI, 91.1%-95.9%).

CONCLUSIONS

MREC is useful for detecting active lesions in the small intestine. However, MR imaging is less sensitive for detecting intestinal damage, such as stenoses. Enteroscopy is preferred for identifying intestinal damage. Suitable imaging approaches should be selected to assess CD lesions in deep small intestine.

Magnetic resonance enterocolonography is useful for simultaneous evaluation of small and large intestinal lesions in Crohn's disease

BACKGROUND

We developed novel magnetic resonance enterocolonography (MREC) for simultaneously evaluating both small and large bowel lesions in patients with Crohn's disease (CD). The aim of this study was to evaluate the diagnostic performance of MREC by comparing results of this procedure to those of endoscopies for evaluating the small and large bowel lesions of patients with CD.

METHODS

Thirty patients with established CD were prospectively examined by newly developed MREC. Patients underwent ileocolonoscopy (ICS) (24 procedures) or double-balloon endoscopy (DBE) (10 procedures) after MREC on the same day. Two gastroenterologists and two radiologists who were blinded to the results of another study evaluated endoscopy and MREC findings, respectively.

RESULTS

In colonic lesions the sensitivities of the MREC for deep mucosal lesions (DML), all CD lesions, and stenosis were 88.2, 61.8, and 71.4%, respectively, while the specificities were 98.1, 95.3, and 97.7%, respectively. In small intestinal lesions, MREC sensitivities for DML, all CD lesions, and stenosis were 100, 85.7, and 100%, respectively, while specificities were 100, 90.5, and 93.1%, respectively. Endoscopic scores were significantly correlated with MREC scores. Eleven (46%) of the 24 patients who were clinically not suspected to show stricture were observed to demonstrate stricture by radiologists.

CONCLUSIONS

Our results demonstrated that MREC can simultaneously detect the CD lesions of the small and large intestine. MREC can be performed without radiation exposure, the use of enema, or the placement of a naso-jejunal catheter. MREC and endoscopy have comparable abilities for evaluating mucosal lesions of patients with CD.

Diffusion-weighted magnetic resonance imaging detection of renal cancer presenting with diffuse peritoneal metastases in a patient with hemodialysis-associated acquired cystic disease of the kidney

A 59-year-old man was admitted with a large amount of ascites, cake-like omental thickening, and dialysis-associated acquired cystic disease of the kidney (ACDK). It was difficult to detect renal cancer, which was revealed as a primary site of peritoneal metastases by autopsy, with conventional cross-sectional imaging, such as enhanced computed tomography and T2, T1, and dynamic gadolinium-enhanced T1-weighted magnetic resonance imaging, because multiple renal cysts caused marked distortion of the renal parenchyma and the cancer had necrosis. We demonstrated the usefulness of diffusion-weighted imaging with a high b-factor to detect renal cancer presenting with peritoneal metastasis in a patient with ACDK.

Further characterization of Nostoc verrucosum ferredoxins

Nostoc verrucosum ferredoxins Fd I and Fd II were found to have different amino acid compositions. Fd I had 98 amino acid residues of Trpo, Lys4, His1, Arg1, Asp14, Thr8, Ser6, Glu14, Pro4, Gly7, Ala10, Cys4, Val5, Met0, Ile6, Leu8, Tyr5, Phe1 while Fd II had 99 residues of Trp1, Lys4, His1, Arg1, Asp18, Thr7, Ser6, Glu14, Pros, Gly5, Ala6, Gys5, Val6, Met1, Ile6, Leu8, Tyr4,Phe1. From the amino acid compositions, molecular weights were calculated to be about 10,500 for Fd I and 10,700 for Fd II. The amino terminals of both Fd I and Fd II were alanine. The carboxyl terminal sequence of Fd I was -Glu-Leu-Tyr and that of Fd II was -Glu-(Ser, Ala)-Leu-Ala. Fd I was more resistant against heat denaturation than Fd II.

Interaction of chromatin components with nuclear 5.0 S RNA fraction that stimulates RNA synthesis

Chick liver nuclear 5.0 S RNA, which stimulates RNA synthesis on chromatin, binds preferentially to the deoxyribonucleoprotein in homologous chromatin. The proteins found in the isolated deoxyribonucleoprotein-5.0 S RNA complex are total amount of both H4 and H3 histone, about 20% of nonhistone protein and about 50% of both H2a and H2b histone found in the original chromatin. Cesium chloride equilibrium centrifugation of the deoxyribonucleoprotein-5.0 S RNA complex after fixation with formaldehyde shows that the 5.0 S RNA is bound to certain proteins (acid-soluble and -insoluble) in the complex. The stimulation of RNA synthesis by the nuclear RNA fraction is due to the conversion of inaccessible region of DNA to RNA polymerase into an accessible one and presumably not due to an increase in the number of binding sites for RNA polymerase in the chromatin. The release of non-histone protein from chromatin following the addition of the nuclear RNA fraction is also briefly discussed.

Two plant-type ferredoxins from a blue-green alga, Nostoc verrucosum

Two plant-type ferredoxins were isolated and purified from a blue-green alga, Nostoc verrucosum. They were separable by chromatography on a DEAE-cellulose column. The slow-moving band was designated ferredoxin I (Fd I) and the fast-moving band was ferredoxin II (Fd II). The ratio of the yield of ferredoxins I and II was about 1 : 0.84. Both ferredoxins had absorption spectra similar to those of plant-type ferredoxins. Two atoms of non-heme iron and two of labile sulfur were found per mol of both ferredoxin I and ferredoxin II. Their molecular weights were identical and estimated to be about 18 000 by a gel filtration method. The biochemical activities of these Nostoc ferredoxins were studied: the NADP photoreduction activity on one hand and the NADP-cytochrome c reductase activity on the other.

Release of template restriction in chromatin by nuclear 4.5s RNA

The stimulatory mechanism of RNA synthesis of calf-thymus chromatin by nuclear 4.5 S RNA from the homologous tissue was investigated by using exogenously added Escherichia coli RNA polymerase. The RNA synthesis was initiated at low concentration of salt, and then the chain elongation was achieved at high concentration of ammonium sulfate in the presence of polyvinyl sulfate. Under these conditions the number of binding sites of RNA polymerase on chromatin which were capable of initiating RNA chain was increased by the addition of the 4.5 S RNA. This stimulation was presumed to result from the release of template restriction in chromatin. The polyvinyl salt minimized ribonuclease activity without changing the RNA polymerase activity bound to the template. Neither rearrangement nor release of chromatin proteins affected the amount or size of RNA produced. Preliminary analysis suggested that the molecular species of RNA produced upon the addition of the 4.5 S RNA from various tissues seemed to be heterologous.