Yoshio Kitazume

Can Malignant and Benign Pulmonary Nodules Be Differentiated with Diffusion-Weighted MRI?

OBJECTIVE The objective of our study was to evaluate whether diffusion-weighted imaging (DWI) with a high b factor can be used to differentiate malignancies from benign pulmonary nodules. MATERIALS AND METHODS This study included 54 pulmonary nodules (>or= 5 mm in diameter) in 51 consecutive patients (37 men, 14 women; mean age, 65.7 years; age range, 31-88 years). Thirty-six (67%) of the 54 pulmonary nodules were malignant, and 18 (33%) were benign. Two radiologists independently reviewed the signal intensity of the nodules on DWI with a b factor of 1,000 s/mm(2) using a 5-point rank scale without knowledge of clinical data. This scale was based on the following scores: 1, nearly no signal intensity; 2, signal intensity between 1 and 3; 3, signal intensity almost equal to that of the thoracic spinal cord; 4, higher signal intensity than that of the spinal cord; and 5, much higher signal intensity than that of the spinal cord. The Mann-Whitney U test and the receiver operating characteristic (ROC) curve were used to calculate the difference between the scores of malignant and benign nodules. RESULTS On DWI, the mean score of malignant pulmonary nodules (4.03 +/- 1.16 [SD]) was significantly higher (p < 0.01) than that of benign nodules (2.50 +/- 1.47), with an area under the ROC curve of 0.796 (95% CI, 0.665-0.927). When a score of 3 was considered as a threshold, the sensitivity, specificity, and accuracy were 88.9% (95% CI, 78.6-99.2%), 61.1% (38.6-83.6%), and 79.6% (68.9-90.3%), respectively. Three small metastatic nodules (13, 16, and 20 mm) and one bronchioloalveolar carcinoma scored 1 or 2 on the 5-point rank scale. Three granulomas, two active inflammatory lung nodules, and one fibrous nodule scored 4 or 5. CONCLUSION The signal intensity of pulmonary nodules may be useful for malignant and benign differentiation on DWI. However, the interpretation of small metastatic nodules, nonsolid adenocarcinoma, some granulomas, and active inflammatory nodules should be approached with caution.

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 Crohns 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 Crohns 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. (Inflamm Bowel Dis 2010;)

Cine Magnetic Resonance Imaging Evaluation of Peristalsis of Small Bowel With Longitudinal Ulcer in Crohn Disease : Preliminary Results

Objective: To evaluate peristalsis of the small bowel with a longitudinal ulcer in Crohn disease using cine magnetic resonance imaging (MRI). Methods: Fifteen patients with suspected or diagnosed Crohn disease were examined by cine MRI using a multislice and multiphase method. Inclusion criteria were pathological evidence of Crohn disease and confirmation of longitudinal ulceration in the small bowel by ileocolonoscopy, single- or double-contrast radiography of the small bowel, or surgery. Six of these patients were included in this study. Cine MRI findings of the small bowels were retrospectively reviewed by 2 radiologists. Results: Asymmetric involvement or mesenteric rigidity with antimesenteric flexibility was seen in all patients by cine MRI. This finding was not seen in normal small bowel segments. A combination of ileocolonoscopy and contrast radiography detected longitudinal ulcers in 5 of the 6 patients, and surgery revealed ulceration in the remaining patient. Conclusions: Cine MRI was a feasible approach for detecting a longitudinal ulcer in small-bowel Crohn disease.

Advancing magnetic resonance imaging in crohn's disease

Crohns 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.

Correlation of the endoscopic and magnetic resonance scoring systems in the deep small intestine in Crohn's disease

Background:There are no widely accepted endoscopic or magnetic resonance scoring systems to evaluate deep small intestinal lesions in Crohns disease (CD). This study aimed to determine whether the simplified endoscopic activity score for Crohns disease (SES-CD) and the Magnetic Resonance Index of Activity (MaRIA) could be adapted for assessing CD lesions in the deep small intestine. Methods:Magnetic resonance enterocolonography and single-balloon enteroscopy were prospectively performed in 125 patients with CD. SES-CD and MaRIA were applied to the deep small intestine. The correlation between the SES-CD and MaRIA was evaluated. Results:Endoscopic and magnetic resonance active lesions were detected in the terminal and proximal ileal segments at a similar rate. The total MaRIA scores correlated well with the total SES-CD scores (R = 0.808, P < 0.001). A MaRIA score of ≥11 had a high sensitivity, specificity, and diagnostic accuracy for ulcerative lesions that were defined by enteroscopy (sensitivity: 78.3%; specificity: 98.0%). Similarly, an MaRIA score of ≥7 had a high sensitivity, specificity, and diagnostic accuracy for all mucosal lesions defined by enteroscopy (sensitivity: 87.0%; specificity: 86.0%). Conclusions:The MaRIA closely correlates with the SES-CD in the deep small intestine, indicating these scoring systems can be used to assess deep small intestinal lesions. We also showed the validity of MaRIA to evaluate the active lesions in the deep small intestine.

Pulmonary emphysema: histopathologic correlation with minimum intensity projection imaging, high-resolution computed tomography, and pulmonary function test results.

Objective: To prospectively evaluate the use of minimum-intensity projection (minIP) imaging, high-resolution (HR) computed tomography (CT), and pulmonary function tests for quantifying emphysema with histopathologic examination. Methods: MinIP and HRCT imaging data (n = 23) were obtained, and relative areas of the lung with attenuation values below thresholds from −940 to −1000 Hounsfield units (HU) and first to 13th percentiles were calculated for both data. Pulmonary function tests were performed before lung resection. These parameters were compared with mean alveolar perimeters measured on resected samples. Results: Strongest correlations with mean alveolar perimeter were obtained at −990 HU and the fifth percentile by minIP, −1000 HU and the seventh percentile by HRCT, and diffusion capacity. The correlation between the mean alveolar perimeter and relative areas below −990 HU by minIP showed significantly higher extension (0%-51%) than those below −1000 HU by HRCT (1%-21%). Conclusions: MinIP imaging is more than 2½ times more predictive for quantifying emphysema than HRCT, although diffusion capacity of lung for carbon monoxide is also a valid index.

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.

Hepatocellular Carcinoma Histological Grade Prediction: A Quantitative Comparison of Diffusion-Weighted, T2-Weighted, and Hepatobiliary-Phase Magnetic Resonance Imaging.

Objectives This study aimed to compare quantitative assessments for predicting hepatocellular carcinoma (HCC) histological grades using magnetic resonance imaging. Methods We retrospectively reviewed magnetic resonance imaging data from 49 patients with 54 surgically resected HCCs (11 well differentiated, 29 moderately differentiated, and 14 poorly differentiated). We measured the lesion-to-liver relative contrast ratio (RCR) on diffusion-weighted (DW), T2-weighted (T2W), and ethoxybenzyl-hepatobiliary images. We also evaluated contrast-to-noise ratio (CNR) on DW images, and the apparent diffusion coefficient. We compared the feasibility of these parameters in predicting HCC histological grade. Results Areas under the receiver operating characteristic curves of both the DW RCR (97%) and DW CNR (97%) were significantly greater compared with those of the apparent diffusion coefficient (79%), T2W RCR (81%), and ethoxybenzyl-hepatobiliary RCR (80%) (P < 0.05, 0.001, and 0.001, respectively). Conclusions The DW RCR and DW CNR might represent accurate predictors of HCC histological grade.

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

For the control of Crohns 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.