Structure-Based Design, Docking and Binding Free Energy Calculations of A366 Derivatives as Spindlin1 Inhibitors.

The chromatin reader protein Spindlin1 plays an important role in epigenetic regulation, through which it has been linked to several types of malignant tumors. In the current work, we report on the development of novel analogs of the previously published lead inhibitor A366. In an effort to improve the activity and explore the structure-activity relationship (SAR), a series of 21 derivatives was synthesized, tested in vitro, and investigated by means of molecular modeling tools. Docking studies and molecular dynamics (MD) simulations were performed to analyze and rationalize the structural differences responsible for the Spindlin1 activity. The analysis of MD simulations shed light on the important interactions. Our study highlighted the main structural features that are required for Spindlin1 inhibitory activity, which include a positively charged pyrrolidine moiety embedded into the aromatic cage connected via a propyloxy linker to the 2-aminoindole core. Of the latter, the amidine group anchor the compounds into the pocket through salt bridge interactions with Asp184. Different protocols were tested to identify a fast in silico method that could help to discriminate between active and inactive compounds within the A366 series. Rescoring the docking poses with MM-GBSA calculations was successful in this regard. Because A366 is known to be a G9a inhibitor, the most active developed Spindlin1 inhibitors were also tested over G9a and GLP to verify the selectivity profile of the A366 analogs. This resulted in the discovery of diverse selective compounds, among which 1s and 1t showed Spindlin1 activity in the nanomolar range and selectivity over G9a and GLP. Finally, future design hypotheses were suggested based on our findings.

Clinical and Radiological Regeneration of Large and Deep Osteochondral Defects of the Knee by Bone Augmentation Combined With Matrix-Guided Autologous Chondrocyte Transplantation.

BACKGROUND: Large osteochondral defects of the knee are a challenge for regenerative treatment. While matrix-guided autologous chondrocyte transplantation (MACT) represents a successful treatment for chondral defects, the treatment potential in combination with bone grafting by cancellous bone or bone block augmentation for large and deep osteochondral defects has not been evaluated. PURPOSE: To evaluate 1- to 3-year clinical outcomes and radiological results on magnetic resonance imaging (MRI) after the treatment of large osteochondral defects of the knee with bone augmentation and MACT. Special emphasis is placed on different methods of bone grafting (cancellous bone grafting or bone block augmentation). STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Fifty-one patients were included. Five patients were lost to follow-up. This left 46 patients (mean age, 28.2 years) with a median follow-up time of 2 years. The 46 patients had 47 deep, large osteochondral defects of the knee joint (1 patient with bilateral defects; mean defect size, 6.7 cm2). The origin of the osteochondral defects was osteochondritis dissecans (n = 34), osteonecrosis (n = 8), or subchondral cysts (n = 5). Depending on the depth, all defects were treated by cancellous bone grafting (defect depth ≤10 mm; n = 16) or bone block augmentation (defect depth >10 mm; n = 31) combined with MACT. Clinical outcomes were followed at 3 months, 6 months, 1 year, 2 years, and 3 years and evaluated using the International Knee Documentation Committee (IKDC) score and Cincinnati score. A magnetic resonance imaging (MRI) evaluation was performed at 1 and 2 years, and the magnetic resonance observation of cartilage repair tissue (MOCART) score with additional specific subchondral bone parameters (bone regeneration, bone signal quality, osteophytes, sclerotic areas, and edema) was analyzed. RESULTS: The clinical outcome scores revealed a significant increase at follow-up (6 months to 3 years) compared with the preclinical results. The median IKDC score increased from 42.6 preoperatively to 75.3 at 1 year, 79.7 at 2 years, and 84.3 at 3 years. The median Cincinnati score significantly increased from 39.8 preoperatively to 72.0 at 1 year, 78.0 at 2 years, and 80.3 at 3 years. The MRI evaluation revealed a MOCART score of 82.6 at 1 year without a deterioration at the later follow-up time point. Especially, the subchondral bone analysis showed successful regeneration. All bone blocks and cancellous bone grafts were integrated in the bony defects, and no chondrocyte transplant failure could be detected throughout the follow-up. CONCLUSION: Large and deep osteochondral defects of the knee joint can be treated successfully with bone augmentation and MACT. The treatment of shallow bony defects with cancellous bone grafting and deep bony defects with bone block augmentation shows promising results.

The effect of tibial slope in acute ACL-insufficient patients on concurrent meniscal tears.

INTRODUCTION: The aim of this study is to evaluate the effect of the medial and lateral posterior tibial slope (MPTS, LPTS) in patients with acutely ruptured ACL on the menisci. It was hypothesized that medial and lateral meniscus lesions are seen more often with high PTS (posterior tibial slope). We hypothesized that in case of a high tibial slope a possible meniscus lesion is more often located in the posterior horn of the meniscus than in knees with a low tibial slope. MATERIALS AND METHODS: We identified 537 patients with ACL insufficiency between 2012 and 2013. Of these, 71 patients were eligible for the study according to the study's criteria. PTS was measured via MRI and classified into two groups: >10° for high tibial slope and ≤10° for low tibial slope. Any meniscal lesion was documented during arthroscopic ACL reconstruction and evaluated regarding meniscal lesion patterns with high and low PTS, taking into account the type and the location of the tear (anterior horn, intermediate part and posterior horn). Statistical analysis for differences in meniscal lesion was performed using Chi-square tests and McNemar tests for dependent variables. The level of significance was set at p ≤ 0.05. RESULTS: High PTS (MPTS and LPTS) was associated with a higher incidence of meniscal lesions with an odds ratio of 2.11, respectively, 3.44; however, no statistical significance was found. Among the total number of ACL-insufficient knees studied, the meniscal lesion spread more often to the posterior part in the group with a low PTS. In contrast, less damage of the posterior horn of the meniscus could be found in the group with a high PTS. CONCLUSION: High PTS seems to predetermine for meniscal lesion in an acute ACL-insufficient knee. More damage to the posterior part of the menisci could generally be seen but was not associated with a high PTS. There was no statistical significance to support the initial hypothesis. Further research is needed to find out if factors other than tibial slope are risk factors for meniscal lesion in acute ACL injury. LEVEL OF EVIDENCE: IV.

Optimized multidetector computed tomographic protocol for the diagnosis of active obscure gastrointestinal bleeding: a feasibility study.

OBJECTIVE: The purpose of this feasibility study was to prospectively evaluate an optimized multidetector computed tomographic protocol for the diagnosis of active obscure gastrointestinal bleeding (OGIB). METHODS: Between October 2006 and February 2008, patients admitted for active OGIB were included in this prospective unicenter study. Water was administered orally and rectally as neutral luminal contrast material. A contrast-enhanced 16-row multidetector computed tomography (MDCT) was performed in the arterial and venous phases. Mesenteric digital subtraction angiography was carried out immediately after MDCT as standard of reference. RESULTS: Six patients were included in this study. Multidetector computed tomography identified the bleeding site and source in 5 (83%) of the patients. Digital subtraction angiography was performed in 4 patients, and the result was positive in 1 (25%) of the patients. Multidetector computed tomography detected the site and source of bleeding in 2 patients whose digital subtraction angiographic result was negative. CONCLUSIONS: The results of this feasibility study indicate that optimized MDCT is an excellent diagnostic tool for the diagnosis of active OGIB.

Comparison of capsule endoscopy and magnetic resonance (MR) enteroclysis in suspected small bowel disease.

BACKGROUND AND AIMS: Small bowel MR enteroclysis and wireless capsule endoscopy (WCE) are new diagnostic tools for the investigation of the small bowel. The aim of this study was to compare the diagnostic yield of WCE with MR enteroclysis in the detection of small bowel pathologies. METHODS: A total of 36 patients were included in the study. Indications for imaging of the small bowel were proven or suspected small bowel Crohn's disease (CD; n=18), obscure gastrointestinal (GI) bleeding (n=14) and tumour surveillance (n=4). RESULTS: In patients with Crohn's disease WCE detected significantly more inflammatory lesions in the first two segments of the small bowel compared with MR enteroclysis (12 patients vs. 1 patient, p=0.016). In 5 out of 14 (36%) patients with GI bleeding, angiodysplasia was detected as a possible bleeding source. Three of these patients had active bleeding sites detected by WCE. One patient had scattered inflammation of the mucosa. MR enteroclysis did not reveal any intestinal abnormalities in this patient group. MR enteroclysis provided extraintestinal pathologies in 10 out of 36 (28%) patients. CONCLUSION: In patients with Crohn's disease WCE revealed significantly more inflammatory lesions in the proximal and middle part of the small bowel in comparison to MR enteroclysis, whereas in patients with obscure GI bleeding WCE was superior to MR enteroclysis.

Site-specific intraoperative efficacy of arthroscopic knee joint synovectomy in rheumatoid arthritis.

PURPOSE: To assess the intraoperative reduction of inflammatory infiltrates achieved by arthroscopic knee joint synovectomy in patients with rheumatoid arthritis (RA) with special regard to the removal site, using preoperative and postoperative synovial tissue (ST) samples. TYPE OF STUDY: A histologic and immunohistochemical study. METHODS: Eleven patients with treatment-refractory RA knee synovitis underwent arthroscopic synovectomy. In each patient, ST specimens were obtained immediately before and after synovectomy from 9 defined sites covering the whole joint. The samples were graded using an acute synovitis score (ASS; presence of polymorphonuclear neutrophilic leukocytes [PMN] and fibrin) and a chronic synovitis score (CSS; e.g., lining cell hyperplasia, presence of diffuse and lymphoid aggregates). Immunohistologic analyses were performed using 7 monoclonal antibodies directed against PMN, macrophages, and T-cell subsets (total of 1,584 preparations). Knee function was assessed after an average follow-up of 28 months by Lysholm score (modified by Klein and Jensen), Insall functional and knee scores, and Lequesne score. RESULTS: Arthroscopic synovectomy led to an overall significant (P between .005 and .05) reduction of the acute inflammatory infiltrates (ASS) by 82.1%, but to a significant reduction of chronic inflammatory infiltrates (CSS) by only 62.5%. Accordingly, the density of PMN was reduced by 81.8%, whereas that of macrophages and different T-cell subsets was only decreased by < or = 61.6%. With respect to the anatomic regions, a significantly (P < or = .05) less marked reduction of inflammatory infiltrates was observed in the upper lateral and central recess, at the medial and lateral capsule, as well as at the femoral insertion of the anterior cruciate ligament. All knee joint scores showed a significant (P < or = .01) improvement over preoperative values at follow-up. CONCLUSIONS: Arthroscopic synovectomy effectively reduces acute and chronic inflammatory infiltrates in patients with RA who have refractory synovitis of the knee joint (immediately after synovectomy) and improves knee function (28-month follow-up). However, the reduction of inflammatory infiltrates appears to depend on the anatomic region of the joint. LEVEL OF EVIDENCE: Level III.

Planimetry of aortic valve area in aortic stenosis by magnetic resonance imaging.

BACKGROUND: The aim of the study was to determine whether noninvasive planimetry of aortic valve area (AVA) by magnetic resonance imaging (MRI) is feasible and reliable in patients with valvular aortic stenosis in comparison to transesophageal echocardiography (TEE) and catheterization. METHODS AND RESULTS: Planimetry of AVA by MRI (MRI-AVA) was performed on a clinical magnetic resonance system (1.5-T Sonata, Siemens Medical Solutions) in 33 patients and compared with AVA calculated invasively by the Gorlin-formula at catheterization (CATH-AVA, n = 33) as well as to AVA planimetry by multiplane TEE (TEE-AVA, n = 27). Determination of MRI-AVA was possible with an adequate image quality in 82% (27/33), whereas image quality of TEE-AVA was adequate only in 56% (15/27) of patients because of calcification artifacts (P = 0.05). The correlation between MRI-AVA and CATH-AVA was 0.80 (P < 0.0001) and the correlation of MRI-AVA and TEE-AVA was 0.86 (P < 0.0001). MRI-AVA overestimated TEE-AVA by 15% (0.98 +/- 0.31 cm2 vs. 0.85 +/- 0.3 cm2, P < 0.001) and CATH-AVA by 27% (0.94 +/- 0.29 cm2 vs. 0.74 +/- 0.24 cm2, P < 0.0001). Nevertheless, a MRI-AVA below 1,3 cm2 indicated severe aortic stenosis (CATH-AVA < 1 cm2) with a sensitivity of 96% and a specificity of 100% (ROC area 0.98). CONCLUSIONS: Planimetry of aortic valve area by MRI can be performed with better image quality as compared with TEE. In the clinical management of patients with aortic stenosis, it has to be considered that MRI slightly overestimates aortic valve area as compared with catheterization despite an excellent correlation.

Intraarterial gadolinium-enhanced MR angiography in humans for the detection of infrainguinal arterial stenoses before and after percutaneous angioplasty.

OBJECTIVE: The objectives of this study were to show the feasibility of intraarterial MR angiography of the infrainguinal arteries and to compare the accuracy of intraarterial MR angiography with selective intraarterial digital subtraction angiography for the detection of stenoses before and after percutaneous balloon angioplasty. SUBJECTS AND METHODS: Fifteen patients underwent digital subtraction angiography and intraarterial MR angiography before and after balloon angioplasty. For intraarterial MR angiography, 30 mL of diluted contrast agent (5 mL of gadodiamide diluted in 55 mL of 0.9% saline solution) was injected through a sheath in the superficial femoral artery using a flow rate of 2.5 mL/sec. A 3D gradient-echo sequence was performed. Four independent blinded observers assessed differences in the quantitative measurement of stenoses and localization of lesions between digital subtraction angiography and intraarterial MR angiography. The overall impression of the intraarterial MR angiography images was documented on a 4-point scale (1 = excellent, 4 = poor). Interobserver variability was calculated. RESULTS: Intraarterial MR angiography from the upper leg to the trifurcation was feasible in all 30 examinations with a mean overall impression of all segments of 1.3 (SD, 0.68). For the detection of significant stenoses (> or = 50% stenosis), the overall sensitivity and specificity for the femoropopliteal and crural vessels were 92.4% and 91.7% and 91.9% and 87.8%, respectively. For the complete leg, sensitivity and specificity were 92.2% and 88.6%, respectively. Interobserver variability for intraarterial MR angiography of the crural vessels exceeded that of the femoropopliteal arteries. CONCLUSION: Intraarterial MR angiography of the infrainguinal arteries is feasible in humans using injections of diluted contrast agent at concentrations as low as 8%. It has a high sensitivity for detecting stenoses and an acceptable interobserver variability.

Planimetry of mitral valve stenosis by magnetic resonance imaging.

OBJECTIVES: We sought to determine whether noninvasive planimetry of the mitral valve area (MVA) by magnetic resonance imaging (MRI) is feasible and reliable in patients with mitral stenosis (MS). BACKGROUND: Accurate assessment of MVA is particularly important for the management of patients with valvular stenosis. Current standard techniques for assessing the severity of MS include echocardiography (ECHO) and cardiac catheterization (CATH). METHODS: In 22 patients with suspected or known MS, planimetry of MVA was performed with a 1.5-T magnetic resonance scanner using a breath-hold balanced gradient echo sequence (true FISP). Data were compared with echocardiographically determined MVA (ECHO-MVA, n = 22), as well as with invasively calculated MVA by the Gorlin-formula at (CATH-MVA, n = 17). RESULTS: The correlation between MRI- and CATH-MVA was 0.89 (p < 0.0001), and the correlation between MRI- and ECHO-MVA was 0.81 (p < 0.0001). The MRI-MVA slightly overestimated CATH-MVA by 5.0% (1.60 +/- 0.45 cm(2) vs. 1.52 +/- 0.49 cm(2), p = NS) and ECHO-MVA by 8.1% (1.61 +/- 0.42 cm(2) vs. 1.48 +/- 0.42 cm(2), p < 0.05). On receiver-operating characteristic curve analysis, a value of MRI-MVA below 1.65 cm(2) indicated mitral stenosis (CATH-MVA < or =1.5 cm(2)), with a good sensitivity and specificity (89% and 75%, respectively). CONCLUSIONS: Magnetic resonance planimetry of the mitral valve orifice in mitral stenosis offers a reliable and safe method for noninvasive quantification of mitral stenosis. In the clinical management of patients with mitral stenosis, it has to be considered that planimetry by MRI slightly overestimates MVA, as compared with MVA calculated echocardiographically and at catheterization.

Dark lumen magnetic resonance enteroclysis in combination with MRI colonography for whole bowel assessment in patients with Crohn's disease: first clinical experience.

BACKGROUND: Magnetic resonance enteroclysis (MRE) is a recently introduced imaging technique that assesses the small bowel with similar sensitivity and specificity as the fluoroscopically performed conventional enteroclysis. Magnetic resonance imaging colonography (MRC) seems to be a promising technique for polyp assessment in the colon. In this feasibility study, we evaluated the combination of small bowel MRI with unprepared MRC as an integrative diagnostic approach of the whole bowel in patients with Crohn's disease. METHODS: Thirty patients with known Crohn's disease were prospectively examined. No particular colonic preparation was applied. Applying the dark lumen technique in all patients, MRE and MRC were performed within 1 session using an integrative examination protocol. T2-weighted and contrast-enhanced T1-weighted sequences were acquired. Inflammation assessment (grades 0 to 2) of the colon was compared with conventional colonoscopy in 29 patient and with surgery in 1 patient. The entire colon was graded fair to good distended in all patients. In 11 of 210 evaluated colonic segments, feces hindered an adequate intraluminal bowel assessment. Twenty-three of 30 patients had complete colonoscopy as the gold standard. In 7 patients, complete colonoscopy could not be performed because of an inflamed stenosis. RESULTS: Correct grading of colonic inflammation was performed with 55.1% sensitivity and 98.2% specificity in all segments. Considering only more extensive inflammation (grade 2), the sensitivity of MRC increased to 70.2% with a specificity of 99.2%. CONCLUSIONS: The combination of MRE and MRC could improve the diagnostic value of abdominal MRI evaluation in patients with Crohn's disease. However, MRC can not replace conventional colonoscopy in subtle inflammation assessment.

Magnetic resonance imaging gastrography: evaluation of the dark lumen technique compared with conventional gastroscopy in patients with malignant gastric disease.

OBJECTIVES: We sought to demonstrate the feasibility of depicting gastric tumors using magnetic resonance imaging (MRI) while applying the dark lumen technique. The findings were correlated with conventional gastroscopy. In addition, we evaluated the screening for lymph nodes and liver metastases during the same session to identify potential tumor spread. MATERIALS AND METHODS: The study included 15 patients with known malignant gastric disease. Conventional gastrointestinal endoscopy was performed in all patients as gold standard. All patients were examined with computed tomography for tumor staging. MRI was performed using 1 L of tap water as oral contrast agent for all protocols. The MRI program included an axial T1-weighted (T1w; 2D-FLASH) sequence, an axial STIR and T2w (TSE) sequence, and 2 postcontrast T1w (3D coronal /2D axial FLASH) sequences using 0.2 mmol/kg gadolinium diethylenetriaminepenta-acetic acid as intravenously injected contrast agent. Qualitative analysis and comparison with conventional gastroscopy were performed. RESULTS: The images obtained with the postcontrast 3D coronal T1w-FLASH sequence were the most suitable in identifying gastric tumors. Complete correlation with conventional gastroscopy was achieved in 80% of the cases and partial correlation in 13% of the cases. The same imaging sequence was also appropriate for the evaluation of lymph nodes. For the identification of liver metastases, the images obtained with the axial postcontrast T1w 2D-FLASH sequence provided a higher diagnostic confidence as compared with other imaging protocols. CONCLUSIONS: Applying the dark lumen technique through MRI is suitable for imaging gastric tumors and has the potential to become a "one-stop shopping" method because of the possibility for lymph node evaluation and screening for metastases during the same session based on the same images.

Intraarterial contrast material-enhanced magnetic resonance angiography of the aortoiliac system.

In a period of 4 months, 10 patients were examined prospectively with intraarterial magnetic resonance (MR) angiography after digital subtraction angiography. Intraarterial MR angiography was performed with use of a 1.5-T MR imaging system. Contrast agent (gadodiamide) was injected with a conventional angiography catheter placed in the proximal abdominal aorta. The increase in vascular signal intensity was determined and the diagnostic value of the MR angiograms was scored according to a five-point scale by four investigators. The MR angiograms were judged good to excellent, and all were scored as diagnostic. In conclusion, this study shows that intraarterial MR angiography is feasible. Intraarterial MR angiography is appropriate to support MR-guided vascular intervention.

Early regression of left ventricular hypertrophy after aortic valve replacement by the Ross procedure detected by cine MRI.

AIM: The primary objective of our study was to assess the time course of left ventricular remodeling after the Ross procedure with the use of cine magnetic resonance imaging (MRI). METHODS: In a prospective study, 10 patients with isolated aortic valve disease were examined prior to aortic valve surgery, as well as at early follow-up (mean 4 weeks) and at late follow-up (mean 8 months) after pulmonary autograft aortic valve replacement (Ross procedure). The heart was imaged with a 1.5 T MR scanner along the short and long axes using a breath-hold, electrocardiogram (ECG)-triggered, cine gradient-echo sequence (FLASH). Myocardial mass and ventricular function were assessed. RESULTS: After aortic valve replacement, left ventricular myocardial mass (LVM) decreased by 13% (261 +/- 74 g to 230 +/- 65 g, p < 0.05) in the early postoperative period and by a further 16% in the late postoperative period to 192 +/- 31 g (p < 0.05). In addition, left ventricular end-diastolic and end-systolic volumes decreased from preoperative 187 +/- 89 mL (LV EDV) and 73 +/- 59 mL (LV ESV) to 119 +/- 55 mL and 56 +/- 42 mL, respectively, in the early postoperative period. In the late postoperative period, there was a further decrease to 98 +/- 30 (p < 0.05) and 33 +/- 19 mL, respectively. Ejection fraction did not change markedly after surgery (preoperatively 61 +/- 13% vs. 56 +/- 14% postoperatively). Patients with leading aortic stenosis were characterized by predominant regression of LVM and patients with leading aortic regurgitation by predominant regression of LV EDV (each p < 0.05). CONCLUSION: Cine MRI allows accurate assessment of left ventricular structure and geometry before and after aortic valve replacement with pulmonary autograft and is very sensitive in detecting relatively small changes of left ventricular myocardial mass and volumes early after hemodynamic relief as well as during serial assessment.

Modern imaging using computer tomography and magnetic resonance imaging for inflammatory bowel disease (IBD) AU1.

Radiologic imaging--especially of the small bowel--plays an important role in the diagnosis and management of patients with inflammatory bowel disease. The radiographic examination of the small intestine with barium either as enteroclysis or as small bowel follow through are still the mainstays in small bowel imaging. However, abdominal CT or MRI, which has the advantage of not utilizing ionizing radiation, or the techniques of CT- or MR-enteroclysis, are overall comparable with regard to the sensitivity and specificity in detecting intestinal pathologies and have already replaced the conventional techniques in centers dedicated to the management of inflammatory bowel disease. Additionally, these cross-sectional imaging techniques provide, in a sense, a "one stop abdominal imaging workup," the diagnosis of extraluminal disease manifestations or complications. Future developments of CT- or MR-based virtual colonography and endoscopy in patients with inflammatory bowel disease are currently being investigated, but should momentarily be considered as purely experimental approaches.

Unilateral adult malignant optic nerve glioma.

INTRODUCTION: Adult malignant optic nerve gliomas are rare and rapidly fatal visual pathway tumours. They represent a clinical entity different from the more common childhood benign optic nerve gliomas, which are frequently associated with neurofibromatosis I. CASE REPORT: A 61-year-old woman presented with rapidly progressing right vision loss, lower altitudinal visual field defect and papilloedema. MRI showed intraorbital and intracranial swelling of the right optic nerve. Resection of the intracranial part of the right optic nerve up to the chiasm revealed anaplastic astrocytoma grade III. Within 1 year, the patient died of leptomeningeal metastasis despite radiotherapy. Clinical and MRI evaluation of the left eye and optic nerve were normal at all times. DISCUSSION: Unilateral adult malignant glioma of the optic nerve is exceptional. The final diagnosis was only confirmed by optic nerve biopsy. In the literature, only one patient has been reported with a unilateral tumour manifestation; he was lost to follow-up 3 months later. All other cases were bilateral. To date, 44 case reports of adult malignant optic nerve glioma have been published, either malignant astrocytoma or glioblastoma. These tumours can mimic optic neuritis in their initial presentation. The diagnosis is seldom made before craniotomy. On MRI images, malignant glioma cannot be distinguished from optic nerve enlargement due to other causes. Although radiotherapy appears to prolong life expectancy, all presently available treatment options (radiation, surgery, radio-chemotherapy) are of limited value. Most patients go blind and die within 1 or 2 years.

Magnetic resonance imaging based colonography for diagnosis and assessment of diverticulosis and diverticulitis.

BACKGROUND AND AIMS: MRI-based colonography is a new minimally invasive imaging modality to assess the colon and abdomen. This new method which is applied mainly for polyp screening could be an integrative approach for colonic diverticulitis assessment. This study evaluated the feasibility of MRI-based colonography to assess diverticulosis or diverticulitis. PATIENTS AND METHODS: Fourteen consecutive patients with clinically suspected diverticulitis were examined by MRI colonography on a 1.5-T scanner. All patients underwent abdominal CT as gold standard. N-Butyl-scopalamin was given intravenously to reduce bowel peristalsis. After rectal administration of a T1-positive enema T1- and T2-weighted acquisitions with additional intravenous contrast were obtained. A 3D FLASH sequence was acquired for virtual colonography. The results were compared with CT and biological parameters such as white blood cell count and C-reactive protein. RESULTS: Of 56 bowel segments (sigmoid colon, descending colon, transverse colon, ascending colon) in all 14 patients 54 were assessed to have good to fair image quality. Having CT as standard of reference, all sigmoid diverticula were diagnosed based on MRI. Inflammation as judged by CT was identically assessed on MRI. 3D models of the colon revealed further diverticula in the remaining colon; additionally, the 3D models gave a comprehensive image for surgical planning. CONCLUSION: In our preliminary study MRI colonography revealed the same diagnosis as CT in all patients without ionizing radiation. Additionally, 3D-rendered models and virtual colonoscopy can be performed. This comprehensive 3D models could replace presurgical planning barium enema with concurrent assessment of the residual colon.

New diagnostic avenues in inflammatory bowel diseases. Capsule endoscopy, magnetic resonance imaging and virtual enteroscopy.

The modalities for diagnostic imaging in patients with inflammatory bowel disease (IBD) have dramatically changed in the last decade. Several years ago the only methods to assess the small bowel were conventional enteroclysis or a small bowel 'follow through'. Nowadays, wireless capsule endoscopy as well as magnetic resonance imaging (MRI) with virtual endoscopy represent new evolving methods to depict and assess the small bowel. This article describes these recently introduced methods in the diagnostic assessment of the small bowel and discusses the clinical significance based on the current literature.

Routine skeleton radiography using a flat-panel detector: image quality and clinical acceptance at 50% dose reduction.

RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate image quality and clinical acceptance of a large-area, flat-panel X-ray detector for routine skeleton examinations at 50% dose reduction. METHODS: A total of 153 examinations (307 images) of 100 consecutive patients were evaluated. The cesium iodide-amorphous silicon active-matrix imager had a panel size of 43 x 43 cm, a matrix of 3000 x 3000, and a pixel pitch of 143 microm. All images were obtained with a kilovoltage setting identical to conventional radiographies of speed class 400. The amperage values were reduced by 50% compared with standard dose. Images were presented to 3 radiologists, who subjectively rated image quality on a 4-point scale according to 5 criteria (bone cortex, bone trabecula, soft tissue, overall contrast, and overall impression). Three trauma surgeons rated the clinical acceptance on a 4-point scale. Clinical acceptance was defined as directly derived consequences or therapy based on the presented image quality. For both evaluations, 1 represented excellent, 2 represented good, 3 represented moderate, and 4 represented nondiagnostic image quality/clinical acceptance. Intermediate scores at 0.5 intervals were allowed. RESULTS: The mean values for all 5 image quality criteria were rated good or excellent (< or = 2). A total of 4.2% (13 of 307) of the images were rated 2.5 to 3.5 concerning the overall impression. None of the imaging features was ranked more than 3.5 by any radiologist. The mean value of the clinical acceptance was between good and excellent (1.47). A total of 98.7% (151 of 153) of the examinations were rated < or = 2.5; 1.3% (2 of 153) of examinations were of moderate clinical acceptance (< or = 3.5). None of the examinations was of nondiagnostic image quality or clinical acceptance (>3.5); therefore, no study had to be repeated. CONCLUSION: Routine skeleton images with 50% dose reduction yield good image quality and good clinical acceptance. In cases with abundant soft tissue, less dose reduction or standard dose is required.