Diagnostic value of diffusion-weighted imaging (DWI) for the assessment of the small bowel in patients with inflammatory bowel disease.

AIM: To evaluate diffusion-weighted imaging (DWI) compared to standard magnetic resonance imaging (sMRI) in the assessment of inflammatory lesions of the small bowel. MATERIALS AND METHODS: Two readers retrospectively analysed MRI images of the small bowel including DWI followed by capsule endoscopy (CE) and ileocolonoscopy (ICS) in 30 consecutive patients with a suspected or established diagnosis of inflammatory bowel disease. Small bowel CE and the combination of CE + ICS were used as the standards of reference. Inflammatory lesions of the small bowel detected at endoscopy were compared with the findings of (1) sMRI alone (MRI without DWI), (2) DWI alone, and (3) sMRI in combination with DWI (sMRI + DWI). The sensitivity, specificity, and accuracy were calculated for all three readouts. The results of the three readouts were compared with each other. RESULTS: Using CE + ICS as the standard of reference, the mean sensitivity and specificity for the detection of inflammatory lesions of the small bowel at sMRI were 55.2% and 99.5%, at DWI 60% and 99%, and at sMRI + DWI 70% and 99%. Interobserver agreement between the two readers was very good (k=0.87-0.95). Two lesions in different patients were only detected at DWI. CONCLUSION: DWI of the small bowel not only allowed for the detection of inflammatory lesions with high accuracy, but also enabled the identification of additional lesions that were not found using sMRI alone.

[Pancreatic neuroendocrine neoplasms]. / Neuroendokrine Neoplasien des Pankreas.

Pancreatic neuroendocrine neoplasms (NEN) account for 1-2% of all pancreatic neoplasms and represent a rare differential diagnosis. While some pancreatic NEN are hormonally active and exhibit endocrine activity associated with characteristic symptoms, the majority are hormonally inactive. Imaging techniques such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) or as combined PET/CT play a crucial role in the initial diagnosis, therapy planning and control. Endoscopic ultrasound (EUS) and multiphase CT represent the reference methods for localization of the primary pancreatic tumor. Particularly in the evaluation of small liver lesions MRI is the method of choice. Somatostatin receptor scintigraphy and somatostatin receptor PET/CT are of particular value for whole body staging and special aspects of further therapy planning.

A Review of Scientific Topics and Literature in Abdominal Radiology in Germany - Part 1: Gastrointestinal Tract.

UNLABELLED: The working group for abdominal and gastrointestinal diagnosis is a group of the German Radiological Society (DRG) focusing clinically and scientifically on the diagnosis and treatment of the gastrointestinal tract with all parenchymatous abdominal organs. In addition to the clinical and scientific further development of abdominal radiology, the education of radiologists within this core discipline of radiology is one of the major aims. In this article we give an up-to-date literature review of scientific radiological topics especially covered by German radiologists. This manuscript focuses on the most recent literature on the diagnosis of the stomach, small bowel, colon and rectum. The review with a focus on the most recent studies published by German radiologists concludes with a synopsis of mesenterial bleeding and ischemia followed by a critical appraisal of the current literature on conventional abdominal radiography. KEY POINTS: Based on recent literature and guidelines there is a change of paradigms regarding the diagnosis of esophagus and gastric cancer towards CT, which is considered equally to endosonography. For small bowel imaging in Crohn's disease ultrasound as well as MRI with a new focus on DWI are the most important imaging modalities scientifically. For colonic diagnosis virtual colonoscopy has replaced the conventional radiological methods. For staging of rectal carcinoma as well as for therapeutic stratification a high resolution MRI of the pelvis is of paramount interest. Multislice CT is considered the most important modality to assess mesenteric ischemia or bleeding.

A Review of Scientific Topics and Literature in Abdominal Radiology in Germany--Part 2: Abdominal Parenchymal Organs.

UNLABELLED: The working group for abdominal and gastrointestinal diagnosis is a group of the German Radiological Society (DRG) focusing clinically and scientifically on the diagnosis and treatment of the gastrointestinal tract as well as the parenchymal abdominal organs. In this article we give an up-to-date literature review of scientific radiological topics especially covered by German radiologists. The working group experts cover the most recent relevant studies concerning liver-specific contrast media with an emphasis on a new classification system for liver adenomas. Additionally studies regarding selective internal radiotherapy (SIRT) are reviewed. For the pancreas the most important tumors are described followed by an introduction to the most recently introduced functional imaging techniques. The manuscript concludes with some remarks on recent studies and concerning chronic pancreatitis as well as autoimmune pancreatitis. KEY POINTS: • Different subtypes of liver adenomas with different therapeutic consequences can be differentiated by MRI • Most recently published studies focus on liver imaging with extracellular liver specific contrast media as well as diffusion weighted imaging. They consider this new method having a high diagnostic potential. • For pancreatic neoplasm diagnosis diffusion--as well as perfusion--imaging is considered as a highly promising method.

Quantitative assessment of small bowel motility in patients with Crohn's disease using dynamic MRI.

BACKGROUND: Assessment of motility alterations by functional magnetic resonance imaging (MRI) contributes to improved evaluation of inflammatory bowel disease. The aim of the study was to quantify motility in inflammatory bowel segments and to compare motility alterations with MR-based parameters for activity of inflammation in Crohn's disease (CD). METHODS: Thirty consecutive patients with CD underwent bowel MRI which included a dynamic sequence for automatic generation of parametric maps facilitating quantification of bowel motility. Mean motility score (MMS) of small bowel segments with signs of inflammation was measured and compared with MMS of the whole gastrointestinal tract (GI tract). MRI-based score of inflammatory activity and lesion length were correlated with the MMS ratio of inflammatory small bowel lesion and whole GI tract. KEY RESULTS: Inflammatory bowel segments showed a mean value of MMSs of 1080, whereas the whole GI tract showed a mean value of MMSs of 2839 (p < 0.0001). Decrease in motility ranged between 20 and 87% in inflammatory bowel segments compared to the MMS of the whole GI tract. The MMS ratio of an inflammatory small bowel segment and whole GI tract showed negative correlation with MR activity score (r = -0.5921, p = 0.0003) and length of the lesion (r = -0.3495, p = 0.0462). CONCLUSIONS & INFERENCES: Quantitative assessment of motility alterations by means of motility scoring in small bowel segments affected by CD provides additional information on inflammatory activity.

Magnetic resonance imaging of the bowel: today and tomorrow.

Magnetic resonance imaging of the small bowel has been feasible for more than 15 years. This review is meant to give an overview of typical techniques, sequences and indications. Furthermore, newly evaluated promising techniques are presented, which have an impact on the advance of MR imaging of the small and large bowel.

Hip imaging of avascular necrosis at 7 Tesla compared with 3 Tesla.

OBJECTIVES: To compare ultra-high field, high-resolution bilateral magnetic resonance imaging (MRI) of the hips at 7 Tesla (T) with 3 T MRI in patients with avascular necrosis (AVN) of the femoral head by subjective image evaluations, contrast measurements, and evaluation of the appearance of imaging abnormalities. MATERIALS AND METHODS: Thirteen subjects with avascular necrosis treated using advanced core decompression underwent MRI at both 7 T and 3 T. Sequence parameters as well as resolution were kept identical for both field strengths. All MR images (MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR) were evaluated by two radiologists with regard to subjective image quality, soft tissue contrasts, B1 homogeneity (four-point scale, higher values indicating better image quality) and depiction of imaging abnormalities of the femoral heads (three-point scale, higher values indicating the superiority of 7 T). Contrast ratios of soft tissues were calculated and compared with subjective data. RESULTS: 7-T imaging of the femoral joints, as well as 3-T imaging, achieved "good" to "very good" quality in all sequences. 7 T showed significantly higher soft tissue contrasts for T2w and MEDIC compared with 3 T (cartilage/fluid: 2.9 vs 2.2 and 3.6 vs 2.6), better detailed resolution for cartilage defects (PDw, T2w, T1w, MEDIC, DESS > 2.5) and better visibility of joint effusions (MEDIC 2.6; PDw/T2w 2.4; DESS 2.2). Image homogeneity compared with 3 T (3.9-4.0 for all sequences) was degraded, especially in TSE sequences at 7 T through signal variations (7 T: 2.1-2.9); to a lesser extent also GRE sequences (7 T: 2.9-3.5). Imaging findings related to untreated or treated AVN were better delineated at 3 T (≤1.8), while joint effusions (2.2-2.6) and cartilage defects (2.5-3.0) were better visualized at 7 T. STIR performed much more poorly at 7 T, generating large contrast variations (1.5). CONCLUSIONS: 7-T hip MRI showed comparable results in hip joint imaging compared with 3 T with slight advantages in contrast detail (cartilage defects) and fluid detection at 7 T when accepting image degradation medially.

Hepatic volume changes after lobar selective internal radiation therapy (SIRT) of hepatocellular carcinoma.

AIM: To assess volume changes of treated and non-treated liver segments after selective internal radiation therapy (SIRT) in patients with hepatocellular carcinoma (HCC) and compromised hepatic function due to cirrhosis over a time course of 12 months after SIRT. MATERIALS AND METHODS: All patients underwent SIRT of the right liver lobe with yttrium 90 (Y-90). Absolute volumes of the right liver lobe (RLV) and left liver lobe (LLV) were assessed using computed tomography (CT) before and 1, 3, 6, 9, and 12 months after SIRT. Changes at follow-up relative to baseline volumes were analysed ("normalized" volumes). Furthermore, the relative volume of the LLV [LLV/(RLV + LLV)] was calculated ("relative" volumes). For statistical analysis p < 0.05 was considered statistically significant. RESULTS: Forty-five HCC patients (36 men, nine women, mean age 71.9 years, range 55-90 years) were studied. The mean baseline RLV and LLV reached 1116 ml [95% confidence intervals (CI): 1006-1226 ml] and 601 ml (95% CI: 514-688 ml), respectively. At 6 months following radioembolization, the LLV increased by 30.8% (RLV -33.9%), with the relative LLV increasing from 35% (pre-radioembolization) to 50.5%. RLV further decreased and LLV increased 12 months after SIRT (nRLV -44.9%, nLLV +40.1%, relative LLV 56.5%). All changes were significant. CONCLUSION: Constraints of liver function after radioembolization of one liver lobe can be partially compensated through hypertrophy of the contralateral lobe. The rate of volumetric changes is the highest in the first 6 months following radioembolization. The present data can also be the basis to propagate radiation lobectomy for selected patients, simultaneously providing tumour control and future remnant liver hypertrophy before curative hemihepatectomy.

Addition of diffusion-weighted imaging can improve diagnostic confidence in bowel MRI.

AIM: To evaluate whether the addition of diffusion-weighted imaging (DWI) in bowel abdominal magnetic resonance imaging (MRI) can improve diagnostic confidence. MATERIALS AND METHODS: One hundred and eleven consecutive patients with suspected or known inflammatory bowel disease (n = 59), tumour disease (n = 31), unspecific abdominal pain (n = 16), and suspected graft-versus-host disease (n = 5) underwent bowel MRI using a 1.5 T MRI machine. In addition to T2-weighted (T2W) and contrast-enhanced T1-weighted (CE-T1W) data, axial and coronal DWI sequences were collected (b = 50, 500, 1000). Diagnostic confidence for lesion detection with and without DWI was evaluated using a four-point Likert scale [1 = certainly no lesion(s), 2 = probably no lesion(s), 3 = probably lesion(s), 4 = certainly lesion(s)]. RESULTS: In 11 of 111 patients (10%), the diagnostic confidence was improved by DWI. In seven patients, readers changed their diagnosis from "probable" to "certain presence of lesions". In another four patients, lesions were diagnosed based on DWI, which were not delineated on CE-T1W and T2W imaging. CONCLUSION: DWI of the bowel can provide additional information to the reader and, therefore, improve diagnostic confidence. Hence, additional DWI should be integrated into a standard bowel MRI protocol.

Bilateral hip imaging at 7 Tesla using a multi-channel transmit technology: initial results presenting anatomical detail in healthy volunteers and pathological changes in patients with avascular necrosis of the femoral head.

OBJECTIVE: To evaluate 7-T MRI of both hips using a multi-channel transmit technology to compensate for inherent B1 inhomogeneities in volunteers and patients with avascular necrosis of the femoral head. MATERIALS AND METHODS: A self-built, eight-channel transmit-receive coil was utilized for B1 modification at 7 T. Two shim modes (individual shim vs. CP2+ mode) were initially compared and the best shim result was used for all further imaging. Robustness of sequences against B1 inhomogeneities, appearance of anatomic and pathologic changes of the femoral heads of MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR sequences at 7 T were evaluated in 12 subjects on a four-point scale (1-4): four male volunteers and eight patients (seven males, one female) suffering from avascular necrosis treated by advanced core decompression. RESULTS: Successful MRI of both femoral heads was achieved in all 12 subjects. CP2+ mode proved superior in ten of 12 cases. DESS proved most robust against B1 inhomogeneity. Anatomical details (labrum, articular cartilage) were best depicted in PDw, MEDIC, and DESS, while for depiction of pathological changes PDw, DESS (0.76 mm(3)) and T1w were superior. CONCLUSIONS: Our initial results of ultra-high-field hip joint imaging demonstrate high-resolution, high-contrast images with a good depiction of anatomic and pathologic changes. However, shifting areas of signal dropout from the femoral heads to the center of the pelvis makes these areas not assessable. For clinical workflow CP2+ mode is most practical. Seven-Tesla MRI of the hip joints may become a valuable complement to clinical field strengths.

First-pass contrast-enhanced renal MRA at 7 Tesla: initial results.

OBJECTIVE: The aim of this study was to assess the feasibility of first-pass contrast-enhanced renal MR angiography (MRA) at 7 T. METHODS: In vivo first-pass contrast-enhanced high-field examinations were obtained in eight healthy subjects on a 7-T whole-body MRI. A custom-built body transmit/receive radiofrequency (RF) coil and RF system suitable for RF shimming were used for image acquisition. For dynamic imaging, gadobutrol was injected intravenously and coronal unenhanced, arterial and venous data sets using a T1-weighted spoiled gradient-echo sequence were obtained. Qualitative image analysis and assessment of artefact impairment were performed by two senior radiologists using a five-point scale (5 = excellent, 1 = non-diagnostic). SNR and CNR of the perirenal abdominal aorta and both main renal arteries were assessed. RESULTS: Qualitative image evaluation revealed overall high-quality delineation of all assessed segments of the unenhanced arterial vasculature (meanunenhanced 4.13). Nevertheless, the application of contrast agent revealed an improvement in vessel delineation of all the vessel segments assessed, confirmed by qualitative (meanunenhanced 4.13 to meancontrast-enhanced 4.85) and quantitative analysis (SNR meanunenhanced 64.3 to meancontrast-enhanced 98.4). CONCLUSION: This study demonstrates the feasibility and current constraints of ultra-high-field contrast-enhanced renal MRA relative to unenhanced MRA.

Neoadjuvant treatment improves capsular integrity and the width of the fibrous capsule of high-grade soft-tissue sarcomas.

BACKGROUND: Neoadjuvant treatment is thought to improve resection with margin-negative surgery in locally advanced soft-tissue sarcomas (STS). Treatment-induced alterations of the tumor peripheryhave not yet been microscopically evaluated. OBJECTIVE: This histopathological study compared limb STS with primary resection and those that had undergone neoadjuvant treatment, emphasizing microscopic changes of the fibrous capsule (FC) and reactive zone (RZ) after neoadjuvant treatment. PATIENTS AND METHODS: Patients with primary high-grade limb sarcomas (N = 76) which have not previously been treated were included. Of those, 37 were primarily resected and 39 were treated with one of the following neoadjuvant treatment modalities: 7x chemotherapy (CTX), 3x radiotherapy (RT), 15x isolated limb perfusion (ILP), 8x CTX + RT, and 6x CTX + ILP. Sizes of the FC and RZ were microscopically measured, and FC-integrity was documented. Histopathologic regression was expressed as a percent. RESULTS: Only 35.1% of untreated sarcomas showed an intact FC. We observed significantly higher capsular integrity after treatment (76.9%). Additionally, the average width of the FC (0.21 mm vs. 0.61 mm) and RZ (0.67 mm vs. 1.48 mm) increased significantly. The extent of histopathologic regression showed a correlation with capsular integrity and width. The combination of two treatment modalities (CTX + RT or ILP) showed strongest effects at the tumor periphery. CONCLUSIONS: Neoadjuvant treatment stabilizes the tumor periphery in STS (e.g., the capsule). Concerning local treatment strategies, these novel histopathologic insights might significantly influence the decision as to whether primary resection is advisable in advanced local soft-tissue sarcoma.

New look at renal vasculature: 7 tesla nonenhanced T1-weighted FLASH imaging.

PURPOSE: To investigate the feasibility of 7 Tesla (T) nonenhanced high field MR imaging of the renal vasculature and to evaluate the diagnostic potential of various nonenhanced T1-weighted (T1w) sequences. MATERIALS AND METHODS: Twelve healthy volunteers were examined on a 7T whole-body MR system (Magnetom 7T, Siemens Healthcare Sector) using a custom-built eight-channel radiofrequency (RF) transmit/receive body coil. Subsequent to RF shimming, the following sequences were acquired (i) fat-saturated two-dimensional (2D) FLASH, (ii) fat-saturated 3D FLASH, and a (iii) fat-saturated 2D time-of-flight MR angiography (TOF MRA). SNR and CNR were measured in the aorta and both renal arteries. Qualitative analysis was performed with regard to vessel delineation (5-point scale: 5 = excellent to 1 = nondiagnostic) and presence of artifacts (5-point scale: 5 = no artifact present to 1 = strong impairment). RESULTS: The inherently high signal intensity of the renal arterial vasculature in T1w imaging enabled moderate to excellent vessel delineation in all sequences. Qualitative (mean, 4.7) and quantitative analysis (SNR(mean) : 53.9; CNR(mean) : 28.0) demonstrated the superiority of TOF MRA, whereas 2D FLASH imaging provided poorest vessel delineation and was most strongly impaired by artifacts (overall impairment 3.7). The 3D FLASH MRI demonstrated its potential for fast high quality imaging of the nonenhanced arterial vasculature, providing homogeneous hyperintense vessel signal. CONCLUSION: Nonenhanced T1w imaging in general and, TOF MRA in particular, appear to be promising techniques for good quality nonenhanced renal artery assessment at 7 Tesla.

Grading luminal Crohn's disease: which MRI features are considered as important?

OBJECTIVES: Magnetic resonance imaging (MRI) is increasingly used for disease activity grading in small bowel Crohn's disease. It is not known which imaging features are essential for grading. For further insight, we solicited the opinion of expert radiologists. METHODS: A questionnaire about the grading of Crohn's disease was sent to 36 radiologists who had published on MRI grading of Crohn's disease between January 2006 and January 2010. Radiologists were asked which MRI protocol they used, how they graded luminal Crohn's disease, which features they used, how important they considered those features for grading, and which reference standards they used. RESULTS: Twenty-four radiologists responded (66%). They used different protocols and features; most frequently T2-weighted sequences (79%) and contrast enhanced fat saturated T1-weighted sequences (83%). MR-enterography was more often used than MR-enteroclysis (88% versus 33%). Features most frequently considered important for grading were bowel wall thickness (79% of radiologists), the presence of an abscess (75%), T1 enhancement (75%), and T1 stratification (46%). Reference standards differed; most commonly (ileo-) colonoscopy (88%) or surgery (75%) were used. CONCLUSIONS: Bowel wall thickness, abscess, T1 enhancement and T1 stratification are most often used for grading. Because of difference in grading, there is need for an international consensus on MRI grading of Crohn's disease.

Radioembolization of hepatic tumors: flow redistribution after the occlusion of intrahepatic arteries.

PURPOSE: Radioembolization using 90yttrium is an emerging therapy option for unresectable liver malignancies. In order to reduce the number of yttrium injections, endovascular occlusion of a segmental hepatic artery has been proposed. The aim of this study was to assess whether sufficient vascular redistribution of the occluded liver segments through intrahepatic collaterals can be observed. MATERIALS AND METHODS: 27 patients with hepatocellular carcinoma (n = 16) or hepatic metastases (n = 11) were studied. Hepatic angiography was performed on average 16 days prior to radioembolization. The segment II/III artery (n = 9) or the segment IV artery (n = 18) was occluded using coils. Technectium-99m-labeled macroaggregated albumin (99mTc-MAA) was injected into the right and the remaining part of the left hepatic artery in order to identify any hepatic volume not included in the perfused area. Patients underwent a SPECT/CT on average 1 h after the 99mTc-MAA injection. Two radiologists evaluated the SPECT/CT scans regarding the presence of non-perfused hepatic segments. Furthermore, hepatic perfusion was assessed by digital subtraction angiography (DSA) on the day of radioembolization. RESULTS: In 16/27 patients (59%) a perfusion of the occluded liver segment was visible on the SPECT/CT scan. In 8/11 patients without flow redistribution at the time of the SPECT/CT, perfusion of the occluded segment through hepatic collaterals was observed during angiography prior to radioembolization. Hence, flow redistribution was eventually found in 24/27 patients (89%). CONCLUSION: Flow redistribution after the occlusion of intrahepatic arteries prior to radioembolization can be successfully induced in the majority of patients with anatomical variants of the hepatic arteries.

[MR colography: technique, indications, and findings]. / MR-Kolonographie: Technik, Indikationen und Befunde.

Magnetic resonance imaging (MRI) has evolved as a powerful tool that has been applied more and more in recent years for the assessment of gastrointestinal structures, owing to its unsurpassed soft tissue contrast, lack of radiation exposure, and implementation of fast scanning techniques. As a virtual endoscopic technique, MR colography (MRC) makes it possible to image inflammatory processes and tumor disease of the large intestine with a high degree of accuracy. In this article we describe current techniques and applications of MRC and give an overview of clinical studies comparing MRC with other diagnostic procedures.

Dark lumen MR colonography: can high spatial resolution VIBE imaging improve the detection of colorectal masses?

PURPOSE: To assess whether the detection of colorectal lesions can be improved using high spatial resolution VIBE imaging. MATERIALS AND METHODS: 48 patients underwent same-day dark lumen MR colonography (MRC) and conventional colonoscopy (CC) as the standard for the detection of colorectal masses. MRC was performed using contrast-enhanced standard and high spatial resolution T1-weighted 3D VIBE sequences. The findings and the image quality of the standard and high spatial resolution VIBE sequences were compared qualitatively and quantitatively. The findings of both sequences regarding colorectal lesions were compared to those of a subsequently performed colonoscopy. RESULTS: The high spatial resolution VIBE sequence significantly improved the quantitative image quality (CNR 54.0 vs. 36.8). However, high spatial resolution VIBE imaging did not detect more colorectal lesions than the standard VIBE sequence. In addition, none of the sequences employed was able to detect lesions with a diameter of less than 5 mm (CC 40 lesions). However, 13 colorectal lesions with a diameter of greater than 5 mm were detected by both sequences (CC 15). CONCLUSION: High spatial resolution VIBE imaging did not improve the detection of colorectal masses and MRC fails to detect colorectal lesions with a diameter of less than 5 mm.

Magnetic resonance colonography for the detection of inflammatory diseases of the large bowel: quantifying the inflammatory activity.

INTRODUCTION: The purpose of this study was to assess the diagnostic accuracy of magnetic resonance colonography (MRC) for its ability to detect and quantify inflammatory bowel disease (IBD) affecting the colon. Endoscopically obtained histopathology specimens were used as the standard of reference. MATERIALS AND METHODS: Fifteen normal subjects and 23 patients with suspected IBD of the large bowel underwent MRC. Three dimensional T1 weighted data sets were collected following rectal administration of water prior to and 75 seconds after intravenous administration of paramagnetic contrast (gadolinium-BOPTA). The presence of inflammatory changes in patients was documented based on bowel wall contrast enhancement, bowel wall thickness, presence of perifocal lymph nodes, and loss of haustral folds. All four criteria were quantified relative to data obtained from normal subjects and summarised in a single score. This MRC based score was compared with histopathological data based on conventional endoscopic findings. RESULTS: MRC correctly identified 68 of 73 segments found to reveal IBD changes by histopathology. All severely inflamed segments were correctly identified as such and there were no false positive findings. Based on the proposed composite score, MRC detected and characterised clinically relevant IBD of the large bowel with sensitivity and specificity values of 87% and 100%, respectively, for all investigated colonic segments. CONCLUSION: MRC may be considered a promising alternative to endoscopic biopsy in monitoring IBD activity or assessing therapeutic effectiveness.

Real time high resolution magnetic resonance imaging for the assessment of gastric motility disorders.

BACKGROUND: The aim of this study was to evaluate whether patients with increased or decreased gastric motility can be differentiated from healthy volunteers by means of real time magnetic resonance imaging (MRI). PATIENTS AND METHODS: Ten healthy volunteers, 10 patients with gastroparesis, and 10 patients with functional pylorospasm/peptic pyloric stenosis underwent real time MRI. All patients were examined on two separate days; once prior to therapy and once after adequate therapy. Antral motility was quantified by calculating the gastric motility index. RESULTS: Patients with gastroparesis showed a lower motility index compared with the reference volunteer group while the mean motility index of the patient group with pylorospasm was more than three times higher than that of the reference value of the volunteer group. However, the gastric motility index in the patient group with gastroparesis increased, and in the group with functional pylorospasm/peptic pyloric stenosis it decreased significantly after therapy. CONCLUSION: Real time MRI is a reliable tool for assessment of gastric motion. Furthermore, differences in gastric motility index in patients with increased or decreased gastric motility could be evaluated and quantified. Due to the non-invasive character of MRI, this imaging modality may be an attractive alternative to conventional invasive diagnostic tools for gastric motility disorders and therapeutic monitoring.

Dark lumen magnetic resonance colonography: comparison with conventional colonoscopy for the detection of colorectal pathology.

BACKGROUND: The purpose of this study was to assess the feasibility and usefulness of a new magnetic resonance (MR) colonography technique for the detection of colorectal pathology in comparison with conventional colonoscopy as the standard of reference. PATIENTS AND METHODS: A total of 122 subjects with suspected colorectal disease underwent "dark lumen" MR colonography. A contrast enhanced T1w three dimensional VIBE sequence was collected after rectal administration of water. The presence of colorectal masses and inflammatory lesions were documented. Results were compared with those of a subsequently performed colonoscopy. RESULTS: MR colonography was found to be accurate regarding detection of clinically relevant colonic lesions exceeding 5 mm in size, with sensitivity and specificity values of 93%/100%. CONCLUSION: Dark lumen MR colonography can be considered as a promising alternative method for the detection of colorectal disease. In addition, it allows assessment of extraluminal organs.