Calcineurin inhibitor sparing with mycophenolate mofetil in liver transplantion: a systematic review of randomized controlled trials.

Liver transplant recipients are at high risk of developing acute and chronic renal failure. Moreover, introduction of the model for end-stage liver disease (MELD) score for primary allocation of liver grafts favors patients with pretransplant kidney dysfunction, which in turn have a higher risk of posttransplant renal failure. Calcineurin inhibitors (CNI) further increase the risk of renal failure and therefore sparing CNI with the use of mycophenolate mofetil (MMF) may improve renal function. MMF may either be used de novo in the immediate posttransplant period in combination with low-dose CNI (scenario 1) or patients that receive immunosuppression based on CNI may be converted to MMF in combination with minimization or elimination of CNI (scenario 2). Although many retrospective cohort studies and nonrandomized trials have implicated efficacy of this approach the evidence from randomized controlled studies has not been summarized. In the current review we report the results of a systematic review and meta-analysis of randomized controlled trials.

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.

Dark lumen MR colonography based on fecal tagging for detection of colorectal masses: accuracy and patient acceptance.

BACKGROUND: Magnetic resonance colonography (MRC) with fecal tagging has recently been investigated in clinical studies for the detection of polyps. We assessed fecal tagging MRC in a field trial. METHODS: Forty-two patients in a private gastroenterologic practice underwent MRC with barium-based fecal tagging (150 mL of 100% barium at each of 6 main meals before MRC) and conventional colonoscopy. Diagnostic accuracy of MRC and patient acceptance were assessed and compared with the respective results of conventional colonoscopy. RESULTS: Eighteen percent of all MRC examinations showed a remaining high stool signal in the colon that impeded a reliable inclusion or exclusion of polyps. On a lesion-by-lesion basis, sensitivities for polyp detection were 100% for polyps larger than 2 cm (n = 1), 40% for polyps between 10 and 19 mm, 16.7% for polyps between 6 and 9 mm, and 9.1% for polyps smaller than 6 mm. The main reason for the low acceptance of MRC was the barium preparation, which was rated worse than the bowel cleaning procedure with conventional colonoscopy. CONCLUSION: MRC with fecal tagging must be further optimized. The large amount of barium resulted in poor patient acceptance, and barium according to this protocol did not provide sufficient stool darkening. Other strategies, such as increasing the hydration of stool, must be developed.

Measuring tongue volumes and visualizing the chewing and swallowing process using real-time TrueFISP imaging--initial clinical experience in healthy volunteers and patients with acromegaly.

This study assessed both two-dimensional (2D) TrueFISP imaging for quantifying tongue volume and real-time TrueFISP imaging for evaluating chewing and swallowing in healthy volunteers and patients with acromegaly. In 50 healthy volunteers, tongue volumes were measured using a 2D TrueFISP sequence. Chewing and swallowing were visualized using a real-time TrueFISP sequence. Ten patients with acromegaly were examined twice with the same magnetic resonance imaging protocol: once prior to therapy and a second time 6 months after therapy. Prior to therapy, healthy volunteers had an average tongue volume of 140 ml for men and 90 ml for women, and patients with acromegaly had an average tongue volume of 180 ml for men and 145 ml for women. However, 6 months after therapy the mean tongue volumes in patients with acromegaly had decreased to 154 ml in the men and to 125 ml in the women. The chewing and swallowing process was normal in all volunteers. Prior to therapy, just two patients showed a chewing and swallowing pathology, which disappeared after therapy. Patients with acromegaly had larger tongue volumes than healthy volunteers, and TrueFISP imaging proved feasible for visualizing chewing and swallowing in real time and is capable of detecting possible pathologies. Furthermore, TrueFISP imaging can be used to monitor therapeutic approaches in patients with acromegaly.

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.

Effects of octreotide on sleep apnoea and tongue volume (magnetic resonance imaging) in patients with acromegaly.

OBJECTIVES: Sleep apnoea has been consistently reported to occur in acromegaly. Both obstructive apnoeas, in which apnoeas are due to intermittent obstruction of the upper airways, as well as central apnoeas are known to occur. Because the relationship between disease activity and severity of sleep apnoea is currently unclear, we have performed a prospective study to address this issue. DESIGN AND METHODS: In 14 newly diagnosed patients with active acromegaly (eight females and six males; mean age 57+/-4 years; IGF-I 583+/-48 microg/l; GH 13.5+/-7.0 microg/l (means+/-s.e.m.)), tongue volume and signal intensity of the tongue were examined by magnetic resonance imaging and sleep apnoea was characterised by polysomnography before and after 6 months of treatment with octreotide acetate (Sandostatin LAR 10-30 mg every 4 weeks i.m.). RESULTS: The initial tongue volume was significantly higher in patients with acromegaly (151+/-9 ml; females 133+/-10 ml; males 172+/-10 ml) in comparison with the body mass index (BMI)- and age-matched healthy control group (97+/-5 ml, P<0.001; females 75+/-1 ml, P<0.001; males 120+/-3 ml, P<0.003). After treatment with octreotide, IGF-I was normalised within the age-adjusted normal range in 50% of the patients. In these patients, tongue volume significantly decreased (120+/-14 ml, P<0.05) in comparison with the persistent uncontrolled group of acromegalics (137+/-10 ml, P=not significant). Overall, tongue volume (128+/-8 ml, P<0.05) and the signal intensity ratio of the tongue decreased significantly after treatment with octreotide acetate (120+/-3 vs 105+/-3, P=0.003). The BMI-adjusted tongue volume correlated with IGF-I levels (r=0.60, P<0.002) and the disease duration (r=0.71, P=0.006). At baseline, 50% had obstructive sleep apnoea with a mean respiratory disturbance index (RDI) of >20/h (range 5.1-91.5) and no patient had central sleep apnoea. After 6 months of octreotide treatment, there was a 28+/-10% decrease in RDI. However, RDI did not correlate with IGF-I or GH levels, but correlated positively with BMI (r=0.58, P=0.001) and age (r=0.46, P=0.02). CONCLUSIONS: Obstructive sleep apnoea but not central sleep apnoea frequently occurs in patients with active acromegaly. Successful treatment with octreotide can decrease tongue volume, which may have benefits for coexisting sleep-disordered breathing.

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 MR colonography.

Magnetic resonance colonography (MRC) has been shown to be an appropriate diagnostic tool for the detection of colorectal pathologies. Recently, dark-lumen MRC has been introduced. This technique is based on the acquisition of a T1-weighted sequence after the administration of water enema and the intravenous administration of paramagnetic contrast. This report describes the underlying techniques of dark-lumen MRC concerning data acquisition and image interpretation. Furthermore, it points out the advantages of this approach as compared with conventional endoscopy or other MR methods. Possible improvements in the future such as the implementation of fecal tagging strategies to avoid bowel cleansing are discussed.

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.