Inflammatory bowel disease evaluated by low-field magnetic resonance imaging. Comparison with endoscopy, 99mTc-HMPAO leucocyte scintigraphy, conventional radiography and surgery.

BACKGROUND: To evaluate the use of low-field magnetic resonance imaging (MRI) in active inflammatory bowel disease (IBD). METHODS: MRI was executed in a consecutive cohort of 28 patients with Crohn disease (CD) and in 17 with ulcerative colitis (UC) prior to glucocorticoid treatment (1 mg prednisolone orally/kg body weight/day). MRI was repeated after 2-3 weeks (22 CD, 12 UC), and again after treatment completion or prior to surgery (18 CD, 6 UC). Five bowel segments were evaluated separately. MRIs were blindly evaluated by two observers, and findings compared with 39 leucocyte scintigraphies, 38 endoscopies, 15 double-contrast barium enemas, 66 small-bowel radiographic examinations and surgery in 23 patients. RESULTS: In CD, blinded evaluation revealed a kappa (kappa) of 0.84 (95% confidence interval (CI) 0.78-0.91). In UC, kappa was 0.66 (95% CI 0.55-0.78). Agreements regarding disease extension between MRI and other modalities in CD were found in 345 bowel segments out of 391 (88.2%) at risk, and in UC in 209/235 (88.9%). Colonic disease activity gradings by radiography and endoscopy correlated significantly with T2-signal intensity (SI(T2)) and increments in T1-signal intensity (%SI(T1)) in both diseases. Significant correlations between MRI indices of disease activity and CDAI in CD (MRI-SI(T2): P <0.0001: MRI% SI(T1): P=0.0008) and the Powell-Tuck index in UC (MRI% SI(T1): P=0.008) were found. CONCLUSIONS: With low interobserver variation and high concordance of findings with other examinations. low-field MRI seems a valuable modality in active IBD. In addition, MRI expressions of disease activity correlate to clinical, radiographic and endoscopic disease activity.

Evaluation of treatment response in active Crohn's disease by low-field magnetic resonance imaging.

BACKGROUND: To evaluate low-field magnetic resonance imaging (MRI) in detecting therapeutic response in active Crohn's disease during treatment with systemic steroids. METHODS: Eight patients with active Crohn's disease were examined before and during treatment with systemic steroids (1 mg/kg/day) using low-field MRI (0.1 T) in transverse and coronal planes before and after an intravenously administered bolus of gadodiamide. Five healthy persons were once examined in the same way. MRI images were evaluated without knowledge of diagnosis, treatment, or findings of endoscopy, conventional radiography, and surgery. Proximal and mid small bowel, terminal ileum, right-sided colon, transverse colon, and left-sided colon were evaluated separately. RESULTS: Statistically significant differences were shown for both signal intensity on T2- (SIT2) and increment in signal intensity on T1-weighted images after contrast (%SIT1) when comparing diseased bowel segments with both nondiseased bowel segments (SIT2: p = 0.0001; %SIT1: p = 0.0009) and segments from the control group (SIT2: p < 0.00005; %SIT1: p < 0.00005). In 53 of 56 bowel segments evaluated (95%), agreement was found between findings by MRI, conventional radiography, endoscopy and/or surgery regarding disease extension. Extension was underestimated in two patients. All bowel segments in the control subjects were evaluated to be normal on MRI. Significant correlation was found between both SIT1 (p < 0.0025) and %SIT1 (p < 0.025) versus endoscopic activity gradings. During treatment, significant decrements of both SIT2 (p < 0.00005), %SIT1 (p = 0.002), and bowel wall thickness (p = 0.03) were found. CONCLUSIONS: Low-field MRI seems to be a promising noninvasive method in the evaluation of response regarding both disease extension and activity in Crohn's disease during treatment with systemic steroids.

Active Crohn's disease and ulcerative colitis evaluated by low-field magnetic resonance imaging.

BACKGROUND: Our aim was to evaluate low-field magnetic resonance imaging (MRI) in the assessment of disease extension and activity in inflammatory bowel disease. METHODS: Nineteen patients with Crohn's disease (CD), 8 with ulcerative colitis (UC), and 5 healthy controls (HC) were examined using MRI (0.1 T) before and after intravenously administered gadodiamide and glucagon. MRI images were evaluated in a blinded fashion and compared with findings at endoscopy, double-contrast barium enema, small-bowel follow-through, and surgery. RESULTS: Comparisons of diseased with both non-diseased bowel segments and segments from HC showed significant differences for both CD and UC with regard to signal intensity on T2-weighted (SI(T2)) images and post-contrast increment of signal intensity on T1-weighted images (%SI(T1). Agreements with regard to disease extension in CD between MRI and other examinations were 97%, underestimating the extension in two patients. For SI(T2) in CD a cut-off value of 1.0 showed a predictive value of a positive finding (PVpos) = 1.0 and a predictive value of a negative finding (PVneg) = 0.96. For %SI(T1) in CD a cut-off value of 15.0% showed values of PVpos = 0.95 and PVneg = 0.92. Agreements between MRI and conventional methods (disease extension) in UC was 87.5%. Extension was underestimated in two patients and overestimated in two patients as compared with barium enemas. Values of PVpos were 1.0 (SI(T2) >1.0) and 1.0 (%SI(T1) >15.0%), respectively, with corresponding values of PVneg being 0.94 and 0.94. CONCLUSION: Low-field MRI seems a promising non-invasive, non-radiating method in the evaluation of inflammatory bowel disease.

Urine profiles and kidney histology after ionic and nonionic radiologic and magnetic resonance contrast media in rats with cisplatin nephropathy.

RATIONALE AND OBJECTIVES: The nephrotoxic drug cisplatin has been used successfully in treating some cancers. Patients with suspected carcinoma frequently undergo examinations with contrast media. We examined whether ionic and nonionic radiologic and magnetic resonance contrast media would have any effect on cisplatin nephropathy in rats. METHODS: Urine and serum profiles were monitored for 24 days after intravenous (i.v.) injections of saline, diatrizoate, iohexol, gadopentetate dimeglumine, and gadodiamide in high doses (4.59 mmol/kg body weight) in rats that received a weekly intraperitoneal (i.p.) injection of cisplatin (1 mg/kg) for 10 weeks. There were 10 rats in each group. Another 10 rats injected with both i.p. and i.v. saline served as control subjects. After euthanization, rats' kidneys were removed for examination by light microscopy and electron microscopy. RESULTS: Light and electron microscopy showed severe morphologic changes, including tubular dilatation, atrophy, and necrosis induced by cisplatin; however, the contrast media did not induce any additional morphologic changes. Gadopentetate dimeglumine, diatrizoate, and iohexol significantly increased (3-20 times) albuminuria compared with i.v. saline in cisplatin nephropathy, whereas gadodiamide did not. Albuminuria was highest after diatrizoate injection. All four contrast media caused an immediate and transient significant increase in the excretion of the brush border enzymes alkaline phosphatase and gamma-glutamyltransferase (125-500 times) and the cytoplasmatic enzymes alanine aminopeptidase and lactate dehydrogenase (16-100 times). Compared with saline, the ionic agents significantly increased the excretion of both glucose (two times) and sodium (three to five times), whereas the nonionic agents did not. CONCLUSION: High doses of radiologic and magnetic resonance contrast agents cause temporary dysfunction in rats with cisplatin nephropathy. Gadodiamide caused the least dysfunction and diatrizoate the most.

[Immediate and late complications of hysterosalpingography. A comparison between Madsen's obturator and intrauterine balloon catheter]. / Umiddelbare og sene bivirkninger ved hysterosalpingografi. Sammenligning mellem Madsens obturator og intrauterint ballonkateter.

Forty females who underwent hysterosalpingography (HSG) were randomized to a procedure using either an external cervical obturator or an intrauterine balloon catheter. All patients were interviewed about adverse events during and after the examination (six days). The balloon catheter turned out to be easier to place correctly and caused the fewest adverse events as regards bleeding and pain. It is concluded that a balloon catheter for HSG is preferable both from the doctor's and the patient's viewpoint.

Urine profiles and kidney histology after intravenous injection of ionic and nonionic radiologic and magnetic resonance contrast media in normal rats.

RATIONALE AND OBJECTIVES: Previous studies showed that both high-osmolality and low-osmolality iodinated contrast media cause temporary albuminuria and enzymuria (presence of enzymes in urine) in normal rats. Whether the same is true with ionic high-osmolality and nonionic low-osmolality magnetic resonance (MR) contrast media is unknown. We studied urine profiles and histology after intravenous injection of four types of contrast media in rats with normal kidneys. METHODS: Urine profiles were monitored 4, 24, 48, and 72 hr after intravenous injection of saline, diatrizoate, iohexol, gadopentetate dimeglumine, and gadodiamide (4.59 mmol/kg of body weight) in normal rats. Each group included 20 male rats. After sacrifice, both kidneys were removed for examination by light microscopy (LM) and electron microscopy (EM). RESULTS: All four contrast agents caused a temporary (< 22 hr) increase in the excretion of albumin (2-5 times) and of cytoplasmic (30-100 times) and brush border (10-100 times) renal enzymes when compared with saline. The degree of albuminuria correlated well (r = 0.90) with the osmolality of the injected media, whereas the increased level of enzymuria was unrelated to the osmolality. No major differences in the enzymuric effects of the four agents were noted. LM revealed vacuoles in all kidneys exposed to radiologic contrast media but not in kidneys exposed to MR contrast media or saline. Slight vacuolation was revealed by EM after the use of MR contrast media, and significant vacuolation was evident via EM after the use of radiologic contrast media. No difference between ionic and nonionic media within each drug group was detected by either LM or EM. CONCLUSIONS: Transient renal effects are induced by both ionic and nonionic high-osmolality and low-osmolality radiologic and MR contrast media in normal rats. Both osmotic (e.g., albuminuria) and chemotoxic (e.g., enzymuria) mechanisms seem to be involved. From a morphologic point of view, the chemotoxic mechanisms seem to be of major importance.

Transverse folds of the adult obstructed ureter. Case report.

Transverse folds in the distal ureter were found on urograms in two adult patients with ureteral obstruction. These folds were associated with but did not cause ureteral obstruction. Histopathological examination of the excised ureter in one patient showed that the folds were made of luminal projections of lamina propria containing prominent bundles of smooth muscle. The folds probably originate as a result of a lower compliance of the distal part of the ureter, which reduces the distension produced by a luminal rise in pressure.

Transabdominal and endoluminal ultrasonic scanning of the lower ureter.

I.v. urography is often insufficient for visualization of the intramural and juxtavesical portion of the ureter. In 30 consecutive patients (July 1st 1993-January 31st 1994) where i.v. urography was inconclusive, but had evoked suspicion of pathology in--or adjacent to--the lower ureter, abdominal ultrasound (including color Doppler) and endoluminal (transrectal or -vaginal) ultrasound were performed. A final diagnosis was obtained in 26: Ureteric stone (14), prostatic cancer (4), bladder cancer (2), stricture of ureteric orifice (1), TURB sequelae (1), ureterocele (1), bladder stone (1), detrusor hypertrophy (1), normal ureter (1). Abdominal ultrasound scanning gave more, same, and less information than i.v. urography in 8, 8, and 10 cases, respectively. In 14 of 22 cases abdominal color Doppler revealed a unilateral abnormal "ureteral jet"--in 13 of the cases on the side with suspected obstruction. Endoluminal ultrasound scanning gave more, same, and less information than i.v. urography in 20, 4, and 2 cases, respectively. The 20 cases where endoscanning gave more information included detection of 14 distal ureteric stones. In 3 cases it identified other types of distal obstruction, in two cases it determined the length of cancer obstruction and in one it detected the presence of ureteral dilatation. It is concluded, that endoluminal ultrasound of the ureter is indicated when i.v. urography evokes suspicion of pathology in the intramural or juxtavesical part of the ureter.

High-osmolar and low-osmolar contrast media. An update on frequency of adverse drug reactions.

During the past 3 years a great number of papers about adverse drug reactions to intravascular injection of high-osmolar and low-osmolar iodinated contrast media (CM) have been published. They include observational studies, randomized trials, meta-analyses and committee reports. Thorough analysis of this material substantiates an improvement in safety of at least 6-fold using nonionic low-osmolar CM compared with ionic high-osmolar CM. The point where only a small minority is continuing to argue effectively that low-osmolar CM are not better than conventional high-osmolar CM has now been reached. High-osmolar CM are used less and less for intravascular purposes, and, in fact, have been totally replaced by low-osmolar CM in 4 countries.

Radiographic evaluation of the urethral Kock ileal bladder substitute.

Fifty male patients who had undergone bladder substitution with a urethral Kock pouch after radical cystectomy for bladder cancer, were evaluated in the immediate postoperative period by retrograde pyelography and pouch cystography, and at later follow-up by pouch cystography. Other radiologic procedures (urography, ultrasonography, CT, etc.) were not part of a routine program, but were used when clinically indicated. In 12% a ureteroileal anastomotic leakage was found; the leaks resolved with continued ureteral stenting. Extravasation at the anastomosis between the pouch and the urethra was seen in 55% at the first cystography. It resolved within one month in all cases by simply leaving a catheter in the bladder. On the late cystograms reflux was observed in 6% of patients, whereas stone formation in the pouch was not encountered. A careful radiologic follow-up of patients with urinary diversions is essential to minimize postoperative complications.

Urine profiles and kidney histologic findings after intravenous injection of mannitol and iohexol in the degeneration phase of gentamicin nephropathy in rats.

RATIONALE AND OBJECTIVES: Previous studies have shown that iodinated contrast media may cause further renal dysfunction in tubulointerstitial nephropathy induced by gentamicin. The current investigation was undertaken to study whether the dysfunction after intravenous injection of a low-osmolar contrast medium is due to a chemotoxic and/or an osmotic effect. METHODS: Urine profiles were followed for 3 or 9 days after intravenous injection of saline, mannitol, and varying dosages of iohexol (1, 2.5, 5, and 10 mL/kg body weight (BW); 350 mg I/mL) in 60 rats, in which intramuscular injection of 40 mg/kg BW gentamicin had been administered daily nine times. A seventh group of 10 rats was given 20 mg/kg BW gentamicin and 5 mL/kg BW of 350 mg I/mL iohexol. Another 10 rats injected with saline served as controls. RESULTS: Both mannitol and iohexol increased the excretion of albumin and the enzyme N-acetyl-B-D-glucosaminidase (NAG) temporarily; the effect was independent of the dose of iohexol. There was a dose-dependent effect on the transient increase in excretion of the enzymes lactate dehydrogenase (LDH), gamma glutamyltransferase (GGT), and alkaline phosphatase (ALK); mannitol did not increase the excretion of these enzymes. In the group given 20 mg/kg BW gentamicin, only the dose-dependent effects of iohexol were seen. Neither various plasma components nor light/electron microscopy showed any changes that could solely be related to the contrast medium. CONCLUSIONS: Iohexol produces transient renal effects in gentamicin nephropathy, which may be due to both chemotoxic and osmotic mechanisms.

One or two samples for determination of total plasma clearance of a nonionic contrast medium in patients undergoing enhanced CT.

Plasma clearance of nonionic iopamidol (300 mg I/ml) was measured in 50 patients in connection with enhanced CT. Before injection of either 50 or 100 ml of the contrast medium, S-creatinine and urine osmolality were measured. Employing Renalyzer PRX 90, the plasma concentration of iodine was determined in blood samples drawn approximately 3 and 4 h after injection of iopamidol. The glomerular filtration rate was calculated by the Renalyzer using 2 different formulas, one requiring only a single sample, and one requiring at least 2 samples (standard). Both the 3- and 4-h single sample values correlated well with the glomerular filtration rate expressed by the standard sample value. The result was independent of whether 50 or 100 ml had been administered and whether or not water soluble contrast medium had been given orally before CT. As could be expected S-creatinine and urine osmolality correlated poorly with the clearance values. It is concluded that in patients receiving either 50 or 100 ml contrast medium for enhanced CT, the glomerular filtration rate can be determined in a single sample as well as with 2 samples taken between 3 and 4 h after contrast medium injection.

Quality of urography and renal clearance of ionic and nonionic contrast media.

The authors evaluated whether urographic quality correlated with patient hydration and the level of their renal function, depending on whether they received ionic or nonionic contrast media. One hundred patients with normal serum creatinine levels were randomly assigned to receive intravenous urography with either an ionic high-osmolar or a nonionic low-osmolar contrast medium. Patient hydration was evaluated by measuring urine osmolality in a sample voided just before the examination. The plasma concentration of iodine was determined in a single blood sample drawn approximately 3 hours later. From these determinations the plasma clearance of contrast medium was calculated. The urograms were assessed blindly with regard to nephrographic and pyelographic opacification, as well as overall diagnostic quality. The clearance varied between 42 and 115 mL x minutes-1 x 1.73 m-2. No systematic correlation of practical significance was found between the clearances and the urogram quality. A high urinary osmolality before the examination tended to improve quality with both media. It is not possible to assess glomerular filtration rate from nephrographic and pyelographic opacification, or from overall quality of routine urograms in patients with normal serum creatinine levels.

Renal clearance of an ionic high-osmolar and a nonionic low-osmolar contrast medium.

One hundred patients with normal serum creatinine concentration underwent intravenous urography with either an ionic high-osmolar (diatrizoate) or a nonionic low-osmolar (iopamidol) contrast medium after randomization. Before injection of the contrast medium, a blood sample was drawn for determinating serum creatinine concentration, and a urine sample for measurement of urine osmolality. Using x-ray fluorescence, the plasma concentration of iodine (contrast medium) was determined on blood samples drawn approximately 3 and 4 hours after injection of the contrast medium. The glomerular filtration rate was calculated by two different formulas: one requiring only a single sample and one requiring at least two samples (standard). There were poor correlations between the standard contrast medium clearance and the serum creatinine concentration, the estimated creatinine clearance (calculated from a nomogram), as well as the urine osmolality. The 3-hour and the 4-hour single-sample values correlated well with the two-sample values for both contrast media. In patients with normal serum creatinine, the glomerular filtration rate determined by measuring the contrast medium concentration in a single plasma sample obtained at 3 hours, is almost identical to the value determined from two samples. Consequently, two samples are unnecessary.

Porous-coated knee arthroplasty. A case report concerning bone ingrowth.

The area of bone-metal interaction in uncemented implants is regarded by many investigators as the key to the success or failure of the implant. The nature of the interaction is poorly understood because the zone is technically difficult to visualize and analyze. In order to test the power of modern imaging, analyzing, and metallurgical methods in this context, a well-functioning porous-coated knee prosthesis (tibial component) removed from the knee of a 65-year-old man was sectioned and examined by light microscopy, roentgenogram, scanning electron microscopy, and radiologic energy dispersive analysis. Independently, these methods demonstrated that the prosthesis was held in situ by collagenous tissue between and below the metal pellets of the prosthesis. Calcified bone did not appear to interact with the prosthesis and is probably not a major factor for prosthesis fixation. The various analytic methods described are suitable and sufficient for further exploration on a larger scale of the zone of bone-metal contact in cementless implants.