Clinical, radiographic and MRI findings of the temporomandibular joint in patients with different rheumatic diseases.

The aim of this study was to investigate the condition of the temporomandibular joint (TMJ) in patients with different rheumatic diseases, and report correlations between the clinical, radiographic and magnetic resonance imaging (MRI) findings. The 67 patients were divided into four groups: 16 with rheumatoid arthritis (RA), 15 with mixed connective tissue disease (MCTD), 18 with ankylosing spondylitis (AS) and 18 with spondyloarthropathy (SPA). They were clinically examined, and panoramic tomography, lateral panoramic radiography and MRI of the TMJ were performed. MRI showed reduced articular cartilage in 25% (4/16) of RA, 0% (0/15) of MCTD, 17% (3/18) of AS and 17% (3/18) of SPA patients. Condylar changes included erosion, osteophytes and abnormal shape. Disc alterations included perforation, abnormal anterior position and decreased movement. These abnormalities were most frequent in RA patients, and least frequent in MCTD and SPA patients. Crepitation and reduced maximum opening of the mouth correlated with abnormalities of the disc and articular cartilage as shown by MRI. Severe condylar erosion in panoramic tomograms significantly correlated with MRI findings of condylar erosion (P<0.01), diminished thickness of condylar cartilage, abnormal condylar shape, and abnormal shape of the temporal surface of the TMJ (P< or =0.001). The presence of crepitation, limited mandibular movement and/or pain on movement of the jaw often indicated structural damage to the TMJ. Panoramic radiographs provide an alternative method to MRI but, to obtain a more detailed anatomic picture, MRI is recommended for patients with acute unexplained pain or as part of preoperative work up. A panoramic recording is not indicated when MRI is planned.

Contrast media-induced renal tubular vacuolization after dehydration. A light and electron microscopic study in rats.

Morphologic studies on the effect of dehydration on contrast media (CM)-induced renal changes were done. Sixty-six healthy Wistar rats were deprived of water for 24 hours before the intravenous (i.v.) injection of 1.0 or 3.0 g iodine (I)/kg of high-osmolal diatrizoate, low-osmolal iopromide or iohexol, iso-osmolal iotrolan, or 0.2 or 0.6 g/kg of high-osmolal magnetic contrast agent, gadolinium-DTPA (Gd-DTPA). Control animals received physiologic saline. After 2 hours, the kidneys were fixed by perfusion for light and electron microscopy, and the morphologic changes were semi-quantitatively reviewed by two independent observers blinded to the treatment. The smaller dose of iohexol or iotrolan and the larger dose of all the CM induced in the proximal convoluted tubule (PCT) cells a statistically highly significant (P less than .001) or significant (Gd-DTPA; P less than .01) cytoplasmic vacuolization. The changes were most prominent (P less than .001) after treatment with iohexol and iotrolan. The results might be related to the higher urinary CM concentration after low- and iso-osmolal agents. Dehydration further potentiates higher CM concentration. The morphologic injury, when compared with the author's earlier findings on normal rats, was clearly intensified by dehydration.

Contrast media-induced renal morphologic changes in rats with acute edematous pancreatitis.

OBJECTIVES: Contrast media (CM)-induced renal morphologic changes were studied in rats during acute edematous pancreatitis. METHODS: The histologically verified, mild pancreatitis was caused in Wistar rats (n = 54) by an injection of peanut oil into the pancreatic duct. After 24 hours, the animals received an intravenous (IV) injection of 1.0 or 3.0 g iodine (I)/kg of high-osmolality diatrizoate, low-osmolality iopromide or iohexol, or 0.2 or 0.6 g/kg of high-osmolality magnetic resonance (MR) CM, gadolinium-DTPA (Gd-DTPA). The controls received physiologic saline. The kidneys were fixed by perfusion after 2 hours, and changes in renal morphology were analyzed semiquantitatively by two independent observers blinded to the treatment. RESULTS: The smaller dose of iohexol and the larger dose of all other CM induced a statistically significant (P less than .05) cytoplasmic vacuolization in the proximal convoluted tubule cells. The changes were most prominent after iohexol (P less than .001). When compared with the authors' earlier findings on healthy rats, the CM-induced renal structural injury was more severe. CONCLUSIONS: Pancreatitis potentiates the renal microstructural changes associated with CM; although the animals' fluid and electrolyte status was not specifically assessed, the enhanced abnormalities may be related to the hypovolemia associated with pancreatitis.

Contrast media-induced renal morphologic lesions during experimental hemorrhagic necrotizing pancreatitis.

RATIONALE AND OBJECTIVES: Contrast media-induced renal morphologic changes were studied in rats. Hemorrhagic pancreatitis was induced as a means of sensitizing the animals to the effects of contrast media. METHODS: The histologically verified hemorrhagic pancreatitis was induced in Wistar rats (n = 66) by injecting 6% sodium taurocholate into the pancreatic duct. After 2 hours, the animals received intravenously 1.0 or 3.0 g iodine/kg of high-osmolal osmolal diatrizoate, low-osmolal iopromide or iohexol, iso-osmolal iotrolan or 0.2 or 0.6 g/kg of high-osmolal magnetic resonance contrast agent, gadolinium-DTPA (Gd-DTPA). Control animals received physiologic saline. The kidneys were fixed by perfusion 2 hours later, and the morphologic changes were reviewed by two independent observers blinded to the injected agent. RESULTS: The smaller dose of iohexol and the larger dose of all the contrast media induced a statistically significant (P < .001 or .01) cytoplasmic vacuolization in the proximal convoluted tubule (PCT) cells. The nonionic, low- and iso-osmolal contrast media caused as much or even significantly more vacuolization than diatrizoate. CONCLUSIONS: Hemorrhagic pancreatitis potentiates the contrast media-induced renal morphologic changes, which depend on the type and dose of the injected contrast media.

Contrast media-induced renal tubular vacuolization. A light and electron microscopic study on rat kidneys.

The morphologic changes in healthy rat kidneys (n = 102) were studied 2 or 48 hours after intravenous injection of 1 or 3 g iodine (I)/kg of high-osmolality diatrizoate, low-osmolality iopromide and iohexol, or iso-osmolality iotrolan, as well as after 0.2 or 0.6 g/kg of the high-osmolality magnetic resonance contrast medium gadolinium DTPA. Physiologic saline was injected in controls. The kidneys were fixed by perfusion and the specimens were analyzed semiquantitatively by two independent observers blinded to the treatment. A statistically significant (P less than .01) cytoplasmic vacuolization was noticed in the proximal convoluted tubule cells 2 hours after injection of 3 g I/kg of diatrizoate or iopromide. Iohexol and iotrolan induced an even more significant (P less than .01) and longer-lasting vacuolization, but gadolinium DTPA did not produce lysosomal alterations. Although the vital cell organelles remained intact, reversible lysosomal alterations may represent the first structural signs of a threatening cellular injury.

Arteriomegaly.

The features of a patient with arteriomegaly of thoracic and abdominal aorta, common and external iliac, and femoral arteries are described.

Double contrast barium meal and acetylcysteine.

In a prospective double blind study, acetylcysteine, a local and systemic respiratory tract mucolytic agent, or a placebo, were given to 100 patients prior to a double contrast barium meal to decrease the gastric mucus viscosity and to make the mucus layer thinner, in order to permit barium to outline the furrows surrounding the areae gastricae instead of the overlying thick mucus. However, acetylcysteine failed to improve either visualization of the areae gastricae or the general quality of the double contrast barium meal.

Dynamic fast-gradient echo MR imaging of pancreatic tumours.

The purpose of this study was to determine the diagnostic utility of dynamic magnetic resonance imaging (MRI) of the pancreas. Twenty-eight adult patients with known or suspected pancreatic tumours were examined. Pre- and post-gadolinium (GdDTPA-BMA) scans were obtained in combination with an oral negative contrast medium (ferristene) to mark the gastrointestinal tract. In 6 cases a more precise diagnosis could be made by dynamic MRI compared to unenhanced MRI. Surgery could confirm the MR diagnosis based on contrast enhancement in 83% compared to 78% for CT. The results of signal intensity (SI) measurements show that a combination of differences in baseline values before enhancement and the slope of enhancement within the first 20 s is a reliable criterion to distinguish between normal pancreas and hypovascular tumours. These tumours already show lower SI values before as well as lower slopes after early enhancement. Mainly two effects facilitate the final MRI diagnosis: (1) the delineation of the pancreas from the duodenum by the negative contrast medium, and (2) the enhancement pattern of pancreatic tumours by gadolinium-enhanced dynamic MRI compared to normal tissue within the early enhancement after contrast injection.

Thoracic and lumbar spine in diastrophic dysplasia: a clinical and magnetic resonance imaging analysis.

STUDY DESIGN: Cross-sectional study to evaluate the thoracic and lumbar spine in patients with diastrophic dysplasia (DD). OBJECTIVES: To find the causative factors behind the spinal deformities and restricted mobility of the spine. SUMMARY OF BACKGROUND DATA: Typical findings in this skeletal dysplasia are short-limbed stature, multiple joint contractures, early degeneration of joints, and spinal deformities such as cervical kyphosis, scoliosis, and exaggerated lumbar lordosis. The pathogenic mechanism of scoliosis is unknown. METHODS: A physical examination was performed on 88 patients (55 females, 33 males) with an average age of 31 years (range, 3-56). Magnetic resonance (MR) images from T2 to S1 and radiographs were obtained. Degree of scoliosis was measured according to Cobb from standing radiographs. The anatomy of the medulla and the size of the spinal canal were assessed. The transverse dural tube area was measured from L2 to S1. Disc space, degeneration, and protrusions were evaluated. Vertebral abnormalities, if any, facet joint degeneration and the state of the spinal muscles were also assessed. RESULTS: Physical examination showed diminished mobility of the spine. Scoliosis was noted in 70 patients with an average of 42 degrees (range, 11-188 degrees ). The mean transverse area of the dural tube ranged from 94 mm(2) at L2-L3 to 57 mm(2) at L5-S1. The area was smaller at all levels compared with reference values (P < 0.001). One patient had severe thoracic and lumbar spinal stenosis. Five patients had compression of neural structures in the lumbar spinal canal in MR images, but had no clinical symptoms. All patients exhibited narrowed disc heights and a decrease in the signal intensity of discs on T2-weighted images. The prevalence of disc protrusions was low; three patients had a prolapse in the lumbar spine. Two patients displayed vertebral anomalies. All patients also had muscular atrophy and degenerative-like facet joint hypertrophy. The severity of these changes increased with age. CONCLUSIONS: Abnormal disc structure and rapid degeneration explain the diminished decreased mobility of the spine and may be a causative factor in the development of scoliosis. Muscular atrophy may be caused by reduced physical activity and rigid spinal deformities. The spinal canal is narrowed, but symptomatic lumbar spinal stenosis is uncommon.

Radiation exposure during percutaneous nephrostomy.

Radiation doses of radiologists, assistants and patients during 21 percutaneous nephrostomies (PN) (including 11 unilateral and 5 bilateral procedures) were measured using an area-exposure meter and thermoluminescent dosimeters. The mean fluoroscopy time per PN was 12 min and the mean product of air kerma and the cross-sectional area of the fluoroscopic beam was 8.0 (range 0.41-24) Gycm2. Doses to the radiologists and assistants were generally modest, and the yearly dose limits of ICRP will not be exceeded in practice. The doses to the radiologist's fingers were found to be the most restrictive in this study. Regarding the mean dose to the radiologist's fingers (190 muGy), the yearly dose limit of 500 mSv would be exceeded after about 2600 PNs provided that his fingers are not otherwise exposed. With the maximal finger dose of 1100 muGy, this would occur after about 450 yearly PNs.

Effect of sodium bicarbonate pretreatment on barium coating of mucosa during double contrast barium meal.

The radiographic pattern of the areae gastricae is produced by barium lying in the intersecting furrows of the gastric mucosal surface. However, if the mucus layer on the gastric mucosa is thick, it interferes with the barium coating of the areae gastricae during double contrast barium meal. As sodium bicarbonate decreases the viscosity of mucus and thus may make the gastric mucus layer thinner, it was evaluated as a pretreatment agent in a routine double contrast upper-gastrointestinal study to improve the visualization of the areae gastricae. In a single blind study, 53 of 106 patients took sodium bicarbonate water mixtures at bedtime the day before and on the morning of the examination. According to the results of the present study mucolysis induced by the used doses of sodium bicarbonate does not significantly affect micromucosal visualization during double-contrast barium meal.

MRI and CT in blunt renal trauma: an update.

In our experience, MRI is as effective as CT in correctly staging renal injury. The coronal and sagittal slice orientations of MRI are particularly helpful in determining the extent of the renal parenchymal damage. Both methods are accurate in finding perirenal hematomas, assessing the viability of renal fragments, and detecting preexisting renal abnormalities but are relatively inaccurate in visualizing urinary extravasation. Although CT remains the method of choice in radiological staging of renal injury, MRI can complement CT in patients with severe renal injury, preexisting renal abnormality, equivocal CT findings, or when repeated radiological follow-up is required. MRI could replace CT in patients with iodine allergy and be used for initial staging if CT is not available.

Scoliosis after solid organ transplantation in children and adolescents.

The occurrence of scoliosis in children after solid organ transplantation is not known. A total of 196 children, which is 93% of patients surviving kidney, liver and heart transplantation in our country, participated in a cross-sectional survey. All children were screened for rib hump, and those with clinically significant hump (over 6 degrees ) underwent radiographs of the spine. The occurrence of scoliosis was compared to data obtained from a previously published comparison group. Forty-three (21.9%) of the patients had scoliosis greater than 10 degrees , and 21 (10.7%) of them had curves greater than 20 degrees . The RR (95% CI) for scoliosis needing treatment (over 20 degrees ) was 17.0 (6.75-42.7) in the patients as compared with control population. The occurrence of scoliosis was 17.9% of the kidney, 13.6% of the liver and 51.7% of the heart transplant patients (p < 0.001). In a logistic regression model, heart transplantation (OR (95% CI) 7.27 (2.62-20.2)) and growth hormone treatment (3.98 (1.77-8.94)) were most significant risk factors for scoliosis. The risk of scoliosis is increased in patients with solid organ transplantation. Pediatricians treating these patients should be aware of this increased risk to diagnose early curves and to refer these patients to an orthopedic surgeon.

Preoperative assessment of focal liver lesions: multidetector computed tomography challenges magnetic resonance imaging.

PURPOSE: To investigate prospectively multidetector computed tomography (CT) (MDCT) and magnetic resonance (MR) imaging (MRI) in the preoperative assessment of focal liver lesions. MATERIAL AND METHODS: Multiphasic MDCT and conventional gadolinium-enhanced MRI were performed on 31 consecutive patients prior to hepatic surgery. All images were blindly analyzed as consensus reading. Lesion counts and their relation to vascular structures and possible extrahepatic disease were determined. The data from the MDCT and MRI were compared with the results obtained by intraoperative ultrasound (IOUS) and palpation. Histopathologic verification was available. RESULTS: At surgery, IOUS and palpation revealed 45 solid liver lesions. From these, preoperative MDCT detected 43 (96%) and MRI 35 (78%) deposits. MDCT performed statistically better than MRI in lesion detection (P=0.008). Assessment of lesion vascular proximity was correctly determined by MDCT in 98% of patients and by MRI in 87%. Statistical difference was found (P=0.002). IOUS and palpation changed the preoperative surgical plan as a result of extrahepatic disease in 8/31 (26%) cases. In MDCT as well in MRI extrahepatic involvement was suspected in two cases. CONCLUSION: MDCT was superior to MRI and nearly equal to IOUS in liver lesion detection and in the determination of lesion vascular proximity. However, both techniques fail to reliably detect extrahepatic disease.

Computed tomographic evaluation of Finnhorse cadaver forefeet with radiographically problematic findings on the flexor aspect of the navicular bone.

Computed tomography (CT) was performed on 12 Finnhorse cadaver forefeet with known radiographic changes in the navicular bone (poor corticomedullary junction, irregular appearance of the flexor central eminence, uneven or unequal thickness of the flexor cortex, and/or irregular outline of the proximal or distal flexor margin). The purpose was to confirm the radiographic findings and to investigate if further information of the flexor aspect of the bone could be gained with CT. In CT, the midsagittal outline as well as the internal structure of the bones varied greatly. Different combinations of trabecular and compact bone were seen within the flexor central eminence. Lucencies within the compact bone were commonly present in the proximal half of the eminence, but in five bones lucencies were also identified in the distal half. Due to partial overlapping of the bone and varying bony composition of the eminence, accurate radiographic evaluation of the shape and internal structure of the flexor central eminence was often found to be difficult. The flexor cortex usually appeared to be thinner in CT than in conventional radiographs. Medullary sclerosis and poor flexor corticomedullary junction were commonly overinterpreted radiographically. New bone formation on the proximal flexor margin of the navicular bone was generally visualized in radiographs, but CT allowed also the evaluation of the internal structure of the bone. In one navicular bone, an avulsion fragment on the distal flexor margin was seen in CT images; radiographically this fragment could not be visualized. It was concluded that the flexor aspect of the navicular bone may be difficult to assess reliably with conventional radiography.