High resolution CT of Wegener's granulomatosis--case reports.

Computed Tomography (CT) of the chest was performed in three patients with Wegener's granulomatosis to define the anatomical basis of pulmonary involvement. Nodules, masses with cavitation, and areas of parenchymal opacities were typical manifestations on CT images. An extremely wide variety of radiologic findings were demonstrated in addition to the commonly described cavitary nodules.

Tc99m sulfur colloid scintigraphy for detection of intrathoracic extramedullary hematopoiesis in patient with beta-thalassemia major--a case report.

Extramedullary hematopoiesis (EMH) refers to the production of blood cells outside the bone marrow and is a compensatory mechanism for bone marrow dysfunction. A 34 year-old female patient with beta thalassemia major was found to have multiple large, well-circumscribed radiopaque paravertibral mass lesions in chest radiography. Magnetic resonance imaging (MRI) of the thorax disclosed a right upper apical and two lower thoracic paraspinal mass lesions with heterogeneous isointensity on T1-weighted images and hypointensity on T2-weighted images. Because intrathoracic EMH is suspected in our case, which had obvious bone marrow dysfunction, radionuclide bone marrow scintigraphy is helpful in supporting the diagnosis. Tc99m sulfur colloid scintigraphy demonstrated three intense radioactive thoracic paraspinal mass lesions corresponding to the lesions seen on MRI. We believe whole body bone marrow scintigraphy with Tc99m sulfur colloid is the best convenient noninvasive method for supporting the diagnosis of EMH.

Gd(DTPA-BBA) as a contrast agent in magnetic resonance imaging in rats.

Gadolinium (III)-di(benzyl carbamoylmethyl) diethylenetrinitrilotriacetic acid [Gd(DTPA-BBA)] is a newly developed paramagnetic complex designed for use as a hepatobiliary-specific contrast agent. The purpose of this study was to examine the relaxivity, biodistribution, and magnetic resonance (MR) imaging characteristics of Gd(DTPA-BBA) in rats. Our results showed that the T1 relaxivity of Gd(DTPA-BBA) (3.89 dm3/mmol/s in aqueous solution) was similar to that of Gd(III) diethylenetriamine-pentaacetate [Gd(DTPA)]2- (4.08 dm3/mmol/s) and Gd(III) benzyloxypropionicte-traacetate [Gd(BOPTA)]2- (4.40 dm3/mmol/s). Biodistribution studies indicated that Gd(DTPA-BBA) exhibited hepatobiliary and urinary elimination. In MR imaging studies, Gd(DTPA-BBA) provided biphasic enhancement of normal liver parenchyma, which was characterized by an initial steep increase in enhancement followed by a plateau. The initial relative enhancement (RE%) of the liver, at 1 minute after administration of 0.2 mmol/kg Gd(DTPA-BBA) was 113 +/- 19. The plateau RE% of the liver (48 +/- 13) occurred within 10 minutes and persisted for at least 60 minutes after injection of the contrast agent. In addition, Gd(DTPA-BBA) provided better RE% of the liver than [Gd(DTPA)]2-. The contrast RE% of liver abscess capsules reached a plateau within 5 minutes after injection of 0.1 mmol/kg Gd(DTPA-BBA). Although the hepatic enhancement of Gd(DTPA-BBA) was inferior to that of [Gd(BOPTA)]2-, the results suggest that Gd(DTPA-BBA) has potential as an MR contrast agent for nonspecific and hepatobiliary uses.

Development of adenoids: a study by measurement with MR images.

Magnetic resonance (MR) imaging, which is able to demonstrate the actual size of adenoids by differentiating them from other soft-tissue structures, can be effectively used to study the normal development of adenoids. To assess the normal development of adenoids and to understand their role in the nasopharyngeal airway compromise, the adenoids of 290 children who had MR examination for other reasons were measured by midsagittal T1-weighted spin-echo MR image. The maximal thickness of adenoids (A), anteroposterior depth of the nasopharynx (N) and the adenoid-nasopharynx (A/N) ratios were obtained using this method. The results showed that of the infants under the age of 3 months only 2 out of 11 adenoids (18%) could be identified. By 4 months of age, adenoids could be identified in 6 of 8 infants (75%). After 5 months of age, all adenoids were well demonstrated by MR imaging. The adenoids developed rapidly during infancy and reached a plateau between 2- and 14 years of age with a mean thickness ranging from 10.7 to 12.2 mm. Finally, the adenoids regressed rapidly after 15 years old. The A/N ratios, which could be used to assess the airway compromise, had a plateau between 2- and 7 years of age. After that, with the steady growth of the nasopharynx, the possible role of adenoid in airway compromise will become increasingly less significant in later childhood.

Magnetic resonance images of neuronal migration anomalies.

Neuronal migration anomalies are a spectrum of brain malformations caused by insults to migrating neuroblasts during the sixth week to fifth month of gestation. To study the characteristics of MRI findings in migration anomalies, MR images of 36 patients (28 children and 8 adults) with migration anomalies were evaluated. Five patients had lissencephaly, eight had pachygyria, twelve had schizencephaly, six had heterotopias of gray matter, three had hemimegalencephaly, and two had polymicrogyria. The frequency of migration anomalies was 0.51% of all cranial MRI studies and 1.21% of pediatric cranial MRI studies at our hospital. The major clinical presentations of these patients were seizure (64%), development delay (42%), motor deficits (42%) and mental retardation (25%). Twenty-five patients (69%) associated with other brain anomalies, including: other migration anomalies in 12 cases (33%), absence of the septum pellucidum in 10 cases (28%), Dandy-Walker malformation/variant in 5 cases, arachnoid cyst in 4 cases, agenesis of the corpus callosum in 3 cases, holoprosencephaly in 2 cases, mega cisterna magna in 1 case and cephalocele in 1 case. Some of them presented with multiple complicated anomalies. As MR imaging provides superb gray-white matter distinction, details of cortical anatomy and multiplanar capability, it can clearly delineate the detail morphologic changes of the brain caused by neuronal migration disorders as well as the associated anomalies.

Etiology, timing of insult, and neuropathology of cerebral palsy evaluated with magnetic resonance imaging.

To define the patterns of pathologic changes in cerebral palsy (CP) and to assess the etiology and time of brain damage, we reviewed the magnetic resonance images and clinical records of 86 pediatric CP patients seen over 8 years. Patients were divided into two groups, based on the gestational age at birth. The majority of CP patients (69) had spasticity. In the premature group (< 37 wk gestational age) n = 27), spastic diplegia (12 patients) and quadriplegia (8) were the major subtypes. In the term group (> or = 37 wk gestational age) ( n = 59), spastic hemiplegia (23) and quadriplegia (12) were most common. The other main clinical manifestations in the two groups were seizures (36) and mental retardation (15). Magnetic resonance (MR) imaging provided significant findings in 82 patients (95%). In the 27 patients born prematurely, MR imaging revealed periventricular leukomalacia (17), multicystic encephalomalacia (3), cortical and subcortical atrophy (4), migration disorders (2), and basal ganglia injury (1). Among the patients born at term, the MR imaging findings were more heterogeneous; they included cortical and subcortical atrophy (17), brain malformations (17), periventricular leukomalacia (6), multicystic encephalomalacia (5), porencephaly (4), hemiatrophy (3), delayed myelination (3), and none (4). MR imaging alone could define the time of brain insults in 73 of our 86 CP patients. Combined with clinical histories, MR imaging could help assess the time of insult in 93% of patients. The brain insults occurred prenatally in 34 of our patients, perinatally in 37, and postnatally in eight. The time of insult could not be determined in six patients. In the premature patients, the insult occurred most frequently perinatally (74%), whereas in the term group it occurred most frequently prenatally (54%). MR imaging was found to be very helpful in the evaluation of the various neuropathologic changes in CP, in the depiction of the etiology, and in the determination of the time of brain injury.

Bacterial meningitis and lumbar epidural hematoma due to lumbar acupunctures: a case report.

A 48-year-old female expressed signs of meningeal irritation after having received several lumbar acupunctures within one week for back pain. Bacterial meningitis was diagnosed from cerebrospinal fluid examinations. Magnetic resonance image (MRI) of spine at admission demonstrated a fusiform lesion with characters of subacute hematoma in the epidural space of the first and second lumbar level. She received antibiotics treatment only and recovered from her central nervous system infection completely. The epidural lesion disappeared spontaneously in the MRI follow up three weeks later. We report the diagnosis and follow-up of epidural hematoma of the lumbar spine by MRI which aided the medical physician to treat meningitis attentively.

Preclinical evaluation of Fe-(5-C2H5-EHPG)- as a contrast agent in MR imaging of hepatobiliary system.

Iron(III)-N, N'-ethylenebis[2-(2-hydroxy-5-phenyl)glycine] [Fe-(5-C2H5-EHPG)-] is a paramagnetic complex designed for use as a hepatobiliary agent. Test procedures included synthesis, characterization, toxicity evaluation, biodistribution and experiments for animal MR images. The dose of LD50 in acute toxicity test of Fe-(5-C2H5-EHPG)- in mice was 3.49 mmol/kg. 111In-(5-C2H5-EHPG)- biodistribution studies revealed that the activities were (4.78 +/- 0.97, 5.34 +/- 0.91, 4.53 +/- 0.35)%ID and (0.88 +/- 0.18, 0.99 +/- 0.17, 0.84 +/- 0.06)%ID/gm in the liver at time intervals of 10, 30 and 60 minutes after injection; (5.76 +/- 0.15, 5.75 +/- 0.15, 4.00 +/- 0.04)%ID and (0.49 +/- 0.03, 0.49 +/- 0.05, 0.34 +/- 0.01)%ID/gm in the blood; (1.27 +/- 0.91, 1.46 +/- 1.00, 1.52 +/- 0.46) %ID and (0.89 +/- 0.17, 1.02 +/- 0.18, 1.06 +/- 0.08)%ID/gm in the kidneys, respectively. The results of image enhancement correlated well to the biodistribution. Analysis of the MR images showed degrees of maximal parenchymal % increase of signal to noise ratio (S/N) was 42.09 +/- 3.59% for normal liver at 30 minutes postinjection, which exceeded the value of pathologic liver with bile duct obstruction 16 hours 17.26 +/- 6.6 %, 1 week 19.80 +/- 6.46% and 4 weeks 32.20 +/- 9.01%, respectively, and acute hepatitis 16.50% +/- 4.02%. Persistent enhancement plateau was documented up to 60 minutes after injection and normalized to precontrast value within 22 hours. The common duct was opacified at 10-15 minutes after injection of contrast agent. These results indicated that the Fe-(5-C2H5-EHPG)- could be rapidly extracted from the blood stream by the hepatocytes and excreted into the bile duct. The initial evaluation of Fe-(5-C2H5-EHPG)- demonstrated that Fe-(5-C2H5-EHPG)- was well suited for enhancement of normal liver parenchyma and was compromised with deterioration of liver function. However, the increase of the liver intensities in the animal model of the total biliary obstruction group normalized to precontrast value within 22 hours, which indicated that renal clearance as an effective alternative pathway for biliary excretion. In conclusion, these results indicate that Fe-(5-C2H5-EHPG)- has the potential of becoming a safe and reliable magnetopharmaceutical for the hepatobiliary system.

Calcification in retroperitoneal non-Hodgkin lymphoma prior to treatment: a case report.

Calcification in malignant lymphoma before treatment is rare. Here we report a case of low grade non-Hodgkin lymphoma of sclerosing type presenting as a retroperitoneal calcified mass. The calcification was demonstrated with various imaging modalities, including conventional radiographs, sonography, computed tomography (CT) and magnetic resonance (MR) imaging. This case and other isolated reports show that radiographical examinations may, rarely, reveal calcification in lymphoma prior to treatment.

Mandibular arteriovenous malformation diagnosed by MR and MRA: a case report.

A case of mandibular arteriovenous malformation (AVM) is presented. Prompt diagnosis and appropriate management are essential due to massive bleeding or even death after dental extraction or biopsy. Angiography remains the gold standard in detecting the lesion. Magnetic resonance (MR) imaging with spin-echo sequences reveals the vascular malformation as signal-void. MR angiography can demonstrate the nidus, dilated artery and vein. MR imaging and MR angiography can supplement angiography in the diagnosis of mandibular AVM.

Abdominal pseudotumors and simulated lymphadenopathy in MRI: differential features with the use of retrograde air insufflation.

In order to evaluate the contribution of retrograde air insufflation in decreasing the occurrence of pseudotumor appearance and mimicked lymphadenopathy due to nonair-distended bowel loops, we retrospectively compared two groups of magnetic resonance (MR) examinations. In the group receiving retrograde air insufflation, 10.8% (67 of 619) of images showed a tumor-like lesion due to nonair-distended bowel loop(s), whereas in the group not receiving air introduction, a tumor-like lesion was simulated in 45.6% (140 of 307) of images. Furthermore, a collapsed bowel loop(s) mimicking an enlarged lymph node close to the aorta, inferior vena cava, or bilateral iliac vessels was found in 9.5% (24 of 252) of images of the latter group, in contrast to only 1.8% (9 of 505) of images of the former group. This study shows that retrograde air insufflation greatly reduces the occurrence of pseudotumor appearance and false impression of paraaortic, paracaval, or parailiac lymphadenopathy secondary to nonair-distended bowel loop(s).

MRI manifestations of gastrointestinal lymphoma.

The magnetic resonance (MR) images of 11 cases of gastrointestinal lymphoma are presented. The findings include irregularly thickened mucosal folds, irregular submucosal infiltration, annular constricting lesion, exophytic tumor growth, mesenteric masses, and mesenteric/retroperitoneal lymphadenopathy. The tumors were homogeneous and intermediate in signal intensity on T1-weighted images. Heterogeneously increased signal intensities were noted on T2-weighted images. There was mild to moderate enhancement after intravenous administration of gadolinium dimeglumine (Gd-DTPA). The submucosal tumor infiltration might be outlined between the strongly GD-DTPA-enhanced mucosa and the low-intensity muscular layer. In one case that received tumor resection, the pathological examination showed destruction of most parts of the muscular layer, and the MR images did not disclose the low-intensity muscular zone.

MRI manifestations of gastrointestinal wall thickening.

The appearance of gastrointestinal wall thickening of various entities is demonstrated on magnetic resonance imaging (MRI). The entities include benign gastric ulcer, gastric carcinoma, pancreatic carcinoma with direct invasion of stomach, duodenal leiomyoma, radiation enteritis, peritonitis, colonic carcinoma, recurrent carcinoma at the gastrojejunal anastomosis with direct extension to the transverse colon, colocolic intussusception, sigmoid diverticulitis with pericolonic abscess and fistula into the urinary bladder, and lymphoma of the stomach, duodenum, small bowel, and colon. Air was introduced antegradedly or retrogradedly into the alimentary tract to act as a contrast agent. When the bowel was distended by air, the normal bowel wall was barely visible or even invisible. Abnormal focal or segmental wall thickening was outlined between the intraluminal air and extraluminal fat. In some instances, the thickenings were better demonstrated on coronal or sagittal sections. The proper muscular layer of the bowel has a low-signal intensity and was delineated between the thickened mucosa-submucosa and extramural fat. Interruption of this low-intensity zone might represent tumor invasion through the muscular layer.

Imaging diagnosis of cavernous hemangioma of the rib--one case report and review of the literature.

Osseous hemangioma is a benign neoplasm, rarely located in the ribs. A 56-year-old female patient without specific complaint had a large extrapleural lesion on chest posteroanterior radiograph. Expansile destruction of left seventh rib and relatively fine trabeculation were noticed in the mass from plain roentgenogram and computed tomography (CT). Contrast enhancement in noncalcified component of the lesion was revealed. Pleural effusion, lung parenchymal or mediastinal abnormality were not identified. Resection of the lesion with part of the originating rib was carried out. The pathologic diagnosis was cavernous hemangioma. We present a case with a large rib hemangioma which often leads to difficulty in radiologically differential diagnosis with other common malignant rib tumors. We also review the literature about hemangioma and malignant neoplasms of the ribs.

Magnetic resonance imaging and computed tomography of transitional cell carcinoma of renal pelvis and ureter.

Fourteen patients with clinically suspicious transitional cell carcinoma of renal pelvis or ureter were preoperatively examined with magnetic resonance imaging (MRI) and computed tomography (CT). All of the cases had surgical approval. In eleven of these patients, the tumor was correctly detected by MRI. Two cases were falsely positive including one squamous cell carcinoma (SCC) and one Wilms' tumor of the kidney. The final case was falsely negative. The positive predictive value of MRI was 92.9%. The sensitivity was 91.7%. In seven of the fourteen patients, the CT findings were truly positive. There were five falsely negative findings and two falsely positive cases. The positive predictive value by CT was 64.3%. The sensitivity was 59.3%. Tumor stagings were done for all patients. The accuracy rate of staging was 7/7 by CT and 10/11 by MRI. MRI showed better identification of distant metastasis in the liver, vertebrae and vascular structure because of its high tissue contrast and larger field of view. MRI had a higher positive predictive rate and sensitivity for identification of uroepithelial tumor than CT.

MRI demonstration of peritoneal implants.

The magnetic resonance imaging (MRI) findings of 12 proven cases of peritoneal implants, mainly carcinomatosis, were reviewed for evidence of peritoneal seedings. The seeded sites include the pouch of Douglas, the ileocecal and retrocecal regions, the right and left paracolic gutters, Morison's pouch, the right subdiaphragmatic parietal peritoneum, the greater and lesser omentum, the gastrocolic, gastrosplenic, and phrenicocolic ligaments, the small bowel mesentery, the sigmoid and transverse mesocolons, and the small and large bowel walls. Sizes varied from less than 1 cm to omental cake and bulky tumors. The findings include linear or tiny nodular infiltrations of the omentum and subperitoneal fat (ligamentous, mesenteric, and mesocolic), focal or segmental wall thickenings, loss of unilateral colonic haustration with sacculation on the contralateral side, and nodular soft tissue masses along different locations of the peritoneal surfaces. Air was introduced via an antegrade or retrograde method to act as a gastrointestinal contrast agent and was found to be useful for delineating the seedings. As is true with computed tomography scan, miliary implants are also not detectable with MRI. The sensitivity and specificity of MRI in detecting peritoneal implants remain to be determined.

Fe(III)-EHPG and Fe(III)-5-Br-EHPG as contrast agents in MRI: an animal study.

The development of specific agents for hepatobiliary magnetic resonance imaging (MRI), iron (III) ethylenebis-(2-hydroxyphenylglycinate) [Fe(EHPG)-] and its derivative iron (III)-N, N' ethylenebis[5-bromo-2-hydroxyphenyl)-glycinate] [Fe(5-Br-EHPG)-] was investigated. Test procedures included method of synthesis, identification, and a test for purity, lipophilicity, toxicity, relaxivity, biodistribution and animal MRIs. Free EHPG and free Fe3+ were undetectable in the purity test. The partition coefficient for the lipophilicity of Fe(EHPG)- was 0.007 and for Fe(5-Br-EHPG)- it was 1.785. The acute toxicity test of Fe(EHPG)- in mice revealed that the LD50 dose of Fe(EHPG)- was 8 mmol/kg. Their relaxivity values were 1.167 and 0.780 s-1mM-1 in an agarose gel system and 1.313 and 0.725 s-1mM-1 in an aqueous solution, respectively. Biodistribution was performed with 59Fe(EHPG)- in anesthetized dogs. There was 1.097% to 1.19% contrast excretion through the opened common bile duct and 54.29% to 61.45% through the urinary tract in a six-hour period. After six hours, the residual contrast agent was only evident in the kidney and liver. The MRIs of dogs with intravenous contrast administration showed significant opacification of the common bile duct within a 10-minute period. Complete opacification of the biliary system could be identified within 1.5 hours. There was no significant difference in the enhancement effect between the inversion recovery sequence and T1-weighted spin echo sequence. The change in signal intensity of the hepatobiliary system on MRIs was similar between Fe(EHPG)- and Fe(5-Br-EHPG)-. The recommended administration dose was 0.083 mmol/kg for both contrast agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal MR imaging following antegrade air introduction into the intestinal loops.

Air was used to distend the gastrointestinal tract and act as a contrast medium to effectively delineate the other abdominal organs/masses and to outline intraluminal or mural lesions. We used a nasogastric tube to introduce air into the stomach. Metoclopramide was administered to propel air throughout the gastrointestinal tract. Bowel peristalsis was then controlled by scopolamine butylbromide. Most of the alimentary tract could be distended by air. The normal bowel walls were barely visible between intraluminal signal-void air and extraluminal high-signal fat. Intraluminal tumor, wall thickening, and adjacent structures could be clearly delineated.