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Biomedical subjects

C E Spritzer

Publications and source records attributed to C E Spritzer.

At least 73 records · Page 4Linked to original sources
PubMed1988

MR imaging of the knee: preliminary results with a 3DFT GRASS pulse sequence.

The knees of 17 patients (18 extremities) with possible meniscal, cruciate ligament, and articular cartilage abnormalities were examined with a three-dimensional Fourier transform (3DFT), gradient-refocused acquisition in a steady state (GRASS) pulse sequence. Arthroscopic confirmation was available in all cases and was the standard for comparison. Thirteen of these extremities were also examined by using a two-dimensional Fourier transform spin-echo pulse sequence with a 2000-msec repetition time and 20- and 80-msec echo time. In these 13 cases, both pulse sequences correctly identified seven of eight meniscal abnormalities. However, interpretation of the 3DFT GRASS images resulted in fewer false-positive meniscal tears (three vs six). Cruciate ligament tears were detected more readily on the 3DFT GRASS images (six vs three with two possible tears on the spin-echo images). These preliminary findings suggest that the overall accuracy of MR imaging of the knee could be improved by including 3DFT gradient-refocused pulse sequences.

Adolescent↗
PubMed1987

Magnetic resonance imaging of pigmented villonodular synovitis: a report of two cases.

The magnetic resonance imaging characteristics of two surgically proven cases of pigmented villonodular synovitis are reported. On the short TR/TE pulse sequences, the synovium has an intermediate signal intensity. Long TR/TE pulse sequences show the synovium containing areas of increased signal interspersed with decreased signal. Hemosiderin deposition is believed to account for the areas of decreased signal; the increased signal results from fluid and inflamed synovium.

Adolescent↗
PubMed1987

Magnetic resonance imaging in the evaluation of suspected osteonecrosis of the knee.

Magnetic resonance imaging (MRI) was performed on 19 patients with suspected or proven osteonecrosis of the knee. The results were compared to radionuclide and plain radiographic studies when possible. The patients were grouped into one of three categories: patients with disease predisposing them to osteonecrosis (e.g., systemic lupus erythematosus (SLE), steroid use, and renal transplants), older patients without risk factors with acute onset of symptoms,and patients with knee pain months or years following trauma. In six patients with symptoms and predisposing diseases, MRI was abnormal in four cases, all of whom had bilateral abnormalities. In the ten older patients with classical symptoms, MRI was abnormal in seven, and bilateral abnormalities were present in three patients. The three patients with a history of antecedent trauma had normal MRI studies. Two patients with history and scintigraphic evidence of osteonecrosis had negative MRI scans. MRI may be of value in patients with suspected or proven osteonecrosis of the knee by demonstrating bilateral disease in patients with unilateral symptoms, showing the extent of involvement, and establishing the presence or absence of bone marrow changes in patients with positive bone scans and negative plain films.

Humans↗
PubMed1987

Adnexal masses: MR imaging observations at 1.5 T, with US and CT correlation.

To assess the role of 1.5-T magnetic resonance (MR) imaging in evaluation of the adnexa, 43 consecutive examinations that revealed 61 adnexal masses were retrospectively reviewed. T1- and T2-weighted images in coronal, axial, and/or sagittal planes were included. Available ultrasound (US) (n = 30) and/or computed tomographic (CT) (n = 9) scans were then correlated with the MR images. On T2-weighted images at least part of all adnexal masses was of higher signal intensity than surrounding muscle and adipose tissue, and therefore the adnexal masses were best seen with these sequences. T1-weighted imaging improved tissue characterization by revealing signal characteristics of fat in teratomas and characteristics of blood in endometriomas or hemorrhagic cysts, pelvic inflammatory disease, ovarian carcinomas, serous cystadenomas, and teratomas. MR imaging provided additional information or increased diagnostic confidence in 25 of 30 patients who underwent US or CT. MR imaging is a promising problem-solving modality after US in the study of adnexal abnormalities.

Adenoma↗
PubMed1987

Abnormal parathyroid glands: high-resolution MR imaging.

High-resolution magnetic resonance (MR) images of the neck were obtained in 23 patients with hyperparathyroidism. Surgical confirmation was available in all cases. MR imaging allowed accurate localization of 14 of 17 parathyroid adenomas, two of two parathyroid carcinomas, and five of eight hyperplastic glands, the latter from three patients. MR depicted nine of 11 (82%) abnormal glands that were 0.5-1.0 cm in size and 12 of 14 (85.7%) glands larger than 1 cm in diameter. In all but one case, abnormal glands had signal intensity greater than or equal to that of fat on spin-echo images with long repetition time and echo time. Parathyroid adenomas, carcinomas, and hyperplasia could not be distinguished from each other. The overall sensitivity and specificity of MR imaging in the detection of parathyroid abnormalities was 77.8% and 95.4% respectively, resulting in an accuracy of 90.2%. This compares favorably with other imaging modalities.

Adenoma↗
PubMed1987

Femoral head avascular necrosis: correlation of MR imaging, radiographic staging, radionuclide imaging, and clinical findings.

To better correlate the appearance of avascular necrosis (AVN) of the femoral head on magnetic resonance (MR) images with the stage of disease, MR images of 56 proved AVN lesions were compared with staging from corresponding radiographs (n = 56), Tc-99m scans (n = 41), and grade of symptoms (n = 28). Fractures complicating AVN were seen in 28 (50%) of 56 radiographs (radiographic stages III-V). With long repetition (TR) and echo delay (TE) times, a characteristic "double line sign" consisting of high signal intensity inside a low-intensity peripheral rim was seen in 45 lesions (80%). The central region within the rim was isointense with marrow fat on both short and long TR and TE images in 20 (71%) of 28 lesions uncomplicated by fracture (stages I-II) but in only four (14%) of 28 stage III-V lesions (P less than .001). Symptoms were least severe in lesions isointense with fat and most severe in lesions with low-signal central regions at short and long TRs and TEs. The peripheral double line sign on long TR/TE images may add specificity to the diagnosis of AVN by MR imaging. A chronologic pattern of central MR signal features is presented which may allow staging of AVN by MR imaging.

Female↗
PubMed1987

Prostatic disorders: MR imaging at 1.5 T.

Pelvic magnetic resonance (MR) images obtained at 1.5 T of 31 men with known genitourinary disease were reviewed retrospectively. In most, peripheral and central prostatic zones could be seen on axial images obtained with long repetition times/echo times (TRs/TEs). The prostate had no specific signal intensity that enabled differentiation between benign and malignant changes. Each patient with known extracapsular prostatic carcinoma had a peripheral zone defect--1 cm or greater in diameter with ill-defined borders and relatively lower signal intensity than that of the remainder of the peripheral zone--that correlated with the site of clinical-pathologic involvement. Correlation of a peripheral zone defect on long TR/TE images as a sign for extracapsular spread of prostatic cancer was 100% sensitive, yet 54% specific, with excellent interobserver agreement. Stage A2 and B1 prostatic carcinoma was not detected. Benign prostatic hyperplasia was seen as centrally located proliferation and nodularity, usually with discrete margins and a wide spectrum of low- to high-signal-intensity features. MR imaging may have a role in differentiating between intracapsular and extracapsular prostatic carcinoma.

Adult↗
PubMed1987

Normal prostate and adjacent structures: MR imaging at 1.5 T.

Pelvic magnetic resonance images obtained at 1.5 T of 29 male patients with no known genitourinary tract disease were retrospectively reviewed. Normal anatomic features of the prostate and its adjacent structures were studied with spin echo techniques with short and long repetition times/echo times (TR/TE). Long TR/TE (T2-weighted) images routinely showed differentiation of peripheral and central prostatic zones, as well as a separate periprostatic venous plexus. Guidelines were developed to optimize imaging of the relationship of the prostate to adjacent structures.

Adult↗
PubMed1987

Thyroid imaging with high-field-strength surface-coil MR.

Magnetic resonance (MR) imaging of the thyroid was performed with a 1.5-T system and local receiver coil in 19 "healthy" subjects and 34 patients with various focal and diffuse thyroid disorders. The normal gland was typically homogeneous with increased intensity relative to that of muscle on images obtained with long repetition times (TRs) and long echo times (TEs). Adjacent structures in the neck and upper mediastinum were well displayed. Thyroid nodules as small as 4-5 mm were identified. Follicular adenomas appeared as well-circumscribed nodules of heterogeneous intensity, increasing significantly in signal with long TRs/TEs. Colloid cysts and hemorrhagic cysts had homogeneous high signal with both short and long TRs/TEs. Two of three carcinomas were seen as poorly marginated lesions with associated cervical lymphadenopathy clearly depicted as increased intensity with long TRs/TEs. A follicular adenoma containing microscopic papillary carcinoma appeared similar to other benign adenomatoid nodules. A functioning nodule was isointense with normal gland at all pulse sequences. Characteristic patterns of diffuse abnormality were observed in cases of multinodular goiter, Hashimoto thyroiditis, and Graves disease, although additional cases are required to determine specificity. High-field-strength surface-coil MR imaging appears to be a sensitive method for identifying gross morphology of focal, multinodular, and diffuse disorders of the thyroid and involvement of surrounding structures in the neck.

Adult↗
PubMed1987

Two-second MR images: comparison with spin-echo images in 29 patients.

MR images can be obtained with a 2-sec scan time when an extremely short repetition rate (22 msec), limited flip angle (30 degrees), and gradient refocused echoes are used. Comparison of 415 such images obtained in 29 patients with routine T1-weighted (TR 500, TE 25) and T2-weighted (TR 2000, TE 80) images showed that images free of respiratory artifacts could be obtained in all patients. Although abdominal organs were well seen with 2-sec scan time, overall evaluation of these organs was better on routine T1-weighted images. Vascular structures, however, were seen as well or better on the 2-sec images in 60% of cases. The images were extremely sensitive to field nonhomogeneity, and metallic artifact was exaggerated in five patients with surgical clips. Two-sec MR images provide a rapid method of localizing abdominal organs for further evaluation. The sensitivity to blood flow may assist in the assessment of vascular patency.

Adrenal Glands↗
PubMed1986

Polycystic ovaries: MR imaging.

To determine the characteristic appearance of polycystic ovaries on magnetic resonance (MR) images, seven women with polycystic ovarian disease (PCOD) underwent MR examination of the pelvis. These MR images were compared with sonograms. Histologic material was available in two patients. Six of the seven women had characteristic, small peripheral cysts, best seen on T2-weighted MR images; these cysts were seen sonographically in only one case. The centers of nine of 14 ovaries were of low intensity with all MR pulse sequences; this low intensity corresponded with low echogenicity in six cases. Histologically, these areas correlated with hypertrophic cellular stroma. Coexisting central teratomas were seen in three ovaries. The ability of MR to display the findings of PCOD better than ultrasound and its ability to demonstrate coexisting pathologic conditions are valuable in imaging the female pelvis.

Adult↗
PubMed1986

Hematopoietic and fatty bone marrow distribution in the normal and ischemic hip: new observations with 1.5-T MR imaging.

The conversion of hematopoietic to fatty marrow is known to correlate with physiologic decreases in intramedullary blood flow. To determine whether the chronology of conversion is altered in patients with hip ischemia, T1-weighted magnetic resonance (MR) images of the hips in 50 healthy people and 27 with documented avascular necrosis (AVN) were reviewed. The distribution of fatty (high-signal) versus hematopoietic (low-signal) marrow was noted with respect to age. All patients had fatty marrow in the femoral capital epiphysis and greater trochanter. Hematopoietic intertrochanteric marrow was seen in 95% (80 of 84) of femurs in control subjects less than 50 years old, but in only 12.5% (two of 16) of those in control subjects older than 50 years (P less than .005). Only 33% (19 of 57) of patients less than 50 years with AVN had predominantly hematopoietic intertrochanteric marrow (P less than .005). The early conversion to fatty marrow in most patients with AVN as depicted by MR imaging may be an effect of decreased vascularity of the proximal femur and may allow the identification of patients at increased risk for AVN.

Adult↗
PubMed1986

Osteopetrosis: MR characteristics at 1.5 T.

Four patients with proved osteopetrosis (three with the infantile malignant form and one with the benign form) were examined with magnetic resonance imaging at 1.5 T. All patients were studied in the coronal and sagittal planes using both short and long repetition time/echo time sequences. The infantile malignant form was characterized by a complete lack of signal from the marrow alternating with a signal intensity equivalent to that of the intervertebral disks, resulting in a "stepladder" appearance. In the benign form or after successful marrow transplantation in the infantile malignant form, intermediate or high signal intensity in the vertebrae was noted, suggesting the presence of some marrow elements.

Child, Preschool↗
PubMed1986

Avascular necrosis of the femoral head: morphologic assessment by MR imaging, with CT correlation.

To better understand the morphologic appearance of avascular necrosis (AVN) of the femoral head on magnetic resonance (MR) images (1.5 T) and computed tomographic (CT) scans, the records of 21 lesions were reviewed retrospectively. All MR imaging studies included T1-weighted images (T1WI) (repetition times [TR] of 400-1,000 msec, and echo times [TE] of 20-25 msec), and 15 included T2-weighted images (T2WI) (TR = 2,000-2,500 msec; TE = 60-80 msec). MR signal features of the lesions were compared with features on the corresponding CT scans. Abnormalities in the superoanterior aspect of the femoral head were noted on both image types in all 21 lesions but were more obvious on MR images in two. A characteristic margin of peripheral sclerosis seen on CT scans in 95% (20 of 21) of lesions corresponded to a line of low intensity on MR images. Fractures complicating AVN were seen in eight lesions at CT scanning. On T1WI, fractures were not clearly delineated. On T2WI, fractures were of high intensity but were depicted less clearly than on CT scans. Central signal intensity of the lesions on T1WI correlated with the presence or absence of fracture: 88% (seven of eight) of the lesions with fractures appeared less intense than fat, compared with only 8% (one of 13) of lesions without fractures (P less than .005). While MR imaging is a sensitive method for early diagnosis of AVN, CT scanning can more accurately identify fractures and is thus important for staging.

Adult↗
PubMed1986

MRI of joint fluid in the normal and ischemic hip.

MR images in 36 hips with documented avascular necrosis and 80 hips without evidence of joint disease were studied to determine the amount and appearance of fluid in the joint. All MRI examinations were done on a 1.5-T machine and included coronal images made with relative T2 weighting (repetition times = 2000-2500 msec, echo delays = 60-100 msec). The amount of joint fluid, which had an intense signal higher than fat, was graded from 0 to 3 and analyzed with respect to the patient's age and radiographic stage of avascular necrosis. Joint fluid was seen in 84% of presumed normal hips. Only four (5%) of 80 had enough fluid to surround the femoral neck (grade 2), and none had sufficient fluid to distend the joint capsule (grade 3). In comparison, 21 (58%) of 36 hips with avascular necrosis had grade-2 or grade-3 effusions (p less than 0.005), and some fluid was seen in all. Grade-3 effusions were seen in seven (50%) of 14 hips with flattening of the femoral head, compared with only one (5%) of 20 in which the femoral contour was normal. It is concluded that small amounts of fluid are present in both normal hips and those with avascular necrosis. In avascular necrosis, increased joint fluid may be present before radiographic abnormalities occur, but it is greatest after there is flattening of the femoral head. MRI is a highly sensitive method for detecting fluid in the hip joint.

Adolescent↗
PubMedDate not supplied

Color flow-encoded MR imaging.

Magnetic resonance phase images can enable identification of any type of motion, including the velocity and direction of flow, and thus provide valuable supplements to magnitude images, which depict stationary tissue most effectively. A method is described for the simultaneous display of phase and magnitude by color encoding the phase data and superimposing it on the magnitude image to facilitate clinical interpretation. Color-encoded data not only depict the location and direction of flow along specific axes but can also provide relative velocity information through shades of color. Implementation of the technique is described, and the factors to be considered during interpretation of color flow-encoded images are discussed.

Aorta↗