Biomedical subjects
Publications and source records attributed to M L Schiebler.
A case of a Morgagni hernia is demonstrated by magnetic resonance imaging (MRI). The correct diagnosis was facilitated by the ability to image directly the anteromedial diaphragmatic defect in the coronal and sagittal planes. The findings from MRI, computed tomography, and radiographic studies are correlated.
Eleven patients with gliomas in the optic chiasm were studied using a 0.5 Tesla superconducting system and third generation computed tomography scanners. All tumors were identified with both modalities, but in the majority of cases, the posterior extension of the tumor and its relationship to adjacent brain, important to both prognosis and management, were shown better by magnetic resonance imaging.
Magnetic resonance (MR) images of the lumbar spine from 150 patients were retrospectively reviewed. In 14 of these patients, at 18 disk levels, a vacuum phenomenon (VP) had been identified on plain radiographs and/or computed tomographic scans. The MR imaging appearance of these gas collections in 17 disks was an area without signal, best seen on spin-echo sequences with short repetition time and echo time in the sagittal view. MR imaging precisely located the VP in the anulus fibrosus, the nucleus pulposus, and Schmorl nodes. In all but one case, degeneration of the disk was complete and associated with adjacent changes in vertebral bone. Pitfalls of MR imaging detection of VP included chemical shift artifact, calcifications, and tears without gas in the disk.
A retrospective study of the magnetic resonance (MR) images of the lumbar spines of 13 healthy subjects and 30 patients with degenerative changes was done. In the healthy subjects, the vertebral facets, thickness of the cartilage and ligamentum flavum, signal characteristics of the bone marrow, and size of the spinal canal were studied. In the patients with degenerative changes in one of these structures, MR images in the sagittal plane were useful in demonstrating hypertrophy of the ligamentum flavum or the vertebral facets, in grading the degree of foraminal stenosis, and in measuring the sagittal diameter of the spinal cord. MR images in the axial plane facilitated detailed analysis of the facet joint and more accurate measurements of the thickness of the ligamentum flavum and spinal canal diameter. MR images were compared with computed tomography scans in 12 patients.
An awareness of potential pitfalls in CT imaging of renal masses helps to reduce needless imaging procedures and surgery.
The clinical diagnosis of cervical aortic arch rests on the detection of a pulsatile mass in the supraclavicular fossa. Unfortunately, clinical differentiation of a cervical arch from an aneurysm of the great vessels can be difficult. Dynamic computed tomography (CT) can aid in this differentiation and avert the need for angiography.
Computed tomography (CT) using a geometric magnification technique was found to improve spatial resolution in phantom studies when compared with conventional third-generation geometry images. The clinical feasibility of using geometric magnification, small focal spot size, and dynamic contrast enhancement was studied in 143 patients referred to CT for clinically suspected pancreatic disease. This population included 46 patients with a normal pancreas and 36 patients subsequently proven to have primary pancreatic carcinoma. Using this new technique in conjunction with dynamic contrast enhancement resulted in high quality pancreatic images. Despite the limitations in tube current associated with a small focal spot size and low total heat capacity of the system, clinical imaging was not adversely affected. Use of the geometric magnification technique is recommended in departments where it is technically feasible.
The authors present their algorithmic approach to the detection, characterization, and staging of renal masses. Based on classification of urographic findings, the patient may be triaged to the appropriate cross-sectional or invasive imaging modality that will result in the most cost-effective management.
The radiologist needs to be aware of the varied appearance of hepatic mass lesions and be prepared to recommend the most cost-effective imaging approach. In this article, the authors discuss their hepatic imaging experience, common pitfalls, and current recommendations.
The magnetic resonance (MR) imaging findings in four patients with mucinous tumors involving the prostate are presented. The MR appearance of these tumors differed from that of typical prostatic adenocarcinomas in that the signal intensity on T2-weighted images approximated or exceeded that of the uninvolved peripheral zone. The unusual appearance of mucinous prostate tumors may present problems in diagnosis and staging with MR imaging.
We present here the first report of an extraskeletal metastasizing presacral chordoma found in a child. MRI of this large lesion showed heterogeneous signal intensity on both the SE 550/30 and on SE 2440/100 images. MRI demonstrated this mass to be separate from the sacrum and provided nonionizing cross-sectional imaging prior to attempted surgical resection.
The magnetic resonance appearance of three lesions of focal nodular hyperplasia observed in two patients is reviewed. All three lesions demonstrated isointensity with the liver on the short repetition time (TR) and echo time (TE) spin echo images. One lesion also showed a central area of low signal intensity that pathologically corresponded to a scar. The long TR and TE images had a varied appearance, from mixed high signal intensity to predominantly isointense with the liver. The histopathology for each lesion was carefully reviewed. The primary microscopic difference between the lesion that was predominantly isointense with liver on the long time TR and TE images and the other two, which were of mixed high signal intensity on the long time TR and TE images, was the former's relative lack of fibromuscular obliteration of septal blood vessels in the scar. Focal nodular hyperplasia can have at least two possible appearances at 1.5 T; in these three lesions there was consistent isointensity with the liver on the short TR and TE images.
Magnetic resonance (MR) imaging of the painful ankle of a 15-year-old boy revealed the nidus of a subarticular osteoid osteoma of the talus along with markedly abnormal signal intensity in the neighboring bone marrow. This MR appearance correlated with alterations in the neighboring bone marrow documented by histopathologic examination.
A patient with hyperparathyroidism underwent magnetic resonance (MR) imaging and two intrathyroidal hyperplastic parathyroid glands were demonstrated. Surgery confirmed MR findings.
We report two cases of fibrolamellar hepatocellular carcinoma, each of which had lower signal intensity than normal liver on short repetition time (TR), short echo time (TE) spin-echo (SE) images and demonstrated a central scar-like area of low signal intensity which did not become hyperintense on long time TR/TE SE images.
Magnetic resonance imaging of a 14-year-old girl with abdominal pain and known vaginal agenesis revealed massive hematocolpos with a normal cervix and uterine body. Prior ultrasound of this area was significantly limited by bowel loops anterior to the retroflexed uterine body and cervix, which were displaced cephalad out of the pelvic inlet and were not seen. Magnetic resonance is the examination of choice in patients with symptomatic vaginal agenesis prior to surgical correction.
Gadolinium-diethylenetriamine pentaacetic acid (DTPA) enhancement of radiation-induced apical pulmonary fibrosis was observed in two patients previously treated for breast cancer. In one case the fibrosis was biopsied twice, with no change in its CT appearance over 3 years. Gadolinium-DTPA may enhance benign apical fibrosis after radiation therapy and should not, in and of itself, be used as evidence of recurrent malignancy.
The pertinent radiologic findings in two cases of a recently described tumor, intraabdominal desmoplastic small cell tumor, are presented. This is an aggressive, usually lethal malignant neoplasm of the peritoneum occurring in boys and young men with a marked predilection for intraperitoneal spread. In both cases, CT or MR demonstrated a necrotic intraperitoneal mass with peritoneal metastases. Given the limited differential diagnosis, intraabdominal desmoplastic small cell tumor should be strongly considered as a diagnosis of an intraperitoneal neoplasm in young males.