Radiologic staging of primary bone sarcoma: MR imaging, scintigraphy, angiography, and CT correlated with pathologic examination

The relative value of magnetic resonance (MR) imaging, computed tomography (CT), technetium-99m bone scintigraphy, and angiography in local tumor staging was prospectively evaluated in 56 patients with primary bone sarcoma. The results of imaging were correlated with findings at surgery and at dissection of the resected specimens. MR imaging was significantly superior to CT and scintigraphy in defining intraosseous tumor length and was as accurate as CT in demonstrating cortical bone and joint involvement. It was definitely superior to CT in demonstrating involvement of muscle compartments. MR imaging was also the best modality in exhibiting the relationship between tumor and major neurovascular bundles; however, these differences were not significant. It is concluded that MR imaging is the modality of choice for local staging of primary bone sarcoma.     

Vascular intracranial lesions: applications of gradient-echo MR imaging

To investigate the role of the gradient-echo (GRE) technique in clinical intracranial magnetic resonance (MR) imaging, 63 patients with a variety of vascular intracranial lesions were examined at 1.5 T with the use of spin-echo (SE) and GRE sequences. In all cases, the sequential section acquisition technique called gradient recalled acquisition in the steady state (GRASS) was employed; a repetition time of 150-200 msec, an echo time of 13-16 msec, and a flip angle of 50 degrees-60 degrees were used to optimize the depiction of blood flow as high intensity and the depiction of stationary fluid as low intensity. In 61 of 63 cases, gradient moment nulling was utilized to compensate for first-order flow effects. Although GRE images rapidly demonstrated flow in vascular intracranial lesions as high intensity, the vascular nature of these lesions was also clearly evident on SE images in most cases. In some cases, GRE images can be used to clarify the vascular nature of a lesion or to characterize a neoplasm. Other applications include the detection of vascular thrombosis, occult vascular malformations, and hemorrhagic complications of vascular lesions.     

Interspecies pharmacokinetic scaling of some iodinated organic acids

We have investigated the possibility of interspecies scaling of relationships between the structure and total plasma clearance in a group of nine organic acids (iododerivatives of benzoic, phenylacetic and hippuric acids) in rabbits, rats and mice. The intercompound comparison established the dependence of total plasma clearance predominantly on the molecular structure in all the animals under study, but the dependence on drug lipophilicity was also meaningful. For interspecies scaling of total plasma clearance, the use of a biological clock with an effective renal plasma flow as the unit seemed most suitable and is probably connected with the principal role of the kidney in the elimination of the compounds under study.     

Fulminant pulmonary calcification complicating renal transplantation: CT demonstration

The authors report a case of fulminant, metastatic lung calcification leading to progressive respiratory failure in a patient who underwent unsuccessful renal transplantation. Premortem computed tomographic (CT) examination of the lung demonstrated the presence of high-attenuation (greater than 100 HU) parenchymal consolidation, compatible with metastatic calcium deposition. By depicting significant pulmonary calcification not seen on conventional radiographs, CT facilitated identification of an important contributing factor to the patient's respiratory failure and death.     

Crohn disease: perirectal and perianal findings at CT

The computed tomographic scans of 200 consecutive patients with Crohn disease were studied to determine the frequency and patterns of perirectal and perianal involvement. In 163 patients (82%) abnormalities in the perirectal-perianal region were demonstrated; findings included inflammation of fat planes (73%), bowel wall thickening (30%), fistulas or sinus tracts (22%), and abscesses (14%). Fistulas or sinus tracts occurred with equal frequency above or below the level of the anterior symphysis pubis. Abscesses, rectal thickening, and inflammatory infiltration of fat occurred more than twice as often above the symphysis pubis. However, 37% of patients had manifestations of Crohn disease below the symphysis pubis, emphasizing the importance of extending scanning sequences to the perineum.