Effects of Susceptibility Artifacts on Perfusion MRI in Patients with Primary Brain Tumor: A Comparison of Arterial Spin-Labeling versus DSC.

BACKGROUND AND PURPOSE: Our aim was to investigate the effects of intratumoral hemorrhage, calcification, and postoperative changes on the sensitivity of arterial spin-labeling and DSC perfusion MR imaging in patients with primary brain tumors. MATERIALS AND METHODS: Eighty-six brain tumor lesions were examined with single-phase and multiphase arterial spin-labeling and DSC perfusion MR imaging. The lesions that had no intratumoral bleeding/calcifications and history of surgery were assigned to group 1 (n = 38), and the lesions that had these were assigned to group 2 (n = 48). The relative regional cerebral blood flow was calculated in both perfusion methods, and relative regional cerebral blood volume was calculated in DSC. Imaging results were correlated with histopathology or follow-up. RESULTS: In the quantitative evaluation, the sensitivity and specificity of relative regional cerebral blood flow in multiphase arterial spin-labeling perfusion were 94.4% and 80% in group 1 and 78.3% and 88% in group 2, respectively. The sensitivity and specificity of relative regional cerebral blood flow in DSC perfusion were 88.9% and 75% in group 1 and 78.3% and 84% in group 2, respectively. The sensitivity and specificity of relative regional cerebral blood volume in DSC perfusion were 66.7% and 100% in group 1 and 69.6% and 96% in group 2, respectively. In the qualitative evaluation, the sensitivities for single-phase and multiphase arterial spin-labeling were 48.2% and 79.3%, respectively, with 100% specificity for both. CONCLUSIONS: The sensitivity and specificity of multiphase arterial spin-labeling were similar to those of DSC perfusion irrespective of bleeding and calcification in primary brain tumors. Thus, we suggest that noncontrast multiphase arterial spin-labeling can be used instead of DSC perfusion MR imaging in the diagnosis and follow-up of intracranial tumors.

The interdomal fat pad of the nose: a new anatomical structure.

The nose is one of the most operated organs in the body and its anatomy has been well defined by plastic and ENT surgeons. Although rhinoplasty is the most commonly performed operation in plastic surgery, some unexpected results and complications may be related to unknown or unclarified anatomical structures in the nose. We aimed to evaluate the interdomal region in four fresh cadavers and 24 patients who underwent open rhinoplasty, since the nasal tip area is the most difficult part of the rhinoplasty. Detailed cartilage and soft tissue interactions were studied in fresh cadavers. The existence of the interdomal fat pad as a separate anatomical structure was proven in necropsy specimens from cadavers using various histochemical dyes. Nasal tip ultrasonography was performed preoperatively in patients who underwent rhinoplasty. All patients had a fat pad in the interdomal space, of varying sizes, but fatty (bulbous) noses had larger fat pads. Interdomal fat pad tissue, which occupies the interdomal space, was demonstrated by ultrasonography. The size of the fat pads varied from 1.2 mm x 2.4 mm to 3.6 mm x 5.2 mm. Anatomical observation and biopsies were performed during surgery. Finally, surgical and radiological anatomy of the interdomal fat pad was demonstrated in all cadavers and patients. We speculate that the interdomal fat pad is an important anatomical structure and may contribute to unexpected postoperative results in rhinoplasty. This newly defined fat pad can be assessed by ultrasonography, a safe and inexpensive technique. The surgical approach to the interdomal fat pad is solely through open rhinoplasty technique. Thus, a consideration of the interdomal fat pad and detection of its size preoperatively may play a key role in choice of technique and success of rhinoplasty.

Technology and archives in radiology research: a sampling analysis of articles published in the AJR and Radiology. American Journal of Roentgenology.

OBJECTIVE: Our aim was to determine the use of advanced technology and archiving and the contribution of countries other than United States in the articles published in the American Journal of Roentgenology (AJR) and Radiology. We analyzed the association of these features with the type of research, the main technical features of the modalities used, and the countries of origin. MATERIALS AND METHODS: We determined the proportion of articles published in 18 randomly selected issues of the AJR and Radiology that required advanced imaging techniques and relied on the analysis of archived data. "Advanced technology" was defined as imaging techniques that serve a purpose other than simple anatomic imaging or that are not widely available because of the high cost of the technology, such as functional imaging and computer programming designed for an individual study or simulation studies. We analyzed the association of these features with the country of origin, the topic, and the methodology used. RESULTS: Sixteen percent of the studies required advanced technology. MR imaging, CT, and sonography were the most frequently used modalities (31%, 27%, and 15% of studies, respectively). Archiving was used in 37% of the studies, and 67% of the original articles were prospective. The articles most commonly originated in North America (67%), Europe (20%), and Asia (12%). CONCLUSION: Only a small percentage of published research studies required advanced technology and approximately one third of the studies used archiving. These results may suggest that other criteria, such as the design of the study, its relevance for daily clinical use, and the originality of the paper, have a major impact on the acceptance of papers in clinically oriented radiology journals.

Breast varices: imaging findings of an unusual presentation of collateral pathways in superior vena caval syndrome.

Imaging findings are presented of an unusual pathway of collateral circulation consisting of bilateral and diffuse dilated breast veins from a patient with long standing superior vena caval syndrome. The main importance of this case is the extent of the collateral development through the breast veins, serving as the major pathway of collateral circulation. Identification of this unusual collateral development, which resembles breast varices, was performed with contrast-enhanced chest CT scans, digital subtraction venography, color Doppler ultrasonography, and mammographic studies. Collateral development was secondary to a long segment idiopathic venous occlusion involving bilateral subclavian and brachiocephalic veins as well as vena cava superior. We conclude that dilated breast veins when detected on any imaging modality should raise the suspicion of central venous obstruction.

Impact of intraoperative ultrasonography on surgical treatment of liver tumours.

PURPOSE: The aim of this study was to evaluate the impact of intraoperative ultrasonography (IOUS) on surgical decision-making in patients with liver tumours. MATERIAL AND METHODS: IOUS of the liver was performed in 116 patients undergoing surgery for liver tumours. The patients were evaluated preoperatively by ultrasonography, CT and in some cases, by ERCP and scintigraphy. IOUS findings were compared with the results of preoperative imaging and surgical findings. RESULTS: The surgical procedures were altered in 50 cases (43%), extended in 19 cases (16%) and reduced in 8 cases (7%). Twenty-three patients (20%) were found inoperable. Intraoperative evaluation caused surgical modification by IOUS in 13 patients (11%), by surgical findings in 14 patients (12%) and by a combination of both in 23 patients (20%). CONCLUSION: IOUS is a precise diagnostic method for staging the operability of liver tumours. Unnecessary surgical procedures can be avoided. In total, IOUS altered the preoperative plan in one-third of our patients and is therefore recommended as a routine procedure in connection with major liver surgery.

Diffusion- and perfusion-weighted magnetic resonance imaging in human acute ischemic stroke: technical considerations.

Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) are recently developed yet steadily evolving magnetic resonance techniques. DWI and PWI typically interrogate the microscopic diffusion and microcirculatory perfusion, and they can provide early, highly sensitive, and specific delineation of ischemic tissue. These techniques also can play a role in selecting patients who may benefit from thrombolytic therapy. This article reviews physical, technical, and pathophysiological background material that can be helpful in the acquisition and interpretation of DWI and PWI.

Magnetic resonance imaging of cerebral hemorrhagic stroke.

Despite a traditional perception of reliance on computed tomography and lack of acceptance of magnetic resonance imaging (MRI) for detecting acute hemorrhage, MRI appears to be used increasingly in hemorrhagic stroke. This review addresses the MRI findings of acute hemorrhagic stroke obtained using relatively new imaging techniques. These new techniques have resulted in more acute stroke patients undergoing MRI examination. New information about the frequency and appearance of hemorrhage is emerging: for example, approximately 15-26% of cases of acute cerebral infarctions appear to be complicated by intracerebral hemorrhage. The MRI appearances of hemorrhagic transformation of ischemic infarction, as well as acute hypertensive intracerebral hemorrhage, are discussed based on clinical, biochemical, and technical aspects.

Unusual migration of a foreign body from the gut to a vertebral body.

We report a unique case in which a needle was accidentally swallowed and migrated into the vertebral body. Plain films and CT of the spine revealed fragmented, linear, metallic-density material in the L3 vertebral body. The possible mechanisms of the migration are discussed.

Intraocular tumors. The value of spectral and color Doppler sonography.

We evaluated the efficacy of spectral and color Doppler sonography as a screening procedure for intraocular tumors. Thirty patients who had intraocular tumors were included in the study. Abnormal Doppler shifts were demonstrated 19 of 20 patients with choroidal malignant melanomas, especially at the base of the tumors. The average maximum systolic blood flow velocity in the vessels of these tumors was 17 +/- 6.8 cm/sec (14 to 28 cm/sec). In one of the choroidal metastasis, blood vessels were seen around the lesion with a 14-cm/sec maximum peak systolic velocity. Intratumoral vascularity could not be demonstrated in the other tumors. Spectral and color Doppler imaging is a relatively new and promising modality in the management of intraocular tumors and may help to provide a more precise preoperative histological diagnosis noninvasively; however, long-term follow-up is needed.