Partial tear of pectoralis major muscle masquerading as a breast mass in an 87-year-old woman. A case report.

We report on a case of a partial tear of the pectoralis major muscle mimicking a breast mass in an elderly patient. Breast MR was useful in identifying the traumatic muscular injury and in demonstrating the lack of any intraparenchymal breast lesion.

Delivering images to the operating room: a web-based solution.

As radiology departments become filmless, they are discovering that some areas are particularly difficult to deliver images. Many departments have found that the operating room is one such area. There are space constraints and difficulty in manipulating the images by a sterile surgeon. This report describes one method to overcome this obstacle. The author's institution has been using picture archiving and communication system (PACS) for approximately 3 years, and it has been a filmless department for 1 year. The PACS transfers images to a webserver for distribution throughout the hospital. It is accessed by Internet Explorer without any additional software. The authors recently started a pilot program in which they installed dual panel flat screen monitors in 6 operating rooms. The computers are connected to the hospital backbone by ethernet. Graphic cards installed in the computers allow the use of dual monitors. Because the surgeons were experienced in viewing cases on the enterprise web system, they had little difficulty in adapting to the operating room (OR) system. Initial reception of the system is positive. The use of the web system was found to be superior by the surgeons because of the flexibility and manipulation of the images compared with film. Images can be magnified to facilitate viewing from across the room. The ultimate goal of electronic radiology is to replace hardcopy film in all aspects. One area that PACS has difficulty in accomplishing this goal is in the operating room. Most institutions have continued to print film for the OR. The authors have initiated a project that may allow web viewing in the OR. Because of limited space in the OR, an additional computer was undesirable. The CPU tower, keyboard, and mouse were mounted on a frame on the wall. The images were displayed on 2 flat screen monitors, which simulated the viewboxes traditionally used by the surgeons. Interviews with the surgeons have found both positive and negative aspects of the system. Overall impression is good, but the timeliness of the intraoperative films needs to be improved. The author's pilot project of installing a web-based display system in the operating room still is being evaluated. Their initial results have been positive, and if there are no major problems that arise the project will be expanded. These results show that it is possible to provide image delivery to the OR over the intranet that is acceptable to the surgeons.

PACS monitors: an evolution of radiologist's viewing techniques.

When initially evaluating picture archiving communication systems (PACS) many radiologists try to duplicate the film environment and believe that multiple monitors are required to maintain the productivity of the radiologist. The authors were under the same impression initially but found that they underwent a paradigm shift over a period of time. This report documents the evolution that the radiologists underwent. The author's department consists of 28 diagnostic radiologists and 21 residents who actively read cases on a PACS. The department has been filmless for 6 months, although they have been reading soft copy films for 2 years. All modalities except mammography are included. The authors conducted interviews with both attending radiologists and residents to evaluate the change in methodology from the preconceptions to initial use to current use. The number and kind of monitors preferred for plain films, ultrasound scan, computed tomography (CT), and magnetic resonance imaging (MRI) were recorded. Additionally, viewing methods of different modalities were discussed. The authors found that there was a decrease in the number of monitors from preconceptions to actual use. Furthermore, to a lesser degree, there is a reduction of monitors used initially to that which is currently being used. The style of viewing cross-sectional images has changed. There has been a decrease in the number of images displayed on each monitor. The use of the roller ball on the mouse has affected this viewing style. Changing from a film-based reading environment to PACS environment not only brings about change in the overall technology in image delivery but also in the viewing techniques by radiologists. At our institution we have evolved from initially expecting to use 4 monitors all the time to actually preferring 2 monitors and occasionally 1 monitor to view images. Presentation software and viewing aids such as the roller ball on a mouse for viewing CTs in stack mode are key contributions to this paradigm shift. The decrease in monitors makes PACS more affordable and will allow further penetration of filmless radiology. The authors have found that after using PACS, radiologists prefer using 2 monitors. The style of reading films has changed with experience. Hospitals that plan to purchase PACS should consider this and ensure that the vendor has presentation software that optimizes the 2 monitor system.

Cable modem access to picture archiving and communication system images using a web browser over the Internet.

This presentation describes our experiences using a web-based viewing software and a browser to view our picture archiving and communication system (PACS) images at a remote site with cable modem-internet communications. Our testing shows that using a cable modem to access our radiology webserver produces acceptable transmission speeds to remote sites. The average time-to-display (TTD) for 16 computed tomography (CT) images on the web-based intranet system in our hospital was 7 to 8 seconds. Using a cable modem and comparable equipment at a remote site, the average TTD is 16 seconds over the internet. The TTD does not significantly change during various hours of the day. Security for our hospital-based PACS is provided by a firewall. Access through the firewall is accomplished using virtual private network (VPN) software, a secure ID, and encryption. We have found that this is a viable method for after-hours subspecialty radiology consultation.

Computed tomography-guided pudendal block for treatment of pelvic pain due to pudendal neuropathy.

BACKGROUND: Severe pelvic pain secondary to pudendal neuropathy can be treated with repeated local anesthetic nerve blocks or with surgical decompression of the nerve. Computed tomographic (CT) needle guidance to identified reliable anatomic points might be useful for improved success rates. TECHNIQUE: A CT scan is used to determine baseline anatomy and identify the sacrospinous process. A metallic marker is used to create a perpendicular pathway from the sacrospinous process upward to the skin surface, where a local anesthetic is injected. A 22-gauge, 5-inch needle is inserted downward in a perpendicular direction to the target. Deep penetration and direction are confirmed by serial CT scans. Medication is injected and the needle is removed. EXPERIENCE: Twenty-six women with diagnoses of pudendal neuropathy were treated with injection therapy once per month, for five total treatments each. About three-quarters experienced improvement. There were no complications in this series. Outcomes were gratifying considering the complex patient population, all having failed multiple therapeutic trials. CONCLUSION: We believe this technique warrants further evaluation and application in instances where noninvasive therapy of pudendal neuropathy is indicated.

High resolution MRI of the deep brain vascular anatomy at 8 Tesla: susceptibility-based enhancement of the venous structures.

PURPOSE: The purpose of this work was to describe the deep vascular anatomy of the human brain using high resolution MR gradient echo imaging at 8 T. METHOD: Gradient echo images were acquired from the human head using a transverse electromagnetic resonator operating in quadrature and tuned to 340 MHz. Typical acquisition parameters were as follows: matrix = 1,024 x 1,024, flip angle = 45 degrees, TR = 750 ms, TE = 17 ms, FOV = 20 cm, slice thickness = 2 mm. This resulted in an in-plane resolution of approximately 200 microm. Images were analyzed, and vascular structures were identified on the basis of location and course. RESULTS: High resolution ultra high field magnetic resonance imaging (UHFMRI) enabled the visualization of many small vessels deep within the brain. These vessels were typically detected as signal voids, and the majority represented veins. The prevalence of the venous vasculature was attributed largely to the magnetic susceptibility of deoxyhemoglobin. It was possible to identify venous structures expected to measure below 100 microm in size. Perforating venous drainage within the deep gray structures was identified along with their parent vessels. The course of arterial perforators was more difficult to follow and not as readily identified as their venous counterparts. CONCLUSION: The application of high resolution gradient echo methods in UHFMRI provides a unique detailed view of particularly the deep venous vasculature of the human brain.

High resolution MRI of the deep gray nuclei at 8 Tesla.

PURPOSE: High resolution MR images obtained from a normal human volunteer at 8 T are utilized to describe the appearance of iron-containing deep gray nuclei at this field strength. METHOD: High resolution (1,024 x 1,024 matrix) near-axial gradient echo images of the deep gray nuclei were acquired on a human volunteer by using an 8 T scanner. The images were acquired using a transverse electromagnetic resonator operating in quadrature. The following parameters were utilized: TR = 750 ms, TE = 17 ms, flip angle = 45 degrees, receiver bandwidth = 50 kHz, slice thickness = 2 mm, FOV = 20 cm. The 8 T images were reviewed and correlated to the known anatomy of the deep nuclei by comparing them with images observed at lower field strength, published diagrams, and histologic sections. In addition, the appearance of the nuclei was related to the known imaging characteristics of brain iron at lower fields. RESULTS: The caudate, globus pallidus, putamen, thalami, substantia nigra, and red nuclei were clearly identified. The structures with the highest levels of iron, the globus pallidus, substantia nigra, and red nuclei, demonstrated significantly decreased signal, providing a map of iron distribution in the human brain. CONCLUSION: Preliminary imaging at 8 T demonstrates the ability to acquire ultra high resolution images of the deep nuclei, with signal characteristics believed to represent the distribution of brain iron. This may prove to be important in the early diagnosis of several neurodegenerative disorders.

Web-based viewing of picture archiving and communications systems images--Part I: Optimal personal computer configuration.

Now that picture archiving and communications systems (PACS) has matured, our challenge is to make the images available to the referring physician and, in a teaching institution, to make these images available for conferences and rounding. One solution is the distribution of the images using web-based technology. We investigated a web-based add-on to our PACS to determine the characteristics of the personal computer that will make this technology useful and affordable. We found that images can be viewed easily through a web-based system. We found that the optimal system to view these images at a reasonable speed and a reasonable cost is on with a medium-range processor (200 to 300 MHz) and a large amount of inexpensive RAM, at least 64 Mb.

Web-based viewing of picture archiving and communications systems images--Part II: The effect of compression on speed of transmission.

Now that picture archiving and communications systems (PACS) has matured, our challenge is to make the images available to the referring physician and, in a teaching institution, to make these images available for conferences and rounding. One solution is the distribution of the images using web-based technology. We investigated a web-based add-on to our PACS to determine the characteristics of the personal computer that will make this technology useful and affordable. We found that images can be viewed easily through a web-based system. We found that the optimal system to view these images at a reasonable speed and a reasonable cost is on with a medium-range processor (200 to 300 MHz) and a large amount of inexpensive RAM, at least 64 Mb.

Polymeric surface modifications of tantalum stents.

PURPOSE: To compare two kinds of polymer-coated tantalum stents with bare tantalum stents (control) to determine if the coatings can improve thromboresistance. METHODS: Twenty-seven Fontaine-Dake stents were balloon expanded in three 8-mm x 80-cm polytetrafluoroethylene (PTFE) grafts; 9 stents were bare tantalum (T); 9 were coated with polyetherurethane (PL); and 9 were coated with parylene (PA). There were 9 stents placed in each graft as follows: 3 tantalum, 3 polyetherurethane, and 3 parylene. In swine whose platelets had been radiolabeled with indium 111, the ends of each stented graft were connected to 14F femoral and venous sheaths to create an ex vivo fistula. Each graft was exposed to blood for 30, 60, and 120 minutes. At the end of each test period, the stented grafts were disconnected from the sheaths, flushed with saline until clear, and then flushed with formalin. The stents were removed from the grafts, and a radionuclide well counter recorded radionuclide counts from each stent type at each period of blood contact. These values were converted to platelet density per 1000 microns 2. Stents were then photographed and scanned with electron microscopy (EM) for qualitative analysis. Possible significant differences in platelet adhesion with the three types of stents (both between stent groups and within stent groups) were examined using a two-tailed Student's t-test. RESULTS: There were significantly fewer platelets adsorbed on PA versus T at all time periods (p < 0.005); on PL versus T at 60 and 120 minutes (p < 0.005); and on PA versus PL at 30 and 120 minutes (p < 0.0005). There was no significant difference in platelet density within each stent group (p = 0.1). Mean platelet density (number of platelets per 1000 microns 2 +/- SD) was as follows: at 30 minutes: T = 1891 +/- 965; PL = 373 +/- 193; and PA = 27 +/- 3; at 60 minutes: T = 6226 +/- 1621; PL = 1573 +/- 793; and PA = 1185 +/- 710; at 120 minutes: T = 5307 +/- 591; PL = 3164 +/- 318; and PA = 180 +/- 100. Gross inspection of the 120-minute groups demonstrated focal areas of thrombus on T, less on PL, and none on PA. Scanning EM demonstrated extensive platelet accumulation covering T at all time periods, less on PL, and even less on PA.

Phased array coils for upper extremity MRA.

A phased array coil was constructed for imaging the upper extremity vasculature for patients undergoing dialysis treatment. The phased array coil exhibits improved signal-to-noise ratio (SNR) over the body coil and allows imaging of the entire upper extremity. SNR as a function of depth was measured on a homogeneous phantom with the arm coil and compared with the body coil. Near the coil there is an improvement of a factor of 7 and at a depth of approximately 6-7 cm, there is an improvement of factor 2. In vivo SNR measurements resulted in similar improvements. Images of the upper extremity vasculature of healthy volunteers were generated using 2D-time-of-flight (2DTOF) angiography. Blood flow velocity was assessed in a CINE-phase contrast study.

Renal artery pressure gradients in patients with angiographic evidence of atherosclerotic renal artery stenosis.

From October 1979 to August 1991, 231 patients underwent renal artery balloon angioplasty at The Ohio State University Hospitals. Atherosclerotic renal vascular disease was present in 171 of these patients. From this cohort, 138 patients undergoing their first angioplasty had renal artery pressure gradients performed before and after renal artery angioplasty. The demographics of this group included age 66.9 +/- 10 years (+/- SD), male 51%, white 94%, black 6%, diabetes mellitus 28%, systolic blood pressure 157 +/- 26 mm Hg, diastolic blood pressure 86 +/- 13 mm Hg, standard daily doses of antihypertensive medications 4.2 +/- 3, and serum creatinine 2.6 +/- 2.3 mg/dL. Plasma renin activity was measured in 25 patients and was shown to be elevated in 16. The renal artery stenoses were main renal artery 75%, orificial 22%, distal renal artery 1.4%, and combinations of the above 2.2%. Solitary kidneys were present in six patients (4.3%). Bilateral renal artery stenosis was present in 45% of patients and bilateral angioplasties were performed in one third of these patients. The preangioplasty systolic blood pressure gradient was 109 +/- 50 mm Hg (range, 20 to 230 mm Hg) and the postangioplasty renal artery pressure gradient was 12 +/- 16 mm Hg (range, 0 to 78 mm Hg) (P < 0.001). There were no complications related to measurement of the pressure gradients. The magnitude of the renal artery pressure gradients did not correlate with blood pressure level, number of antihypertensive medications, or serum creatinine level.(ABSTRACT TRUNCATED AT 250 WORDS)

Stent-induced intimal hyperplasia: are there fundamental differences between flexible and rigid stent designs?

PURPOSE: To evaluate possible differences in neointimal development resulting from overdilation of rigid versus flexible vascular stents. MATERIALS AND METHODS: Twelve vascular sheaths were placed bilaterally through femoral arteries in six swine. After angiographic measurement, 12 stents (six flexible and six rigid) were balloon expanded to 8-mm diameters in 12 6-mm iliac arteries (approximately 30% overdilation). All stents were similar in surface area, gauge, and type of wire (tantalum). The primary difference was longitudinal flexibility (low hoop strength) versus rigidity (high hoop strength). Stents were studied with angiography and intravascular ultrasound 5 weeks after implantation. The animals were killed, and the stented segments were removed and examined histologically. RESULTS: Rigid stents maintained larger diameters than flexible stents: mean, 6.52 mm versus 5.82 mm (mean difference, 0.70; standard deviation [SD], 0.47; confidence interval [CI], +/- 0.49; P < .05). In addition, rigid stents developed a thicker, eccentric neointimal reaction relative to flexible stents: mean 1.08 mm versus 0.74 mm (mean difference, 0.338; SD, 0.315; CI, +/- 0.331; P < .05). CONCLUSION: Rigid stents maintain larger diameters over the long term relative to flexible stents when overdilated in normal swine arteries. However, a thicker neointima develops within the lumen of rigid stents at follow-up (greater late loss).