Ultrasound localization for percutaneous renal biopsy in children.
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Biomedical subjects
Publications and source records attributed to D Spigos.
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PURPOSE: The purpose of this work was to determine potential causes of foot pain in patients who have had a surgical release of the plantar fascia for treatment of fasciitis. METHOD: We studied 17 patients (15 women, 2 men; age range 22-59 years, mean 40 years) with foot pain after undergoing a fasciotomy. Fourteen unilateral and three bilateral procedures accounted for the 20 ankles evaluated. Mean duration after surgery was 22 months (range 3-53 months). Each patient was instructed to localize the pain to a region of the foot; classify the pain as new onset, persistent, or recurrent; and characterize it as to the action that produced the greatest pain. T1-weighted sagittal and dual-echo T2-weighted images in the sagittal, coronal, and axial planes were obtained in a 1.5 T magnet. The MR studies were evaluated for abnormalities of the plantar fascia, perifascial soft tissues, tendons, and osseous structures. RESULTS: The plantar fascia appeared thick in all ankles (mean 8.0 mm, range 6-12 mm). A total of 25 symptomatic sites were assessed. An acute plantar fascia rupture explained plantar symptoms in two feet. In another 16 feet (12 with plantar heel pain and 4 with nonspecific heel pain), 6 had documentation of acute plantar fasciitis and 9 demonstrated perifascial edema. Of the latter nine feet, five demonstrated abnormalities of the posterior tibialis, peroneus longus, and peroneus brevis tendons. The pain localized to the medial arch in six feet; five feet had abnormalities of the posterior tibialis tendon and one foot demonstrated edema in the flexor digitorum brevis muscle. The pain localized to the lateral midfoot in one foot, which had a cuboid stress fracture. CONCLUSION: The cause of foot pain in patients who had a plantar fasciotomy appeared to be multifactorial. Three likely causes of pain were identified: persistent or recurrent acute plantar fasciitis, pathology related to arch instability, and structural failure from overload.
PURPOSE: The purpose of this work was to describe the human leptomeningeal and cortical vascular anatomy as seen at high resolution on an 8 T UHFMRI system. METHOD: With a 1024 x 1024 matrix, axial gradient echo images of the cerebral cortex were acquired on a human volunteer at 8 T with TR 500 ms, TE 16 ms, flip angle 22.5 degrees, bandwidth 53 kHz, and slice thickness 2.84 mm. The same subject was evaluated at 1.5 T using similar parameters. The images were then reviewed in detail and compared with known cortical and leptomeningeal vascular anatomy. RESULTS: Two hundred forty micron in-plane resolution images of the human brain were acquired at 8 T without evident artifact from susceptibility distortions, RF penetration, or dielectric resonances. The CSF, gray matter, and white matter structures were well discerned. The microscopic leptomeningeal vascular anatomy was well visualized, and the course of small perforating cortical vessels could be followed from the cortical surface to the white matter junction. CONCLUSION: Initial 8 T images of the brain demonstrate detailed leptomeningeal and cortical vascular anatomy.
PURPOSE: In this manuscript, we present our initial experience with MRI of the abdomen at 8 T of canine subjects both alive and dead. Our hypothesis is that abdominal imaging at 8 T should be possible and should demonstrate unique information. To our knowledge, this is the first description of imaging characteristics of the abdomen at such field strengths using a human MR scanner. METHOD: An 8 T, 80 cm magnet housed in our department since 1998 was used for our study. GRE and rapid acquisition by relaxation enhancement (RARE) pulse sequences were selected to give reasonable slice profiles with relatively low power. Three dogs were imaged alive and after being killed. RESULTS: Our initial results show excellent signal-to-noise ratio and good RF penetration. Structures in the center of the abdomen were well visualized. Homogeneous signal was noted throughout each image without dielectric resonance artifact. Magnetic susceptibility artifacts were most severe on the GRE sequences. On the GRE sequences, the images appeared relatively T2 weighted. Signal voids were seen due to gas in the lung and bowel and susceptibility artifact at subcutaneous fat-muscle boundaries. The liver and spleen showed similar signal intensity, hypointense to subcutaneous muscle at low TE values. There was little internal anatomy of the liver or spleen visible except for the vessels. The kidney, in contrast, demonstrated very good internal structure with visualization of the cortex and medulla. Linear signal voids were depicted in the expected location of normal renal vascular anatomy on the GRE sequences. On the RARE sequences, the images also appeared T2 weighted. Magnetic susceptibility artifacts at subcutaneous fat-muscle boundaries were absent. Signal voids were noted in vessels with blood flow and gas. The liver and spleen were of similar signal intensity and slightly hypointense to muscle. The kidney and pancreas were of higher signal intensity than liver and subcutaneous muscle. The gallbladder wall demonstrated a striated pattern of two layers, with an inner hypointense and an outer hyperintense layer on the RARE sequence. The gastric wall demonstrated a striated pattern of five layers on the RARE sequence. CONCLUSION: Images of the dog abdomen with the world's first ultra high field 8 T magnet show robust image quality and excellent spatial resolution. Image contrast is greatest on the RARE sequence, and susceptibility artifact is strongest on the GRE sequence.
This report summarizes a recent 24-month experience with 9 patients who were treated for injuries to the innominate or subclavian arteries at a large urban hospital. All patients were male, age range was 17 to 47 years, and mean age was 29 years. The mechanism of injury included major arterial avulsions sustained during cancer operations at the base of the neck (2), blunt injuries secondary to motor vehicle accidents (2), stab wounds (1), and gunshot wounds (4). The vessels injured included the right subclavian artery (2), the innominate artery (1), and the left subclavian artery (6). Associated major venous injuries were seen in 4 cases (44%) and major non-vascular injuries in 5 cases (55%). Arterial exposure involved a variety of incisions, including left thoracotomy, median sternotomy, clavicular resection, or a combination of these. Arterial continuity was restored in all cases using primary repair (2), autogenous saphenous vein graft (6), or prosthetic graft (1). Venous injuries were treated by ligation (2) or lateral venorraphy (2). One patient died unexpectedly on the tenth postoperative day for an overall mortality of 11 percent. Three of the 8 survivors sustained nonfatal complications (38%). All 8 survivors had patent arterial repairs at the time of hospital discharge, and 5 of 8 survivors were available for follow-up with intravenous digital subtraction angiography (DSA), revealing arterial repair patency in all.(ABSTRACT TRUNCATED AT 250 WORDS)