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R C Lange
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Fourier analysis, frequency, phase, and signal sampling.
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Patient perception of magnetic resonance arthrography.
OBJECTIVE: Magnetic resonance (MR) arthrography has been demonstrated to be more accurate than MR imaging alone in the identification of a variety of musculoskeletal pathology. While the complication rate of intra-articular gadolinium: saline injection has been shown to be relatively low, MR arthrography is more invasive, painful, and costly, and less convenient, than MR imaging alone. The purpose of this study was to evaluate patients' perception of the fear and discomfort, and to assess their overall acceptance of the intra-articular gadolinium injection. DESIGN AND PATIENTS: Between October 1997 and January 1998, 113 outpatients who were referred to Yale-New Haven Hospital for MR arthrography of the ankle, elbow, hip, knee, shoulder, or wrist were asked to complete a questionnaire rating their fear of factors most commonly associated with the procedure including "pain", "needles", "complications", and "discovery of results that would lead to surgery". In addition, after having undergone the intra-articular gadolinium:saline injection, patients were asked to rate their perception of pain. RESULTS: While many patients expressed fear of "pain" and "needles", after having undergone the injection their overall pain rating score was low. Only 6% actually found gadolinium arthrography more painful than expected. CONCLUSION: Despite the fact that patients expressed apprehension about certain aspects of MR arthrography, subjects who underwent the intra-articular gadolinium injection considered the discomfort less than expected. Clinicians should not hesitate to order MR arthrography because the accuracy of the procedure is high enough that patients accept the discomfort.
Ductal carcinoma in situ diagnosed with stereotactic core needle biopsy: can invasion be predicted?
PURPOSE: To determine whether mammographic or histologic features can be used to predict which cases diagnosed as ductal carcinoma in situ (DCIS) without invasion by means of stereotactic core needle biopsy (SCNB) will have invasive disease at surgery. MATERIALS AND METHODS: From July 1992 to March 1999, DCIS without invasion was diagnosed by means of SCNB in 59 patients. Seventeen (29%) were found to have invasive disease after surgery. The underestimation rate for SCNB was compared with that obtained by means of open surgical biopsy. Mammographic and histologic features of cases with and those without invasion were compared. RESULTS: All patients had calcifications on mammograms. There was no significant difference (P: =.26) between the underestimation rate for SCNB with the 11-gauge vacuum-assisted device and that for open surgical biopsy. No statistically significant differences between cases with and those without invasion were seen in patient age, mean number of core specimens, level of suspicion, size of lesion, distribution and morphology of the calcifications, presence of an associated mass or density, subtype of DCIS, nuclear grade, or presence of necrosis or desmoplasia. CONCLUSION: Mammographic and histologic features cannot be used reliably to predict cases that are underestimated with SCNB. However, SCNB with the 11-gauge vacuum-assisted device was as reliable as open surgical biopsy for diagnosing DCIS without invasion.
Underestimation of breast cancer with II-gauge vacuum suction biopsy.
OBJECTIVE: The purpose of this study was to determine the mammographic and histologic features of cancerous lesions underestimated using 11-gauge vacuum suction biopsy. MATERIALS AND METHODS: Retrospective review of 11-gauge vacuum suction biopsy was performed to identify lesions diagnosed as atypical ductal hyperplasia or carcinoma. The histology of the core and surgical specimens was compared. Of 158 cases of cancer, underestimation occurred in 15 (9.5%). The mammographic and histologic features were assessed. RESULTS: Of 15 underestimated cases, six were atypical ductal hyperplasia that proved to be cancer (5 ductal carcinoma in situ and 1 invasive) and nine were ductal carcinoma in situ that proved to have invasion. The underestimation rate for calcifications was 16.3% (14/86) and for masses was 1.6% (1/64) (p = 0.007). Most (5/6) underestimated atypical ductal hyperplasia cases were reported as "markedly atypical," and four of nine underestimated ductal carcinoma in situ cases were reported as "possible invasion." No significant difference was seen in the number of core specimens obtained or the sizes of the lesions for underestimated cases versus accurately diagnosed cases. The percentage of calcifications retrieved was significantly different (p = 0.017). No underestimations were found among cases in which the entire mammographic lesion was removed at vacuum suction biopsy. CONCLUSION: The cancer underestimation rate with vacuum suction biopsy was 9.5%. The underestimation rate for calcifications (16.3%) was significantly higher than that for masses (1.6%) (p = 0.007). The percentage of the lesion removed was an important factor in reducing underestimation, as reflected by the percentage of calcifications retrieved and the instances of complete resolution of the lesion seen on mammography.
Delta-9-tetrahydrocannabinol delays the gastric emptying of solid food in humans: a double-blind, randomized study.
BACKGROUND: Delta-9-tetrahydrocannabinol (THC), the active constituent of marijuana, is an effective agent in the prevention of chemotherapy-induced nausea and vomiting. AIM: To determine the effect of THC on gastric emptying of a radiolabelled solid food in humans. METHODS: Thirteen healthy volunteers underwent gastric emptying studies after receiving THC and placebo in a randomized double-blind fashion on 2 separate days. THC, at a dose of 10 mg/m2 of body surface area, or placebo were administered. RESULTS: Gastric emptying after THC was slower than placebo in all subjects. Mean percentage of isotope remaining in the stomach was significantly greater than after placebo from 30 min (85.5 +/- 4.3% vs. 94.2 +/- 1. 4% placebo and THC, respectively, P < 0.05) to 120 min (45.6 +/- 7. 2% vs. 73.9 +/- 7.1% placebo and THC, respectively, P < 0.001) after the test meal. No correlation was found between plasma THC levels and the delay in gastric emptying. CONCLUSIONS: THC at a dose used for preventing chemotherapy-induced nausea and vomiting significantly delays gastric emptying of solid food in humans. Therefore, the anti-emetic property of THC may be mediated through the central nervous system.
Pneumothorax and dependent versus nondependent patient position after needle biopsy of the lung.
PURPOSE: To test the hypothesis that placing the patient in a position with the puncture site dependent (down) after transthoracic needle biopsy reduces the incidences of pneumothorax and of pneumothorax that requires chest tube placement. MATERIALS AND METHODS: Four hundred twenty-three needle biopsies of the lung were performed in 390 patients from October 1991 to August 1994 with computed tomographic guidance, fluoroscopic guidance, or both. Two hundred forty-two biopsies were performed from the posterior approach, 166 from the anterior approach, and 15 from the lateral approach. The patients were assigned on an alternating basis to either the puncture-site-dependent recumbent position (210 biopsies) or the puncture-site-nondependent recumbent position (213 biopsies) for at least 1 1/2 hours after biopsy. RESULTS: No significant differences were found in either the incidence of pneumothorax (dependent position, 62 of 210 biopsies [30%], vs nondependent position, 57 of 213 biopsies [27%]; P = .60) or the incidence of pneumothorax that required chest tube placement (dependent position, 10 of 210 biopsies [5%], vs nondependent position, six of 213 biopsies [3%]; P = .43). CONCLUSION: The results suggest that the puncture-site-down postbiopsy position may not affect either the incidence of postbiopsy pneumothorax or the incidence of pneumothorax that requires chest tube placement.
Comparison of rebiopsy rates after stereotactic core needle biopsy of the breast with 11-gauge vacuum suction probe versus 14-gauge needle and automatic gun.
OBJECTIVE: The 11-gauge vacuum suction probe is an alternative to the 14-gauge needle and automatic gun for performing stereotactic core needle biopsies. This study compares rebiopsy rates after stereotactic core needle biopsies that were performed with the two methods. The study also assesses the outcomes of those repeat biopsies. MATERIALS AND METHODS: Five hundred ninety-two stereotactic core needle biopsies using a 14-gauge needle and automatic gun and 354 using an 11-gauge vacuum suction probe were performed consecutively. Excluding malignancies, the number of cases requiring rebiopsy and the reasons for rebiopsy were determined for each group. The histologic diagnoses of the repeat biopsies were assessed. RESULTS: The rebiopsy rate was significantly lower with the 11-gauge vacuum suction probe (9.0%) than with the 14-gauge needle and automatic gun (14.9%) (p = .013). Significant reductions were found in cases of insufficient sampling (probe, 1.7%; needle, 4.4%; p = .042) and mammographic-pathologic discrepancy (probe, 0.8%; needle, 3.4%; p = .026). The rebiopsy rate for masses was 6.1% with the vacuum probe versus 10.7% with the 14-gauge needle (p = .12) and for calcifications was 11.6% with the vacuum probe versus 23.7% with the 14-gauge needle (p = .003). After rebiopsy, the percentage of cases in which malignancy was found was 18.5% with the vacuum probe versus 13.7% with the 14-gauge needle. On rebiopsy, the percentage of malignancies found in each category were atypical hyperplasia: probe 26.7%, needle 20.0%; insufficient sample: probe 0%, needle 9.5%; pathologist recommendation: probe 50.0%, needle 12.5%; and lobular carcinoma in situ: probe 0%, needle 100%. CONCLUSION: Use of the 11-gauge vacuum-assisted device significantly decreases but does not eliminate the need for rebiopsy after stereotactic core needle biopsy. The rebiopsy rate for calcifications was significantly reduced by using the vacuum suction probe rather than the 14-gauge needle; however, the rate for masses was reduced only slightly. On rebiopsy, malignancies were found in both groups.
Prevalence of impaired gastric emptying of solids in systemic sclerosis: diagnostic and therapeutic implications.
The aims of this study were to evaluate the gastric emptying of solids in patients with progressive systemic sclerosis, correlate the esophageal motility abnormalities with their gastric emptying status, delineate the symptoms suggestive of abnormal gastric emptying, and assess the effect of metoclopramide in patients with abnormally slow gastric emptying. Twenty patients underwent esophageal motility evaluation and gastric emptying studies with a radiolabeled solid meal. Gastric emptying was also measured in 13 healthy volunteers. Four patients in whom esophageal motility was normal also had an accompanying normal rate of gastric emptying. In 16 patients with abnormal esophageal motility, mean gastric emptying was significantly delayed as compared with that in normal subjects (67.4% vs 49.8% retention of isotope at 2 hours, P < .05). Ten patients had absolute criteria for slow gastric emptying (>+2 SD). However, only postprandial bloating and early satiety were symptoms that accurately predicted slow radionuclide emptying. In four of these patients in whom gastric emptying was slow, 10 mg intramuscular metoclopramide significantly (P < .05 vs baseline) accelerated the gastric emptying of the same test meal. We conclude that (1) gastric emptying of solids was delayed in approximately two thirds of patients with abnormal esophageal motility, whereas it was normal in patients with normal esophageal motor function; (2) metoclopramide significantly accelerated this slow gastric emptying; and (3) delayed gastric emptying contributes to the severity of the gastroesophageal reflux frequently present in patients with progressive systemic sclerosis, and promotility agents offer a valuable therapeutic approach.
Economic impact of replacing CT with MR imaging for refractory epilepsy.
PURPOSE: To evaluate the economic costs of using computed tomography (CT) vs. magnetic resonance (MR) imaging in the preoperative evaluation of refractory epilepsy patients. METHODS: Preoperative CT and MR imaging findings from 117 patients who underwent surgery for medically refractory epilepsy during a 3.5-year period were reviewed. Cost savings were based on the paradigm that intracranial electroencephalogram monitoring (costing about $50,000) would have been necessary for preoperative localization of the epileptogenic zone in those patients without positive imaging findings. Savings attributed to replacing CT with MR were based on patients with positive MR and normal CT. A similar paradigm was used to calculate savings for replacing MR with CT. National savings were based solely on patients with neoplasms or vascular lesions because paradigms for other lesions vary considerable depending on institutional philosophy. RESULTS: Replacing CT with MR imaging would have eliminated preoperative intracranial electrode procedures in 29 of 117 patients, with potential savings of $1,450,000 at our institution. In the 37 patients with neoplastic or vascular substrates, MR would have eliminated 10 invasive electrode procedures with estimated savings of $0.5 million institutionally and $3 to $4 million per year nationally. There were no cases to support replacing MR with CT. CONCLUSION: Replacing CT with MR decreases health costs associated with preoperative evaluation of intractable epilepsy requiring surgical amelioration.
Chest radiograph interpretation of Pneumocystis carinii pneumonia, bacterial pneumonia, and pulmonary tuberculosis in HIV-positive patients: accuracy, distinguishing features, and mimics.
The purpose of this study was to assess the accuracy of chest x-ray (CXR) interpretation in the diagnosis of pneumocystis carinii pneumonia (PCP), bacterial pneumonia (BP), and pulmonary tuberculosis (TB) in human immunodeficiency virus (HIV)-positive patients and to identify the frequency with which these infections mimic one another radiographically. The admitting CXRs of 153 HIV-positive patients with laboratory proven BP (n = 71), PCP (n = 73), and TB (n = 9) and those of 10 HIV-positive patients with no active disease were reviewed retrospectively and independently by three radiologists who were blinded to clinical and laboratory data. Median percent accuracies were as follows: TB, 84%; PCP, 75%; BP, 64%; and no active disease, 100%. Fifteen of 153 cases (9.8%) were shown to mimic other infections radiographically. A confident and accurate diagnosis can be made radiographically in the majority of cases of PCP, BP, and TB in HIV-positive patients at the time of hospitalization. In approximately 10% of cases, these infections may mimic one another radiographically.
Rotator cuff: evaluation with fast spin-echo versus conventional spin-echo MR imaging.
PURPOSE: To determine if fast spin-echo (SE) magnetic resonance (MR) imaging can provide similar information to that of conventional SE imaging for evaluation of the rotator cuff. MATERIALS AND METHODS: One hundred twenty-six patients underwent MR imaging with conventional SE and non-fat-suppressed fast SE sequences (65 patients) or conventional SE and fat-suppressed fast SE sequences (61 patients). Two radiologists independently graded the rotator cuff with separate and side-by-side assessment of the fast SE and conventional SE images. RESULTS: For detection of full-thickness tears, agreement between non-fat-suppressed fast SE and conventional SE images was 93.8% (kappa = 0.78 [good]) and 95.4% (kappa = 0.82 [very good]) for the two readers, respectively, and agreement between fat-suppressed fast SE and conventional SE images was 98.4% (kappa = 0.96 [very good]) and 91.8% (kappa = 0.73 [good]) for the two readers, respectively. Rotator cuff grading was similar for fast SE and conventional SE: weighted kappa = 0.77 (good) and 0.68 (good) for non-fat-suppressed and weighted kappa = 0.83 (very good) and 0.67 (good) for fat-suppressed fast SE images for the two readers, respectively. CONCLUSION: Fast SE sequences yield similar interpretations as those obtained with a conventional SE sequence for evaluation of the rotator cuff.
Fibroma and fibrothecoma of the ovary: MR imaging findings.
PURPOSE: To describe the morphologic and signal intensity characteristics on magnetic resonance (MR) images of fibromas and fibrothecomas. MATERIALS AND METHODS: MR images of 11 female patients with histologically proved fibromas or fibrothecomas were reviewed, and morphologic and signal intensity characteristics of the lesions were analyzed. MR imaging findings were correlated with histologic findings. RESULTS: All fibromas and fibrothecomas showed homogeneous low signal intensity on T1-weighted images. On T2-weighted images, the two smallest lesions showed homogeneous low signal intensity, and eight of the other nine lesions showed predominantly low signal intensity. Edema was noted only in larger lesions, and cystic degeneration was noted only in three of the largest lesions. On T2-weighted images, the percentage of low signal intensity in the lesion was not found to be related to lesion size, and the percentage of low signal intensity in fibromas was not significantly different from that in fibrothecomas (P = .55). Many lesions showed heterogeneous signal intensity; the solid component was distributed peripherally, and the cystic component was located centrally or eccentrically. Free intraperitoneal fluid was noted in 10 of 11 lesions and was not significantly correlated with lesion size (r = .52 and P = .10). CONCLUSION: Because of their predominantly low signal intensity on T2-weighted images, fibromas and fibrothecomas display a relatively specific appearance on MR images.
Qualitative MR imaging of refractory temporal lobe epilepsy requiring surgery: correlation with pathology and seizure outcome after surgery.
OBJECTIVE: The purpose of this study was to compare MR imaging findings with histologic findings of either hippocampal sclerosis or gliosis in patients with intractable temporal lobe epilepsy requiring surgery and to correlate MR imaging findings with seizure outcome after surgery and with clinical parameters such as febrile seizure history. MATERIALS AND METHODS: A retrospective study of MR scans of 66 patients with medically refractory temporal lobe epilepsy requiring surgery was performed. Qualitative diagnosis was done by visual inspection of MR images. MR imaging findings of hippocampal atrophy, signal intensity changes, and segmental findings were correlated with histopathology and with neuronal density. The final MR imaging diagnosis was also correlated with seizure outcome after surgery and with febrile seizure history. RESULTS: Histologic findings consisted of hippocampal sclerosis in 55 patients and nonspecific gliosis in 11 patients. Two variables, MR imaging findings of hippocampal sclerosis (hippocampal atrophy or signal intensity change) and a febrile seizure history, were significantly associated with hippocampal sclerosis. MR images of nonspecific gliosis usually showed normal findings, although some cases showed mild hippocampal atrophy. When comparing MR imaging findings with histology, our observers achieved sensitivities of 87-98% and specificities of 45-100%. In patients with successful outcomes after surgery, sensitivity ranged from 85% to 98% for MR imaging findings suggesting hippocampal sclerosis, specificity ranged from 17% to 85%, and positive predictive values ranged from 82% to 90%. CONCLUSION: Qualitative visual analysis of MR images correlates well with histologic findings, febrile seizure history, and seizure outcome after surgery. MR imaging findings and febrile seizure history help differentiate between hippocampal sclerosis and nonspecific gliosis, two similar clinical conditions associated with temporal lobe epilepsy that often have different outcomes after surgery.
Transrectal sonography in staging rectal carcinoma: the role of gray-scale, color-flow, and Doppler imaging analysis.
OBJECTIVE: The purpose of this study was to evaluate the efficacy of combining gray-scale sonography with color-flow imaging and pulsed Doppler transrectal sonography in the staging of rectal carcinoma. SUBJECTS AND METHODS: Thirty-nine patients with primary rectal carcinoma underwent transrectal sonography. The rectal masses were staged T1-T2 or T3-T4 on the basis of gray-scale imaging. The local nodes were classified as benign or malignant on the basis of size and echogenicity. In 22 patients, color-flow imaging and pulsed Doppler imaging of the rectal mass and of the local lymph nodes were performed. The peak systolic velocity (PSV) and end diastolic velocity were documented, and the resistive index was calculated. RESULTS: Gray-scale imaging alone was used to stage T1-T2 masses with 88% sensitivity and 82% specificity. T3-T4 masses were staged with 82% sensitivity and 88% specificity. Overall accuracy was 85%. Gray-scale imaging of lymph nodes using a discriminatory size of less than or equal to 5 mm for benign nodes and greater than 5 mm for malignant nodes yielded a sensitivity of 100%, a specificity of 28%, and an accuracy of 52%. Using receiver operating characteristic curve analysis, we determined that a size of greater than or equal to 7 mm was optimal for characterizing nodes. Such a size provided an accuracy of 83%. PSV of less than 25 cm/sec distinguished T3-T4 from T1-T2 rectal masses with 75% sensitivity, 80% specificity, and 77% accuracy. A PSV of greater than 20 cm/sec classified a node as malignant with 100% sensitivity, 62% specificity, and 76% accuracy. A resistive index of greater than 0.61 classified a node as malignant with 71% sensitivity, 85% specificity, and 80% accuracy. CONCLUSION: Color-flow imaging and pulsed Doppler imaging are useful additions to gray-scale transrectal sonography in staging primary rectal carcinomas. The combination has most value when evaluating perirectal nodes.
Stereotaxic core needle biopsy of breast microcalcifications: correlation of target accuracy and diagnosis with lesion size.
PURPOSE: To determine if lesion size or number of calcifications affects the ability to obtain microcalcifications or a specific histologic diagnosis at stereotaxic core needle biopsy (SCNB). MATERIALS AND METHODS: Mammographic findings and histopathologic reports of 138 lesions in 124 patients (aged 30-87 years; mean age, 56.2 years) who underwent SCNB of calcifications were reviewed. Calcifications in the specimen and attainment of a specific diagnosis were correlated with lesion size and number of calcifications. RESULTS: Calcifications were obtained in 118 cases (86%). A specific diagnosis was reported in 72 cases (52%). Differences in retrieval of calcifications or ability to establish a specific diagnosis with decreasing lesion size or decreasing number of calcifications were not statistically significant. Attainment of a specific diagnosis was significantly related to retrieval of calcifications (P<.005). CONCLUSION: SCNB was successful in obtaining calcifications in a high percentage of cases regardless of lesion size or number of calcifications. When calcifications were retrieved, a specific diagnosis was attained in most cases (72 of 118).