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Biomedical subjects

R C Lange

Publications and source records attributed to R C Lange.

At least 19 recordsLinked to original sources
PubMed1999

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.

Adult↗
PubMed1999

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.

Adult↗
PubMed1999

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.

Biopsy, Needle↗
PubMed1998

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.

Adult↗
PubMed1997

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.

Adolescent↗
PubMed1997

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.

AIDS-Related Opportunistic Infections↗
PubMed1997

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.

Adolescent↗
PubMed1997

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.

Adolescent↗
PubMed1997

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.

Adolescent↗
PubMed1997

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.

Carcinoma↗
PubMed1996

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).

Adult↗
PubMed1996

Refractory epilepsy: comparison of MR imaging, CT, and histopathologic findings in 117 patients.

PURPOSE: We compared computed tomography (CT) and magnetic resonance (MR) imaging for the detection of abnormalities underlying epilepsy. MATERIALS AND METHODS: CT and MR imaging findings in 117 patients (56 female, 61 male patients; age at surgery, 12-56 years) who underwent surgery for medically refractory epilepsy were compared with histopathologic findings by using the McNemar and chi 2 statistics. RESULTS: Sensitivities for detecting abnormalities were 95% (104 of 109) for MR imaging and 32% (35 of 109) for CT; specificities were 87% (13 of 15) for MR imaging and 93% (14 of 15) for CT (P < .001 for MR versus histopathologic findings). In the subgroup of 113 patients with solitary findings, MR imaging depicted an abnormality at the surgical site in 86% (n = 97) of 113 patients compared to 28% (n = 32) for CT (P < .001). In this same subgroup, histopathologic findings were predicted by using MR imaging in 88% (n = 99) of 113 patients versus 35% (n = 40) with CT (P < .001). Multiple findings were observed in 3% of CT (three of 117) and 17% of MR (20 of 117) images. CONCLUSION: CT has no role in the diagnostic evaluation of medically refractory epilepsy. Even in patients with medically controlled epilepsy, use of less costly CT instead of MR imaging seems imprudent.

Adolescent↗
PubMed1996

Mammographic findings of recurrent breast cancer after lumpectomy and radiation therapy: comparison with the primary tumor.

PURPOSE: To compare the mammographic findings of recurrent breast cancer with those of the primary tumor in patients who underwent lumpectomy and radiation therapy. MATERIALS AND METHODS: Mammograms were reviewed of primary and recurrent tumors in 25 patients (26 lesions). Mammographic appearance, location, and histopathologic characteristics were retrospectively compared between primary and recurrent tumors. RESULTS: Primary and recurrent tumors were mammographically similar in 21 (81%) of the 26 lesions. Of 14 primary tumors with calcifications, 12 (86%) recurred with calcifications, and of the 12 masses, nine (75%) recurred as masses. Recurrent tumors that occurred in the lumpectomy quadrant were more often similar in mammographic appearance to the primary tumor (20 of 22 tumors) than those in other quadrants (one of four tumors) (P < .02). CONCLUSION: After conservative treatment of breast cancer, the majority of recurrent tumors appear to be mammographically similar to primary tumors. It is prudent to review preoperative mammograms during follow-up of patients after lumpectomy and radiation therapy.

Adult↗
PubMed1995

MR characteristics of neoplasms and vascular malformations associated with epilepsy.

We assessed the magnetic resonance (MR) imaging characteristics of two categories of epileptogenic substrates, neoplasms, and vascular malformations, to determine MR sensitivity and typical imaging features. A blinded retrospective analysis was performed on MR scans from 41 patients who had a neoplasm or vascular malformation surgically resected as treatment for medically refractory epilepsy. Abnormalities were assessed for sensitivity of MR detection, prediction of pathologic category, location, calvarial remodelling, signal intensity, and effect on adjacent tissue. Pathologic findings consisted of 33 tumors and 8 vascular malformations. We correctly localized 100% of the 41 lesions and predicted the correct pathologic category for 95% of these lesions. Neoplastic and vascular lesions (NVLs) associated with epilepsy had certain characteristic features. The temporal lobe was the most common site for NVL, involved in 68%. NVL were located in the brain periphery in 85% and remodelled the calvarium in 32%. NVL were associated with mass effect in 61%, volume loss in 1%, and no effect on adjacent tissue in 37%. NVL associated with epilepsy can be detected with high sensitivity using MR imaging. The temporal lobe location, cortical involvement, and calvarial remodelling are findings typical of NVL. MR characteristics can successfully predict the pathologic substrate of these lesions.

Brain Neoplasms↗
PubMed1995

Clinical stage I endometrial carcinoma: pitfalls in preoperative assessment with MR imaging. Work in progress.

PURPOSE: To identify potential pitfalls in using magnetic resonance (MR) imaging to determine the depth of myometrial invasion in patients with clinical stage I endometrial carcinoma. MATERIALS AND METHODS: Forty women with clinical stage I endometrial carcinoma underwent preoperative pelvic MR imaging. Uterine length, tumor signal intensity, appearance of the junctional zone, presence of large polypoid tumors, leiomyomata, and congenital uterine anomalies were analyzed. Univariate logistic-regression analysis was performed to identify associations between incorrect MR staging and these variables. RESULTS: MR staging of IA, IB, and IC disease was 55% accurate (22 of 40 cases); MR differentiation of deep myometrial invasion (stage IC) from superficial disease (stages IA and IB) was 78% accurate (31 of 40 cases). Older age (P = .025), presence of polypoid tumors (P = .025), and difficulty in pathologic staging (P < .005) were significantly associated with incorrect MR assessment. CONCLUSION: When present, large polypoid tumors, leiomyomata, congenital anomalies, small uteri, and indistinct zonal anatomy may make it difficult to assess myometrial invasion at MR imaging.

Aged↗
PubMed1995

Acute flank pain: comparison of non-contrast-enhanced CT and intravenous urography.

PURPOSE: To compare non-contrast-enhanced computed tomography (CT) and intravenous urography (IVU) in the evaluation of patients who present with acute flank pain and in whom ureteric obstruction is suspected. MATERIALS AND METHODS: The findings at non-contrast-enhanced CT and IVU in 20 patients with acute flank pain were compared for the presence or absence of ureteric obstruction and delineation of ureteric stones. RESULTS: Twelve of the 20 patients had non-contrast-enhanced CT and IVU findings consistent with ureteric obstruction. Of these 12 patients, five had a ureteric stone that was demonstrated on both non-contrast-enhanced CT scans and IVU radiographs, six had a stone that was depicted on non-contrast-enhanced CT scans only, and in one patient a stone could not be delineated definitively on either non-contrast-enhanced CT scans or IVU radiographs. Eight patients had findings at non-contrast-enhanced CT and IVU consistent with the absence of obstruction. CONCLUSION: Non-contrast-enhanced CT is more effective than IVU in precisely identifying ureteric stones and is equally effective as IVU in the determination of the presence or absence of ureteric obstruction.

Acute Disease↗
PubMed1993

Pelvic MR imaging findings in gestational trophoblastic disease, incomplete abortion, and ectopic pregnancy: are they specific?

Thirty-nine patients with abnormally elevated levels of serum beta subunit of human chorionic gonadotropin (beta-hCG) were studied to determine whether findings at magnetic resonance (MR) imaging are specific for primary molar disease, persistent gestational trophoblastic disease (GTD), incomplete abortion, and ectopic pregnancy. Among the latter three groups, the only significant differences were a higher prevalence of endometrial distention in the group with incomplete abortion (P < .0035) and the absence of junctional zone disruption in the group with ectopic pregnancy (P < .05). In the group with primary molar disease, total intrauterine volume was significantly increased (P < .001), and endometrial distention and presence of an endometrial mass had a significantly higher prevalence than that in the persistent GTD groups with (P < .04) or without (P < .001) metastases. Myometrial or extrauterine disease was identified in 65% of the patients with persistent disease and a beta-hCG level greater than 500 mIU/mL (500 IU/L). Thus, although MR imaging findings in persistent GTD, incomplete abortion, and ectopic pregnancy are relatively nonspecific, MR imaging can depict invasive disease that may alter therapeutic management in patients with documented GTD.

Abortion, Incomplete↗