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P L Molina

Publications and source records attributed to P L Molina.

At least 19 recordsLinked to original sources
PubMed2001

Newly diagnosed pulmonary sarcoidosis in HIV-infected patients.

PURPOSE: To determine the radiologic and clinical features of newly diagnosed pulmonary sarcoidosis in human immunodeficiency virus (HIV)-infected patients. MATERIALS AND METHODS: Ten HIV-infected patients (seven women, three men; age range, 26-66 years; mean age, 37 years) with newly diagnosed sarcoidosis between 1989 and 1997 were retrospectively identified. Charts were reviewed for the interval between the two diagnoses, CD4 cell count, signs or symptoms, angiotensin-converting enzyme level, and initiation of highly active antiretroviral therapy (HAART). Chest radiographs (n = 10) and computed tomographic (CT) scans (n = 8) were assessed for lymphadenopathy, pulmonary nodules, focal consolidation, reticular or granular opacities (thickened interlobular septa and ground-glass opacities at CT), cysts or cavities, and fibrosis. RESULTS: Mean interval between the two diagnoses was 3 years. Mean CD4 cell count was 213 cells per cubic millimeter. When sarcoidosis was diagnosed, eight patients had pulmonary signs or symptoms. The angiotensin-converting enzyme level was elevated in five of six patients; two developed sarcoidosis after beginning HAART. Chest radiographs revealed lymphadenopathy, pulmonary nodules, focal consolidation, reticular opacities, granular opacities, and cysts or cavities. Chest CT scans revealed lymphadenopathy, nodules, thickened interlobular septa, focal consolidation, reticular opacities, ground-glass opacities, and cysts or cavities. There was no relationship between the radiographic findings of sarcoidosis and the CD4 cell count. CONCLUSION: The radiologic features of newly diagnosed sarcoidosis in HIV-infected patients resemble the findings of sarcoidosis in non-HIV-infected patients. In HIV-infected patients receiving HAART, sarcoidosis may be a manifestation of disease related to restoration of the immune system.

Adult↗
PubMed2000

Breath-hold 3D gradient-echo MR imaging of the lung parenchyma: evaluation of reproducibility of image quality in normals and preliminary observations in patients with disease.

This study evaluates the reproducibility and image quality of a three-dimensional (3D) gradient-echo sequence for imaging the lung parenchyma, with and without gadolinium administration, using a 2D spoiled gradient-echo sequence for comparison. Twenty patients without lung disease (normals) and five patients with lung disease (lung disease) underwent paired 2D and 3D gradient-echo sequences, without contrast (24 patients) and with contrast (18 patients). Images were retrospectively reviewed independently in a blinded fashion by two investigators. Artifacts and demonstration of central lung, peripheral lung, heart, pulmonary arteries, and esophagus were evaluated. Image quality of the central lung was rated as fair or good in 5 and 4 (reader one and two) patients with non-contrast 2D gradient-echo, 24 and 25 patients with non-contrast 3D gradient-echo, 3 and 1 patient(s) with contrast-enhanced 2D gradient-echo, and 19 and 19 patients with contrast-enhanced 3D gradient-echo imaging. Differences in image quality between 2D and 3D sequences were significant (P < 0.001). Heart-related phase artifacts were negligible in 2 and 0 patients with non-contrast 2D gradient-echo, 23 and 25 patients with non-contrast 3D gradient-echo, 0 and 0 patients with contrast-enhanced 2D gradient-echo, and 17 and 19 patients with contrast-enhanced 3D gradient-echo imaging. Differences in heart-related phase artifact in the central lung between 2D and 3D sequences were significant (P = 0.001). Infiltrates, lung cancer, and pulmonary metastasis were better shown on the gadolinium-enhanced 3D gradient-echo sequences than on the other sequences. Breath-hold 3D gradient-echo imaging results in good image quality and negligible image artifacts and is superior to 2D spoiled gradient-echo imaging. Preliminary results in patients with disease appear promising.

Artifacts↗
PubMed1999

High-resolution computed tomography of the chest in children with cystic fibrosis: support for use as an outcome surrogate.

BACKGROUND: Outcome surrogates are indicators that reflect, rather than directly measure, patient benefit. In order to provide useful results, however, outcome surrogates must be carefully chosen and must meet specific criteria. OBJECTIVE: To support development of high-resolution computed tomography (HRCT) as an outcome surrogate in cystic fibrosis (CF) by demonstrating the ability of HRCT to show short-term improvement in the appearance of the lungs in children with CF. MATERIALS AND METHODS: HRCT was performed at admission and after discharge on 8 children during 15 admissions for acute pulmonary exacerbation of CF. Three radiologists scored each study separately, then compared admission and discharge pairs. RESULTS: HRCT scores improved in 13/15 admissions. Mean score decreased from 25 to 22. The decrease was significant (P = 0.014). Comparison of admission and discharge scans showed improvement in peribronchial thickening (P = 0.007), mucous plugging (P = 0.002), and overall appearance (P = 0.025). CONCLUSION: HRCT has the potential to be a useful outcome surrogate in CF. A necessary attribute of an outcome surrogate is that it improves rapidly with effective therapy. Despite widespread belief among radiologists and pulmonologists that HRCT meets this criterion, no previous report has demonstrated this ability in children. These findings support further development of HRCT as an outcome surrogate in children with CF.

Adolescent↗
PubMed1999

Magnetic resonance imaging of the abdominal aorta and iliac vessels using combined 3-D gadolinium-enhanced MRA and gadolinium-enhanced fat-suppressed spoiled gradient echo sequences.

This study evaluates a combined protocol consisting of breath hold immediate post gadolinium 3-D gradient echo MR angiography and blood pool phase gadolinium-enhanced breath hold 2-D fat-suppressed spoiled gradient echo (SGE) sequences in the examination of diseases of the abdominal aorta and iliac vessels. Thirty-two patients with suspected disease of the abdominal aorta, major aortic branches, or iliac vessels underwent MR angiographic study from January 1996 to January 1997. Examinations were performed on a 1.5 T MR imager using 2-D axial SGE, coronal 3-D fast imaging in steady state precession (3-D FISP) following bolus administration of 40 mL of gadolinium, and axial and coronal blood pool phase gadolinium-enhanced fat-suppressed SGE. Post-processed data, including 3-D reconstructions using maximum intensity projection (MIP), targeted MIP, and multiplanar reconstruction (MPR) were evaluated. MR findings in all patients were correlated as follows: surgery (13 patients), angiography (11 patients), contrast enhanced CT (3 patients), non-contrast enhanced CT (1 patient), color doppler US (2 patients), and previous MR study (2 patients). MR findings correlated closely with findings at surgery or other imaging studies in 31 of 32 patients. One patient had renal artery occlusion that was misinterpreted as mild stenosis. The following vascular diseases were present: aneurysm disease [10 patients: aortic aneurysm (8 patients), inflammatory aneurysm (2 patients)], thoracoabdominal aortic dissection (2 patients), arteriovenous fistula (1 patient), stenoses and/or occlusion of the abdominal aorta, major aortic branches and iliac vessels [12 patients: stenoses and/or occlusion of the abdominal aorta with stenoses of the iliac vessels (9 patients), renal artery stenosis (2 patients), occlusion of the abdominal aorta (1 patient)], and occluded artery to pancreatic transplant artery (1 patient). Five patients had normal studies. The 3-D FISP technique accurately defined the luminal contours of vessels, allowing precise depiction of vessel stenosis (i.e., renal artery stenosis or common iliac artery stenosis) and clear demonstration of relationship of aortic branch vessels (i.e., renal arteries) to underlying aortic pathology (i.e., aortic aneurysm or dissection). Blood pool phase gadolinium-enhanced fat-suppressed SGE images were useful in the evaluation of the external surface of vessel walls, and providing accurate measurement of aneurysm diameter and other associated vascular entities (i.e., inflammatory aneurysm, left-sided IVC). Targeted MIP or MPR reconstruction were important for assessing stenoses of medium sized vessels such as renal arteries and branches of the iliac arteries, and for identifying accessory arteries. The combination of immediate post gadolinium 3-D FISP and blood pool phase gadolinium-enhanced fat-suppressed SGE is useful in the evaluation of the abdominal aorta, major aortic branches and iliac vessels. Immediate post gadolinium 3-D FISP images provides diagnostically useful information regarding vessel luminal contour, while blood pool phase gadolinium-enhanced fat-suppressed SGE provides ancillary information on the vessel wall and surrounding tissue.

Adolescent↗
PubMed1997

Hepatic enhancement and metastatic lesion conspicuity on CT scans: influence of intravenous glucagon and oral CT contrast material.

PURPOSE: To determine the effect of glucagon and orally administered contrast material on hepatic enhancement and metastatic lesion conspicuity on computed tomographic (CT) scans. MATERIALS AND METHODS: Nine patients with a history of hepatic metastasis underwent two CT examinations with intravenously administered contrast material. Each patient was given orally administered CT contrast material for the first examination. No oral contrast material was given in the second examination. Five patients underwent the initial CT with intravenous administration of 1 mg of glucagon; the second examination was performed without glucagon. Four patients were administered glucagon before the second examination, but no glucagon was administered before the first. Attenuation in the liver, portal vein, and aorta was measured by observers blinded to whether the patient had been given glucagon. Lesion conspicuity was rated on a continuous scale. RESULTS: Greater mean hepatic enhancement was noted on scans of patients in whom oral contrast material was administered (mean, 52 HU) versus those in whom no oral contrast material was administered (mean, 47 HU; P = .019). Glucagon was not associated with greater hepatic enhancement. Neither oral contrast material nor glucagon had a significant effect on lesion conspicuity. CONCLUSION: Oral CT contrast material is associated with a small increase in hepatic enhancement that does not appear to be clinically important. Glucagon does not appear to affect hepatic enhancement or lesion conspicuity in humans.

Administration, Oral↗
PubMed1996

Delayed tuberculin reactivity in persons of Indochinese origin: implications for preventive therapy.

OBJECTIVES: To 1) study a variant delayed reaction to tuberculin testing as a way to enhance screening for tuberculosis among high-risk persons and 2) correlate the delayed reaction with lymphocyte blastogenesis. DESIGN: Cross-sectional study. SETTING: 2 public health department clinics in North Carolina. PARTICIPANTS: 121 adults who had recently emigrated from Vietnam to North Carolina and who were ethnic Vietnamese and ethnic Dega, a minority population group from the central highlands region of Vietnam. MEASUREMENTS: Medical history, physical examination, laboratory evaluation, and standard purified protein derivative (PPD) testing (Mantoux method). Skin test results were read at 72 hours and again at 6 days. Variant reactivity was defined as induration of less than 10 mm at 72 hours that, when reassessed at 6 days, had increased in size to 10 mm or greater. Persons with negative (n=54) and variant (n=32) PPD results also had booster testing at 10 to 12 weeks. Serum samples were obtained from 57 participants for lymphocyte blastogenesis studies. RESULTS: 26% of participants had variant tuberculin reactivity. Variant reactivity was strongly associated with booster positivity: Sixty-five percent of persons with variant PPD results had booster positivity compared with 16% of persons with negative PPD results (P<0.001). The lymphocyte blastogenesis response of persons with variant PPD results was between the response of persons with negative PPD results and that of persons with positive PPD results. CONCLUSION: Variant reactivity in this high-risk group was a predictor of booster positivity. Together with the blastogenic response pattern, this association strongly suggests that variant reactivity has a high positive predictive value for tuberculous infection. Clinicians should incorporate these findings into their approach for choosing candidates for preventive therapy.

Adult↗
PubMed1996

Imaging evaluation of obstructive atelectasis.

Segmental or lobar atelectasis is a common radiographic finding in patients with bronchial obstruction. Although in many cases the presence and cause of atelectasis can be ascertained from the plain chest radiograph, computed tomography (CT) often provides valuable additional information, particularly with regard to the precise location and extent of the obstructing process. CT also can be used to differentiate between benign and malignant causes of obstructive atelectasis. After administration of intravenous contrast material, CT may distinguish a proximal obstructing tumor from collapsed lung or adjacent mediastinal structures. In some patients, magnetic resonance imaging (MRI) can provide comparable and/or complementary information. In this article, we review the major applications of CT and MRI, as well as the capabilities and limitations of both techniques, in the evaluation of patients with obstructive atelectasis.

Diagnosis, Differential↗
PubMed1995

Innominate artery and tracheal compression due to aberrant position of the thymus.

A 3-month-old infant with failure to thrive was found on bronchoscopy to have tracheal obstruction thought to be secondary to innominate artery compression. Subsequent diagnostic evaluation with magnetic resonance imaging revealed superior and posterior extension of the thymus with resultant compression of the innominate artery and trachea within the narrow confines of the thoracic inlet. Resection of the aberrantly positioned and enlarged thymus and aortopexy resulted in relief of tracheal compression.

Brachiocephalic Trunk↗
PubMed1995

Nodular sarcoidosis of the liver and spleen: analysis of 32 cases.

PURPOSE: To describe the computed tomographic (CT) appearance of nodular hepatosplenic sarcoidosis and its association with stage with chest radiography and clinical status. MATERIALS AND METHODS: Thirty-two patients (21 women, 11 men; aged 25-68 years) with nodular hepatosplenic sarcoidosis were evaluated. CT findings were described along with chest radiographic stage, clinical status, and level of angiotensin-converting enzyme (ACE). RESULTS: Nodules were small, multiple, and of low attenuation. Organomegaly was common. Abdominal adenopathy was present in 76% of the patients. Chest radiographs were normal in 25%; 61% had stage 1 or 2 radiographs. Abdominal or systemic symptoms were present in 66%. ACE level was elevated in 10 (91%) of 11 patients tested. No change in chest radiographic stage was noted in 74% of patients with follow-up radiographs. CONCLUSION: Nodular hepatosplenic sarcoidosis is associated with organomegaly, adenopathy, and symptoms. Nodules were not associated with advanced lung disease and did not herald a change in chest radiographic stage. An elevated ACE level may be helpful in diagnosis.

Adult↗
PubMed1995

Hepatic spiral CT: reduction of dose of intravenous contrast material.

PURPOSE: To assess the potential for reduction of contrast material dose in hepatic spiral computed tomography (CT). MATERIALS AND METHODS: Four hundred eighty-seven outpatients were randomized prospectively into nine biphasic and eight uniphasic injection protocols: 75, 100, or 125 mL of 240, 300, or 350 mg of iodine per milliliter of iohexol (18-44 grams of iodine). Protocols were compared according to the maximum hepatic enhancement (MAX) and the contrast enhancement index (CEI). RESULTS: Uniphasic injection was superior to biphasic injection for all protocols. No statistically significant difference in contrast enhancement was present for 38-44 grams of iodine with the uniphasic technique. Adequate enhancement thresholds (MAX > 50 HU, CEI at 30 HU > 300 HU x sec) were exceeded in more than 70% of heavy patients ( > 183 lb [83 kg]) with uniphasic injection of 38 g. For thin patients ( < 183 lb [83 kg]), uniphasic injection of 26 g produced adequate enhancement. CONCLUSION: Contrast material dose may be reduced by up to 40% in thin patients undergoing hepatic spiral CT after uniphasic injection of contrast material; this may result in substantial cost savings.

Adult↗
PubMed1995

Hepatic contrast enhancement at CT: influence of intravenous glucagon in a canine model.

PURPOSE: To investigate the effect of glucagon on the timing and degree of hepatic enhancement at computed tomography. MATERIALS AND METHODS: Each of 11 dogs underwent injection of contrast material at two uniphasic rates (0.5 mL/sec and 1.5 mL/sec) with without previous intravenous administration of 0.5 mg of glucagon. Scans were obtained at a single intrahepatic level every 3.5 seconds for 120-160 seconds. Attenuation values in the liver, aorta, portal vein, and inferior vena cava (IVC) were measured. RESULTS: Glucagon administration was associated with greater hepatic enhancement throughout the study: Peak hepatic enhancement was greater at contrast injection rates of 0.5 mL/sec (P = .021) and 1.5 mL/sec (P = .0001). Peak hepatic enhancement also occurred earlier during the glucagon runs. Portal vein enhancement was greater during the glucagon runs at an injection rate of 1.5 mL/sec (P = .032). IVC enhancement was greater during the nonglucagon runs at 0.5 mL/sec (P = .013) and at 1.5 mL/sec (P = .005). CONCLUSION: Intravenous administration of glucagon before contrast material injection produces greater and more rapid hepatic enhancement in a canine model.

Animals↗
PubMed1995

Interpretation time of serial chest CT examinations with stacked-metaphor workstation versus film alternator.

PURPOSE: Interpretation time of serial staging chest CT cases, which each contained current and previous examinations, with a simple prototype workstation called filmstack was experimentally compared with interpretation time with a film alternator. MATERIALS AND METHODS: The filmstack displayed a "stack" of sections for each examination; user controls allowed rapid selection of preset attenuation windows and both synchronized and unsynchronized scrolling. Eight radiologists were timed as they used the filmstack and the film alternator to interpret four ergonomically complex serial CT cases. RESULTS: All reports dictated on the basis of findings with filmstack and film were of acceptable clinical accuracy. The time to examine a case with filmstack was significantly faster than the time with film, including the time to load and unload the alternator (99% confidence [P = .01]). There was no statistically significant difference in interpretation time between filmstack and prehung film. CONCLUSION: Use of a low-cost stacked CT workstation with a single 1,024 x 1,024 monitor is an effective means of interpreting cases that require comparison of multiple CT examinations.

Computer Systems↗
PubMed1994

Abdominal CT findings in sarcoidosis: radiologic and clinical correlation.

PURPOSE: To estimate the prevalence of abdominal computed tomographic (CT) findings in sarcoidosis and to correlate these findings with those at chest radiography, clinical status, and level of angiotensin converting enzyme (ACE). MATERIALS AND METHODS: Abdominal CT examinations in 59 patients with sarcoidosis were evaluated for adenopathy, liver and spleen size, and discrete lesions within the liver or spleen. RESULTS: Extensive adenopathy was seen in 10% of patients. Marked hepatic and splenic enlargement was seen in 8% and 6%, respectively. Nodules were seen in the spleen in eight (15%) patients and in the liver in three (5%). Although liver size, spleen size, and adenopathy were directly related (P < .0001), the presence of nodules was not strongly related to organ size. Abdominal CT findings were related to clinical status and elevated ACE levels but not to chest radiographic stage. CONCLUSION: Marked abdominal CT findings are uncommon in sarcoidosis and correlate with disease activity but not chest radiographic stage.

Abdomen↗
PubMed1994

Hypervascular malignant liver lesions: comparison of various MR imaging pulse sequences and dynamic CT.

PURPOSE: To compare the appearance of hypervascular liver lesions on gadolinium-enhanced fast low-angle shot (FLASH) imaging with T2-weighted fat-suppressed spin-echo imaging, dynamic nonequilibrium-phase FLASH imaging, and dynamic nonequilibrium-phase iodine-enhanced computed tomography (CT) and to characterize the appearance of lesions on serial postgadolinium FLASH images. MATERIALS AND METHODS: Twenty-nine patients with hypervascular malignant liver lesions were examined with dynamic contrast-enhanced CT and magnetic resonance (MR) imaging within a 1-month interval. MR sequences included T2-weighted fat-suppression, precontrast FLASH, and postgadolinium FLASH at 1 second (sinusoid phase), 45 seconds (nonequilibrium phase), and 10 minutes. RESULTS: More than five lesions were detected in 12 patients with CT, 15 patients with T2-weighted fat-suppression imaging, 16 with sinusoid-phase FLASH imaging, and 11 with nonequilibrium-phase FLASH imaging. In six patients, a statistically significant (P = .03) increase in the number of lesions detected, by category, was observed on sinusoid-phase FLASH images compared with CT images. CONCLUSION: Sinusoid-phase FLASH imaging is superior to nonequilibrium-phase imaging with MR or CT for the demonstration of hypervascular malignant lesions.

Adolescent↗
PubMed1993

High-resolution computer display of portable, digital, chest radiographs of adults: suitability for primary interpretation.

OBJECTIVE: The suitability of using a high-resolution computer-display system for primary interpretation of adult chest radiographs obtained with portable apparatus and storage phosphor technology was evaluated with receiver operating characteristic analysis and subjective methods. MATERIALS AND METHODS: Sixty portable digital chest radiographs showing abnormalities that approached the resolution limits of our computed radiography system were selected. The original digital data making up the 2140 x 1760 x 10 bit images were transferred to a cathode ray tube (CRT) display system composed of two Megascan monitors. Postprocessing rendered two images, one for each monitor, to emulate the two-on-one hard-copy format produced by the computed radiography system. Each image set was interpreted independently by three radiologists experienced with hard-copy format. Limited level and window adjustments were allowed during CRT interpretation. For both CRT and hard-copy display, images were graded on the basis of the interpreter's confidence in the presence of pneumothorax and parenchymal abnormalities. Three types of foreign devices were subjectively analyzed: endotracheal tubes, nasogastric tubes, and temporary epicardial pacer wires. RESULTS: No significant differences were found in detecting pneumothorax or focal infiltrates. One radiologist found the hard copy better for detecting diffuse infiltrates (p = .02); two radiologists favored CRT for visualizing nasogastric tubes (p < .005, p < .02); and one radiologist favored CRT for visualizing temporary epicardial pacer wires (p = .05). CONCLUSION: We conclude that an optimized high-resolution CRT system is quite promising for primary interpretation of digital portable chest radiographs, but further investigation and greater statistical power are necessary to confirm our results.

Adult↗
PubMed1992

Pulmonary nodular opacities after transbronchial biopsy in patients with lung transplants.

Focal nodular opacities were seen on 26 of 74 (35%) postbiopsy radiographs obtained in 39 patients who underwent lung transplantation. The subsequent clinical course and diagnostic evaluation suggested that the opacities were due to focal hemorrhage at the biopsy sites. This finding was evident on only three of 40 (8%) postbiopsy radiographs obtained in 40 control patients who underwent transbronchial biopsy for diffuse interstitial lung disease. The differential diagnosis of new pulmonary nodular opacities in lung transplantation patients should include focal postbiopsy hematomas, because of their relatively frequent occurrence in this clinical situation.

Adult↗