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PubMed2001

Radiation dose to the lens in sequential and spiral CT of the facial bones and sinuses.

A tendency for over-utilization of the radiological examinations of facial bones and sinuses has been observed. The radiosensitive lens is exposed to radiation during such examination. Comparison of routine roentgenography and spiral axial and coronal CT in sequential and spiral acquisition modes with different mAs values was undertaken using Alderson Rando Phantom. The spiral-CT technique with pitch 1.5 performed in the coronal plane gave the lowest radiation dose to the lens as compared with other CT methods and only seven times higher than routine sinus roentgenography.

Humans↗

PubMed1998

Pulmonary circulatory parameters as indices for the early detection of acute rejection after single lung transplantation.

We investigated the relationship between the changes in the pulmonary blood flow and histology during acute rejection following single lung transplantation. In single lung transplantation using adult mongrel dogs, immunosuppression with cyclosporine and azathioprine was discontinued after postoperative day 14 to induce rejection. Doppler flow probes were placed adjacent to the ascending aorta and the left pulmonary artery to measure the blood flow on a daily basis. In addition, chest roentgenograms were also examined daily. The pulmonary pressure was measured using a Swan-Ganz catheter prior to and following the induction of rejection. Open lung biopsies were performed when the left pulmonary artery flow decreased to half of the prerejection value. The pulmonary artery flow decreased to 14.3% of the aortic flow 5 days after the discontinuation of immunosuppression. The graft pulmonary vascular resistance increased significantly compared to the prerejection values (P < 0.001). This was not accompanied by any abnormalities on chest roentgenography. The histology was consistent, with marked perivascular lymphocytic infiltration with little alveolar or interstitial changes. During rejection, the increased pulmonary vascular resistance in the graft was probably the result of perivascular inflammatory cell infiltration, which was seen prior to changes on chest roentgenography. Changes in the left pulmonary artery flow and histology thus appear to be closely correlated in the early stages of acute rejection.

Animals↗

PubMed2000

Histological study of articular cartilage in experimental rat knee arthritis induced by intracapsular injection of cationic polyethyleneimine.

Degeneration of proteoglycans and abnormalities in their metabolism have been assumed to be critical at an early stage of osteoarthritis. To clarify a trigger mechanism of osteoarthritis, anionic sites of knee articular cartilage were blocked by intracapsular injection of cationic polyethyleneimine of 2000 or 70,000 molecular weight (MW) into rat knee joints. Experimental or normal rats were examined by gross observation, roentgenography, cytokine interleukin-1beta (IL-1beta) assay, and light or electron microscopy. In both groups with the polyethyleneimine injection, the rats showed temporarily limping and swelling of their knee joints. By light or electron microscopic studies, knee articular cartilage was found to be degenerated at an early stage, but IL-1beta was within normal levels. At 2, 4, or 6 months, the deformity of the knee joints was obvious by roentgenography. Degeneration and hypofunction of proteoglycans might be related to the ultrastructural changes of articular cartilage at an early stage, though the inflammatory cytokine was not involved. At later stages the pathophysiology of the knee joints advanced chronically to typical osteoarthritis, which was more radically induced by the large molecular polyethyleneimine (70,000 MW). The functional impairment of anionic sites is a key point for elucidating the mechanism of osteoarthritic development in this animal model.

Animals↗

PubMed2002

Postoperative follow-up of patients with early breast cancer: reappraisal of serum tumor markers.

The purpose of this study was to determine the most appropriate tests and procedures to detect disease progression effectively during the postoperative follow-up of patients with early breast cancer. We reevaluated our current surveillance protocol which involves the intensive follow-up of 643 patients with stage I disease. With the exception of one case of bone metastasis, all cases of recurrence (97%) were suspected from abnormal results detected during surveillance involving physical examination, serial determination of tumor markers, and chest roentgenography. Among 15 patients with asymptomatic distant metastasis, disease recurrence was suspected in 12 (80%) because of increased levels of serum tumor markers. No disease recurrence was detected by routine complete blood counts or automated chemistry studies alone. Our experience indicates that an effective follow-up regimen for patients with early breast cancer may include careful history-taking, physical examination, and the determination of serum tumor markers every 3-6 months for the first 3 years, then less frequently thereafter, and chest roentgenography every 6 months for 5 years, in addition to annual mammography. Serial determination of the tumor markers tumor polypeptide antigen, NCC-ST-439, and either carcinoembryonic antigen or carbohydrate antigen 15-3, seems to be of value for the selection of patients who should undergo radiologic exploration. The health benefits and cost-effectiveness of a follow-up focused on the measurement of serum tumor markers need to be evaluated in large prospective randomized trials.

Adult↗

PubMed1983

Lung transplantation in the rat. III. Functional studies in iso- and allografts.

Recently a microsurgical technique for orthotopic left lung transplantation in the rat was developed. The aim of this study was to investigate the influence of the operation itself and of an unmodified rejection reaction on the function of the transplanted rat lung. Orthotopic left lung transplantation was performed in 59 rats (34 isografts and 25 allografts). Isografts demonstrated a mean left lung perfusion of 23.1% in the first two postoperative weeks. Seven out of the 10 animals, subjected to a repeated scintigraphy 5-10 weeks later, had an increased graft perfusion, resulting in an almost normal mean left lung perfusion of 34.8%. At that time chest roentgenography revealed a good aeration of the grafts, that at autopsy had a normal aspect. Allografts showed an initial mean left lung perfusion (24.6%) similar to the isografts, which, however, declined sharply a few days later (4.3%). At that time chest roentgenography revealed totally opalescent grafts that at autopsy had the hepatized aspect characteristic of lung allograft rejection. These results of isogeneic and allogeneic lung transplantation in the rat were comparable with those of canine auto- and allotransplantation. For immunogenetic and economical reasons lung transplantation in the rat is a good alternative animal model in lung transplantation research.

Animals↗

PubMed1992

Roentgenographic changes after arthroscopic meniscectomy: five-year follow-up in patients more than 45 years old.

Fifty knees with a mean follow-up time of greater than 5 years after arthroscopic meniscectomy were evaluated clinically and roentgenographically. Clinically, patients did well, with 98% patient satisfaction and 90% good or excellent results based on a modified Lysholm score. Although postoperative roentgenography showed some progression of Fairbank's changes in 61% with significant progression in 15% of knees, when changes in the nonoperative knee were considered, only 40% of operative knees showed progression, with only 4% of these knees showing significant progression. Normal results on preoperative anteroposterior roentgenography with the patient weight bearing and an anatomic tibiofemoral axis of greater than or equal to 4 degrees of valgus correlated with better long-term roentgenographic results.

Age Factors↗

PubMed1982

Lung transplantation in the rat: II. lung perfusion scintigraphy in normal and left lung-transplanted rats.

Lung perfusion scintigraphy with technetium 99m-labeled microspheres was performed in a series of 14 normal rats. The mean value of left lung perfusion was 36.9 +/- 4.9% of total lung perfusion. Duplicate determinations on three possible error levels were evaluated statistically: (1) separation of the lung fields on the computer scintigram, (2) positioning of the animal under the gamma camera, and (3) measurement after a one-week interval. The determinations resulted in standard deviations of (1) 2.8%, (2) 0, and (3) 1.4%, respectively. These results are comparable with those of lung perfusion studies in dogs. Lung perfusion scintigraphy, chest roentgenography, and postmortem examination were used in the functional evaluation of two groups of left lung-transplanted rats: Group A (n = 12) had short-term follow-up and Group B (n = 11) had long-term follow-up. A common finding in Group A was a subnormally perfused and aerated graft, showing normal lung tissue for the most part at postmortem examination. In Group B, grafts were rarely perfused and aerated. At postmortem examination, they were fibrotic or abscessed, possibly due to chronic rejection. A good correlation was found between perfusion scintigraphy, chest roentgenography, and postmortem findings.

Animals↗

PubMed1996

Calcium oxalate stone morphology: fine tuning our therapeutic distinctions.

PURPOSE: We determined specific radiographic morphological patterns of crystallographically analyzed pure and mixed calcium oxalate dihydrate and calcium oxalate monohydrate urinary calculi. MATERIALS AND METHODS: A total of 86 greater than 1 cm. calculi crystallographically analyzed as pure calcium oxalate monohydrate, calcium oxalate dihydrate or admixtures of the 2 types was studied to determine whether various forms of calcium oxalate differed in radiographic morphology. RESULTS: Four distinct radiographic patterns could be identified by plain film roentgenography: group 1--14 patients with smooth edged, homogeneously dense calculi, some with dentate shapes (12 had pure calcium oxalate monohydrate stones), group 2--33 with multinodular calculi with irregular edges and variegated areas of more and less radiodensity (32 had greater than 60% calcium oxalate monohydrate), group 3--33 with a uniform, stippled pattern, often with identifiable radial striations, and with a larger amount of calcium oxalate dihydrate than groups 1 or 2, and group 4--6 with poorly radiodense, loosely aggregated crystals with a lacy structure. CONCLUSIONS: At least 4 patterns of calcium oxalate stones are recognizable by plain film roentgenography. Because the fragility of calcium oxalate calculi is determined by the relative calcium oxalate monohydrate and dihydrate content, pretreatment recognition of these radiographic patterns may affect the selection of a therapeutic modality.

Calcium Oxalate↗

PubMed1998

Pleurotomy, pneumothorax, and surveillance during living donor nephroureterectomy.

OBJECTIVES: To determine the incidence of and risk factors associated with pneumothorax after donor nephroureterectomy and to determine the utility of postoperative chest roentgenography. METHODS: A retrospective review was made of 130 living donor nephroureterectomies performed at one institution (Yale-New Haven Hospital) using an extraperitoneal flank incision. RESULTS: Incidental pleurotomy occurred in 11 cases (8.5%). Rib resection was associated with pleurotomy. Patient age, sex, and side of operation were not associated with pleurotomy. Ten (91 %) of the 11 cases were identified intraoperatively. One unrecognized pneumothorax was identified postoperatively with chest roentgenography; no specific intervention was necessary. CONCLUSIONS: The extraperitoneal flank incision poses a significant risk for pneumothorax. Most pneumothoraces will be recognized intraoperatively. No adverse effects were noted secondary to pneumothorax.

Adolescent↗

PubMed1997

[Anuric renal insufficiency caused by bilateral ureteral lithiasis].

A 73-year-old man was admitted to the ICU for anuria. He reported no history of urinary disease. The abdominal roentgenography and two echographies showed an empty urinary bladder, a right ureteral calculus without dilatation of the urinary tract. Computed tomography demonstrated the presence of a left ureteral stone. Bilateral retrograde ureteroscopy and drainage allowed a rapid recovery. When the abdominal roentgenography and echography cannot explain the occurrence of anuria, the computed tomography, or better the helical CT, can demonstrate the presence of otherwise unrecognized calculi.

Acute Kidney Injury↗

PubMedDate not supplied

CT of calcified chronic aortic dissection simulating atherosclerotic aneurysm.

Calcification along the outermost aspect of the aorta usually means atherosclerotic aneurysm. On occasion, however, this peripheral type calcification is seen in chronic aortic dissection and leads to a misdiagnosis. Conventional chest roentgenography and CT of 50 cases of chronic dissection proven by angiography were reviewed. Four of these cases (8%) showed calcification in the outermost wall of the affected portion of the aorta. Two cases were Stanford type A and the other two cases were type B. In type A cases chest roentgenography showed calcification in the wall of the dilated ascending aorta closely mimicking aneurysm. In type B cases, calcification was in the outer wall of a localized hump in the descending aorta. Computed tomography clearly demonstrated that this peripheral calcification was located in the outermost wall of the false lumen. Review of the pathologic literature shows sporadic reports of such phenomenon and a theory of endothelialization of the false lumen. It is presumed that the endothelialized false lumen may develop atheromatous changes much more rapidly than the true lumen since two of four cases showed calcification only in the wall of the false lumen with the intimal flap and the wall of the true lumen remaining noncalcified.

Aged↗

PubMed1989

Thoracic spine injuries in victims of motorcycle accidents.

Spinal cord injury can be devastating. Cervical spine roentgenography has been recommended in all severe multisystem trauma patients but little attention has been given to the thoracic spine. In a series of 266 motorcycle accident victims, seen over a 42-month period, 13 cases of thoracic spine injury were identified. During this same time interval four cases of cervical spine injury were identified. Eleven of the 13 cases involved a catapulting ejection from the motorcycle and resultant axial loading to the thoracic spine. Thoracic spine injuries are more common in these patients and therefore the thoracic spine should be immobilized until full thoracic spine roentgenography can be carried out.

Accidents, Traffic↗

PubMed1991

Lamina repair and replacement to control laminectomy membrane formation in dogs.

This study examined the efficacy of lamina repair by the use of various techniques to prevent postlaminectomy scar formation in a canine system. Five-level noncontiguous laminectomies were performed on six adult canines. The most caudal (Site 1) was left uncovered and served as the control. Exposed dura at each of the remaining four levels was covered with one of the following: Site 2, free autogenous laminar bone graft; Site 3, polymethylmethacrylate; Site 4, Teflon-Proplast composite; Site 5, collagen gel. The dogs used in the study were killed 16 weeks after surgery. Three specimens were examined by plain roentgenography and computerized tomography, two specimens were examined histologically, and the remaining four specimens were graded according to scar volume and scar adherence, as detected during gross dissection of the postlaminectomy scar. No repair technique interfered with roentgenography evaluation. The least scar and fewest adhesions were present under the free bone graft repair site. The Teflon-Proplast composite and polymethylmethacrylate both limited the amount and adherence of scar. Collagen gel and control sites were indistinguishable in this study. It is concluded that lamina repair with a solid material covering exposed dura significantly reduces the formation of postlaminectomy membrane and scar.

Aluminum Oxide↗

PubMed1986

Lung cancer screening: the Mayo program.

The National Cancer Institute has sponsored three randomized controlled trials of screening for early lung cancer in large, high-risk populations to determine whether lung cancer detection can be improved by adding sputum cytological screening every 4 months to chest roentgenography done either yearly or every 4 months; and lung cancer mortality can be significantly reduced by this type of screening program, followed by appropriate treatment. Results of the three trials suggest that sputum cytology alone detects 15% to 20% of lung cancers, almost all of which are squamous cancers with a favorable prognosis; and chest roentgenography may be a more effective test for early-stage lung cancer than previous reports have suggested. Nevertheless, results of the randomized trial conducted at the Mayo Clinic showed that offering both procedures to high-risk outpatients every 4 months conferred no mortality advantage over standard medical practice that included recommended annual testing.

Clinical Trials as Topic↗

PubMed2004

Can chest roentgenogram predict the posture dependent changes of atrial sensing performance in patients with a VDD pacemaker?

The VDD pacemaker is useful for sequential pacing with a single lead but carries a risk of sensing failure. This study was designed to evaluate the relationship between the relative position of atrial lead and atrial sensitivity in different postures in patients with VDD pacemakers. Atrial sensitivity determination and chest roentgenography was performed in the supine and standing position 3 months after implantation in 25 patients with VDD pacemakers. Measurements of cardiac longitudinal length (from the top of the aortic arch to the diaphragm) and distances from the floating electrode to the upper margin of the seventh thoracic vertebra (D-T7), to the top of the aortic arch (D-knob), to the lateral wall of right atrium (D-wall), and the D-knob/cardiac longitudinal length (D-Ratio) were performed. Atrial signal amplitude decreased with the standing compared to the supine position in eight patients (group I) and increased or did not change in the other 17 patients (group II). In group I, the change of the D-ratio was greater (0.073 vs 0.035, P < 0.01), and the change of the cardiac longitudinal length with standing position was greater (18.4 +/- 7.3 vs 12.1 +/- 8.8 mm, P < 0.05) than in group II. The change of atrial sensitivity was related to the change of the atrial electrode position with different postures. Decreased atrial-sensed amplitude was observed in patients who had a greater change in the cardiac longitudinal length while standing. Thus, a decrease in atrial sensitivity with standing may be predicted by the positional changes of the cardiac silhouette on roentgenography before the procedure.

Atrial Function↗

PubMed1981

Radiation exposure to the child during cardiac catheterization.

Few data are available regarding radiation exposure to children during cardiac catheterization. Using lithium fluoride thermoluminescent dosimeters, radiation exposure was measured during precatheterization chest roentgenography, fluoroscopy (hemodynamic assessment phase of catheterization) and cineangiography in 30 infants and children, ages 3 days to 21 years. Dosimeters were placed over the eyes, thyroid, anterior chest, posterior chest, anterior abdomen, posterior abdomen and gonads. Average absorbed chest doses were 24.5 mR during chest roentgenography, 5810 mR during catheterization fluoroscopy and 1592 mR during cineangiography. During the complete catheterization, average doses were 26 mR to the eyes, 431 mR to the thyroid area, 150 mR to the abdomen and 11 mR to the gonads. Radiation exposure during pediatric cardiac catheterization is low to the eyes and gonads but high to the chest and thyroid area. To decrease radiation dosage we suggest (1) low pulse-rate fluoroscopy; (2) substitution of contrast echocardiography for cineangiography; (3) large-plate abdominal/gonadal shielding; (4) a selective shield for thyroid area; (5) a very small field during catheter manipulation. Minimum radiation consistent with accurate diagnosis is optimal; however, erroneous or incomplete diagnosis is more dangerous than radiation-related hazards.

Adolescent↗

PubMed1984

Early lung cancer detection: results of the initial (prevalence) radiologic and cytologic screening in the Johns Hopkins study.

The Johns Hopkins Lung Project was designed to determine whether the addition of cytologic screening to the radiographic screening of high-risk volunteers could enhance the early detection of asymptomatic lung cancer and whether early therapeutic intervention in detected cases could significantly reduce the mortality from this disease. Male volunteers, 45 yr of age and older, who smoked at least 1 pack of cigarettes per day were recruited from the Baltimore metropolitan area. All of the 10,387 acceptable high-risk volunteers received annual chest radiographic screening. By random assignment, one half received cytologic examination of induced sputum in addition to the roentgenogram. This report describes the results of the initial screening. Compared with usual methods of clinical diagnosis, screening by both roentgenography and cytology identified a greater proportion of the lung cancer cases at an earlier stage. Screening by sputum cytology was found to improve the detection only of squamous cell carcinoma. In the dual-screen group, sputum cytology accounted for 28% of the detected cases, and resulted in 39% additional detection of lung cancer over that achieved by roentgenography. There was no corresponding decrease in prevalence. Lung cancers detected by cytology alone were found at very early stages. Although there has been an increase in average survival, much of this increase, if not all, may have resulted from lead-time and sampling bias.

Adenocarcinoma↗

PubMed1999

Pneumonia in febrile neutropenic patients and in bone marrow and blood stem-cell transplant recipients: use of high-resolution computed tomography.

PURPOSE: To obtain statistical data on the use of high-resolution computed tomography (HRCT) for early detection of pneumonia in febrile neutropenic patients with unknown focus of infection. MATERIALS AND METHODS: One hundred eighty-eight HRCT studies were performed prospectively in 112 neutropenic patients with fever of unknown origin persisting for more than 48 hours despite empiric antibiotic treatment. Fifty-four of these studies were performed in transplant recipients. All patients had normal chest roentgenograms. If pneumonia was detected by HRCT, guided bronchoalveolar lavage was recommended. Evidence of pneumonia on chest roentgenograms during follow-up and micro-organisms detected during follow-up were regarded as documentation of pneumonia. RESULTS: Of the 188 HRCT studies, 112 (60%) showed pneumonia and 76 were normal. Documentation of pneumonia was possible in 61 cases by chest roentgenography or micro-organism detection (54%) (P < 10(-6)). Sensitivity of HRCT was 87% (88% in transplant recipients), specificity was 57% (67%), and the negative predictive value was 88% (97%). A time gain of 5 days was achieved by the additional use of HRCT compared to an exclusive use of chest roentgenography. CONCLUSION: The high frequency of inflammatory pulmonary disease after a suspicious HRCT scan (> 50%) proves that pneumonia is not excluded by a normal chest roentgenogram. Given the significantly longer duration of febrile episodes in transplant recipients, HRCT findings are particularly relevant in this subgroup. Patients with normal HRCT scans, particularly transplant recipients, have a low risk of pneumonia during follow-up. All neutropenic patients with fever of unknown origin and normal chest roentgenograms should undergo HRCT.

Adult↗