Are screening serum creatinine levels necessary prior to outpatient CT examinations?

PURPOSE: To determine the percentage of outpatients with elevated serum creatinine levels (>/=2.0 mg/dL [177 micromol/L]) and associated reported risk factors for contrast material-induced nephrotoxic reactions (eg, diabetes, renal disease, male, age >/= 60 years, chemotherapy) who undergo computed tomography (CT) and to define a true high-risk population. MATERIALS AND METHODS: The serum creatinine levels were obtained in a total of 2,034 consecutive outpatients (969 male, 1,065 female) who underwent contrast material-enhanced CT. In addition, selected patient charts were reviewed to determine the presence of risk factors for contrast material-induced nephrotoxic reactions. RESULTS: Only 66 (3.2%) had an elevated serum creatinine level. Risk factors were identified in 64 of the 66 (97%) patients with an elevated serum creatinine level. Renal disease was present in 62 of the 66 (94%) patients. Two of the 66 patients with an elevated creatinine level had no identifiable risk factors, representing 0.1% of the total number of patients. CONCLUSION: The data suggest that the majority of patients with a serum creatinine level of at least 2.0 mg/dL (177 micromol/L) will be identified by screening for risk factors. Careful patient screening, especially for renal disease, at the time of scheduling could result in considerable savings in terms of radiology man-hours expended and laboratory costs.

Outcome of examinations self-referred as a result of spiral CT of the abdomen.

RATIONALE AND OBJECTIVES: The interpretation of an abdominal computed tomographic (CT) scan is occasionally inconclusive. In many of these cases, the radiologist suggests an additional imaging test for further confirmation or clarification. The purpose of this study was to evaluate the outcome of self-referral by the radiologist after abdominal CT scanning. MATERIALS AND METHODS: Reports from 545 consecutive abdominal CT scans were reviewed to track recommendations for additional imaging. In patients who underwent the additional work-up, a determination of the effect of the study was attempted. In patients who did not, explanations were sought. Wording of the recommendations was also recorded. RESULTS: Recommendations were made for additional imaging studies in 105 (19.3%) patients. Of these, 32 (30.5%) were performed and 31 (96.9%) were helpful by confirming malignancy (n = 5), confirming a benign process (n = 24), or being therapeutic (n = 2). In one, no information was added. There were 63 (60.0%) patients who did not undergo the recommended studies. Reasons included "no clinical indication" (n = 51), alternative study performed (n = 9), or study previously performed (n = 3). In eight (7.6%) patients the chart provided insufficient information about whether the patient underwent the study, and in two (1.9%) the chart was unavailable. Wording of the recommendation had no effect on whether the study was performed (P > .05). CONCLUSION: Although interpretation of abdominal CT scans leads to recommendations for additional imaging in a minority of cases, these recommendations were infrequently followed. When followed, however, the findings from the recommended studies were usually helpful. Better clinical information is perhaps the best way to reduce self-referral by radiologists.

Imaging and radiologic management of upper urinary tract infections.

Most infections of the upper urinary tract respond promptly to antibiotic therapy and imaging is not necessary. Patients with urinary obstruction, diabetes, or immunocompromise are more likely to develop complicated infection, abscess, or have unusual organisms. Chronic granulomatous processes involving the kidney are usually related to recurrent bacterial infections. Again, stone disease or obstruction is often an underlying problem. In those patients who do not respond promptly to treatment or have a more complicated clinical picture, imaging can assess the severity and extent of disease. CT scan is the study of choice for diagnostic evaluation in these patients and directs percutaneous intervention when appropriate. Placement of drainage catheters is often curative but also may allow the patient to stabilize until surgical treatment is accomplished. One exception is the diagnosis of pyonephrosis, which may be accomplished more easily by ultrasound. In these cases, PCN placement is generally needed and is performed under fluoroscopic guidance. Ultimately, however, definitive surgical intervention often is needed to relieve the underlying obstruction.

Developmental and age-related processes that influence the longevity and senescence of photosynthetic tissues in arabidopsis.

Factors that influence the longevity and senescence of photosynthetic tissues of Arabidopsis were investigated. To determine the influence of reproductive development on the timing of somatic tissue senescence, the longevity of rosette leaves of the Landsberg erecta strain and of isogenic mutant lines in which flowering is delayed (co-2) or sterile flowers are produced (ms1-1) were compared. No difference in the timing of senescence of individual leaves was observed between these lines, indicating that somatic tissue longevity is not governed by reproductive development in this species. To examine the role of differential gene expression in the process of leaf senescence, cDNA clones representing genes that are differentially expressed in senescing tissues were isolated. Sequence analysis of one such clone indicated homology to previously cloned cysteine proteinases, which is consistent with a role for the product of this gene in nitrogen salvage. RNA gel blot analysis revealed that increased expression of senescence-associated genes is preceded by declines in photosynthesis and in the expression of photosynthesis-associated genes. A model is presented in which it is postulated that leaf senescence is triggered by age-related declines in photosynthetic processes.

Hepatocellular carcinoma: CT appearance after percutaneous ethanol ablation therapy. Work in progress.

Nine patients with biopsy-proved hepatocellular carcinoma underwent percutaneous ethanol ablation therapy (PEAT) with computed tomographic (CT) guidance. Twenty-five ablation sessions were performed in nine lesions ranging in size from 1.8 to 6.5 cm. Repeat biopsy was performed in seven of those nine lesions between 1 and 2 months after completion of therapy. CT scans obtained immediately after ablation demonstrated a necrotic area equal in size to the target lesion in five patients; four of those five patients have had negative findings at biopsy and are free of known disease. None of the patients with CT evidence of limited necrosis are currently free of disease. Peripheral nodularity was demonstrated after ablation in three patients at CT; none are free of disease. All four patients in whom there was no peripheral nodularity are free of known disease. Thus, CT evidence of necrosis and lack of nodularity immediately after PEAT are suggestive of absence of disease.

Prognostic factors for gastrointestinal and bronchopulmonary carcinoid tumors.

Data collected by population-based cancer registries in Iowa and metropolitan Atlanta were evaluated to determine prognostic factors for gastrointestinal (n = 270) and bronchopulmonary (n = 151) carcinoids. The predictors considered in univariate and multivariate analyses were: age, sex, race, marital status, anatomic subsite, stage, occurrence of other malignancies, and surgery. For surgically treated gastrointestinal tumors, the cumulative percentages of survivors at five years were: appendix, 85.6%; small intestine, 66.0%; and large intestine, 37.7%. The likelihood of death from gastrointestinal carcinoids was found to be related independently to increasing age (P = 0.001), advanced stage (P less than 0.0001), location within the large intestine (P less than 0.0001), and occurrence of another malignancy (P = 0.02). The overall five-year survival rate for bronchopulmonary carcinoids was 87.6%, and lack of surgical treatment (P less than 0.0001) and advanced stage (P = 0.006) were associated independently with unfavorable prognosis.