SEARCH · PubMed Health

Results for “Nomogram”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed2006

How far is the preoperative Kattan nomogram applicable for the prediction of recurrence after prostatectomy in patients presenting with PSA levels of more than 20 ng/ml? A validation study.

OBJECTIVE: We present an external validation study investigating the applicability of the preoperative Kattan nomogram for predicting recurrence after prostatectomy in a population of patients with serum prostate-specific antigen (PSA) levels exceeding 20 ng/ml. MATERIALS: In the evaluation of clinical parameters pooled from a total of 191 patients presenting with PSA levels ranging between 20.1 and 100 ng/ml, the PSA-free survival rate 60 months after surgery was calculated according to Kattan nomograms. Subsequently, the results were statistically compared with the corresponding actual survival rates obtained from Kaplan-Meier analysis. For this purpose, the patients were assigned to one of four different risk groups according to predictions derived from the Kattan nomograms, enabling a direct comparison of expected (as predicted by Kattan nomogram) versus actual survival of each patient investigated in our study. RESULTS: Predicted PSA-free survival rates were determined to be as follows: 83% (low risk group); 66% (intermediate risk group); 39% (intermediate-high risk group), and 10% (high risk group) in comparison with the actual survival rates determined to be 63, 62, 40 and 21%, respectively. For PSA levels ranging between 20.1 and 30 ng/ml, 30.1 and 50 ng/ml, and 50.1 and 100 ng/dl, PSA-free survival rates were found to be 57, 37, and 27% (p=0.0017), respectively, during a 5-year post-prostatectomy follow-up. CONCLUSIONS: The Kattan nomogram shows good statistical concordance with actual survival rates in the mean risk quadrants, but considerable differences were demonstrated concerning individuals with either a high or with a low risk of cancer progression.

Aged↗

PubMed2005

Can the Memorial Sloan-Kettering Cancer Center nomogram predict the likelihood of nonsentinel lymph node metastases in breast cancer patients in the Netherlands?

BACKGROUND: According to Dutch guidelines, an axillary lymph node dissection (ALND) is recommended whenever a sentinel lymph node (SLN) contains metastatic disease. However, only in approximately 50% of patients with metastatic disease in the SLN are additional nodal metastases detected in the completion ALND. To identify the individual patient's risk for non-SLN metastases, a nomogram containing eight predictors was developed by the Breast Service of Memorial Sloan-Kettering Cancer Center (New York, NY). The aim of this study was to test the accuracy of the nomogram on a population of Dutch breast cancer patients. METHODS: Patient, tumor, and SLN metastasis characteristics were collected for 222 consecutive patients who underwent a completion ALND. The data of the index and test populations were compared. A receiver operating characteristic curve was drawn, and the area under the curve was calculated to assess the discriminative power of the nomogram. RESULTS: Even though our patient population differed in many respects from the source population, the area under the receiver operating characteristic curve amounted to .77, a value very much comparable to the one found in the source population. CONCLUSIONS: The nomogram provides a fairly accurate predicted probability for the likelihood of non-SLN metastases in a general population of breast cancer patients at a regional teaching hospital in The Netherlands. This suggests that the nomogram's originally calculated predictive accuracy may be valid for patient populations that differ considerably from the population in which it was developed.

Breast Neoplasms↗

PubMed2006

Nomogram prediction for prostate cancer and aggressive prostate cancer at time of biopsy: utilizing all risk factors and tumor markers for prostate cancer.

BACKGROUND: There is a large amount of confusion in interpreting prostate specific antigen (PSA) values for prostate cancer. More precise risk assessments for prostate cancer detection are needed for men faced with an abnormal PSA. METHODS: We studied a sample of 2,637 men who underwent a prostate biopsy for an abnormal digital rectal exam (DRE) or PSA. Using factors including age, ethnicity, family history of prostate cancer, previous negative biopsy, presence of voiding symptoms, prostate volume, DRE and PSA, we constructed nomograms to predict the probability of prostate cancer at biopsy. RESULTS: Of the 2,637 men, 1,282 men (48.6%) had prostate cancer detected. Age, ethnicity, family history of prostate cancer, a previous negative biopsy, prostate volume, DRE and PSA were all significant predictors of prostate cancer. Nomograms were constructed based on these factors to predict the risk of prostate cancer and of aggressive prostate cancer (defined as a Gleason Score 7 or more). The positive predictive value varied from 5% to 95% based on the nomograms. The nomograms were validated using bootstrapping methods and the expected and observed proportions were found to be highly concordant. CONCLUSIONS: For men with an abnormal PSA or DRE, the risk for prostate cancer can be accurately estimated using a nomogram based on age, ethnicity, family history of prostate cancer, previous negative biopsy, presence of voiding symptoms, prostate volume, DRE and PSA. This tool will aid physicians and patients in determining the need for prostate biopsy.

Adult↗

PubMed1995

The Abrams-Griffiths nomogram.

The treatment of benign prostatic hyperplasia and the definition of bladder-outlet obstruction has preoccupied urologists and researchers in recent years. Bladder-outlet obstruction can be defined only by pressure-flow measurement. Various methods of analysis of pressure-flow data have been proposed. The Abrams-Griffiths nomogram is an easy method of classifying these data to distinguish between the presence or absence of obstruction. Using the values for the maximal flow and the corresponding voiding detrusor pressure a point can be plotted on the nomogram that determines whether the bladder outlet is obstructed, unobstructed, or equivocally obstructed. For those that fall in the equivocal zone, further criteria for the mean slope of the pressure-flow plot and the minimal voiding detrusor pressure are used to determine whether there is obstruction or not. The nomogram's prognostic value in predicting the outcome of prostatectomy has been studied and found to be excellent. The Abrams-Griffiths nomogram can be modified by assigning an Abrams-Griffiths number to each set of pressure-flow data. This number is easy to calculate and use and gives a continuous variable that can be used to evaluate the effects of therapy. Although the Abrams-Griffiths nomogram and number are somewhat simplistic, none of the more complex methods of pressure-flow analysis have been shown to be better predictors of treatment outcome to date.

Data Interpretation, Statistical↗

PubMed1976

Acid-base curve nomogram for dog blood.

Pooled canine blood of different hemoglobin concentration was equilibrated with two carbon dioxide tensions and the resulting pH's of the samples were measured at 38 degrees C. Readings obtained provided data for the construction of a cartesian nomogram for the dog, based on the pH/log pCO2 coordinate system. The nomogram can be used to evaluate both respiratory and non-respiratory acid-base parameters. For contrast, a control nomogram on human blood was also constructed. Both nomograms show broad similarity. This is to be expected as the normal criteria used to define base excess relating to dog blood are the same as those used for human blood. Nonetheless, base excess and buffer base calculations using the nomogram for the dog and that for man show a deviation of 2.5-10%, and we consider this deviation to be more due to a species difference than to any summated experimental error.

Acid-Base Equilibrium↗

PubMed2006

Nomograms of total renal volume, urinary bladder volume and bladder wall thickness index in 3,376 children with a normal urinary tract.

BACKGROUND: We have previously shown that urinary bladder volume index (BVI = length x width x depth of bladder) and bladder volume wall thickness index (BVWI = BVI at full bladder/average bladder wall thickness) are useful indicators of bladder dysfunction in children with enuresis and urinary tract infection. These indices show a good correlation with urodynamic studies. We have expanded the study to include normal paediatric subjects with a wide age range. We illustrate a simple sonography protocol with nomograms of different parameters, which provide useful references for functional assessment in children with urological abnormalities. OBJECTIVE: To construct nomograms of total renal volume, maximum BVI and BVWI based on a Chinese paediatric population with age range from newborn to adolescence. MATERIALS AND METHODS: Sonography was performed in consecutive children with normal urinary tracts on imaging, using a standardized protocol. Data were collected for construction of nomograms for different parameters. RESULTS: Nomograms of total renal volume, BVI and BVWI were constructed based on 3,376 consecutive paediatric subjects. All parameters consistently increased with age. CONCLUSION: Nomograms of total renal volume, BVI and BVWI could provide useful references for studying bladder dysfunction in children using noninvasive dynamic sonography.

Adolescent↗

PubMed1993

Nomogram based on metabolic equivalents and age for assessing aerobic exercise capacity in men.

OBJECTIVES: The goal of this study was to create a nomogram, based on maximal exercise capacity (in metabolic equivalents [METs]) and age, for assessing a patient's ability to perform dynamic exercise to quantify the level of physical disability or relative capacity for physical activity. BACKGROUND: Providing an estimation of exercise capacity relative to age is clinically useful. Such an estimate can be derived from measured or estimated maximal oxygen uptake (in METs) from treadmill exercise testing and age. It is an effective means of communicating to patients their cardiopulmonary status, encouraging improvement in exercise capacity and quantifying disability. METHODS: Exercise test results of 1,388 male patients (mean age 57 years, range 21 to 89) free of apparent heart disease who were referred for exercise testing for clinical reasons were retrospectively reviewed. This referral group as well as subgroups of active (n = 346) and sedentary (n = 253) patients were analyzed to determine norms for age and for age by decades for exercise test responses, including METs, maximal heart rate and maximal systolic blood pressure. Regression equations were calculated from this information, and a nomogram for calculating degree of exercise capacity from age and MET level achieved by a patient was created. A similar analysis was performed in a separate group of 244 apparently healthy, normal male volunteers (mean age 45 +/- 14 years, range 18 to 72) who underwent exercise testing with direct measurement of expired gases. RESULTS: Equations for predicted METs for age were derived for the entire clinical referral group (METs = 18.0-0.15[Age]) and for the subgroups of active (METs = 18.7-0.15[Age]) and sedentary (METs = 16.6-0.16[Age]) patients. All results achieved statistical significance, with p values < 0.001. In the volunteer group of normal men who performed exercise testing with ventilatory gas exchange, the decline in maximal heart rate and METs with age was not as steep as in the referral group. Although the normal group confirmed nomograms published previously among similar subjects, the equations derived from the patients differed from those previously reported; in contrast to previous studies using healthy volunteers, the equations and nomograms for the referral group are more appropriate for patients typically referred for testing in a hospital or office-based internal medicine practice. CONCLUSIONS: Norms for METs based on age are presented as well as population-specific nomograms that enable physicians to assess patients' exercise capacity relative to their age group.

Adult↗

PubMed2006

Evaluation of an existing nomogram for predicting the response to clomiphene citrate.

OBJECTIVE: To evaluate the ability of an existing nomogram to predict response to clomiphene citrate (CC) in infertile couples with World Health Organization group II ovulatory disorders, using the free androgen index, body mass index, and menstrual-cycle history. DESIGN: Retrospective case-notes study. SETTING: Reproductive medicine and fertility center at a university teaching hospital in the United Kingdom. PATIENT(S): One hundred four anovulatory women. INTERVENTION(S): One hundred four anovulatory women who had been treated with CC were studied retrospectively. Age, body mass index, free androgen index, and cycle history were used to assign a likelihood of response for each patient on the basis of a published nomogram. Predicted and observed responses were compared. MAIN OUTCOME MEASURE(S): Ovulation rate. RESULT(S): The diagnostic characteristics of the model on the basis of the optimal cutoff points were as follows: sensitivity, 96% (95% confidence interval [CI]: 90%-99%); specificity, 33% (95% CI: 18%-49%); positive predictive value, 73% (95% CI: 63%-82%); negative predictive value, 80% (95% CI: 60%-99%); likelihood ratio for ovulation, 1.34 (95% CI: 1.1-1.8); likelihood ratio for resistance, 0.13 (95% CI: 0.04-0.43); kappa, 0. 26 (95% CI: 0.09-0.44). CONCLUSION(S): The accurate prediction of response to CC would allow more rapid transfer of nonresponders to alternative treatments and may shorten the treatment to pregnancy interval. Although the current nomogram could identify 80% of nonresponders to CC, it was insufficiently accurate for use in the present clinical setting. Moreover, the nomogram could not identify the most appropriate dose to achieve ovulation. This nomogram should be tested on patients in other clinical settings, where it may perform better.

Body Mass Index↗

PubMed2003

Predicting clinical end points: treatment nomograms in prostate cancer.

Due to the generally indolent nature of prostate cancer, patients must decide among a wide range of treatments, which will significantly affect both quality of life and survival. Thus, there is a need for instruments to aid patients and their physicians in decision analysis. Nomograms are instruments that predict outcomes for the individual patient. Using algorithms that incorporate multiple variables, nomograms calculate the predicted probability that a patient will reach a clinical end point of interest. Nomograms tend to outperform both expert clinicians and predictive instruments based on risk grouping. We outline principles for nomogram construction, including considerations for choice of clinical end points and appropriate predictive variables, and methods for model validation. Currently, nomograms are available to predict progression-free probability after several primary treatments for localized prostate cancer. There is need for additional models that predict other clinical end points, especially survival adjusted for quality of life.

Algorithms↗

PubMed2003

Is intraoperative nomogram-based overplanning of prostate implants necessary?

PURPOSE: Several investigators have described intraoperative planning of prostate implants based on a nomogram. The aim of this work was to investigate the adequacy of the nomogram in predicting the total activity necessary for optimal dosimetry. METHODS AND MATERIALS: Eighty CT-based postimplant treatment plans were performed for patients who underwent ultrasound guided I-125 permanent implants alone between April 2000 and March 2001. The cohort of 40 patients had early stage (T1-T2) prostatic carcinoma and pre-treatment prostate volumes of 19-50 cc. I-125 seeds (0.391 mCi/seed) were implanted to achieve a distribution of 75% of the activity peripherally and 25% centrally. The CT studies were obtained on the day of (CT1) and at 1 month (CT2) after implant. All patients were catheterized at CT1, and 28 patients were catheterized at CT2 to visualize the urethra. For each patient, the percentage difference (dA) between the total implanted and nomogram predicted activity for a known prostate volume was calculated. The V200 (volume receiving 200% of the prescribed dose), V150, V100, V90, D100 (maximum dose received by 100% of the volume), D90, and D80 were measured for the prostate at CT1 and CT2. For the urethra, V275, V250, V200, and V150 were evaluated, and V100 and V70 were evaluated for the rectum. The Pearson test was used to correlate the dosimetric parameters with dA. Linear regression was used to fit the correlation of the volume and dose parameters with dA. RESULTS: The median V100 at CT1 and CT2 was 91.8% and 94.2%, respectively. The Pearson test was significant for the prostate V100 and dA measured at CT1 (p = 0.005) but not at CT2 (p = 0.106). A similar correlation was found for the prostate D90 at CT1 (p = 0.002), but not at CT2 (p = 0.076). D100 (maximum dose received by 100% of volume) for prostate did not correlate with dA at CT1 (p = 0.094) and CT2 (p = 0.148). The volume of the prostate receiving higher doses (greater than 150% and 200% of the prescribed dose) correlated with dA. There were no significant correlations between V275, V250, V200, and V150 at CT1 and CT2 as a function of dA for the urethra. V100 and V70 for the rectum correlated significantly with dA; for V100, p = 0.041 at CT1 and p = 0.014 at CT2 and for V70, p = 0.041 at CT1 and p = 0.026 at CT2. A linear regression model fitted to the prostate data obtained from CT1 with the goal of achieving a V100 of 90% and D90 of 145 Gy suggests that no increase in the number of seeds may be warranted using intraoperative planning. The implants examined showed no concomitant increase of urethral doses with increase in activity relative to the nomogram, but showed an increase in the rectal doses for the same increase in activity. CONCLUSION: The doses evaluated at CT1 represent an underestimate, whereas those obtained at CT2 represent an overestimate of the actual delivered protracted permanent implant dose. Based on these results and consideration of the dynamic nature of the dose distribution, target coverage obtained with intraoperative planning using the nomogram predicted activity is consistent with published guidelines for a quality implant and critical structure doses are within tolerance.

Brachytherapy↗

PubMed1982

Nomogram for 2-deoxyglucose lumped constant for rat brain cortex.

The quantitation of local cerebral metabolic rate of glucose with the 2-deoxyglucose technique of Sokoloff requires the use of a correction factor, or lumped constant. We have shown previously (Pardridge et al., 1982) that a simple model may be formulated to predict changes in the lumped constant that occur due to alterations in the distribution of glucose and 2-deoxyglucose in brain. Given experimentally observed values for brain and plasma glucose concentrations, the 2-deoxyglucose lumped constant may be determined from a nomogram constructed from knowledge of the blood-brain barrier transport constants (KM, Vmax, KD) for glucose and for 2-deoxyglucose. However, the nomogram is constructed from transport constants determined in the barbiturate-anesthetized state. The applicability of the nomogram to other physiologic states was examined in the present studies. Large changes in blood-brain barrier hexose transport constants do not appreciably alter the shape of the nomogram, if the changes in KM or Vmax for glucose or for 2-deoxyglucose are the same. Moreover, glucose and 2-deoxyglucose are both transported by the same hexose carrier, and selective changes in the transport of only one hexose have not been reported. Therefore, it is probable that the nomogram constructed from transport constants measured under barbiturate anesthesia is useful in predicting the lumped constant in a variety of physiologic states.

Animals↗

PubMed2002

Pre-treatment nomogram for biochemical control after neoadjuvant androgen deprivation and radical radiotherapy for clinically localised prostate cancer.

Phase III studies have demonstrated the clinical benefit of adding neo-adjuvant androgen deprivation to radical radiotherapy for clinically localised prostate cancer. We have developed a nomogram to describe the probability of PSA control for patients treated in this way. Five hundred and seventeen men with clinically localised prostate cancer were treated with 3-6 months of neo-adjuvant androgen deprivation and radical radiotherapy (64Gy in 32#) between 1988 and 1998. Median presenting PSA was 20 ng x ml(-1), and 56% of patients had T3/4 disease. Multivariate analysis of pre-treatment factors was performed, and a nomogram developed to describe PSA-failure-free survival probability. At a median follow-up of 44 months, 233 men had developed PSA failure. Presenting PSA, histological grade and clinical T stage were all highly predictive of PSA failure on multivariate analysis. The nomogram score for an individual patient is given by the summation of PSA (<10=0, 10-19=16, 20-49=44, > or =50=100), grade (Gleason 2-4=0, 5-7=44, 8-10=81) and T stage (T1/2=0, T3/4=35). For a nomogram score of 0, 50, 100 and 150 points the 2 year PSA control rate was 93, 87, 75 and 54%, and the 5 year PSA control rate was 82, 67, 44 and 18%. These results are comparable to those using surgery or higher doses of radical radiotherapy alone. The nomogram illustrates the results of multivariate analysis in a visually-striking way, and facilitates comparisons with other treatment methods.

Administration, Oral↗

PubMedDate not supplied

Utility of a weight-based heparin nomogram for patients with acute coronary syndromes.

BACKGROUND: Unfractionated heparin has been pivotal in the management of acute coronary syndromes (ACS), and continues to be used widely despite the emerging role of low molecular weight heparins (LMWH). The apparent superiority of LMWH over unfractionated heparin may, at least partially, reside in its more predictable achievement of therapeutic effect, with high rates of non-therapeutic activated partial thromboplastin time (APTT) results being observed in the intravenous heparin treatment groups. AIM: To evaluate the impact of introduction of a weight-based heparin nomogram developed for use in patients with ACS on frequency of 'therapeutic' APTT results. METHODS: The effectiveness of an existing non-weight-based heparin nomogram in achieving a therapeutic APTT was compared sequentially with that of a weight-based heparin nomogram in 89 and 84 consecutive patients admitted with a diagnosis of ACS. RESULTS: Patients in whom heparin dosage adjustment was weight based rapidly achieved therapeutic APTT. The median time to achieve an APTT within the target range was 8.75 h in the weight-based group versus >24 h in the non-weight-based group. Utilization of a weight-based nomogram was associated with markedly increased proportions of readings within the therapeutic APTT range at 6 h and at 24 h (51%vs. 26% and 72%vs. 36%, respectively). CONCLUSIONS: The current study confirms the marked superiority of the weight-based heparin regimen for treatment of patients with ACS. The nomogram dramatically facilitated the attainment of therapeutic APTT, and may represent the optimal method for titration of heparin dosage to individual heparin requirements in patients with ACS.

Aged↗

PubMed2005

The prognostic value of a nomogram for exercise capacity in women.

BACKGROUND: Recent studies have demonstrated that exercise capacity is an independent predictor of mortality in women. Normative values of exercise capacity for age in women have not been well established. Our objectives were to construct a nomogram to permit determination of predicted exercise capacity for age in women and to assess the predictive value of the nomogram with respect to survival. METHODS: A total of 5721 asymptomatic women underwent a symptom-limited, maximal stress test. Exercise capacity was measured in metabolic equivalents (MET). Linear regression was used to estimate the mean MET achieved for age. A nomogram was established to allow the percentage of predicted exercise capacity to be estimated on the basis of age and the exercise capacity achieved. The nomogram was then used to determine the percentage of predicted exercise capacity for both the original cohort and a referral population of 4471 women with cardiovascular symptoms who underwent a symptom-limited stress test. Survival data were obtained for both cohorts, and Cox survival analysis was used to estimate the rates of death from any cause and from cardiac causes in each group. RESULTS: The linear regression equation for predicted exercise capacity (in MET) on the basis of age in the cohort of asymptomatic women was as follows: predicted MET = 14.7 - (0.13 x age). The risk of death among asymptomatic women whose exercise capacity was less than 85 percent of the predicted value for age was twice that among women whose exercise capacity was at least 85 percent of the age-predicted value (P<0.001). Results were similar in the cohort of symptomatic women. CONCLUSIONS: We have established a nomogram for predicted exercise capacity on the basis of age that is predictive of survival among both asymptomatic and symptomatic women. These findings could be incorporated into the interpretation of exercise stress tests, providing additional prognostic information for risk stratification.

Adult↗

PubMed2004

Nomogram to estimate age-related MAC.

BACKGROUND: In clinical practice it is difficult to estimate rapidly two important values: (i) the total age-corrected MAC multiple from measured end-expired concentrations of volatile agent and nitrous oxide; (ii) the end-expired concentration of volatile agent needed to obtain a given total MAC multiple. We have developed a nomogram to do this. METHODS: We used standard nomogram methods to construct one single nomogram covering wide ranges of age (1-100 yr) and MAC (0.1-1.8 MAC) for halothane, enflurane, isoflurane, sevoflurane, and desflurane, alone or in combination with various concentrations of nitrous oxide. The user only has to draw two straight lines to obtain the desired result. RESULTS: The nomogram is simple to use. End-expired concentrations of halothane 0.48%, enflurane 1.05%, isoflurane 0.75%, sevoflurane 1.18%, or desflurane 4.3% in the presence of nitrous oxide 50% will give 1.4 MAC in a patient of 75 yr vs 0.9 MAC in a 1-yr-old. A reverse example is: a total MAC of 1.3 when using sevoflurane and nitrous oxide 67% in oxygen, requires an end-expired sevoflurane concentration of 1.8% in a 3-yr-old whereas 0.55% is needed in a patient of 90 yr. CONCLUSIONS: The nomogram gives accurate results if it covers a whole A4 sheet in landscape format and could be extended to apply to other agents, for example xenon.

Adolescent↗

PubMed2001

Intravenous insulin nomogram improves blood glucose control in the critically ill.

OBJECTIVE: To improve control of blood glucose concentrations in critically ill patients through use of a bedside, nurse-managed, intravenous insulin nomogram. DESIGN: Retrospective, before-after cohort study. SETTING: Fifteen-bed mixed medical/surgical intensive care unit in a tertiary, teaching hospital. PATIENTS: A total of 167 intensive care unit patients requiring intravenous insulin infusions during two 9-month periods. INTERVENTION: The sliding scale group was treated using ad hoc sliding scale infusion therapy. The intervention group was treated using a dosing nomogram that allowed the nurse to adjust the insulin infusion rate based on current glucose concentration and concurrent insulin infusion rates. The adjustments were made independent of physician input. MEASUREMENTS AND MAIN RESULTS: Time from initiating the insulin infusion to initial control of glucose concentration (<11.5 mmol/L) was determined. Effectiveness of glucose control was determined retrospectively by measuring the area under the curve of blood concentrations >11.5 mmol/L versus time of insulin infusion, divided by total duration of insulin infusion. The median time to initial control of glucose (<11.5 mmol/L) was 4 hr (range 1-38 hr) for the baseline and 2 hr (range 1-22 hr) for nomogram group (p =.0004). The median area under the curve of glucose concentration divided by duration of insulin infusion was 0.9 (range 0.0-5.9) for sliding scale group and 0.3 (range 0.0-11.1) for nomogram (p =.0001), without any increase in the frequency of episodes of hypoglycemia. CONCLUSION: Use of an insulin nomogram in critically ill patients improves control of blood glucose concentrations and is safe.

Area Under Curve↗

PubMedDate not supplied

A contrast agent delivery nomogram for hepatic spiral CT.

PURPOSE: A nomogram for hepatic spiral CT (SCT) was constructed based on randomization of patients into a prospective study using four different injection protocols. Its utility in a separate prospective randomized trial was subsequently evaluated in a new group of patients. METHODS: Thirty-nine patients randomized into four groups underwent SCT (Somatom-Plus S; 24 s exposure, 10 mm collimation, 10 mm/s) using 90 ml Omnipaque 240 (22 g I) at 2.5, 4, 5, or 6 ml/s. Peak and mean aortic and liver enhancement and time to peaks were measured and correlated with patients' age, weight, dose, rate, and contrast agent concentration, and a nomogram was constructed. In the validation experiment, 20 new patients were randomized to nomogram-guided and control groups for contrast dose administration during SCT. All patients underwent SCT (Somatom-Plus S; 32 s exposure, 10 mm collimation, 10 mm/s) using 90 ml Omnipaque 240 or 140 ml Hypaque 60 at 1.5-6 ml/s. Peak and mean aortic and liver enhancement and time to peaks were measured and correlated with patients' age, weight, dose, rate, and contrast agent concentration. Mean and peak aortic and hepatic enhancements were measured and rated by three blinded reviewers. RESULTS: Peak hepatic enhancement occurred 32 s after termination of contrast bolus administration in all groups. Correlation between the predicted and actual enhancement was very good (r = 0.7-0.9). Ninety-eight percent of the nomogram-guided group had optimal timing and utilized 10% less contrast agent than the control group. CONCLUSION: The phenomenon of peak hepatic enhancement occurring 32 s after the termination of contrast bolus regardless of injection rate may be of use in a nomogram for optimal contrast delivery for hepatic SCT.

Contrast Media↗

PubMed1997

A renal size nomogram for the patient with myelomeningocele.

PURPOSE: Renal anatomy and function are usually monitored in the myelomeningocele population using routine ultrasound as the child grows. Clinical questions arise when a renal unit is of marginal size when evaluated with nomograms derived from normal patient populations. Our goal was to construct a renal size nomogram using ultrasound for the myelomeningocele population to help the clinician identify abnormal growth. MATERIALS AND METHODS: We reviewed the charts and radiological files of 96 patients with myelomeningocele followed at our institution. Images of 930 renal units were included to construct the nomogram. Patients were excluded from study due to hydronephrosis or hydroureter, solitary kidney, recurrent symptomatic urinary tract infection, vesicoureteral reflux, reconstructive surgery or known high bladder storage pressure. RESULTS: A renal size nomogram was constructed by plotting patient age against maximal renal length on real-time ultrasound. Expected mean and standard deviations were calculated for each age group. CONCLUSIONS: Previous studies using excretory urography have shown that kidneys in the myelomeningocele population are smaller than in a healthy control population. Ultrasound is now the modality most commonly used to monitor renal anatomy. The creation of a renal nomogram based on ultrasound should help the clinician identify abnormal renal growth more accurately.

Adolescent↗