Wilmington VA Medical Center

BACKGROUND: Impaired endothelium-mediated relaxation contributes to vasospasm and myocardial ischemia in patients with coronary artery disease. We hypothesized that cholesterol-lowering therapy with the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor lovastatin could improve endothelium-mediated responses in patients with coronary atherosclerosis. METHODS: In a randomized, double-blind, placebo-controlled trial, we studied coronary endothelial responses in 23 patients randomly assigned to either lovastatin (40 mg twice daily; 11 patients) or placebo (12 patients) plus a lipid-lowering diet (American Heart Association Step 1 diet). Patients were studied 12 days after randomization and again at 5 1/2 months. These patients had total cholesterol levels ranging from 160 to 300 mg per deciliter (4.1 to 7.8 mmol per liter) and were undergoing coronary angioplasty. At the initial and follow-up studies, patients received serial intracoronary infusions (in a coronary artery not undergoing angioplasty) of acetylcholine to assess endothelium-mediated vasodilatation. The responses of the coronary vessels were analyzed with quantitative angiography. RESULTS: The patients in the placebo and lovastatin groups had similar responses to acetylcholine at a mean of 12 days of therapy (expressed as the percentage of change in diameter in response to acetylcholine doses of 10(-9) M, 10(-8) M, 10(-7) M, and 10(-6) M). In the placebo group, the respective mean (+/- SE) changes were 1 +/- 2, 0 +/- 2, -2 +/- 4, and -19 +/- 4 percent; in the lovastatin group, they were -2 +/- 2, -4 +/- 4, -12 +/- 5, and -16 +/- 7 percent (P = 0.32). (Coronary-artery constriction is reflected by negative numbers). The responses to acetylcholine in the placebo group after a mean of 5.5 months of therapy were -3 +/- 3, -1 +/- 2, -8 +/- 4, and -18 +/- 5 percent, respectively; there was significant improvement in the lovastatin group, which had responses of 3 +/- 3, 3 +/- 3, 0 +/- 2, and 0 +/- 3 percent (P = 0.004). CONCLUSIONS: Cholesterol lowering with lovastatin significantly improved endothelium-mediated responses in the coronary arteries of patients with atherosclerosis. Such improvement in the local regulation of coronary arterial tone could potentially relieve ischemic symptoms and signal the stabilization of the atherosclerotic plaque.

Abstract Twenty‐five recurrent traumatic unidirectional anterior shoulder dislocators were stabilized arthroscopically with a transglenoid absorbable suturing technique. A Bankart lesion was documented and repaired in all cases. Postoperative follow‐up averaged 17 months (range 1 year to 30 months). All results were rated excellent. All patients achieved full, painless range of motion (ROM), and no instances of postoperative instability occurred. There were no complications. The details of the operative technique are described.

Fibrinogen is essential for aggregating platelets with adenosine diphosphate (ADP) and was recently shown to bind to platelets stimulated with ADP. The present work confirms the specific and saturable nature of the platelet-fibrinogen interaction. Binding of 125iodine-labeled fibrinogen to human gel-filtered platelts was maximal at 1 min, and the receptors were saturated when the fibrinogen concentration in the suspending medium approached 0.8 mg/ml. Assuming that one fibrinogen molecule interacts with a single receptor, experiments with 9 normal donors revealed the presence of 12,896 +/- 2456 receptors per platelet. Much of the bound material dissociated from platelets after incubation with apyrase or EDTA. Binding was markedly inhibited at pH 6.5, in the presence of EDTA, and with platelets from 3 thrombasthenic patients but not with those from a patient with the Bernard-Soulier syndrome. Fibrinogen binding was also virtually absent with platelets that had been incubated with EDTA for 8 min at 37 degrees C and pH 7.8. These platelets could not aggregate when mixed with ADP and adequate CaCl2 and fibrinogen, although they could still change their shape. Thus, ADP-induced binding of fibrinogen correlates with platelet aggregability.

Postoperative nausea and emesis, especially in ambulatory surgical patients, remains a troublesome problem. This study was performed to compare the incidence of nausea and emesis during the 24-h postoperative period in ondansetron-treated patients versus placebo-treated patients.Using a randomized prospective double-blind study design, women between the ages of 18 and 70 yr undergoing gynecologic surgical procedures with general opioid anesthesia on an outpatient basis were enrolled. Ondansetron or placebo was administered prior to induction of anesthesia. Patients were stratified according to history of nausea and emesis during previous exposure to general anesthesia and randomized to dose received.Data from the 544 women showed that all doses of intravenous ondansetron tested (1, 4, and 8 mg) were significantly more effective (62%, 76%, and 77%, respectively) than placebo (46%) in reducing the incidence of emesis following surgery until 24 h after recovery room entry. All these doses were more effective than placebo in patients with no prior history of emesis following surgery and the 4- and 8-mg doses were more effective than placebo in patients with a prior history of emesis following surgery. All doses of ondansetron tested were generally well tolerated with adverse events, clinical laboratory tests, and recovery room vital signs similar to those of placebo. Serum aspartate transaminase (AST) was increased in five patients (1 mg, 2 patients; 4 mg, 1 patient; 8 mg, 2 patients). In the three patients in whom subsequent analysis were performed, the serum AST had decreased to preoperative levels.Ondansetron given intravenously to prevent postoperative nausea and emesis was highly effective in the 4- and 8-mg doses in women having ambulatory gynecologic surgery.

BACKGROUND: Experimental and clinical observations suggest that lowering serum lipid levels may reduce the risk of restenosis after coronary angioplasty. We report the results of a prospective, randomized, double-blind trial evaluating whether lowering lipid levels with lovastatin can prevent or delay restenosis after angioplasty. METHODS: Seven to 10 days before angioplasty, we randomly assigned eligible patients to receive lovastatin (40 mg orally twice daily) or placebo. Patients who underwent successful, complication-free, first-time angioplasty of a native vessel (the index lesion) continued to receive therapy for six months, when a second coronary angiogram was obtained. The primary end point was the extent of restenosis of the index lesion, as assessed by quantitative coronary arteriography. Of 404 patients randomly assigned to study groups, 384 underwent angioplasty; 354 of the procedures were successful, and 321 patients underwent angiographic restudy at six months. RESULTS: At base line, the patients in the lovastatin group (n = 203) and the placebo group (n = 201) were similar with respect to demographic clinical, angiographic, and laboratory characteristics. At base line the mean (+/- SD) degree of stenosis, expressed as a percentage of the diameter of the vessel, was 64 +/- 11 percent in the lovastatin group, as compared with 63 +/- 11 percent in the placebo group (P = 0.22). Despite a 42 percent reduction in the serum level of low-density lipoprotein cholesterol in the lovastatin group, after six months of treatment the amount of stenosis seen in the second angiogram was 46 +/- 20 percent in the placebo group, as compared with 44 +/- 21 percent in the lovastatin group (P = 0.50). Similarly, there were no significant differences in minimal luminal diameter or other measures of restenosis. A trend was noted toward more myocardial infarctions in the lovastatin group, as a result of acute vessel closure or restenosis at the site of angioplasty, but there were no other important differences between the two groups in the frequency of fatal or nonfatal events at six months. CONCLUSIONS: Treatment with high-dose lovastatin initiated before coronary angioplasty does not prevent or delay the process of restenosis in the first six months after the procedure.

Beta-lactamase-producing (Bla+) enterococci have been reported in three state and two countries. Pulsed-field gel electrophoresis was used to compare 14 Bla+ Enterococcus (Streptococcus) faecalis isolated from hospitalized patients in seven states and three continents. The restriction endonuclease digestion patterns of isolates from Connecticut, Massachusetts, Lebanon, and Argentina were all markedly different, indicating that these were different strains. However, isolates from Delaware, Texas, Pennsylvania (Philadelphia and Pittsburgh), Florida, and Virginia were similar, indicating that these isolates were derivatives of a single strain. This conclusion was supported by hybridization using individual fragments as probes. Spread of Bla+ enterococci within the hospital setting was also demonstrated. These findings illustrate the value of pulsed-field gel electrophoresis for epidemiologic analyses and support the importance of identifying and containing organisms with new resistance properties in an effort to decrease their transmission to and from, as well as within, hospitals.

Importance: Selecting effective antidepressants for the treatment of major depressive disorder (MDD) is an imprecise practice, with remission rates of about 30% at the initial treatment. Objective: To determine whether pharmacogenomic testing affects antidepressant medication selection and whether such testing leads to better clinical outcomes. Design, Setting, and Participants: A pragmatic, randomized clinical trial that compared treatment guided by pharmacogenomic testing vs usual care. Participants included 676 clinicians and 1944 patients. Participants were enrolled from 22 Department of Veterans Affairs medical centers from July 2017 through February 2021, with follow-up ending November 2021. Eligible patients were those with MDD who were initiating or switching treatment with a single antidepressant. Exclusion criteria included an active substance use disorder, mania, psychosis, or concurrent treatment with a specified list of medications. Interventions: Results from a commercial pharmacogenomic test were given to clinicians in the pharmacogenomic-guided group (n = 966). The comparison group received usual care and access to pharmacogenomic results after 24 weeks (n = 978). Main Outcomes and Measures: The co-primary outcomes were the proportion of prescriptions with a predicted drug-gene interaction written in the 30 days after randomization and remission of depressive symptoms as measured by the Patient Health Questionnaire-9 (PHQ-9) (remission was defined as PHQ-9 ≤ 5). Remission was analyzed as a repeated measure across 24 weeks by blinded raters. Results: Among 1944 patients who were randomized (mean age, 48 years; 491 women [25%]), 1541 (79%) completed the 24-week assessment. The estimated risks for receiving an antidepressant with none, moderate, and substantial drug-gene interactions for the pharmacogenomic-guided group were 59.3%, 30.0%, and 10.7% compared with 25.7%, 54.6%, and 19.7% in the usual care group. The pharmacogenomic-guided group was more likely to receive a medication with a lower potential drug-gene interaction for no drug-gene vs moderate/substantial interaction (odds ratio [OR], 4.32 [95% CI, 3.47 to 5.39]; P < .001) and no/moderate vs substantial interaction (OR, 2.08 [95% CI, 1.52 to 2.84]; P = .005) (P < .001 for overall comparison). Remission rates over 24 weeks were higher among patients whose care was guided by pharmacogenomic testing than those in usual care (OR, 1.28 [95% CI, 1.05 to 1.57]; P = .02; risk difference, 2.8% [95% CI, 0.6% to 5.1%]) but were not significantly higher at week 24 when 130 patients in the pharmacogenomic-guided group and 126 patients in the usual care group were in remission (estimated risk difference, 1.5% [95% CI, -2.4% to 5.3%]; P = .45). Conclusions and Relevance: Among patients with MDD, provision of pharmacogenomic testing for drug-gene interactions reduced prescription of medications with predicted drug-gene interactions compared with usual care. Provision of test results had small nonpersistent effects on symptom remission. Trial Registration: ClinicalTrials.gov Identifier: NCT03170362.

Clinical trials first began in 1960 with methylprednisolone acetate (Depo-Medrol) administered intrathecally, in an attempt to treat both disk disease and multiple sclerosis. After a few reports of salubrious results, there began an outpouring of contradictory data, which continues in 1988. During this time span, researchers who cautiously tested the different theses of improvement began to publish serious warnings of many complications. For ten years prior to the intraspinal use of methylprednisolone acetate, basic scientists in anesthesiology and neurochemistry had published the following facts: (1) Methylprednisolone acetate's content of polyethylene glycol raises the risks of using it near the central nervous system. (2) Deleterious effects follow the use of glycols when they are placed into or near the neuraxis. (3) Methylprednisolone acetate contains approximately 30 mg of polyethylene glycol per milliliter. (4) When that glycol, which is both alcohol and detergent, is injected intraspinally, sterile meningitis, arachnoiditis, or pachymeningitis will occur. It has also been recognized since the 1960s that the epidural space is not wholly separate from the subdural and/or subarachnoid space. Many thousands of arachnoid villi subtend all the membranes from the intrathecal space, and many of these end in the large epidural veins. Therefore, the various spaces and membranes are not only contiguous, but continuous. It follows that an injection of methylprednisolone acetate into the epidural space does not guarantee that it will remain isolated there. Finally, the inadvertency of injections by the epidural route occurs with the following frequency: 40% of injections can be inadvertently made into interspinous ligaments, and 2.5% into the subarachnoid space.

Cardiovascular abnormalities are important features of Costello syndrome and other Ras/MAPK pathway syndromes ("RASopathies"). We conducted clinical, pathological and molecular analyses of 146 patients with an HRAS mutation including 61 enrolled in an ongoing longitudinal study and 85 from the literature. In our study, the most common (84%) HRAS mutation was p.G12S. A congenital heart defect (CHD) was present in 27 of 61 patients (44%), usually non-progressive valvar pulmonary stenosis. Hypertrophic cardiomyopathy (HCM), typically subaortic septal hypertrophy, was noted in 37 (61%), and 5 also had a CHD (14% of those with HCM). HCM was chronic or progressive in 14 (37%), stabilized in 10 (27%), and resolved in 5 (15%) patients with HCM; follow-up data was not available in 8 (22%). Atrial tachycardia occurred in 29 (48%). Valvar pulmonary stenosis rarely progressed and atrial septal defect was uncommon. Among those with HCM, the likelihood of progressing or remaining stable was similar (37%, 41% respectively). The observation of myocardial fiber disarray in 7 of 10 (70%) genotyped specimens with Costello syndrome is consistent with sarcomeric dysfunction. Multifocal atrial tachycardia may be distinctive for Costello syndrome. Potentially serious atrial tachycardia may present in the fetus, and may continue or worsen in about one-fourth of those with arrhythmia, but is generally self-limited in the remaining three-fourths of patients. Physicians should be aware of the potential for rapid development of severe HCM in infants with Costello syndrome, and the need for cardiovascular surveillance into adulthood as the natural history continues to be delineated.

BACKGROUND: Renal medullary carcinoma is a newly described, aggressive kidney tumor. All patients with the disease have been African-American with sickle cell (SC) trait or hemoglobin SC disease. METHODS: Patient information was obtained from individual patient records and from the Department of Defense national data bank, The Defense Enrollment and Eligibility Reporting System. Data were obtained from either personal review of the patient's records or from discussion with the patient's physician. Cytogenetic studies were performed on one patient. RESULTS: Six patients are presented. All had SC trait. Median age was 24.5 years and 1 patient was female. Time from diagnosis to death averaged 3 months (range 1-7 mos). No objective responses were reported to a wide variety of chemo and immunotherapies: cyclophosphamide, doxorubicin, cisplatin; methotrexate, vinblastine, doxorubicin, and cisplatin; single agent interferon; single agent paclitaxel; or single agent vinblastine. Investigational regimens included topotecan, doxorubicin, and filgrastim; alpha-interferon, interleukin-2, and 5-fluorouracil; and single agent paclitaxel. Cytogenetic studies revealed numerous structural, as well as numerical anomalies. Of the cells successfully karyotyped (n=4), 2 contained abnormalities of chromosome 3 and all contained monosomy 11. CONCLUSIONS: Renal medullary carcinoma is an aggressive, chemoresistant tumor. Time from discovery of tumor to patient death is very short and has been altered by a wide variety of chemotherapies and immunotherapies. An unidentified genetic component is likely present.

Long non-coding RNAs (lncRNAs) are a kind of RNAs with regulation that participate fundamental cellular processes via diverse mechanisms. Despite the potential importance of lncRNAs in multiple kinds of cancer has been well studied, no comprehensive survey of cancer subtype associated lncRNAs. Here, we performed an array-based transcriptional survey of lncRNAs across 150 lung cancer samples comprising both adenocarcinoma and squamous cell carcinoma and 306 breast cancer patients with clear clinical information. In lung cancer, 72 lncRNAs are identified to be associated with tumor subtypes and their functions as well as the associated proteins are predicted by constructing coding-non-coding co-expression network. The results suggest that they are mostly related with epidermis development, cell adhesion and response to stimulus. The validation results show the high concordance and confirmed the robust of the identification results. In breast cancer, we found 3 lncRNA genes are associated with estrogen receptor α (ER) positive and ER negative subtypes and tumor histologic grade. Survival (Kaplan-Meier) analysis results suggest that the expression pattern of the 3 lncRNAs is significantly correlated with clinical outcomes. The current study provides the first large-scale survey of lncRNAs within cancer subtypes and may offer new targets for their diagnosis, therapy and prognosis.

BACKGROUND: Patients often seek care from hospital emergency departments (EDs) for conditions medical personnel perceive as nonurgent. The purpose of this study was to examine ED patients' perceptions of urgency, and to determine whether patients with no regular source of medical care are more likely to use the ED for problems they perceive as nonurgent. METHODS: We surveyed 268 patients in an urban ED waiting area who were considered nonurgent by the ED triage nurse. Using structured interviews, we determined patients' perceptions, about the urgency of their medical condition, whether they had a regular source of medical care, and their reasons for choosing the ED for care. After controlling for other variables, we determined whether having non regular source of care was associated with patient-rated nonurgent ED utilization. RESULTS: Eighty-two percent of patients rated their condition as urgent. Patient-rated urgency was not associated with having a regular source of care. The most common reason for seeking care in the ED was expediency. CONCLUSIONS: A large majority of ED patients perceive the problems for which they seek care from an ED as urgent, even when they are assessed as nonurgent by a health professional. Lack of a regular source of care has no significant impact on ED utilization for problems that patients perceive as nonurgent. Simply providing patients with a regular source of care is unlikely to have a significant impact on nonurgent ED utilization without efforts to manage utilization and ensure adequate access to primary care.

Rhodococcus equi is an aerobic, intracellular, gram-positive rod-coccus that is partially acid fast. The organism is primarily a pathogen in animals and has only rarely been seen in immunocompromised humans. Its most common manifestation is a slowly progressive pneumonia that may cavitate. Infections are thought to be acquired via respiratory exposure to animals or soil. R. equi infections are difficult to treat, usually requiring prolonged administration of parenteral antibiotics and often necessitating surgical drainage. A case of cavitary pneumonia and recurrent bacteremia with R. equi in a patient with AIDS is reported, and the current literature on R. equi infections in humans is reviewed.

BACKGROUND: In the ultrasound evaluation of masses, elastography measures stiffness, which may predict malignancy. Studies of small or selected subgroups suggest that elastography may be useful in the evaluation of thyroid nodules (TNs). We prospectively tested the hypothesis that TN stiffness, as measured by strain elastography (SE), is an independent predictor of thyroid cancer (TC) in unselected TNs. METHODS: In 706 unselected patients with 912 TNs meeting the ATA criteria for a fine-needle aspiration biopsy (FNAB), we first performed conventional thyroid ultrasound and SE. Nodule stiffness was graded from least to most stiff by an elastography score (ES) of ES 0 to ES 3. Surgical resection was recommended for FNAB results that were not clearly benign. Bivariate and multivariate regression analyses identified the independent predictors of TC. RESULTS: There were 86 malignant TNs. ES was a significant predictor of TC (p=0.0001). The prevalence of TC was 57 of the 158 TNs (36.1%) for the ES 3 group, 12 of the 158 TNs (7.7%) for the ES 2 group, 16 of the 565 TNs (2.8%) for the ES 1 group, and 1 of the 33 TNs (3%) for the ES 0 group. By multivariate regression analysis, the independent predictors of TC were ES, microcalcifications, hypoechogenicity, and isthmus location. The positive predictive value (PPV) of ES was 36.1%, which was similar to the PPV of microcalcifications (35.9%), but greater compared with hypoechogenicity (13.6%) and isthmus location (16.9%). The negative predictive value (NPV) of ES was 97.2%, which was better than any other predictor for malignancy. CONCLUSIONS: We conclude that TN stiffness measured by elastography is an independent predictor of TC with a PPV that is equal to or greater than that of conventional ultrasonographic characteristics. NPV was greater than any other predictor of malignancy.

The intraspinal use of methylprednisolone acetate (Depo-Medrol, Upjohn Company, Kalamazoo MI) began in 1960, followed 10 years later by reports of complications. In 1960, methylprednisolone acetate was first injected by the epidural route to treat low-back syndromes. Then in 1961, the intrathecal route was more widely used to treat arachnoiditis and multiple sclerosis. Epidural therapy again came into general use in 1980 for the treatment of the failed-back syndrome because intrathecal therapy was virtually abandoned after 10 years of spirited scientific controversy. Epidural steroid therapy is now employed extensively, and there are many sanguine reports of its efficacy in treating chronic pain secondary to the failed-back syndrome, but there have also been reports of complications. This review was prompted by recent manufacturer warnings, as well as by an ongoing heated controversy in Australia regarding its use epidurally. During the last 30 years, one can define 5 instructive historical parallels between intrathecal and epidural steroid therapy, and this historicity points up several principles that should govern any further epidural therapy with methylprednisolone acetate. This critical chronologic review surveys neurosurgical use from 1960 to 1970, neurologic use from 1970 to 1980, and anesthesiology use from 1980 to present.

There is a lack of defined reference points for reproducible femoral tunnel placement during posterior cruciate ligament (PCL) reconstruction. The PCL, consisting of two major bands, anterolateral (AL) and posteromedial (PM), has a femoral origin that spans 3 cm, which cannot be covered by a substitute graft positioned in one femoral tunnel to reconstruct the PCL. The purpose of this study was to define the location of the anatomic origin of both bands of the PCL in reference to local anatomy to develop landmarks that can be used to reproducibly position two femoral tunnels (one to each band's origin) during PCL reconstruction. The anatomy of the PCL origin was dissected and studied in 20 knees at the time of total knee replacement. The central origin point for each band was marked, and its distance was measured in reference to three axes. The AL band centrally originated 13 +/- 0.5 mm posterior to the medial articular cartilage-intercondylar wall interface and 13 +/- 0.5 mm inferior to the articular cartilage-intercondylar roof interface. The PM band centrally originated 8 +/- 0.5 mm posterior to the medial articular cartilage-intercondylar wall interface and 20 +/- 0.5 mm inferior to the articular cartilage-intercondylar roof interface. These distances were noted to be relatively constant despite varying knee morphologies and size. For this reason, referencing the articular cartilage-intercondylar roof, and wall interfaces may be used as a method to facilitate more reproducible anatomic femoral tunnel placements during PCL reconstruction.

Tumors of the small bowel, both benign and malignant, are relatively uncommon and often present a diagnostic challenge as their symptoms are often vague. This review article outlines the incidence, presentation, diagnosis, and management of small bowel tumors.

A B S T R A C T The platelet membrane receptor for quinidineand quinine-dependent antibodies was studied in three patients with the Bernard-Soulier syndrome (BSS) and in normal subjects with immuno- logic techniques based on the release of 5'Cr from labeled platelets. The receptor could not be detected on BSS platelets but was present on platelets from each of 180 normal subjects. BSS platelets reacted normally with other allo-and autoantibodies. In confirmation of previous reports, BSS platelets were found to be deficient in glycoproteins lb and Is. However, after apparently total cleavage of these proteins from the membrane of normal platelets by controlled hydrolysis with trypsin or chymotrypsin, 80% of the drug-dependent antibody receptor activity was retained. These observations suggest the existence of an additional, hitherto unrecognized membrane defect in Bernard- Soulier platelets.

Unusual infections associated with colorectal tumors may, in some instances, be the sole clue to the presence of a malignancy. The infections are either related to invasion of tissues or organs in close proximity to the tumor or secondary to distant seeding by transient bacteremia arising from necrotic tumors. Seven patients seen at one hospital over a 5-year period illustrate the clinical presentations of such infections. The infections identified in these seven patients include endocarditis, meningitis, nontraumatic gas gangrene, empyema, hepatic abscesses, retroperitoneal abscess, clostridial sepsis, and colovesical fistulae with urosepsis. A computer-assisted search of the English-language literature and cross-checks from other review articles identified other infections associated with colon cancer, which include nontraumatic crepitant cellulitis, suppurative thyroiditis, pericarditis, appendicitis, pulmonary microabscesses, septic arthritis, and fever of unknown origin. The clinical importance of these infections and their correlation with colorectal malignancies are reviewed.

Blood volume studies using the indicator dilution technique and radioactive tracers have been performed in nuclear medicine departments for over 50 y. A nuclear medicine study is the gold standard for blood volume measurement, but the classic dual-isotope blood volume study is time-consuming and can be prone to technical errors. Moreover, a lack of normal values and a rubric for interpretation made volume status measurement of limited interest to most clinicians other than some hematologists. A new semiautomated system for blood volume analysis is now available and provides highly accurate results for blood volume analysis within only 90 min. The availability of rapid, accurate blood volume analysis has brought about a surge of clinical interest in using blood volume data for clinical management. Blood volume analysis, long a low-volume nuclear medicine study all but abandoned in some laboratories, is poised to enter the clinical mainstream. This article will first present the fundamental principles of fluid balance and the clinical means of volume status assessment. We will then review the indicator dilution technique and how it is used in nuclear medicine blood volume studies. We will present an overview of the new semiautomated blood volume analysis technique, showing how the study is done, how it works, what results are provided, and how those results are interpreted. Finally, we will look at some of the emerging areas in which data from blood volume analysis can improve patient care. The reader will gain an understanding of the principles underlying blood volume assessment, know how current nuclear medicine blood volume analysis studies are performed, and appreciate their potential clinical impact.