Visualization Of Inferior Vena Cava Research Articles

Inferior vena cava distensibility during pressure support ventilation: a prospective study evaluating interchangeability of subcostal and trans‑hepatic views, with both M‑mode and automatic border tracing

The Inferior Vena Cava (IVC) is commonly utilized to evaluate fluid status in the Intensive Care Unit (ICU),with more recent emphasis on the study of venous congestion. It is predominantly measured via subcostal approach (SC) or trans-hepatic (TH) views, and automated border tracking (ABT) software has been introduced to facilitate its assessment. Prospective observational study on patients ventilated in pressure support ventilation (PSV) with 2 × 2 factorial design. Primary outcome was to evaluate interchangeability of measurements of the IVC and the distensibility index (DI) obtained using both M-mode and ABT, across both SC and TH. Statistical analyses comprised Bland–Altman assessments for mean bias, limits of agreement (LoA), and the Spearman correlation coefficients. IVC visualization was 100% successful via SC, while TH view was unattainable in 17.4% of cases. As compared to the M-mode, the IVC-DI obtained through ABT approach showed divergences in both SC (mean bias 5.9%, LoA -18.4% to 30.2%, ICC = 0.52) and TH window (mean bias 6.2%, LoA -8.0% to 20.4%, ICC = 0.67). When comparing the IVC-DI measures obtained in the two anatomical sites, accuracy improved with a mean bias of 1.9% (M-mode) and 1.1% (ABT), but LoA remained wide (M-mode: -13.7% to 17.5%; AI: -19.6% to 21.9%). Correlation was generally suboptimal (r = 0.43 to 0.60). In PSV ventilated patients, we found that IVC-DI calculated with M-mode is not interchangeable with ABT measurements. Moreover, the IVC-DI gathered from SC or TH view produces not comparable results, mainly in terms of precision.

Inferior vena cava ultrasound and other techniques for assessment of intravascular and extravascular volume: an update.

Goals of volume management are to accurately assess intravascular and extravascular volume and predict response to volume administration, vasopressor support or volume removal. Data are reviewed that support the following: (i)Dynamic parameters reliably guide volume administration and may improve clinical outcomes compared with static parameters, but some are invasive or only validated with mechanical ventilation without spontaneous breathing. (ii)Ultrasound visualization of inferior vena cava (IVC) diameter variations with respiration reliably assesses intravascular volume and predicts volume responsiveness. (iii)Although physiology of IVC respiratory variations differs with mechanical ventilation and spontaneous breathing, the IVC collapsibility index (CI) and distensibility index are interconvertible. (iv)Prediction of volume responsiveness by IVC CI is comparable for mechanical ventilation and spontaneous breathing patients. (v)Respiratory variations of subclavian/proximal axillary and internal jugular veins by ultrasound are alternative sites, with comparable reliability. (vi)Data support clinical applicability of IVC CI to predict hypotension with anesthesia, guide ultrafiltration goals, predict dry weight, predict intra-dialytic hypotension and assess acute decompensated heart failure. (vii)IVC ultrasound may complement ultrasound of heart and lungs, and abdominal organs for venous congestion, for assessing and managing volume overload and deresuscitation, renal failure and shock. (viii)IVC ultrasound has limitations including inadequate visualization. Ultrasound data should always be interpreted in clinical context. Additional studies are required to further assess and validate the role of bedside ultrasonography in clinical care.

Applicability and feasibility of intraprocedural tip location of femorally inserted central catheters by transhepatic ultrasound visualization of the inferior vena cava in adult patients.

The ideal intraprocedural method for tip location during insertion of femorally inserted central catheters (FICCs) is still a matter of debate. When the catheter tip is meant to be in the right atrium or in the supradiaphragmatic inferior vena cava (IVC), tip location by either intracavitary electrocardiography or transthoracic echocardiography may be accurate and easy to perform. When the catheter tip is planned to be placed in the subdiaphragmatic IVC, fluoroscopy-though inaccurate and unsafe-has been regarded as the only option for intraprocedural tip location. We have investigated prospectively the applicability and feasibility of transhepatic ultrasound as intraprocedural method for assessing the location of the catheter tip in the subdiaphragmatic tract of IVC, during FICC insertion. We enrolled 169 consecutive patients undergoing FICC insertion by ultrasound guided puncture of the superficial femoral vein. In 165 out of 169 patients, the subdiaphragmatic IVC was visualized by the transhepatic ultrasound view. In all cases of IVC visualization, the catheter tip could be identified by ultrasound, either directly (direct evidence of the tip inside the vein) or indirectly (enhanced visualization of the tip after "bubble test"). There was no immediate or early complication, and very few late complications. The intraprocedural method of tip location of FICCs by transhepatic ultrasound was applicable in 97.6% of cases and feasible in 100%. When the position of the catheter tip is planned to be in the subdiaphragmatic IVC, this method of tip location is accurate, safe, and inexpensive, and should be considered as an alternative to fluoroscopy.

Agreement between subcostal and transhepatic longitudinal imaging of the inferior vena cava for the evaluation of fluid responsiveness: A systematic review.

Assessment of fluid-responsiveness is a key aspect of daily management in critically ill patients. Non-invasive evaluation of the variation of inferior vena cava (IVC) diameter during ventilation may provide useful information. However, a standard sagittal IVC visualization from the subcostal (SC) region is not always feasible. An alternative method to visualize the IVC is a coronal trans-hepatic (TH) approach. We performed a systematic search to explore the interchangeability of IVC evaluation with SC and TH views. We searched Medline and EMBASE to identify prospective studies. We did not consider the relationship between axial and sagittal visualization of the IVC. We included seven studies reporting data on IVC evaluation with both SC and TH IVC views. Four studies were conducted on spontaneously breathing patients/volunteers, two on fully mechanically ventilated patients, and one in a mixed population, with large heterogeneity regarding the analyses reported. Limits of agreement between SC and TH were large. Concordance of the IVC collapsibility/distensibility indices are not interchangeable between SC and TH view. Correlation between diameters measured with SC and TH approach and intra/inter-observer correlation produced variable results. An overview of the included studies suggests that longitudinal TH and SC assessment of IVC size and respiratory variation are not interchangeable. New studies with accurate data reporting and appropriate statistical analysis are needed to define proper cut-offs for fluid responsiveness when using TH approach for IVC visualization.

Non-heat-stressed Method to Isolate Hepatic Stellate Cells From Highly Steatotic Tumor-bearing Liver Using CD49a.

Non-heat-stressed Method to Isolate Hepatic Stellate Cells From Highly Steatotic Tumor-bearing Liver Using CD49a.

New method for ultrasound-guided inferior vena cava filter placement

ObjectiveTransabdominal ultrasound (TAUS)-guided inferior vena cava filter (IVCF) placement currently uses an inferior vena cava (IVC) longitudinal plane with cross-section of the right renal artery or the transverse plane of the right renal vein (RRV)-IVC intersection. The goal of this study was to introduce a new method for TAUS-guided IVCF placement. MethodsThe study enrolled patients who were at high risk for or had pulmonary embolism from October 22, 2010, to June 30, 2016. The probe was positioned on the right flank to centralize the RRV-IVC junction during imaging and to permit a straight line through the midpoint of the probe on the surface and a parallel line 1.0 cm below the straight line as a marker. The probe was subsequently placed on the abdominal wall with the upper edge at the marker line to show the long axis of the IVC during the process of filter placement. The upper edge of the probe was considered the filter tip position. ResultsA total of 1029 patients were evaluated, and 98 patients (9.5%) were excluded because of poor IVC visualization (n = 14 [1.4%]), IVC or bilateral iliac vein thrombosis (n = 79 [7.7%]), and unsuitable anatomy (n = 5 [0.5%]). The remaining 931 patients (90.5%) were selected for TAUS-guided IVCF placement, and all filters (100%) were successfully placed. There were no procedure-related complications. Suprarenal IVCF was observed in 4 patients (0.4%) by computed tomography, and the filter tip exceeded the upper edge of L2 in 15 patients (1.6%) by plain film radiography; one of them had two RRVs. Severe filter tilting (20.8 degrees) occurred in one patient. ConclusionsThis new method of TAUS-guided IVCF placement was simple, safe, and effective. It may be widely applied for the bedside placement of vena cava filters.

Ultrasound measurement of inferior vena cava collapse predicts propofol-induced hypotension

Study ObjectivesHypotension is a common side effect of propofol, but there are no reliable methods to determine which patients are at risk for significant propofol-induced hypotension (PIH). Ultrasound has been used to estimate volume status by visualization of inferior vena cava (IVC) collapse. This study explores whether IVC assessment by ultrasound can assist in predicting which patients may experience significant hypotension. MethodsThis was a prospective observational study conducted in the operating suite of an urban community hospital. A convenience sample of consenting adults planned to receive propofol for induction of anesthesia during scheduled surgical procedures were enrolled. Bedside ultrasound was used to measure maximum (IVCmax) and minimum (IVCmin) IVC diameters. IVC-CI was calculated as [(IVCmax-IVCmin)/IVCmax × 100%]. The primary outcome was significant hypotension defined as systolic blood pressure (BP) below 90mmHg and/or administration of a vasopressor to increase BP during surgery. ResultsThe study sample comprised 40 patients who met inclusion criteria. Mean age was 55years, (95%CI, 49–60) with 53% female. 55% of patients had significant hypotension after propofol administration. 76% of patients with IVC-CI≥50% had significant hypotension compared to 39% with IVC-CI<50%, P=.02. IVC-CI≥50% had a specificity of 77.27% (95%CI, 64.29%–90.26%) and sensitivity of 66.67% (95%CI, 52.06%–81.28%) in predicting PIH. The odds ratio for PIH in patients with IVC-CI≥50% was 6.9 (95%CI, 1.7–27.5). ConclusionPatients with IVC-CI≥50% were more likely to develop significant hypotension from propofol. IVC ultrasound may be a useful tool to predict which patients are at increased risk for PIH.

346 Ultrasound Measurement of Inferior Vena Cava Collapse Predicts Propofol-Induced Hypotension

Propofol is frequently used for deep sedation. Hypotension from propofol is a commonly observed side effect but there are no reliable methods to determine which patients are at risk for propofol-induced hypotension. Bedside ultrasound, widely available in emergency department (EDs), has been used to estimate volume status by visualization of inferior vena cava (IVC) collapse. We hypothesized that an IVC collapse index (IVC-CI) of 50% or greater will predict hypotension in patients receiving a bolus dose of intravenous propofol.

Flank bruits due to giant renal arteriovenous malformation.

A 58-year-old woman was referred to the nephrology department because of a continuous bruit over the right flank heard by her primary care physician. Blood pressure was 120/80 mmHg. Complete blood count and urinary analysis were within normal limits. She had no history of prior renal surgery or trauma. A large cyst-like lesion at the right kidney with turbulent blood flow was found on colour Doppler ultrasound. Volume-rendered computed tomography (CT) angiography (Figure 1A) demonstrated giant cirsoid aneurysmal dilations of the right renal artery with early opacification of right renal vein (arrow) and inferior vena cava (arrowhead), indicating congenital renal arteriovenous malformations (AVMs). Therefore, right renal artery angiography (Figure 1B) confirmed the diagnosis of right giant renal AVMs by demonstrating cirsoid arterial communication with early visualization of the right renal vein (arrow) and inferior vena cava (arrowhead). At the same time, endovascular embolization of right AVMs was performed successfully with preservation of renal parenchymal vascular supply. The patient’s post-operative course was uneventful, and she was well 6 months later. Fig. 1 Volume-rendered computed tomography angiography (A) showing giant cirsoid aneurysmal dilations of right renal artery with early opacification of right renal vein (arrow) and inferior vena cava (arrowhead), indicating of congenital renal arteriovenous ... Renal AVMs are an uncommon disease of abnormal communications between intrarenal arterial and venous systems. These malformations can be congenital or acquired due to trauma, surgery and tumours. Acquired AVMs are often termed renal arteriovenous fistula. Congenital AVMs are a rare disease and account for 25% of renal AVMs [1]. Most congenital AVMs are asymptomatic. Symptomatic AVMs usually present with microscopic or gross haematuria, abdominal pain and flank bruit [2]. Renal Doppler sonography is a non-invasive tool that can help in distinguishing vascular lesions from cystic lesions based on a turbulent blood flow [3]. Renal CT angiography showed a typical appearance of cirsoid arterial communication with early visualization of inferior vena cava, indicating congenital arteriovenous malformations. Renal arteriography is still the gold standard modality which can help in a clearly visualization of abnormal vessels with early draining veins and the nidus of the AVM. Transcatheter embolization of renal AVMs can successfully obliterate the nidus of AVMs and preservation of renal normal parenchyma with reduced morbidity in comparison with surgical resection of renal AVMs [4]. Conflict of interest statement. None declared.

Non‐contrast‐enhanced MR angiography for selective visualization of the hepatic vein and inferior vena cava with true steady‐state free‐precession sequence and time‐spatial labeling inversion pulses: Preliminary results

To selectively visualize the hepatic vein and inferior vena cava (IVC) using three-dimensional (3D) true steady-state free-precession (SSFP) MR angiography with time-spatial labeling inversion pulse (T-SLIP), and to optimize the acquisition protocol. Respiratory-gated 3D true SSFP scans were conducted in 23 subjects in combination with two different T-SLIPs (one placed in the thorax to suppress the arterial signal and the other in the abdomen to suppress the portal venous signal). One of the most important factors was the inversion time (TI) of abdominal T-SLIP, and the image quality was evaluated at four different TIs of 800, 1200, 1600, and 2000 msec in terms of relative signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and mean visualization scores. No significant difference was observed in SNR and CNR between each TI. However, IVC visualization scores were better at TIs of 1600 and 2000 msec, and overall image quality was better at TIs of 1200 and 1600 msec. Therefore, the TI of 1600 msec was considered to provide the optimal balance between IVC visualization and signal suppression of the portal vein in our protocol. True SSFP scan with T-SLIPs enabled selective visualization of the hepatic vein and IVC without an exogenous contrast agent.

Percutaneous portal venoplasty and stenting for anastomotic stenosis after liver transplantation

To review percutaneous transhepatic portal venoplasty and stenting (PTPVS) for portal vein anastomotic stenosis (PVAS) after liver transplantation (LT). From April 2004 to June 2008, 16 of 18 consecutive patients (11 male and 5 female; aged 17-66 years, mean age 40.4 years) underwent PTPVS for PVAS. PVAS occurred 2-10 mo after LT (mean 5.0 mo). Three asymptomatic patients were detected on routine screening color Doppler ultrasonography (CDUS). Fifteen patients who also had typical clinical signs of portal hypertension (PHT) were identified by contrast-enhanced computerized tomography (CT) or magnetic resonance imaging. All procedures were performed under local anesthesia. If there was a PVAS < 75%, the portal pressure was measured. Portal venoplasty was performed with an undersized balloon and slowly inflated. All stents were deployed immediately following the predilation. Follow-ups, including clinical course, stenosis recurrence and stent patency which were evaluated by CDUS and CT, were performed. Technical success was achieved in all patients. No procedure-related complications occurred. Liver function was normalized gradually and the symptoms of PHT also improved following PTPVS. In 2 of 3 asymptomatic patients, portal venoplasty and stenting were not performed because of pressure gradients < 5 mmHg. They were observed with periodic CDUS or CT. PTPVS was performed in 16 patients. In 2 patients, the mean pressure gradients decreased from 15.5 mmHg to 3.0 mmHg. In the remaining 14 patients, a pressure gradient was not obtained because of > 75% stenosis and typical clinical signs of PHT. In a 51-year-old woman, who suffered from massive ascites and severe bilateral lower limb edema after secondary LT, PVAS complicated hepatic vein stenosis and inferior vena cava (IVC) stenosis. Before PTPVS, a self-expandable and a balloon-expandable metallic stent were deployed in the IVC and right hepatic vein respectively. The ascites and edema resolved gradually after treatment. The portosystemic collateral vessels resulting from PHT were visualized in 14 patients. Gastroesophageal varices became invisible on poststenting portography in 9 patients. In a 28-year-old man with hepatic encephalopathy, a pre-existing meso-caval shunt was detected due to visualization of IVC on portography. After stenting, contrast agents flowed mainly into IVC via the shunt and little flowed into the portal vein. A covered stent was deployed into the superior mesenteric vein to occlude the shunt. Portal hepatopetal flow was restored and the IVC became invisible. The patient recovered from hepatic encephalopathy. A balloon-expandable Palmaz stent was deployed into hepatic artery for anastomotic stenosis before PTPVS. Percutaneous transhepatic internal-external biliary drainage was performed in 2 patients with obstructive jaundice. Portal venous patency was maintained for 3.3-56.6 mo (mean 33.0 mo) and all patients remained asymptomatic. With technical refinements, early detection and prompt treatment of complications, and advances in immunotherapy, excellent results can be achieved in LT.

A New Window of Opportunity in Echocardiography

Improvements in echocardiographic technology have made technically difficult studies a rare entity. However, physical barriers such as bandages, inability for patients to turn because of intubation, arterial lines, and organ and life support machines make echocardiographic imaging challenging. We performed echocardiographic imaging from left and right posterior thoracic approach using acoustic properties of pleural fluid to assist in obtaining good imaging windows in patients who had pleural effusion (PE). In this study we describe one author's (T. Z. N.) experience with the mid to lower posterior thoracic window in 18 patients who had PE and in whom conventional transthoracic windows either provided suboptimal images or incomplete clinical information. The posterior approach allowed excellent differentiation of pericardial effusion versus PE, detection of pericardial disease and pericardial infiltration, and excellent endocardial border definition of left and right ventricle in those with poor anterior transthoracic windows. Native and prosthetic aortic valve gradients could be assessed adequately as a result of perfectly parallel Doppler alignment beam to left ventricular outflow tract and aortic valve. In addition, right posterior thoracic window provided views comparable with subcostal view and allowed visualization of inferior vena cava, right atrium, and liver. In patients with PE, imaging from low to midposterior thorax can provide additional diagnostic echocardiographic images and should be used in patients in whom conventional images are technically difficult or require additional information.

Comparison of Bedside Transabdominal Duplex Ultrasound versus Contrast Venography for Inferior Vena Cava Filter Placement: What Is the Best Imaging Modality?

While contrast venography is considered the gold standard for imaging prior to inferior vena cava (IVC) filter insertion, bedside placement via transabdominal duplex ultrasound (DUS) has been recognized as a safe and effective alternative. To date, there has been no direct comparison of the efficacy of both imaging modalities for IVC filter placement. A concurrent cohort of patients who underwent IVC filter placement at a single institution over a 7-year period with either contrast venography or transabdominal DUS performed at bedside was retrospectively reviewed. Patient demographics, venous thromboembolism risk factors, indications, technical success, and procedural complications were compared. Of 439 patients initially imaged with transabdominal DUS, IVC filter placement was determined to be technically feasible in 382 patients (87%). The procedural technical success rate for IVC filter placement using transabdominal DUS when IVC visualization was adequate was 97.4% (n = 382 patients), compared to 99.7% (n = 318 patients) for contrast venography (p = 0.018). Patients undergoing IVC filter placement with transabdominal DUS more commonly required IVC filter for venous thromboembolism prophylaxis (81.1% vs. 27.8%, p < 0.001), had increased incidence of multiple traumatic injuries (28% vs. 10%, p < 0.001), and had increased risk from immobilization (91.3% vs. 34.1%, p < 0.001). Overall complication rates were 0.6% for venography and 1.8% for transabdominal DUS (p = NS). When IVC visualization was adequate, contrast venography and transabdominal duplex ultrasound both had high rates of success and a low incidence of complications. A technical success advantage was observed for contrast venography; this difference in technical success must be weighed against the bedside insertion advantage offered by DUS, which may be especially important in the immobilized or critically ill patient. Transabdominal DUS remains our preferred technique when feasible, especially when bedside placement is desired.

Expanding Options for Bedside Placement of Inferior Vena Cava Filters with Intravascular Ultrasound When Transabdominal Duplex Ultrasound Imaging Is Inadequate

Although bedside placement of inferior vena cava (IVC) filters by means of transabdominal duplex ultrasound is possible in most patients, those with inadequate visualization have traditionally required fluoroscopy. The purpose of this study was to assess the safety and efficacy of bedside IVC filter placement with intravascular ultrasound (IVUS) when transabdominal duplex ultrasound imaging is inadequate. Between January 1, 1999 and December 31, 2002, 256 IVC filter placements were performed (207 with transabdominal duplex ultrasound [81%], 21 with fluoroscopy [8%], and 28 with IVUS [11%]). IVC filter placement with IVUS was performed only if visualization with transabdominal duplex ultrasound was determined to be inadequate. Demographics, technical data, and outcome for patients undergoing IVC filter placement with IVUS were reviewed and form the basis of this report. Bedside IVC filter placement with IVUS was technically successful in 26 of 28 patients (93%). Post-procedure abdominal radiographs confirmed proper placement, based on bony landmarks in 24 of 26 patients (92%). Post-procedure complications included insertion site thrombosis in two patients and possible recurrent pulmonary embolism in one patient 2 months following filter placement. One patient died from causes unrelated to IVC filter placement. From these results we conclude that IVC filter placement with IVUS is technically feasible and safe. This may allow for expanded bedside IVC filter placement capabilities in patients with inadequate IVC visualization on transabdominal duplex ultrasound.

Duplex scan–directed placement of inferior vena cava filters: A five-year institutional experience

Purpose: The purpose of this study was the assessment of the safety, efficacy, and hospital charges of bedside duplex ultrasound–directed inferior vena cava (IVC) filter placement. Methods: All duplex ultrasound–directed IVC filters that were placed from August 8, 1995, to December 31, 2000, are reviewed. Chart review combined with mailed questionnaires and telephone follow-up examinations were used to collect demographic and outcome data. Results: Three hundred twenty-five patients underwent evaluation, and 284 underwent duplex ultrasound–directed IVC filter placement. Two hundred three (71%) were male patients, and 81 (29%) were female patients. Poor IVC visualization, IVC thrombosis, and unsuitable anatomy prevented duplex-directed filter placement in 41 patients (12%). Indication for filter placement included venous prophylaxis in the absence of thromboembolism in 235 patients (83%), contraindication to anticoagulation therapy in 34 patients (12%), prophylaxis with therapeutic anticoagulation therapy in the presence of thromboembolism in 7 patients (2%), and complication of anticoagulation therapy in 8 patients (3%). There were no procedure-related deaths or septic complications. Technical complications occurred in 12 patients (4%). Filter misplacement occurred in 6 patients (2%), access thrombosis in 1 (<1%), migration in 1 (<1%), bleeding in 1 (<1%), and IVC occlusion in 3 (1%). Pulmonary emboli after IVC filter placement occurred in one patient with a misplaced filter. Average hospital charges related to duplex ultrasound–directed filter placement were $2388 less than fluoroscopic placement charges in the year 2000. Conclusion: Our experience indicates that duplex ultrasound–directed IVC filter placement is safe, cost-effective, and convenient for patients who need IVC filter placement. (J Vasc Surg 2002;35:286-91.)

Scintigraphic criteria for the diagnosis of renal arteriovenous fistulas.

Visualization of the inferior vena cava (IVC) on renal perfusion imaging occurs in cases of renal arteriovenous (AV) fistulas. A review of consecutive renal scans demonstrated IVC visualization in three of 217 patients without AV fistulas. IVC visualization occurred 3-6 seconds after peak aortic activity in normal patients. With renal AV fistulas, an intrarenal focus of increased activity is seen and IVC visualization occurs coincident with peak aortic activity.

The placement of vena cava umbrella filters. The value of phlebography.

Vena cava umbrella filters, employed to treat pulmonary embolism, are usually positioned at the level of the inferior pole of the right kidney as determined from intravenous pyelography (IVP). Using inferior cavography to define caval anatomy, we found anomalies in two of ten patients (single left inferior vena cava, double inferior vena cava). One patient, in whom an umbrella was previously placed at the level of the inferior pole of the right kidney, developed recurrent pulmonary emboli from the cul-de-sac between the occluded umbrella and the right renal vein; a second umbrella was placed. In another patient, postplacement vena cavography identified umbrella obstruction of the right renal vein; repositioning with a second umbrella was successful. Combined vena cavography and umbrella placement allows (1) visualization of inferior vena cava, including anomalies; (2) precise placement of umbrella filter; (3) occasional detection of source of emboli; and (4) confirmation of diagnosis of pulmonary embolus.

Ergebnisse der medizinischen Strahlenforschung: Diagnostik, Therapie, Nuklearmedizin, Biologie

This volume, edited by Drs. Schinz, Glauner, and Ruttimann, reviews in a superb fashion the most recent work in diagnostic radiology, radiation therapy, nuclear medicine, and radiation biology. It crystallizes the significant work of recent years in these fields, the procedures and techniques which should be routine in the departments of all teaching institutions. The print is easily read, the roentgenographic illustrations excellent, and the illustrations splendid (in black and white as well as color). Several sections are particularly noteworthy. Rosch's review of splenoportography is well conceived and executed, placing this study in its proper and useful niche in the diagnostic armamentarium. Olsson's section on renal artery angiography is an excellent review. Lindbom's review of inferior vena cava visualization describes the values and pitfalls of this study. Some investigators might not share the enthusiasm these authors have for the described studies, but the articles should be required reading. Zuppinger's section