Prognostic value of pulmonary blood volume by first-pass contrast-enhanced CMR in heart failure outpatients: the PROVE-HF study.

Aims: Pulmonary blood volume (PBV) is a novel clinical application of cardiovascular magnetic resonance (CMR) imaging for the quantitative grading of haemodynamic congestion. In this study, we aimed to assess the prognostic value of PBV in a cohort of outpatients with chronic heart failure (HF). Methods and results: One hundred and twelve consecutive patients (91 men, 67 ± 12 years) and 53 age- and sex-matched healthy controls underwent echocardiography and contrast-enhanced CMR. PBV was calculated as the product of stroke volume and the number of cardiac cycles for an intravenous bolus of gadolinium contrast to pass through the pulmonary circulation determined by first-pass perfusion imaging. Compared with healthy controls, HF outpatients showed significantly higher PBV index (PBVI, 308 ± 92 vs. 373 ± 175, mL/m2, P = 0.012) and pulmonary transit time (6.8 ± 1.8 vs. 9.5 ± 4 s, P ≤0.001). During a median follow-up of 26 ± 17 months, 27 patients (24%) reached the composite end point of cardiovascular death, HF hospitalization, or sustained ventricular arrhythmias/appropriate implantable cardioverter-defibrillator intervention. Using a cut-off point of PBVI >492 mL/m2, corresponding to two standard deviations above the mean of healthy controls, event-free survival was significantly lower in patients with higher PBVI (P < 0.001). At multivariable-adjusted Cox regression analysis, PBVI was an independent predictor of the composite cardiovascular end point (per 10% increase hazard ratio 1.31, 95% confidence interval: 1.02-1.69, P = 0.03). Conclusions: PBVI is a novel application of perfusion CMR potentially useful to quantitatively determine haemodynamic congestion as a surrogate marker of left ventricular diastolic dysfunction. PBVI might prove to be helpful in stratifying the prognosis of asymptomatic or mildly symptomatic patients with left ventricular dysfunction.

Spinal cord microstructure integrating phase-sensitive inversion recovery and diffusional kurtosis imaging.

PURPOSE: The aim of this prospective study was to determine the feasibility in terms of repeatability and reproducibility of diffusional kurtosis imaging (DKI) for microstructural assessment of the normal cervical spinal cord (cSC) using a phase-sensitive inversion recovery (PSIR) sequence as the anatomical reference for accurately defining white-matter (WM) and gray-matter (GM) regions of interests (ROIs). METHODS: Thirteen young healthy subjects were enrolled to undergo DKI and PSIR sequences in the cSC. The repeatability and reproducibility of kurtosis metrics and fractional anisotropy (FA) were calculated in GM, WM, and cerebral-spinal-fluid (CSF) ROIs drawn by two independent readers on PSIR images of three different levels (C1-C4). The presence of statistically significant differences in DKI metrics for levels, ROIs (GM, WM, and CSF) repeatability, reproducibility, and inter-reader agreement was evaluated. RESULTS: Intra-class correlation coefficients between the two readers ranged from good to excellent (0.75 to 0.90). The inferior level consistently had the highest concordance. The lower values of scan-rescan variability for all DKI parameters were found for the inferior level. Statistically significant differences in kurtosis values were not found in the lateral white-matter bundles of the spinal cord. CONCLUSION: The integration of DKI and PSIR sequences in a clinical MR acquisition to explore the regional microstructure of the cSC in healthy subjects is feasible, and the results obtainable are reproducible. Further investigation will be required to verify the possibility to translate this method to a clinical setting to study patients with SC involvement especially in the absence of MRI abnormalities on standard sequences.

Comparing 3T T1-weighted sequences in identifying hyperintense punctate lesions in preterm neonates.

BACKGROUND AND PURPOSE: The loss of contrast on T1-weighted MR images at 3T may affect the detection of hyperintense punctate lesions indicative of periventricular leukomalacia in preterm neonates. The aim of the present study was to determine which 3T T1-weighted sequence identified the highest number of hyperintense punctate lesions and to explore the relationship between the number of hyperintense punctate lesions and clinical outcome. MATERIALS AND METHODS: The presence of hyperintense punctate lesions was retrospectively evaluated in 200 consecutive preterm neonates on 4 axial T1-weighted sequences: 3-mm inversion recovery and spin-echo and 1- and 3-mm reformatted 3D-fast-field echo. Statistically significant differences in the number of hyperintense punctate lesions were evaluated by using a linear mixed-model analysis. Logistic regression analysis was used to assess the relation between the number of hyperintense punctate lesions and neuromotor outcome at 3 months. RESULTS: Thirty-one neonates had at least 1 hyperintense punctate lesion indicative of periventricular leukomalacia in at least 1 of the 4 sequences. The 1-mm axial reformatted 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions (P < .001). No statistically significant differences were found among the 3-mm T1-weighted sequences. The greater number of hyperintense punctate lesions detected by the 1-mm reformatted T1 3D-fast-field echo sequence in the central region of the brain was associated with a worse clinical outcome. CONCLUSIONS: At 3T, the 1-mm axial reformatted T1 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions in the central region of preterm neonate brains, and this number was associated with neuromotor outcome.

Diffusion-weighted magnetic resonance for prediction of response after neoadjuvant chemoradiation therapy for locally advanced rectal cancer: preliminary results of a monoinstitutional prospective study.

PURPOSE: To evaluate diffusion-weighted imaging (DWI) for assessment of treatment response in locally advanced rectal cancer (LARC) 8 weeks after neoadjuvant chemoradiotherapy (CRT). METHODS AND MATERIALS: A total of 28 patients with LARC underwent magnetic resonance imaging (MRI) prior to and 8 weeks after CRT. Tumor volume (TV) was calculated on T2-weighted MRI scans as well as the apparent diffusion coefficient (ADC) was calculated using Echo-planar DWI-sequences. All data were correlated to surgical results and histopathologic tumor regression grade (TRG), according to Mandard's classification. Post-treatment difference ADC (%ΔADC) and TV (%ΔTV) changes at 8 weeks were compared complete response (CR; TRG1) and non-complete response tumors (non-CR; TRG2-5). RESULTS: The mean % ADC increase of CR group was significantly higher compared to non-CR group (77.2 ± 54.63% vs. 36.0 ± 29.44%; p = 0.05). Conversely, the mean % TV reduction did not significantly differ in CR group from non-CR group (73.7% vs. 63.77%; p = 0.21). Accordingly, the diagnostic accuracy of the mean % ADC increase to discriminate CR from non-CR group was significantly higher than that of the mean % TV reduction (0.913 vs. 0.658; p = 0.022). No correlation was found between mean % TV reduction and TRG (rho = 0.22; p = 0.3037), whereas a negative correlation between mean % ADC increase and TRG was recorded (r = -0.69; p = 0.006). CONCLUSION: The mean % ADC increase appears to be a reliable tool to differentiate CR from non-CR after CRT in patients with LARC.

Malpractice claims in interventional radiology: frequency, characteristics and protective measures.

PURPOSE: The use of interventional radiology procedures has considerably increased in recent years, as has the number of related medicolegal litigations. This study aimed to highlight the problems underlying malpractice claims in interventional radiology and to assess the importance of the informed consent process. MATERIALS AND METHODS: The authors examined all insurance claims relating to presumed errors in interventional radiology filed by radiologists over a period of 14 years after isolating them from the insurance database of all radiologists registered with the Italian Society of Medical Radiology (SIRM) between 1 January1993 and 31 December 2006. RESULTS: In the period considered, 98 malpractice claims were filed against radiologists who had performed interventional radiology procedures. In 21 cases (21.4%), the event had caused the patient's death. In >80% of cases, the event occurred in a public facility. The risk of a malpractice claim for a radiologist practising interventional procedures is 47 per 1,000, which corresponds to one malpractice claim for each 231 years of activity. DISCUSSION: Interventional radiology, a discipline with a biological risk profile similar to that of surgery, exposes practitioners to a high risk of medicolegal litigation both because of problems intrinsic to the techniques used and because of the need to operate on severely ill patients with compromised clinical status. CONCLUSIONS: Litigation prevention largely depends on both reducing the rate of medical error and providing the patient with correct and coherent information. Adopting good radiological practices, scrupulous review of procedures and efficiency of the instruments used and audit of organisational and management processes are all factors that can help reduce the likelihood of error. Improving communication techniques while safeguarding the patient's right to autonomy also implies adopting clear and rigorous processes for obtaining the patient's informed consent to the medical procedure.

Multi-detector CT angiographic imaging in the follow-up of patients after endovascular abdominal aortic aneurysm repair (EVAR).

BACKGROUND: Multidetector computed tomography (MDCT) angiography represents the standard of reference in the follow-up of patients after endovascular abdominal aortic aneurysm repair (EVAR), being effective in the detection of the full spectrum of possible complications on both axial and 3D images. METHODS: The purpose of this article is to review the normal CT angiography findings of the different types of stent-grafts and to describe the radiological findings of early and late complications after EVAR on axial and reconstructed images. A selection of cases of post-EVAR MDCT angiography is presented to learn the techniques most commonly used for endovascular treatment, the correct CT scanning technique to acquire the data, the full gamut of possible procedure-related complications and how these complications usually appear on CT images. CONCLUSION: MDCT angiography is an effective and specific technique in both the pre- and postoperative settings of EVAR procedures. A better understanding of the procedure, the devices, the normal postoperative imaging features and the possible procedure-related complications ensures optimal planning and follow-up of patients undergoing an EVAR procedure.

Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm after endovascular repair.

PURPOSE: To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm. MATERIALS AND METHODS: In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement. RESULTS: Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p<0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p=0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63±6.97 vs. 11.48±8.13; p=0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol. CONCLUSION: In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.

Endoleaks after endovascular repair of abdominal aortic aneurysm: value of CEUS.

Endovascular repair (EVAR) is playing an increasingly role in the treatment of abdominal aortic aneurysm. A successful procedure depends on the complete sealing of the aneurysm sac from blood flow to achieve general pressure relief and avoid aneurysm rupture, with a shrinkage of the aneurysm sac. The most common complication of EVAR is endoleak that is the persistence of perigraft flow within the aneurysm sac, which has to be considered the major cause of enlargement and rupture of the aneurysm, and the main indication for surgical late conversion. For this reason, strict surveillance of these patients is mandatory for the early detection of endoleaks and the preferred method of follow-up is represented by CT angiography. However, CTA has limitations. The investigation is repeated several times, making radiation exposure a necessary concern. Therefore, it would be useful to have another reliable diagnostic examination during follow-up. Color duplex ultrasound is non-invasive, does not use radiation or contrast medium, is less expensive, easy to perform and widely available. However, this technique obtained poor results in terms of sensitivity in the detection of endoleaks. In the last years, the introduction of ultrasound contrast agents and contrast-specific imaging has, however, rekindled interest in this modality and its potential for replacing of CTA in routine surveillance. The purpose of this review is to highlight the diagnostic value of CEUS in the post-EVAR endoleaks detection.

Pre-hepatectomy portal vein embolization: single center experience.

AIM: To evaluate the feasibility and the effectiveness of portal vein embolization (PVE) as preoperative treatment in patients scheduled to undergo right hepatectomy, when the volume of the future remnant liver (FRL) appears to be insufficient to prevent the risk of post-surgical hepatic failure. MATERIALS AND METHODS: Thirty-one consecutive patients (19 men, 12 women; age range: 54-77 years; mean age: 66.2 years) with liver malignancy (7 hepatocellular carcinoma, 13 metastases, 9 cholangiocarcinoma, and 2 gallbladder carcinoma) were selected after clinical-radiological evaluation for PVE. After the embolization changes in volume of FRL, portal pressure, liver enzymes, and complications before and after hepatectomy were assessed. RESULTS: PVE was successful in all patients without major complications. The mean volume of FRL, calculated before and 4 weeks after PVE, increased from 319.2 +/- 45.1 to 460.2 +/- 27.7 cm(3) (+44.2%) in the non-cirrhotic group and from 458.4 +/- 38.3 to 605.2 +/- 27 cm(3) (+32.1%) in the cirrhotic group. The FRL/TELV ratio increased by 9%. CONCLUSION: In our experience, PVE resulted feasible, safe, with a very low rate of complications, and effective to induce liver regeneration before right hepatectomy in patients with liver malignancy.

Endovascular treatment of femoropopliteal steno-obstructive disease with percutaneous transluminal angioplasty: midterm results.

PURPOSE: This study aimed to evaluate midterm outcomes of conventional percutaneous transluminal angioplasty (PTA) in the treatment of femoropopliteal steno-obstructive disease and assess the effect of risk factors on patency rates. MATERIALS AND METHODS: One hundred consecutive patients with femoropopliteal steno-obstructive disease underwent PTA, for a total of 104 procedures. Presence of cardiovascular risk factors, TransAtlantic Inter-Society Consensus (TASC) classification, runoff status, pre-and postprocedural clinical data and procedure outcome were recorded. Follow-up consisted of clinical assessment and colour Doppler ultrasonography at 1, 6 and 12 months. RESULTS: Technical success was 96% (96/100). Seven lesions required stent placement. Primary and secondary patency rates were 82.7% and 88.8% at 6 months and 74.3% and 81.5% at 12 months, respectively. Primary patency rates at 12 months were significantly higher for TASC A-B-C lesions than for TASC D lesions (p < 0.05). Primary patency rates at 12 months were 61.6% and 78.8% (p<0.05) for poor or adequate runoff status, respectively. CONCLUSIONS: Conventional PTA is a minimally invasive alternative to bypass surgery for treating TASC A-C atherosclerotic lesions in the presence of adequate runoff.

Endovascular abdominal aortic aneurysm repair and renal complications: a comparison between suprarenal and infrarenal fixation of stent grafts.

PURPOSE: This study was performed to compare the rate of morphological (renal infarction and/or ischaemic lesions) and functional renal complications after the suprarenal and infrarenal fixation of aortic stent-grafts for endovascular abdominal aortic aneurysm repair (EVAR). MATERIALS AND METHODS: We retrospectively reviewed all followup computed tomography (CT) angiograms (obtained at 1, 6 and 12 months and yearly thereafter) and laboratory data pertaining to 102 patients who underwent suprarenal (60 patients, group A) or infrarenal (42 patients, group B) placement of aortic stent-grafts. The groups were compared in terms of complications affecting kidney function (creatinine clearance) and morphology (renal artery steno-occlusions, morphological and structural parenchymal changes), and pre- and postprocedural arterial pressure (AP). RESULTS: Analysis of patient demographics revealed no statistically significant difference between the two groups. The proximal neck was shorter in group A (2.14 cm+/-0.84 cm) than in group B (3.41 cm+/-1.21 cm). Creatinine clearance (CrCl) decreased in both groups (group A: from 64.24 ml/min to 60.66 ml/min; group B: from 72.41 ml/min to 68.73 ml/min) without any significant difference in terms of changes in renal function (CrCl variation: -8.75% vs. -6.4%) or morphology (post-EVAR stenosis: 2.6% vs. 0%; progression of existing steno-occlusive lesions: 1% vs. 0%; ischaemic lesions: 3.2% vs. 0%), or in AP. CONCLUSIONS: In our experience, the use of abdominal endografts with suprarenal fixation did not lead to any significant increase in morphological and/or functional renal complications compared with those with infrarenal fixation.

Endovascular abdominal aortic aneurysm repair: how many patients are eligible for endovascular repair?

PURPOSE: The purpose of this study was to determine how many patients with abdominal aortic aneurysm (AAA) are eligible for endovascular abdominal aortic aneurysm repair (EVAR). MATERIALS AND METHODS: We retrospectively reviewed computed tomography (CT) angiograms obtained between January 2002 and June 2003 in 182 patients with suspected AAA. Indication for surgical or endovascular treatment was based on clinical and radiological criteria. The percentage of patients eligible for EVAR was evaluated. RESULTS: Out of a total of 182 patients with suspected AAA studied by CT angiography, after combined radiological-surgical assessment, 130 were considered eligible for surgical or endovascular treatment (71.4%). EVAR was indicated in 51 patients (39.3%, group A) and surgical repair was indicated in 79 patients (60.7%, group B). The reasons for ineligibility for EVAR were the following: unfavourable anatomy of the proximal neck in 41 patients (51.9%), diameter of the aneurysm sac >7 cm in 13 patients (16.4%), markedly tortuous/dilated iliac axis in six patients (7.6%), age <65 years in 17 patients (21.5%) and patient refusal in two cases (2.5%). There were no statistically significant differences in aneurysm diameter (52.7+/-0.8 versus 49.8+/-1.2 mm, p=ns), patients' age (73.2+/-1.2 versus 70.6+/-2.02 years, p=ns) or proximal neck length (2.95+/-1 versus 3.03+/-1.2 cm, p=ns) between groups A and B. CONCLUSIONS: Endovascular repair of abdominal aortic aneurysms through the placement of aortic stent-grafts has now become a viable alternative to open surgery. In recent years, the number of patients treated with EVAR has steadily risen as a result of increased physician experience, availability of new and more versatile devices and improvements in noninvasive imaging techniques. Unfavourable neck anatomy is the primary factor for exclusion from endovascular repair.

Computed tomography imaging of vena cava filter complications: a pictorial review.

Caval filters are widely used in the prevention of pulmonary embolism. Filters have proved to be effective, but the complication rate is not negligible. Computed tomography (CT) provides a complete evaluation of the filter, including both caval and extracaval complications. In this review, we describe the normal CT aspect of cava filters, the classification of complications and their CT findings. Technical considerations for adequate CT imaging are also highlighted.

Endovascular repair of abdominal aortic aneurysms: CTA evaluation of contraindications.

Endovascular aortic aneurysm repair (EVAR) is considered an acceptable alternative to open surgery in selected patients. Its feasibility depends mainly on anatomic factors that represent the important predictors of success and the most important exclusion criteria. Poor anatomic patient selection is generally associated with a higher risk for procedural complications and compromised long-term outcomes. Therefore pretreatment imaging is crucial for evaluating patient suitability for EVAR. Multidetector computed tomographic angiography represents the current standard of reference in the evaluation of the abdominal aorta and iliac axis anatomy because it provides all the details needed for selection of patients who are suitable for endograft and the choice of the appropriate device. This report identifies and reviews computed tomographic angiographic anatomic contraindications for EVAR.

Color Doppler sonography in the diagnosis and monitoring of arterial complications after liver transplantation.

PURPOSE: We assessed the usefulness of color Doppler imaging in the diagnosis and monitoring of arterial complications after liver transplantation. METHODS: Subjects were 142 liver transplant recipients who underwent serial color Doppler sonographic evaluations of the hepatic arteries after surgery. Patients with abnormal sonographic findings underwent subsequent angiography. RESULTS: Eighteen subjects experienced 20 hepatic arterial complications (13 thromboses and 7 stenoses). In 7 of the 13 thrombosis incidents, hepatic arterial obstruction occurred within a month of surgery and was evident from the absence of Doppler signals; angiography confirmed the absence of hepatic arterial perfusion in these cases. In the other 6 thrombosis cases, the thrombosis developed 3 or more months after surgery and became apparent from the absence of color Doppler signals at the level of the main arterial trunk and the presence of intraparenchymal "tardus parvus" waveforms. In these cases, angiography showed obstruction of the main arterial trunk and the development of compensatory collateral vessels. In 3 of the 7 cases of stenosis, high flow velocities were recorded at the site of the narrowing, and intrahepatic tardus parvus waveforms were present. In the other 4 stenosis cases, the site of stenosis could not be identified, but intraparenchymal tardus parvus waveforms were recorded. CONCLUSION: The use of color Doppler sonography allows the early diagnosis of hepatic arterial complications after liver transplantation. Tardus parvus waveforms indicated severe impairment of hepatic arterial perfusion, from either thrombosis or severe stenosis. The presence of these waveforms enhanced the accuracy of color Doppler diagnosis (100% positive predictive value), and their detection should prompt angiography.

Delayed MR imaging of hepatocellular carcinoma enhanced by gadobenate dimeglumine (Gd-BOPTA).

The purpose of this study was to determine the efficacy of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging for evaluation of hepatocellular carcinoma HCC. MR images were obtained in 14 patients with 31 HCC nodules as a part of a phase III clinical trial. T1- and T2-weighted images were obtained before and after iv administration of 0.1 mmol/kg of Gd-BOPTA. Two blinded readers evaluated pre- and delayed postcontrast images separately for detection of tumor nodules. Quantitative measurements of signal-to-noise (SNR) and tumor/liver contrast-to-noise (CNR) ratios were also performed. A signal/intensity ratio was calculated. Tumor enhancement was correlated with histologic findings. Consensus agreement of precontrast T1- and T2-weighted images revealed 23/31 HCC nodules in 14 patients; postcontrast T1-weighted images demonstrated 24/31 HCC nodules in the same number of patients. Combining both pre- and postcontrast images, 27/31 lesions were detected. Four patients had four well-differentiated HCC nodules detected only on postcontrast images, while three well-differentiated lesions in two patients were only seen on precontrast images. Quantitative evaluation showed an SNR ratio increase in both liver parenchyma and HCC nodules, as well as a significant increase in the absolute CNR ratio on postcontrast T1-weighted gradient-recalled images (P < 0.05). Well-differentiated HCC lesions showed a greater enhancement than poorly differentiated HCC lesions.

Gadobenate dimeglumine (BOPTA) enhanced MR imaging: patterns of enhancement in normal liver and cirrhosis.

To determine whether gadobenate dimeglumine (BOPTA) will adequately enhance cirrhotic liver parenchyma, and to document the enhancement patterns in cirrhosis, 14 cirrhotic and 20 non-cirrhotic patients were evaluated before and 60-120 minutes after gadolinium-BOPTA. Proof of liver cirrhosis was biopsy (6), surgical resection (3), and clinical follow-up (5). Enhancement effects were compared quantitatively by determining the liver signal-to-noise ratio (SNR) and signal enhancement in both populations. Qualitatively assessment of the liver enhancement was performed and classified as homogeneous or heterogeneous. Quantitative analysis: cirrhotic liver parenchyma presented a higher increase in SNR values, relative to non-cirrhotic liver parenchyma, on postcontrast images. Likewise the signal enhancement of cirrhotic liver parenchyma was superior to non-cirrhotic liver on T1-weighted SE images (P = .02) and in-phase GRE images (P < .001). There was no statistical difference on out-of-phase GRE images. Qualitative analysis: on T1-weighted SE postcontrast images, cirrhotic liver parenchyma showed a homogeneous enhancement in 7 patients and heterogeneous in 7. Whereas on GRE images, cirrhotic parenchyma showed heterogeneous enhancement in 9 patients and homogeneous in 5 patients. The heterogeneous enhancement was due to the presence of hypointense nodules in 7 patients and hyperintense nodules in 2 patients. In conclusion, our study has shown that the hepatobiliary contrast agent Gd-BOPTA is effective in the cirrhotic liver, demonstrating an increased liver enhancement compared with non-cirrhotic patients.

Sonographic and Doppler assessment of the inferior mesenteric artery: normal morphologic and hemodynamic features.

BACKGROUND: We wanted to evaluate prospectively the feasibility of sonographic and Doppler assessment of the inferior mesenteric artery (IMA) and to provide data on its normal morphological and hemodynamic characteristics. METHODS: Sonography and Doppler study of the IMA were performed on 116 patients without splanchnic vessel pathology. Vessel diameter, systolic, diastolic, and time-averaged mean flow velocities, pulsatility index values, and flow volumes were correlated with patient age (< 50 years vs. > or = 50 years) using the Wilcoxon rank-sum test. Findings were verified by splanchnic angiography in 11 cases. RESULTS: Technically valid studies were obtained in 103/116 cases (88.8%). Flowmetric data showed high peripheral resistance (mean +/- SD: systolic flow velocity, 1.41 m/s +/- 0.48; minimal diastolic flow velocity, 0.10 m/s +/- 0.16; pulsatility index, 3.49 +/- 0.49). Mean flow volume calculated in 80 cases was 0.13 L/min +/- 0.06. Older subjects presented significantly higher time-averaged mean flow velocities and lower resistance than those younger than 50 years. CONCLUSIONS: The success rate for sonographic and Doppler study of the IMA is similar to that observed with larger splanchnic vessels. Knowledge of its normal characteristics is necessary for recognition of pathological conditions and for studies of its physiological behavior.