Doppler ultrasonographic evaluation of splanchnic blood flow in coeliac disease

A systematic review and meta-analysis of portal vein morphometry in pediatric and adult populations: Drawing the line between normal and abnormal findings

PURPOSE

The morphometry of the hepatic portal vein is of clinical importance, particularly in pre-operative assessments, surgical management, and diagnoses of liver conditions. This systematic review and meta-analysis aimed to characterize the morphometry of the normal portal vein in both pediatric and adult patients.

METHODS

The study, conducted using the PRISMA guidelines and registered with PROSPERO, utilized the MEDLINE, EMBASE, SCOPUS and Web of Science databases up to May 2020, and updated to May 2023. All studies reporting extractable data on diameter, length, and cross-sectional area (CSA) of the main, left, and right portal veins (PV, LPV, RPV, respectively) were included. The AQUA Tool was used to assess the quality of the included studies. Data analysis included subgroup analyses based on geographical location, sex, age, and imaging modality.

RESULTS

A total of 122 studies with 11,637 subjects were eligible for inclusion. Overall, the pooled mean diameter of the PV (PVD) was 10.09 mm (95% CI: 9.56-10.62). Significant differences in diameter were found between pediatric (6.60 mm; 95% CI: 5.38-7.82) and adult (10.72 mm; 95% CI: 10.25-11.19) subjects. Additionally, there was a significantly larger PVD measurement from computed tomography (CT) than other imaging modalities: CT, 13.28 mm (95% CI: 11.71-14.84); magnetic resonance imaging (MRI), 10.50 mm (95% CI: 9.35-11.66) and ultrasound (US), 9.81 mm (95% CI: 9.47-10.16). The mean diameters of the LPV and RPV were 8.27 mm (95% CI: 6.78-9.77) and 8.33 mm (95% CI: 6.70-9.95), respectively. Mean PV length in adults is 48.63 mm (95% CI: 35.63-61.64). Mean CSA of the PV was 1.09 cm2.

CONCLUSIONS

The study obtained aim to improve the understanding of portal vein anatomy, especially with relevance to surgical interventions of the liver in both pediatric and adult patients. Measurements from ultrasound imaging closely approximates the generated pooled PVD mean for pediatric and adult patients. CT imaging, however, significantly exceeded the established 13 mm threshold for adults. For pediatric patients, a threshold of 8 mm is proposed as a diagnostic upper limit for a normal PVD. Although not significant, the PVD decreased from the portal confluence towards its bifurcation.

Cerebral hemodynamic changes to transcranial Doppler sonography in celiac disease: A pilot study

Background

Sonographic mesenteric pattern in celiac disease (CD) suggests a hyperdynamic circulation. Despite the well-known CD-related neurological involvement, no study has systematically explored the cerebral hemodynamics to transcranial Doppler sonography.

Materials and methods

Montreal Cognitive Assessment (MoCA) and 17-item Hamilton Depression Rating Scale (HDRS) were assessed in 15 newly diagnosed subjects with CD and 15 age-, sex-, and education-matched healthy controls. Cerebral blood flow (CBF) velocities and indices of resistivity (RI) and pulsatility (PI) from the middle cerebral artery (MCA), bilaterally, and the basilar artery (BA) were recorded. We also assessed cerebral vasomotor reactivity (CVR) through the breath-holding test (BHT).

Results

Worse scores of MoCA and HDRS were found in patients compared to controls. Although patients showed higher values of CBF velocity from MCA bilaterally compared to controls, both at rest and after BHT, no comparison reached a statistical significance, whereas after BHT both RI and PI from BA were significantly higher in patients. A significant negative correlation between both indices from BA and MoCA score were also noted.

Conclusion

These treatment-naïve CD patients may show some subtle CVR changes in posterior circulation, thus possibly expanding the spectrum of pathomechanisms underlying neuroceliac disease and in particular gluten ataxia. Subclinical identification of cerebrovascular pathology in CD may help adequate prevention and early management of neurological involvement.

Effect of aortic arch surgery in newborns' cerebral and gastrointestinal hemodynamics: evaluation by Doppler ultrasonography

AIM

In this study, we investigated changes in newborns' cerebral and intestinal blood flow who had undergone aortic arch surgery.

METHOD

This study was carried out prospectively as a preliminary study in patients younger than 30 days at the time of aortic arch reconstruction between 1 August and 1 December, 2019. Cerebral and gastrointestinal hemodynamics were evaluated with Doppler USG before and 7 days after the operation. The middle cerebral artery (MCA) and celiac artery (CA) were used as measurement sites. Patients' peak systolic velocity (PSV), mean systolic velocity (MV), end diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) were evaluated.

RESULTS

A total of 16 patients enrolled in the study. The patients' median weight was 3.2 kg (2.7-4.5 kg), and age was 21 days (7-30 days). Six of them were female. Seven of the patients who underwent arcus reconstruction had an additional ventricular septal defect. The preoperative Doppler USG values of patients' were as follows: for MCA, the mean PSV was 37 ± 12 cm/s, EDV 12 ± 5 cm/s, MV 22 ± 19 cm/s, RI 0.70 ± 0.03, PI 1.24 ± 0.23, and for CA mean PSV was 67 ± 32 cm/s, EDV 29 ± 14 cm/s, MV 24 ± 9 cm/s, RI 0.79 ± 0.27, and PI 1.63 ± 0.89. Doppler USG values of patients' at the postoperative seventh day were as follows: for the MCA, mean PSV 41 ± 13 cm/s, EDV 13 ± 4 cm/s, MV 25 ± 10 cm/s, RI 0.64 ± 0.05, PI 1.23 ± 0.20, and for the CA mean PSV 70.5 ± 34 cm/s, EDV 32 ± 16 cm/s, MV 26 ± 8 cm/s, RI 0.75 ± 0.1, and PI 1.60 ± 0.38. There was a significant decrease in RI of both MCA and CA on the postoperative 7th day compared to the preoperative period (p < 0.05).

CONCLUSION

In newborns, there are significant changes in cerebral and intestinal blood flows after aortic arch surgery. RI decreased significantly, especially in the CA and MCA.

Duplex Doppler Sonographic Assessment of the Superior Mesenteric Artery in Patients With Mesenteric Panniculitis

OBJECTIVES

We aimed to determine how the hemodynamic parameters of the superior mesenteric artery are affected in mesenteric panniculitis.

METHODS

Twenty-one patients with a diagnosis of mesenteric panniculitis on computed tomography were evaluated with duplex Doppler sonography. The control group consisted 20 asymptomatic volunteers. The peak systolic velocity, end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI), blood flow volume, and body mass index were measured in the group of patients with mesenteric panniculitis, and the findings were compared with those of the control group.

RESULTS

The mean blood flow volume and EDV were significantly higher in the patient group: The mean superior mesenteric artery blood flow volume ± SD was 917.86 ± 228.97 mL/min in the patient group versus 389.73 ± 92.72 mL/min in the control group (P < .001). The mean EDV was 31.56 ± 8.44 m/s in the patient group versus 19.27 ± 4.19 m/s in the control group (P < .001). The mean RI and PI were significantly lower in the patient group: The mean RI was 0.81 ± 0.04 in the patient group versus 0.85 ± 0.03 in the control group (P = .001). The mean PI was 2.69 ± 0.68 in the patient group versus 3.81 ± 1.13 in the control group (P = .001). the mean superior mesenteric artery diameter was 7.30 ± 0.67 mm in the patient group versus and 6.46 ± 0.66 mm in the control group (P < .001). The mean BMI was 27.95 ± 3.80 kg/m² in the patient group versus 23.16 ± 3.47 kg/m² in the control group (P < .001).

CONCLUSIONS

In patients with mesenteric panniculitis, the Doppler spectrum of the superior mesenteric artery shows detectable changes, which are characterized by decreased vascular resistance and increased blood flow.

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

Beyond moulage sign and TTG levels: the role of cross-sectional imaging in celiac sprue

Celiac disease is an autoimmune disorder that causes inflammation and destruction in the small intestine of genetically susceptible individuals following ingestion of gluten. Awareness of the disease has increased; however, it remains a challenge to diagnose. This review summarizes the intestinal and extraintestinal cross-sectional imaging findings of celiac disease. Small intestine fold abnormalities are the most specific imaging findings for celiac disease, whereas most other imaging findings reflect a more generalized pattern seen with malabsorptive processes. Familiarity with the imaging pattern may allow the radiologist to suggest the diagnosis in patients with atypical presentations in whom it is not clinically suspected. Earlier detection allows earlier treatment initiation and may prevent significant morbidity and mortality that can occur with delayed diagnosis. Refractory celiac disease carries the greatest risk of mortality due to associated complications, including cavitating mesenteric lymph node syndrome, ulcerative jejunoileitis, enteropathy-associated T cell lymphoma, and adenocarcinoma, all of which are described and illustrated. Radiologic and endoscopic investigations are complimentary modalities in the setting of complicated celiac disease.

Thermal therapy of pancreatic tumours using endoluminal ultrasound: Parametric and patient-specific modelling

PURPOSE

The aim of this study is to investigate endoluminal ultrasound applicator configurations for volumetric thermal ablation and hyperthermia of pancreatic tumours using 3D acoustic and biothermal finite element models.

MATERIALS AND METHODS

Parametric studies compared endoluminal heating performance for varying applicator transducer configurations (planar, curvilinear-focused, or radial-diverging), frequencies (1-5 MHz), and anatomical conditions. Patient-specific pancreatic head and body tumour models were used to evaluate feasibility of generating hyperthermia and thermal ablation using an applicator positioned in the duodenal or stomach lumen. Temperature and thermal dose were calculated to define ablation (> 240 EM(43 °C)) and moderate hyperthermia (40-45 °C) boundaries, and to assess sparing of sensitive tissues. Proportional-integral control was incorporated to regulate maximum temperature to 70-80 °C for ablation and 45 °C for hyperthermia in target regions.

RESULTS

Parametric studies indicated that 1-3 MHz planar transducers are the most suitable for volumetric ablation, producing 5-8 cm(3) lesion volumes for a stationary 5-min sonication. Curvilinear-focused geometries produce more localised ablation to 20-45 mm depth from the GI tract and enhance thermal sparing (T(max) < 42 °C) of the luminal wall. Patient anatomy simulations show feasibility in ablating 60.1-92.9% of head/body tumour volumes (4.3-37.2 cm(3)) with dose < 15 EM(43 °C) in the luminal wall for 18-48 min treatment durations, using 1-3 applicator placements in GI lumen. For hyperthermia, planar and radial-diverging transducers could maintain up to 8 cm(3) and 15 cm(3) of tissue, respectively, between 40-45 °C for a single applicator placement.

CONCLUSIONS

Modelling studies indicate the feasibility of endoluminal ultrasound for volumetric thermal ablation or hyperthermia treatment of pancreatic tumour tissue.

Contribuição da ultrassonografia abdominal para o diagnóstico da doença celíaca em crianças e adolescentes

Objetivos: comparar as características clínicas e parâmetros ultrassonográficos em um grupo de crianças e adolescentes, recentemente diagnosticados como portadores de doença celíaca, com um grupo controle. Métodos: estudo clínico conduzido com amostra de 20 pacientes recentemente diagnosticados com doença celíaca e 35 pacientes assintomáticos sem doença celíaca. Ultrassonografias abdominais foram realizadas em todos os pacientes. Os casos foram submetidos às ultrassonografias durante a fase de investigação diagnóstica, ainda consumindo glúten. Foram avaliados parâmetros ultrassonográficos e ao Doppler, relacionados às características das alças intestinais, linfonodomegalias e alterações no fluxo sanguíneo esplâncnico. As diferenças de proporções entre os grupos foram avaliadas pelos testes do quiquadrado e exato de Fisher e a diferença de médias pelo teste t de Student. Resultados: as principais manifestações clínicas relacionadas à doença celíaca foram as digestivas, como diarréia (12/20), dor abdominal (14/20) e distensão abdominal (15/20). Pacientes com doença celíaca apresentaram maior diâmetro transverso das alças do delgado (p=0,001), maior peristaltismo intestinal (p=0,002), aumento do conteúdo líquido intestinal (p=0,02), e maior espessura parietal (p<0,001). Conclusões: alterações sugestivas de má digestão/absorção (aumento do diâmetro transverso das alças do intestino delgado, maior peristaltismo intestinal, aumento do conteúdo líquido) e o espessamento da parede intestinal em pacientes com queixas digestivas devem alertar o clínico para investigar a doença celíaca.

Ultrasound of selected pathologies of the small intestine

Intestines, especially the small bowel, are rarely subject to US assessment due to the presence of gases and chyme. The aim of this paper was to analyze ultrasound images in selected pathologies of the small intestine in adults, including the aspects of differential diagnosis.

MATERIAL AND METHODS

In 2001-2012, abdominal ultrasound examinations were conducted in 176 patients with the following small bowel diseases: Crohn's disease (n=35), small bowel obstruction (n=35), yersiniosis (n=28), infectious diarrhea (n=26), bacterial overgrowth syndrome (n=25), coeliac disease (n=15) and small bowel ischemia (n=12). During examinations patients were fasting and no other particular preparations were needed. Convex transducers of 3.5-6 MHz and linear ones of 7-12 MHz were used. The assessment of the small intestine in four abdominal quadrants constituted an integral element of the examination. The following features of the small bowel ultrasound presentation were subject to analysis: thickness and perfusion of the walls, presence of thickened folds in the jejunum, reduction of their number, presence of fluid and gas contents in the intestine, its peristaltic activity, jejunization of the ileum and enteroenteric intussusception. Furthermore, the size of the mesenteric lymph nodes and the width of the superior mesenteric artery were determined and the peritoneal cavity was evaluated in terms of the presence of free fluid.

RESULTS

Statistically significant differences were obtained between the thickness of the small intestine in Crohn's disease or in ischemic conditions and the thickness in the remaining analyzed pathological entities. Small bowel obstruction was manifested by the presence of distended loops due to gas and fluid as well as by severe peristaltic contractions occurring periodically. In the course of ischemic disease, the intestinal walls were thickened without the signs of increased perfusion and in the majority of cases intestinal stenosis was observed. Fluid in the intestine was detected in all patients with coeliac disease, gas in 86.7% of patients, thickening of the folds in the jejunum in 86.7%, their reduction in 80%, increased (enhanced) peristalsis in 93.3% and jejunization in 40%. In 80% of coeliac disease cases, the intestine showed the features of hyperemia on color Doppler examination and in 53.3% of patients the dilated lumen of the superior mesenteric artery was detected. Enlarged mesenteric lymph nodes were visualized in 73.3% of the subjects, enteroenteric intussusception in 33.3% and free fluid in the peritoneal cavity in 60%.

CONCLUSIONS

Small bowel obstruction is manifested by the presence of evidently dilated intestinal loops filled with gas and fluid and periodical severe deepened peristalsis.Ischemic changes and Crohn's disease are characterized by the presence of fragmentarily thickened intestinal walls and intestinal stenosis. Moreover, in Crohn's disease, increased wall perfusion and mesenteric adenomegaly is encountered.Coeliac disease is manifested by: increased amount of fluid mainly in the jejunum, thickened and hyperemic jejunal walls, increased peristalsis;hypertrophied mucosal folds - often their number is reduced, jejunization and transient enteroenteric intussusception;ultrasound changes that require the differentiation with small intestinal bacterial overgrowth syndrome and, to a lesser degree, with infectious diarrhea.

Sonographic assessment of splanchnic arteries and the bowel wall

The intestinal wall can be visualized using high resolution transabdominal ultrasound. The normal intestinal wall thickness in the terminal ileum, cecum, and right and left colon is <2mm when examined with graded compression. It is important to appreciate that a contracted intestinal segment can be misinterpreted as a thickened wall. Vascularisation can be mainly displayed in the second hyperechoic layer (submucosal layer) as well as vessels penetrating the muscularis propria. Imaging of the gastrointestinal wall is dependent on the experience of the examiner as well dependent on the equipment used. Acute or chronic inflammation of the intestinal wall is accompanied by increased perfusion of the mesentery, which can be displayed non-quantitatively with colour duplex. In contrast, ischemia is characterised by hypoperfusion of the mesenteric arteries and the bowel wall. The most promising sonographic approach in assessing splanchnic arteries and the bowel wall is combining the analysis of superior and inferior mesenteric inflow by pulsed Doppler scanning (systolic and diastolic velocities, resistance index) with the end-organ vascularity by colour Doppler imaging diminishing the influence of examination technique only displaying bowel wall vascularity. Colour Doppler imaging has been described as helpful in a variety of gastrointestinal disorders, particularly in patients with Crohn's disease, celiac disease, mesenteric artery stenosis and other ischemic gastrointestinal diseases, graft versus host disease and hemorrhagic segmental colitis.

Bowel sonography in adult celiac disease: diagnostic accuracy and ultrasonographic features

BACKGROUND

Celiac disease (CD) is a chronic intolerance to gluten, which induces intestinal mucosal lesions in genetically predisposed individuals. Transabdominal bowel sonography (TABS) is a safe and noninvasive procedure that allows to detect intestinal abnormalities in many conditions, but actually is not routinely part of the diagnostic management of CD.

AIM

To evaluate the diagnostic accuracy of TABS in CD patients.

PATIENTS AND METHODS

Fifty CD patients and 50 dyspeptic subjects (control group) underwent TABS. The presence of fluid-distended small bowel loops with thickened valvulae conniventes and increased peristalsis was considered a TABS sign of CD. All clinical, biochemical, and TABS features were assessed at the diagnosis and revaluated after 1 year of gluten-free diet.

RESULTS

TABS signs were present in 66% of CD patients. Sensitivity, specificity, positive and negative predictive value were 66%, 96%, 94%, and 74%, respectively. TABS findings were recorded in 82% of patients with endoscopical markers of CD, in 87.5% of symptomatic patients, and in 61% of patients without symptoms. After 1 year of gluten-free diet TABS was still abnormal in 20% patients, with no correlation with laboratory tests e/o symptoms.

CONCLUSIONS

Patients with CD frequently present TABS signs of the disease and operators performing sonography every day have to consider the possibility to suggest CD diagnosis and aTTG determination in these subjects.

The role of ultrasonography in patients with celiac disease

The aim of the present review was to summarize the current evidence on the role of ultrasonography (US) and doppler-US in the diagnosis of celiac disease.

Several ultrasonographic signs have been reported in the association with celiac disease in studies using real-time US. Firstly, case control studies identified some of these US signs and then in a prospective series some of these parameters, due to their high specificity, have been shown to be of value in confirming CD diagnosis, whereas others, due to their high sensitivity, have been demonstrated to be useful in excluding the presence of the disease.

The pattern of splanchnic circulation in CD have extensively been investigated by several studies all of which reported similar results and identified a hy-perdynamic mesenteric circulation that reverts to no-rmal values after successful a gluten-free regimen.

The last part of this review will deal with the possible role of US in identyfing the most severe and common intestinal complication of CD, i.e. the enteropathy-associated T cell non-Hodgkin lymphoma.

Pre- and postprandial alterations of portal venous flow: Evaluation with single breath-hold three-dimensional half-fourier fast spin-echo MR imaging and a selective inversion recovery tagging pulse

PURPOSE

To evaluate the influence of food intake on portal flow using unenhanced magnetic resonance imaging (MRI).

MATERIALS AND METHODS

The study population included 29 healthy subjects. A selective inversion recovery tagging pulse was used on the superior mesenteric vein (SMV) and splenic vein (SpV) to study the correlation of tagged blood in the portal vein (PV). MRI was performed before and 60-90 min after a meal.

RESULTS

The flow signal from the SMV increased in 97% of the subjects after the meal. Before the meal the portal flow was dominated by flow from the SpV in 59% of the subjects, while it was dominated by flow from the SMV in 76% of the subjects after the meal. The most common distribution pattern of the flow signal from the SpV before the meal was in the central part of the main PV (55%), while it was in the left side (45%) after the meal. The most common distribution pattern of the flow signal from the SMV was in the bilateral sides of the main PV both before and after the meal (62%).

CONCLUSION

This technique shows potential for evaluating pre- and postprandial alterations of flow from the SpV and SMV in the PV under physiological conditions.

Small intestinal contrast ultrasonography-based scoring system: a promising approach for the diagnosis and follow-up of celiac disease

BACKGROUND

Small intestinal ultrasonography with anechoic contrast agents (SICUS) has been shown to have a diagnostic accuracy on small bowel morphology similar to X-ray barium follow-through. Although extremely investigated by transabdominal ultrasonography, celiac disease, a common disorder of the small bowel, has been never studied by SICUS.

AIM

To asses SICUS characteristics of celiac disease patients.

PATIENTS AND METHODS

SICUS was performed using PEG 4000 as contrast agent. Twenty-three patients with celiac disease at the first diagnosis were enrolled and 30 healthy volunteers, matched for sex and age, were selected as control group. Celiac disease diagnosis was based on anti-gluten, anti-endomysium, and anti-transglutaminase positivity as well as jejunal histology. The following seven echographic parameters were considered: liquid endoluminal content before contrast, loop diameter, Kerckring's folds, peristaltic waves, ileal jejunalization, mesenteric lymphoadenomegaly, and Doppler resistance index (RI) of mesenteric superior artery. Statistical analysis was performed by Student's t test for unpaired data; one-way analysis of variance was used to correlate echographic and histologic pictures.

RESULTS

Loop diameter, Kerckring's fold number, peristaltic waves, and Doppler RI appeared to be significantly different between celiac disease patients and controls. Additionally, liquid content, ileal jejunalization, and mesenteric lymphoadenomegaly were present only in the celiacs (52.1%, 47.7%, and 95.6%, respectively), but not in controls. Only Doppler RI values significantly correlated with the histologic degree of damage.

CONCLUSIONS

SICUS could be a reliable and noninvasive technique to confirm a diagnosis of celiac disease performed using conventional investigations. The possibility of investigating the whole small bowel and the safety of repeating examinations could be useful in the follow-up of celiac patients.

Regional cerebral hypoperfusion in patients with celiac disease

BACKGROUND

Neurological and psychiatric disorders occur in approximately 10% of patients with celiac disease. Although some of these alterations respond to a gluten-free diet, the etiology of these abnormalities is uncertain. Because of a case report that cerebral hypoperfusion in a celiac patient resolved after a gluten-free diet, we studied brain perfusion changes in untreated celiac patients, treated celiac patients, and healthy controls.

METHODS

A total of 15 untreated celiac patients without conditions affecting brain perfusion were enrolled; none had neurological or psychiatric disorders other than anxiety or depression. We also studied 15 celiac patients who were on a gluten-free diet for almost 1 year, and 24 healthy volunteers of similar sex and age. All subjects underwent cerebral single photon emission computed tomography examination.

RESULTS

Of the 15 untreated celiac patients, 11 (73%) had at least one hypoperfused brain region, compared with only 1 (7%) of the 15 celiac patients on a gluten-free diet and none of the controls (P = 0.01). Cerebral perfusion was significantly lower (P <0.05) in untreated celiac patients, compared with healthy controls, in 7 of 26 brain regions. No significant differences in cerebral perfusion were found between celiac patients on a gluten-free diet and healthy controls.

CONCLUSION

There is evidence of regional cerebral blood flow alteration in untreated celiac patients.

Splanchnic haemodynamics in patients with coeliac disease: effects of a gluten-free diet

BACKGROUND

Coeliac disease is characterized by structural and functional changes in the small bowel which may also result in haemodynamic changes.

AIMS

To establish whether splanchnic haemodynamics can be modified by a gluten-free diet.

PATIENTS

Ten coeliac patients and 10 paired healthy subjects.

METHODS

Echo-Doppler measurements were made of splanchnic vessels both fasting and after a standard meal before and after 9 months of a gluten-free diet.

RESULTS

In comparison to controls, coeliac patients had higher superior mesenteric artery blood velocity and flow, with lower resistance indexes and higher portal vein velocity and flow, particularly 3 h after a meal. Postprandial hyperaemia was reduced and delayed in time. Intrasplenic resistance indexes were also significantly lower both fasting and after a meal. After 9 months of a gluten-free diet, no significant differences were observed between coeliac patients and controls, both fasting and after a meal.

CONCLUSIONS

Splanchnic haemodynamics is significantly changed in coeliac patients, mainly after a meal. On treatment with a gluten-free diet, both fasting and postprandial haemodynamics became normal.

Intraportal venous flow distribution: evaluation with single breath-hold ECG-triggered three-dimensional half-Fourier fast spin-echo MR imaging and a selective inversion-recovery tagging pulse

OBJECTIVE

The purpose of this study was to evaluate the intraportal blood flow distribution from splenic and superior mesenteric veins with an unenhanced MR angiographic technique using single breath-hold ECG-triggered three-dimensional (3D) half-Fourier fast spin-echo sequence and selective inversion-recovery tagging pulse.

SUBJECTS AND METHODS

Seventeen healthy volunteers were included in this prospective study. After obtaining regular single breath-hold ECG-triggered 3D half-Fourier fast spin-echo images without applying a tagging pulse, we placed the selective inversion-recovery tagging pulse on the superior mesenteric vein (TAG-A), the splenic vein (TAG-B), or on both (TAG-C) to study the inflow correlation of tagged or marked blood into the portal vein. MR images were evaluated subjectively by three reviewers.

RESULTS

On MR images obtained using the TAG-A pulse to suppress the signal flow from the superior mesenteric vein into the portal vein, the most common pattern of signal loss was observed on the right half of the main portal vein (8/17 subjects). Conversely, on the MR images obtained using the TAG-B pulse, signal loss of the left half of the main portal vein was the most common pattern (11/17 subjects). Signal reduction from the splenic venous flow in the left portal vein was significantly greater than that from the superior mesenteric venous flow (p<0.05).

CONCLUSION

The unenhanced MR angiographic technique using single breath-hold ECG-triggered 3D half-Fourier fast spin echo with selective inversion-recovery tagging pulse has the potential to assess the intraportal blood flow distribution from the splenic and superior mesenteric veins.

Duplex ultrasound for assessment of superior mesenteric artery blood flow

Duplex ultrasound (DU) is recognised as a valuable tool for the assessment of blood flow in many vascular territories. The application of this technique to the superior mesenteric artery (SMA) has increased rapidly throughout the last decade. The purpose of this review is to collate currently available information on the utility of SMA DU, both in terms of research and clinical practice. Research investigations have revealed low intra- and interobserver variability in the estimation of Doppler variables, while reliable evaluation of B-mode dimensions requires repeated measurements. SMA blood flow velocity has been found to be dependent upon changes in central haemodynamics and in peripheral resistance, which was documented in studies with hypotension, medication and post-prandially. Food intake induces mesenteric vasorelaxation reflected by a 10-fold increase in the diastolic velocity. This feature has been utilised in studies on mesenteric physiology, which confirmed parasympathetic activity during hypovolaemia, and showed that exercise increases splanchnic resistance and reduces its blood flow following a 50% reduction in the hepato-splenic and a 25% reduction in the mesenteric blood flow. Clinical studies have documented high sensitivity and specificity of DU in detection of disease in splanchnic arteries. Diastolic velocity was found to be the most accurate indicator of SMA stenosis, while an absent Doppler signal from a well visualised vessel has been found to be a reliable predictor of occlusion. The high predictive value of DU in the detection of mesenteric artery disease, together with its simplicity and non-invasiveness, suggests that DU should take precedence over arteriography in both clinical practice and laboratory investigations.

Color Doppler imaging discloses reduced ocular blood flow velocities in nonexudative age-related macular degeneration

PURPOSE

To study ocular perfusion defects in age-related macular degeneration.

METHODS

Twenty-five subjects with nonexudative age-related macular degeneration were compared with 25 age-matched control subjects in studies of flow velocities in several retrobulbar vessels. Color Doppler imaging, which was performed by an examiner who was masked to the subjects' assignment to the control or age-related macular degeneration group, measured peak systolic and end diastolic velocity in the ophthalmic, central retinal, and nasal and temporal posterior ciliary arteries of one eye. A resistive index was calculated from the peak systolic and end diastolic velocity.

RESULTS

Subjects with nonexudative age-related macular degeneration showed a consistent trend toward lower peak systolic and end-diastolic velocities in the posterior ciliary arteries. For example, in the nasal posterior ciliary artery, the mean end diastolic velocity measured 1.45 +/- 0.34 cm per sec in the age-related macular degeneration group compared with 1.96 +/- 0.66 cm per sec in the control group, yielding a 26% decrease in the age-related macular degeneration group, which represented the largest difference and was highly statistically significant (P = .0012). The resistive index was not significantly altered in the nasal or temporal posterior ciliary artery. Subjects with nonexudative age-related macular degeneration did not differ from control subjects in peak systolic velocity, end diastolic velocity, or resistive index in the ophthalmic artery. In the central retinal artery, the end diastolic velocity was lower (1.37 +/- 1.95 cm per sec vs 1.95 +/- 0.66 cm per sec), whereas the resistive index was higher (0.83 +/- 0.05 vs 0.76 +/- 0.06 cm per sec), in the age-related macular degeneration group; these results were highly statistically significant (P = .0007 and P < .0001, respectively).

CONCLUSIONS

Retrobulbar vascular changes in nonexudative age-related macular degeneration subjects include reduced flow velocities in the nasal and temporal posterior ciliary arteries. The reduced peak systolic velocity, combined with the reduced end diastolic velocity at a constant resistive index, seen in nonexudative age-related macular degeneration, is consistent with reduced bulk flow in these vessels, suggesting that choroidal perfusion is abnormal in this form of age-related macular degeneration. The changes in the central retinal artery suggest there may be a more generalized perfusion abnormality beyond the choroid in patients with age-related macular degeneration or that the central retinal artery exhibits a secondary autoregulatory response to a primary change elsewhere.

Superior mesenteric artery blood flow in children with celiac disease

BACKGROUND

Knowledge of splanchinic hemodynamics in celiac disease is scarce. The hemodynamic parameters of the superior mesenteric artery were evaluated by duplex Doppler ultrasonography in children with celiac disease to show whether histomorphologic changes in small bowel mucosa led to any alteration in splanchinic blood flow.

METHODS

The hemodynamic parameters of the superior mesenteric artery were evaluated by Doppler ultrasonography in 23 children with celiac disease. Ten patients were studied at the time of diagnosis. The remaining 13 children were studied after complete clinical and histologic recovery induced by gluten-free diet. Additionally, 9 patients out of 13 who were on a gluten-free diet for about 2 years were given gluten challenge, and superior mesenteric artery blood flow was measured after the challenge. The results were compared with those of healthy children.

RESULTS

Peak systolic velocity of the superior mesenteric artery was higher in untreated celiac patients than in healthy controls and treated celiac patients. Peak systolic velocity of the superior mesenteric artery in the treated group of children was close to that of control subjects, implying that successful treatment with gluten-free diet improves hemodynamic changes. The comparison of Doppler ultrasonographic measurements of the challenge group before and after the gluten challenge revealed that the peak systolic velocity, resistive index, and blood flow of the superior mesenteric artery were changed significantly.

CONCLUSIONS

The pathophysiologic events in small bowel mucosa during the active phase of celiac disease induce some hemodynamic changes that can be detected noninvasively by duplex Doppler ultrasonography.