A practical evidence-based approach to management of type 2 diabetes in children and young people (CYP): UK consensus

BACKGROUND

Type 2 diabetes in young people is an aggressive disease with a greater risk of complications leading to increased morbidity and mortality during the most productive years of life. Prevalence in the UK and globally is rising yet experience in managing this condition is limited. There are no consensus guidelines in the UK for the assessment and management of paediatric type 2 diabetes.

METHODS

Multidisciplinary professionals from The Association of Children's Diabetes Clinicians (ACDC) and the National Type 2 Diabetes Working Group reviewed the evidence base and made recommendations using the Grading Of Recommendations, Assessment, Development and Evaluation (GRADE) methodology.

RESULTS AND DISCUSSION

Young people with type 2 diabetes should be managed within a paediatric diabetes team with close working with adult diabetes specialists, primary care and other paediatric specialties. Diagnosis of diabetes type can be challenging with many overlapping features. Diabetes antibodies may be needed to aid diagnosis. Co-morbidities and complications are frequently present at diagnosis and should be managed holistically. Lifestyle change and metformin are the mainstay of early treatment, with some needing additional basal insulin. GLP1 agonists should be used as second-line agents once early ketosis and symptoms are controlled. Glycaemic control improves microvascular but not cardiovascular risk. Reduction in excess adiposity, smoking prevention, increased physical activity and reduction of hypertension and dyslipidaemia are essential to reduce major adverse cardiovascular events.

CONCLUSIONS

This evidence-based guideline aims to provide a practical approach in managing this condition in the UK.

Opportunities, approaches and challenges to the engagement of citizens in filling small water body data gaps

Monitoring the condition (water quality, biodiversity, hydromorphology) of small water bodies presents a challenge for the relevant authorities in terms of time and resources (labour and financial) due to the extensive length of the stream network or the sheer number of small standing water bodies. Citizen science can help address information gaps, but the effort required should not be underestimated if such projects are to generate reliable and sustained data collection. The overall aim of this paper is to propose a framework for operationalisation of citizen science targeting collection of data from small water bodies. We first consider the data gaps and the elements (water chemistry, ecology, hydromorphology) to be addressed, in order to define where citizen science could best make an impact. We review examples of tools and methods that are appropriate for small water bodies, based on experience from a selection of freshwater citizen science projects, and the support that is needed for effective and sustained small water body projects across Europe.

A practical approach to continuous glucose monitoring (rtCGM) and FreeStyle Libre systems (isCGM) in children and young people with Type 1 diabetes

Real-time continuous glucose monitoring (rtCGM) and FreeStyle Libre glucose monitoring systems (isCGM) are new evolving technologies used in the management of Type 1 diabetes. They offer potential to improve diabetes control and reduce hypoglycaemia. rtCGM can be linked to insulin pump providing hybrid closed loop therapy. Families of children and young people are keen to have the benefit from these technologies. These are relatively expensive so it is important that health care professionals, families of children and young people (CYP) with diabetes are adequately trained in the use of these devices. Health care professionals need to be able to make patient selection based on individual needs and preferences to achieve maximum benefit. Association of Children's Diabetes Clinicians (ACDC) developed a comprehensive guideline in 2017 to help identify which patients may be most likely to benefit and how these technologies may be practically implemented. Since then new technologies have been introduced and the use of GCM has expanded in routine clinical practice. This article, aims to provide a practical approach and help identify which patients may be most likely to benefit and how the technology may be implemented in order to maximise the clinical benefits.

Prenatal Management of Pregnancies at Risk of Fetal Neonatal Alloimmune Thrombocytopenia (FNAIT): Scientific Impact Paper No. 61

WHAT IS IT?: Fetal neonatal alloimmune thrombocytopenia (FNAIT), also known as neonatal alloimmune thrombocytopenia (NAIT) or fetomaternal alloimmune thrombocytopenia (FMAIT), is a rare condition which affects a baby's platelets. This can put them at risk of problems with bleeding, particularly into the brain. One baby per week in the UK may be seriously affected and milder forms can affect one in every 1000 births. HOW IS IT CAUSED?: Platelets are blood cells that are very important in helping blood to clot. All platelets have natural proteins on their surface called human platelet antigens (HPAs). In babies, half of these antigens are inherited from the mother and half from the father. During pregnancy, some of the baby's platelets can cross into the mother's bloodstream. In most cases, this does not cause a problem. But in cases of FNAIT, the mother's immune system does not recognise the baby's HPAs that were inherited from the father and develops antibodies, which can cross the placenta and attack the baby's platelets. These antibodies are called anti-HPAs, and the commonest antibody implicated is anti-HPA-1a, but there are other rarer antibody types. If this happens, the baby's platelets may be destroyed causing their platelet count to fall dangerously low. If the platelet count is very low there is a risk to the baby of bleeding into their brain before they are born. This is very rare but if it happens it can have serious effects on the baby's health. HOW IS IT INHERITED?: A baby inherits half of their HPAs from its mother and half from its father. Consequently, a baby may have different HPAs from its mother. As the condition is very rare, and even if the baby is at risk of the condition we have no way of knowing how severely they will be affected, routine screening is not currently recommended. WHAT CAN BE DONE?: FNAIT is usually diagnosed if a previous baby has had a low platelet count. The parents are offered blood tests and the condition can be confirmed or ruled out. There are many other causes of low platelets in babies, which may also need to be tested for. As the condition is so rare, expertise is limited to specialist centres and normally a haematologist and fetal medicine doctor will perform and interpret the tests together. Fortunately, there is an effective treatment for the vast majority of cases called immunoglobulin, or IVIg. This 'blood product' is given intravenously through a drip every week to women at risk of the condition. It may be started from as early as 16 weeks in the next pregnancy, until birth, which would be offered at around 36-37 weeks. Less common treatments that may be considered depending on individual circumstances include steroid tablets or injections, or giving platelet transfusions to the baby. WHAT DOES THIS PAPER TELL YOU?: This paper considers the latest evidence in relation to treatment options in the management of pregnancies at risk of FNAIT. Specifically, we discuss the role of screening, when IVIg should be started, what dose should be used, and what evidence there is for maternal steroids. We also consider in very rare selected cases, the use of fetal blood sampling and giving platelet transfusions to the baby before birth. Finally, we consider the approaches to blood testing mothers to tell if babies are at risk, which is offered in some countries, and development of new treatments to reduce the risk of FNAIT.

Recent developments in sensing methods for eutrophying nutrients with a focus on automation for environmental applications

A comprehensive review focusing on eutrophying nutrient monitoring using autonomous sensors, including novel analysis methods, standard analysis methods and state-of-the-art sensor technology.

Use of non-irradiated blood components in Campath (alemtuzumab)-treated renal transplant patients

BACKGROUND

The prevention of transfusion-associated graft-versus-host disease (TA-GvHD) through the irradiation of components is key as there is no effective treatment. Universal leucodepletion reduces but may not eliminate TA-GvHD; therefore, irradiation is still recommended. In 2010, Campath (alemtuzumab) was added as an indication for irradiation but was not implemented everywhere.

OBJECTIVES

To identify any cases of TA-GvHD in our Campath-conditioned renal transplant patients, who were transfused with non-irradiated components.

METHODS

Retrospective study of Campath-conditioned renal transplant patients transfused with non-irradiated components. In those transfused up to 9 months following Campath who survived to 1-year follow-up, TA-GvHD was excluded. For patients not followed-up for a full year, we reviewed medical records for features of TA-GvHD. For patients transfused after 9 months following Campath, survival of at least 3 months following last transfusion excluded TA-GvHD.

RESULTS

Six hundred and forty-seven Campath-conditioned renal transplant patients were transfused; 616 were transfused within 9 months following Campath; 601 were alive at 1 year, excluding TA-GvHD. Twelve died and three were not followed-up for a full year, but a review of medical records excluded TA-GvHD. The 31 patients transfused 9 months or longer following Campath were all alive 6 months following the last transfusion, excluding TA-GvHD.

CONCLUSIONS

Despite receiving non-irradiated components, none of the 647 Campath-conditioned renal transplant patients developed TA-GvHD. Further reviews to replicate our data could enable change to guidance, at least in UK where components are leucodepleted, as an unnecessary requirement for irradiated components has both clinical delay and cost implications.

3D printed metal columns for capillary liquid chromatography

Coiled planar capillary chromatography columns (0.9 mm I.D. × 60 cm L) were 3D printed in stainless steel (316L), and titanium (Ti-6Al-4V) alloys (external dimensions of ~5 × 30 × 58 mm), and either slurry packed with various sized reversed-phase octadecylsilica particles, or filled with an in situ prepared methacrylate based monolith. Coiled printed columns were coupled directly with 30 × 30 mm Peltier thermoelectric direct contact heater/cooler modules. Preliminary results show the potential of using such 3D printed columns in future portable chromatographic devices.

Characterization and anti-settlement aspects of surface micro-structures from Cancer pagurus

Tuning surface and material properties to inhibit or prevent settlement and attachment of microorganisms is of interest for applications such as antifouling technologies. Here, optimization of nano- and microscale structures on immersed surfaces can be utilized to improve cell removal while reducing adhesion strength and the likelihood of initial cellular attachment. Engineered surfaces capable of controlling cellular behaviour under natural conditions are challenging to design due to the diversity of attaching cell types in environments such as marine waters, where many variations in cell shape, size and adhesion strategy exist. Nevertheless, understanding interactions between a cell and a potential substrate for adhesion, including topographically driven settlement cues, offers a route to designing surfaces capable of controlling cell settlement. Biomimetic design of artificial surfaces, based upon microscale features from natural surfaces, can be utilized as model surfaces to understand cell-surface interactions. The microscale surface features of the carapace from the crustacean Cancer pagurus has been previously found to influence the rate of attachment of particular organisms when compared to smooth controls. However, the nature of microscale topographic features from C. pagurus have not been examined in sufficient detail to allow design of biomimetic surfaces. In this work, the spatial distribution, chemical composition, size and shape descriptors of microscale surface features from C. pagurus are characterized in detail for the first time. Additionally, the influence of topography from C. pagurus on the settlement of marine diatoms is examined under field conditions.

Recommendations for a standard UK approach to incorporating umbilical cord blood into clinical transplantation practice: conditioning protocols and donor selection algorithms

Allogeneic haematopoietic cell transplantation is an established curative treatment modality for patients with malignant and non-malignant haematological disorders. Since the first related umbilical cord blood transplant (UCBT) in 1988, the use of UCB as a stem cell source for transplantation has become a standard practice in many countries, with approximately 8000 such transplants having been performed worldwide to date.

A randomized cross-over trial to identify the optimal use of insulin glargine in prepubertal children using a three-times daily insulin regimen

AIMS

The long-acting insulin analogue glargine reduces nocturnal hypoglycaemia and stabilizes morning blood glucose levels in patients with Type 1 diabetes (T1DM) on multiple injection therapy. However, young children may not tolerate such intensive insulin regimens. We investigated the effects of glargine in various three-injections-daily insulin combinations on 24-h glucose control in prepubertal children.

METHODS

Seventeen T1DM prepubertal children (10 boys), median age 10.2 years (range 6.0-12.4), glycated haemoglobin (HbA(1c)) 8.8% (6.8-11.5) were recruited to a randomized, open-label, cross-over study. After a 2-week run-in period (with NPH pre-bed), every child underwent three different 3-week treatment blocks in random order. All treatment blocks included glargine pre-bed, but used different morning insulins: block 1, soluble only; block 2, soluble + NPH; block 3, aspart + NPH. Continuous glucose monitoring was performed for 3 days at the end of the run-in and each treatment block.

RESULTS

Compared with the run-in period on NPH, the three glargine treatment blocks were associated with lower (P < 0.0001) and less variable (P < 0.05) pre-breakfast glucose levels, and with an 8-15% reduction in total daily insulin dose (P < 0.0001). Risk of nocturnal hypoglycaemia detected by continuous glucose monitoring varied significantly between the three glargine treatment blocks, and was lowest when children were given aspart + NPH in the morning (block 3).

CONCLUSION

Insulin glargine pre-bed can be used in three-injections-daily regimens in prepubertal children to lower and stabilize pre-breakfast glucose levels. However, to avoid the risk of nocturnal hypoglycaemia, the pre-bed glargine dose should be lowered by giving a further long-acting insulin, such as NPH, in the morning.

Does a full bladder aid upper tract visualization in magnetic resonance urography?

The aim of this study was to evaluate whether a full bladder improved the visualization of the upper renal tract during magnetic resonance urography (MRU). Twenty volunteers were recruited into the study. The MRU imaging was carried out on a 1.5-T MR system. Imaging was carried out in the coronal plane using a half-Fourier acquired single-shot turbo-spin-echo technique. All volunteers were examined in two separate MRU studies to visualize the urinary tract. The first study was carried out with a 'full' bladder followed by a study with an 'empty' bladder, leading to a total of 40 examinations. Two radiologists then reviewed maximum intensity projection images from both 'full' and 'empty' studies independently. Both left and right upper tracts were divided into five segments. A three-point grading system was used to evaluate visualization. Excellent visualization = 3, good visualization = 2 and poor visualization = 1. Maximum score per patient was 30. Results were tabulated and analysed using an Excel database. The average score for visualization for the 'full' bladder group was 22.1/30 (73.8%) and the average score for the empty bladder was 16.2/30 (54%). Overall improvement in visualization was 5.9/30 (19.8%). There was strong interobserver agreement, with a concordance value of 92.5%. The MRU carried out in healthy young adult volunteers with a full bladder allows improved visualization of the upper tracts.

Improving the accuracy of estimated blood loss at obstetric haemorrhage using clinical reconstructions

OBJECTIVES

Following the results of the Confidential Enquiries into Maternal Deaths report, which claims two maternal deaths annually in the UK from postpartum haemorrhage, our aim was to assess the accuracy of 'visual estimation of blood loss' and produce suitable pictorial and written algorithms to aid in the recognition and management of massive obstetric haemorrhage.

DESIGN

Observational study to determine discrepancy between actual blood loss (ABL) and estimated blood loss (EBL).

SETTING

Teaching hospital.

POPULATION

Hundred and three obstetricians, anaesthetists, midwives, nurses and healthcare assistants.

METHODS

Clinical scenarios were reproduced in the form of 12 Objective Structured Clinical Examination (OSCE) style stations augmented with known volumes of whole blood. Individual staff estimated the blood loss visually and recorded their results. Digital photographs were used to produce a pictorial 'algorithm' suitable for use as a teaching tool in labour ward.

MAIN OUTCOME MEASURES

Areas of greatest discrepancy between EBL and ABL.

RESULTS

Significant underestimation of the ABL occurred in 5 of the 12 OSCE stations: 500-ml (50-cm diameter) floor spill, 1000-ml (75-cm diameter) floor spill, 1500-ml (100-cm diameter) floor spill, 350-ml capacity of soaked 45- x 45-cm large swab and the 2-l vaginal postpartum haemorrhage on bed/floor.

CONCLUSIONS

Accurate visual estimation of blood loss is known to facilitate timely resuscitation, minimising the risk of disseminated intravascular coagulation and reducing the severity of haemorrhagic shock. Participation in clinical reconstructions may encourage early diagnosis and prompt treatment of postpartum haemorrhage. Written and pictorial guidelines may help all staff working in labour wards.

Prematurity – Another Example of Perinatal Metabolic Programming?

Low birth weight is associated with both later adult diseases such as type 2 diabetes mellitus and a number of metabolic abnormalities, the foremost of which is insulin resistance. Indeed the link between an adverse perinatal environment, manifested by low birth weight, and adult life pathology may be an early, permanent reduction in insulin sensitivity. A reduction in insulin sensitivity has been demonstrated in small for gestational age (SGA), term subjects from childhood through to adulthood. Less is known about children born premature into an adverse neonatal environment. We present data demonstrating that premature infants also have metabolic abnormalities similar to those observed in term, SGA children and that these occur irrespective of whether they are SGA or appropriate for gestational age (AGA).

Preoperative autologous blood donation for bone marrow harvests: Are we wasting donors' time and blood?

Predeposit autologous blood donation (PAD) is frequently offered to bone marrow donors, but its cost-effectiveness is dubious. We assessed the impact of PAD and bone marrow donation on transfusion requirements; and the use of donated blood units in a retrospective study of 61 bone marrow donors. The mean haemoglobin (Hb) concentration fell from 12.9 to 11.8 g dL(-1) in women who predonated one unit and from 13.2 to 10.9 g dL(-1) in those who predonated two units. In men who donated two units of blood, the Hb concentration decreased to 12.9 g dL(-1). Bone marrow harvest led to a further decline in Hb concentration by 2.3 g dL(-1) in women and by 2.4 g dL(-1) in men. The postharvest Hb fell to <or=9.0 g dL(-1) in 39% of female and in 6% of the male donors; all but one of them had predonated blood. The utilization rate of autologous units was 45.6%, with 55% of women and 24% of men receiving autologous blood. In females, 59% of transfused autologous units were given with the donor's Hb of >or= 9.0 g dL(-1); overtransfusion was even more apparent in men: 71% units were given with a Hb >or= 10.0 g dL(-1). PAD in bone marrow donors is associated with high wastage and increases the likelihood of requiring a transfusion. We recommend that PAD should not be routinely offered to bone marrow donors.

ABO incompatibility due to immunoglobulin G anti-B antibodies presenting with severe fetal anaemia

ABO incompatibility is a common haematological problem affecting the newborn. The haemolysis is widely accepted to follow a relatively benign course rarely causing the escalating levels of hyperbilirubinaemia and significant anaemia associated with Rh haemolytic disease of the newborn. Case reports of fetal hydrops secondary to ABO incompatibility are particularly rare. We describe two cases, first that of a twin pregnancy with both fetuses developing severe anaemia at 20 weeks gestation, and then a second case of a preterm baby demonstrating aggressive haemolysis and anaemia within hours of delivery. Both mothers were of black Africian origin and both were identified to have elevated titres of IgG anti-B antibodies.

Acute ureteric calculus obstruction: unenhanced spiral CT versus HASTE MR urography and abdominal radiograph

The aim of this study is to compare the performance of unenhanced spiral CT to the combination of HASTE MR urography (MRU) and plain abdominal radiography (KUB) in patients suspected of having acute calculus ureteric obstruction. 64 patients with suspected acute calculus ureteric obstruction were evaluated. The presence of perirenal fluid, presence and level of ureteric obstruction and calculi were assessed on both techniques. 44 of 64 (69%) patients had acute calculus ureteric obstruction based on clinical, radiographic or surgical findings. MRU showed perirenal fluid in acute ureteric obstruction (77%) with a greater sensitivity than CT showed stranding (45%). The combination of fluid and ureteric dilation on MRU showed a sensitivity of 93% (CT 80%), specificity of 95% (CT 85%), and accuracy of 94% (CT 81%). There were 61 findings of either fluid or ureteric dilatation on MRU in 44 acutely obstructed kidneys compared with 37 similar findings on CT (p<0.005). Although there was excellent reproducibility (Kappa=/>0.75) in the finding of perirenal fluid on MRU, there was only fair interobserver agreement (Kappa<0.4) regarding perirenal stranding on CT. MRU/KUB showed ureteric calculi in 21/29 (72%) of patients with calculi seen by CT. Overall, MRU/KUB revealed 2.4 abnormalities per acutely obstructed ureter compared with 1.8 abnormalities detected by CT. MRU/KUB using HASTE sequences can diagnose the presence of acute calculus ureteric obstruction with similar accuracy to spiral CT. The technique has less observer variability and is more accurate than CT in detecting evidence of obstruction such as perirenal fluid.

The metabolic consequences of prematurity

An association between low birth weight, commonly a reflection of an adverse in utero environment, and the subsequent development of diseases such as type 2 diabetes and hypertension in later life is now generally accepted - as is an association between an adverse perinatal environment and a permanent reduction in insulin sensitivity. This and other metabolic abnormalities have been demonstrated from childhood through to adulthood in subjects who were born full-term but small for gestational age (SGA). Less is known about children born prematurely into an adverse neonatal environment. We present data demonstrating that premature infants also have metabolic abnormalities similar to those observed in full-term, SGA children, and that these occur irrespective of whether the premature infants are SGA or appropriate for gestational age (AGA).

Potential of microemulsion electrokinetic chromatography for the separation of priority endocrine disrupting compounds

This work examines the potential of microemulsion electrokinetic chromatography for the separation of several priority endocrine disrupting compounds (EDCs). The optimised microemulsion system comprised 25 mM phosphate buffer pH 2, 80 mM octane, 900 mM butanol, 200 mM sodium dodecyl sulphate and was further modified with 20% propanol. The use of a low pH buffer resulted in the suppression of electroosmotic flow within the capillary. Reversal of the conventional electrode polarity resulted in faster migration of hydrophobic compounds. Test analytes included the octylphenol, nonylphenol and nonylphenol diethoxylate, which are breakdown products of the alkylphenolic detergents. The synthetic oestrogens diethylstilbestrol and ethynyloestradiol were also included in the separation along with the plastic monomer bisphenol-A. Test analytes were selected due to their reported presence in environmental samples namely industrial and domestic wastewater treatment effluents and sludges. Using the optimised method a separation of six EDCs was achieved within 15 min. The optimised method was then applied to the analysis of a spiked wastewater influent sample with UV detection of all six compounds at 214 nm.

Are changes in admission practices for elective surgery posing a transfusion threat to patients?

There is an increasing emphasis on reducing in-patient hospital stay for elective surgical procedures. As a result, pre-operative stay has shortened, with less time available for performing baseline investigations before surgery, including those required to ensure a supply of safe, compatible blood. We have estimated the frequency of failure to complete 'group and screen' (G&S) testing before surgery where indicated, so that neither group-compatible blood nor crossmatched blood could be provided promptly if an unexpected haemorrhage occurs. Retrospective data were obtained from elective surgical procedures performed over a 3-week period. Of the 309 procedures performed, 21 patients were exposed to the risk of failure to provide appropriately matched blood had an emergency arisen. (In 20, a G&S was required; in one, a crossmatch was required.) Late samples and lack of information on the request form regarding the date and time of surgery were the main causes. Procedures requiring G&S only as opposed to crossmatch posed the greatest risk. Urgent measures are needed to ensure that, where indicated, a pre-operative G&S result is available before surgery begins. Educating colleagues, redesigning request forms and improving out-of-hour laboratory services and hospital information systems are the main steps needed to reduce this latent risk.

Imaging bowel obstruction: a comparison between fast magnetic resonance imaging and helical computed tomography

AIM

To compare the accuracy of fast magnetic resonance (MR) imaging using the half-Fourier single shot turbo spin echo (HASTE) sequence with helical computed tomography (CT) in diagnosing bowel obstruction.

MATERIALS AND METHODS

Prospective evaluation of 44 patients with clinical evidence of bowel obstruction was conducted using various investigations including HASTE MR and helical CT. MR was performed with a Siemens 1.5 Tesla MR Imaging System and CT was performed with one of two Siemens ARHP CT systems using helical technique. MR acquisition allowed data to be gathered in 6-10 minutes and no contrast media were administered. CT imaging consisted of consecutive helical CT through the abdomen and pelvis with oral and intravenous contrast medium used when indicated. Bowel dilation along with the presence and level of obstruction were determined.

RESULTS

Twenty-eight patients had bowel obstruction confirmed at laparotomy or by radiographic assessment. Of these, 25 had small bowel obstruction and three had colonic obstructions. The obstruction was due to fibrous adhesions in nine patients, metastases or primary carcinoma in seven, Crohn's disease in four, hernias in two, and inflammation or abscess in two. Other causes of obstruction included lymphoma, intussusception and anastomotic stricture. The cause of obstruction was correctly diagnosed by CT in 71%, and by MR in 95% of cases. The sensitivity, specificity and accuracy for HASTE MR imaging was 95%, 100% and 96% respectively as compared to 71%, 71% and 71% for helical CT.

CONCLUSION

Fast MR imaging using the HASTE sequence is more accurate than helical CT in diagnosing bowel obstruction.

Development of comparative methods using gas chromatography-mass spectrometry and capillary electrophoresis for determination of endocrine disrupting chemicals in bio-solids

Two analytical separation techniques are being investigated for their potential in determining a wide range of endocrine disrupting chemicals (EDCs) in the environment. Capillary electrophoresis (CE) in the micellar mode in conjunction with a cyclodextrin (CD) modifier is shown to have potential for determination of alkylphenol breakdown products. Gas chromatography with mass spectrometric (GC-MS) detection is being utilised for validation of the CE method development and in addition as a separation technique to optimise preconcentration using solid-phase extraction. GC has demonstrated potential for the separation of 26 priority chemicals suspected as being endocrine disrupting compounds. The challenge of the method development process lies in the fact that these compounds are of differing polarities, size and charge and therefore are difficult to separate in a single run. Capillary electrophoresis in the CD-MEKC (micellar electrokinetic chromatography) mode is showing potential in this regard. Limits of determination are in the low mg/l range for CE and GC, however, using preconcentration it is possible to improve detection sensitivity with >80% recovery for some analytes and up to 100% recovery for most target species.

Plain abdominal x-ray versus computerized tomography screening: sensitivity for stone localization after nonenhanced spiral computerized tomography

PURPOSE

Urolithiasis followup with plain abdominal x-ray requires adequate visualization of the calculus on the initial x-ray or computerized tomography (CT) study. We compared the sensitivity of plain abdominal x-ray versus CT for stone localization after positive nonenhanced spiral CT.

MATERIALS AND METHODS

We evaluated 46 consecutive nonenhanced spiral CT studies positive for upper urinary tract lithiasis for which concurrent plain abdominal x-rays were available. X-ray and CT studies were compared for the ability to visualize retrospectively a stone given its location by CT. A consensus of 1 radiologist and 3 urologists was reached in each case. Cross-sectional stone size and maximum length were measured on plain abdominal x-ray.

RESULTS

Plain abdominal x-ray and scout CT had 48% (22 of 46 cases) and 17% (8 of 46) sensitivity, respectively, for detecting the index stone (p <0.00004). Of the 39 stones overall visualized on plain abdominal x-ray only 19 (49%) were visualized on scout CT. Mean cross-sectional area and length of the stones on scout CT were 0.34 cm.2 (approximately 6 x 5.5 mm.) and 6. 5 mm., respectively, while the average size of those missed was 0.11 cm.2 (approximately 4 x 3 mm.) and 3.6 mm. The mean size differences in the groups were highly significant (p <0.0009).

CONCLUSIONS

Plain abdominal x-ray is more sensitive than scout CT for detecting radiopaque nephrolithiasis. Of the stones visible on plain abdominal x-ray 51% were not seen on CT. To facilitate outpatient clinic followup of patients with calculi plain abdominal x-ray should be performed when a stone is not clearly visible on scout CT.

Hypereosinophilic sclerosing cholangitis: findings using half-Fourier magnetic resonance imaging

Hypereosinophilic sclerosing cholangitis is a rare disease caused by eosinophilic infiltration of the gallbladder and biliary tract seen in the idiopathic hypereosinophilic syndrome. We report a 42-year-old woman who presented with symptoms of cholecystitis and obstructive cholangitis. Imaging with magnetic resonance cholangiography using a half-Fourier spinecho sequence, we were able to visualize rapidly and non-invasively a severely abnormal gallbladder, evidence of liver parenchymal inflammation, and biliary duct dilatation.

MR cholangiopancreatography using HASTE sequences

AIM

The aim of this pictorial review is to describe applications of cholangiopancreatography (MRCP) using half-Fourier (HASTE) MR sequences.

MATERIALS AND METHODS

350 patients were imaged over a four-year period with a 1.54 Tesla Siemens Vision scanner and a phased array body coil. The HASTE MR sequence was applied in multiple planes with an acquisition time of 13 seconds allowing breath hold techniques. In addition, a single-shot technique provided single slice acquisitions with a thickness of 20 mm. A chemical fat suppression algorithm reduced intra-abdominal MR high signal.

RESULTS

HASTE MRCP accurately determines the presence of level of biliary obstruction in up to 97% of patients. Common bile duct stones are detected with a sensitivity of 93%. Acute cholecystitis is depicted on HASTE MR as pericholecystic high signal in 41/45 (91%) patients and gall stones are detected with a 93% sensitivity.

CONCLUSION

HASTE MRCP offers a non-invasive, rapid imaging method to evaluate the gallbladder, common bile duct and pancreas. Its multi-planar, fluid sensitive capabilities are of particular value in detecting common bile duct stones and acute cholecystitis.

Ventilation-perfusion scintigraphic evaluation of pulmonary clot burden after percutaneous thrombolysis of clotted hemodialysis access grafts

The objective of this study is to determine, by using rigorous methods, if pulmonary perfusion defects were detectable by ventilation-perfusion scintigraphy after percutaneous thrombolysis of clotted hemodialysis access grafts. Thirteen patients were studied. Four patients underwent pharmacomechanical thrombolysis with urokinase and the remainder had mechanical thrombolysis alone. Pre- and postthrombolysis scintigraphic studies were performed on all patients. Perfusion defects were described as vascular (well-defined borders confined to segmental boundaries) or nonvascular. Vascular defects were graded by severity (0 to 3) and area (0 to 3) for each involved segment. Nonvascular defects were graded by severity (0 to 1) and area (0 to 1). Two experienced readers evaluated the scans blinded to each other's results and all other clinical data, including thrombolysis outcomes. Twelve patients did not have any significant worsening of their perfusion defect scores postthrombolysis. In only one patient did a study show a new nonvascular perfusion defect with a matching ventilation abnormality. The defect was believed to be caused by mucus plugging. The patient had no evidence of pulmonary embolism. Our study suggests emboli that resulted from the pharmacomechanical or mechanical thrombolysis procedure were either small, underwent lysis before impacting the lung, or were below the limit of detection of ventilation-perfusion scintigraphy.

Cerebral embolism after mechanical thrombolysis of a clotted hemodialysis access

Clinically significant embolic complications after thrombolysis of clotted hemodialysis grafts are uncommon. Most of the concern has focused on the risks associated with pulmonary emboli. We report a case of a hemodialysis patient who developed a cerebral embolism after percutaneous graft thrombolysis who was found to have a patent foramen ovale and intermittent right-to-left shunt.

Utility of magnetic resonance cholangiography in the evaluation of biliary obstruction

BACKGROUND

Evaluation of suspected biliary obstruction has traditionally involved a variety of imaging modalities including ultrasound, CT, and invasive cholangiography. These techniques have limitations because of poor visualization of intraductal stones (ultrasound and CT) and the need for an invasive procedure (ERCP and percutaneous transhepatic cholangiography). Magnetic resonance cholangiography (MRC) is a noninvasive imaging modality that provides good visualization of the hepatobiliary system. The aim of the present study was to determine the utility of MRC in evaluating patients with suspected biliary obstruction.

STUDY DESIGN

One hundred forty-three patients were identified with suspected acute biliary obstruction and underwent MRC. Patient selection was based on clinical criteria including an elevation in serum liver chemistries or evidence of biliary ductal dilatation on conventional imaging. MRC was performed using a half-Fourier acquisition single-shot turbo spin-echo sequence involving single breath-hold rapid image acquisition. A final diagnosis was determined in each patient based on invasive cholangiography, findings at surgery, and clinical course.

RESULTS

Of the 143 patients, 73 had an obstructing biliary lesion. A malignant process was identified in 25 patients with final diagnoses of pancreatic cancer (n = 15), ampullary cancer (n = 4), cholangiocarcinoma (n = 3), and hepatic or nodal metastases (n = 3). MRC correctly identified biliary obstruction in all these patients and accurately identified the level of biliary obstruction in 24 of 25 patients. Based on the MRC images alone, a malignant process was suspected in 21 of the 25 patients. Forty patients were found to have common bile duct stones and eight patients had a benign distal bile duct stricture. MRC correctly identified common bile duct stones in 37 patients with one false-positive exam (sensitivity = 92%; specificity = 99%). MRC also correctly identified distal biliary strictures in eight patients. In the remaining 70 patients, no definite biliary obstruction was identified by MRC, and in all patients the absence of mechanical obstruction was confirmed by invasive cholangiography or overall clinical course.

CONCLUSIONS

This study demonstrates that MRC is able to accurately identify the level and cause of biliary obstruction in both malignant and benign disease. MRC may prove to be an important noninvasive tool in preoperative evaluation of patients with suspected biliary obstruction and identification of patients most likely to benefit from an invasive radiologic or surgical procedure.

Clinical applications of half-Fourier (HASTE) MR sequences in abdominal imaging

Endoscopic retrograde cholangiography remains a valuable technique in biliary disease, because therapeutic intervention, such as stone extraction and biliary drainage, can be carried out at the same time as diagnosis. Spatial resolution is superior to that of noninvasive imaging methods. HASTE MR cholangiopancreatography is as sensitive as sonography in detecting cholelithiasis. It is superior to sonography in diagnosing common bile duct stones, malignant biliary obstruction, and benign pancreatic disease. The noninvasive nature of HASTE MR imaging insures an expanding role in imaging patients with suspected pancreaticobiliary disease.

Hydronephrosis in pregnancy: simultaneous depiction of fetal and maternal hydronephrosis by magnetic resonance urography

Magnetic resonance urographic (MRU) techniques possess image quality and diagnostic capability that are improving with increasingly sophisticated imaging sequences and shorter scanning times. We describe the application of a fast breath-hold MR sequence (HASTE) in the assessment of ureteric obstruction in pregnancy. In the patient presented, HASTE MRU was successful in depicting ureteral anatomy and demonstrated dilation of both ureters below the level of the pelvic brim. This observation suggested distal ureteral obstruction rather than simple hydronephrosis of pregnancy. As a result, bilateral nephrostomies were performed and neonatal prematurity was avoided. Interestingly, in this patient, HASTE MR imaging also showed evidence of concurrent fetal hydronephrosis.

Indium-111 capromab pendetide (ProstaScint) imaging to detect recurrent and metastatic prostate cancer

This study evaluated the utility of In-111 capromab pendetide imaging to detect prostate cancer metastases or local recurrence. The specific goal was to identify clinical factors such as prostate-specific antigen, pathologic stage, and Gleason score that were most predictive of a positive scan outcome. In addition, a new concept of a weighted Gleason score was defined and correlated with the scan outcome. Fifty-one patients with an elevated prostate-specific antigen level and otherwise negative workup were studied. Forty-eight patients had been treated by radical prostatectomy, two by radiation therapy, and one patient was studied before prostatectomy. Each patient received an intravenous injection of approximately 5 mCi of In-111 containing 0.5 mg of CYT 356, a conjugated site-specific monoclonal antibody against prostate specific membrane antigen. Tomographic blood pool images were obtained the day of injection. Four days later planar images and tomographic images of the abdomen and pelvis were obtained. Scans were interpreted by two experienced nuclear medicine physicians. Differences in the scan interpretation were settled by consensus. Scan outcomes were correlated with prostate-specific antigen levels, pathologic stage, Gleason score, weighted Gleason score, and clinical data. Of 51 scans, 70.6% (36 of 51) were positive. Eight patients had abnormal activity in the prostatic fossa, 12 patients had abnormal activity in the abdominal or pelvic lymph nodes, and 16 patients demonstrated abnormal activity in both areas. One patient with a positive scan underwent lymphadenectomy and was confirmed to be a true positive. Patients with a prostate-specific antigen level greater than 10 ng/ml, a weighted Gleason score higher than 4.5, or prostate-specific antigen levels greater than 2 ng/ml plus a weighted score higher than 4.5 showed positive rates of 100% (6 of 6), 88.2% (14 of 16), and 100% (6 of 6), respectively. In-111 capromab pendetide imaging was useful to detect metastases or local recurrence. Serum prostate-specific antigen levels and weighted Gleason scores are good predictive factors of the likelihood of a positive scan outcome.

Hepatomegaly and multiple liver lesions

Images

The diagnostic utility of HASTE MRI in the evaluation of acute cholecystitis. Half-Fourier acquisition single-shot turbo SE

PURPOSE

The purpose of this study was twofold: (a) to determine the significance of high signal intensity surrounding the gallbladder as seen on T2-weighted HASTE (half-Fourier acquisition single shot turbo SE) MR images in patients with acute cholecystitis and (b) to determine the sensitivity of T2-weighted HASTE MR images in detecting gallbladder and common bile duct (CBD) calculi in patients with acute cholecystitis.

METHOD

Seventy-two patients with a suspicion of acute cholecystitis were referred for HASTE MRI over a 2 year period. Forty-one patients underwent MRI after sonography and the remaining 31 patients before sonography. MR images were independently evaluated for the presence of MR pericholecystic high signal and gallbladder and CBD calculi. Findings were correlated with results obtained at sonography and at surgery.

RESULTS

Of the 72 patients imaged with HASTE MRI, 55 had cholecystitis based on clinical, sonographic, and/or surgical findings. Of these, 45 had acute and 10 had chronic cholecystitis. HASTE MRI demonstrated MR pericholecystic high signal in 41 of 45 (91%) of the patients with acute cholecystitis. The sensitivity of HASTE MRI in diagnosing acute cholecystitis was 91%. The specificity was 79%. The positive predictive value was 87%, the negative predictive value was 85%, and the overall accuracy of the test was 89%. Gallbladder stones were seen by HASTE MRI in 38 of 41 (93%) of patients with acute calculus cholecystitis demonstrated at sonography. CBD stones were demonstrated by HASTE MRI in seven of nine (78%) patients and by sonography in five of nine (56%) patients with documented choledocholithiasis on conventional cholangiography.

CONCLUSION

HASTE MRI has a high degree of accuracy in diagnosing acute cholecystitis based on the single finding of pericholecystic MR high signal. A similar level of accuracy is demonstrated in detecting gallbladder stones. Biliary duct calculi are detected with even greater accuracy than with sonography in patients with acute cholecystitis. Invasive preoperative endoscopic retrograde cholangiography may therefore be limited to only those patients with acute cholecystitis and CBD stones demonstrated on HASTE MRI. These features make HASTE MRI and ideal imaging modality in the initial evaluation of acute biliary pain and may ultimately replace sonography in the preoperative evaluation of acute cholecystitis.

Fast MR imaging and the detection of small-bowel obstruction

OBJECTIVE

Our aim was to determine whether fast MR imaging using the half-Fourier acquisition single-shot turbo spin-echo (HASTE) MR sequence is accurate for diagnosis of small-bowel obstruction.

MATERIALS AND METHODS

Forty-three nonconsecutive patients with suspected small-bowel obstruction were evaluated with HASTE MR imaging during a 12-month period. Images were retrospectively assessed for the presence, level, and cause of bowel obstruction. Data were compared with results of conventional radiography and findings at surgery when available.

RESULTS

Of the 43 patients imaged, 29 patients had small-bowel obstruction revealed by unenhanced or contrast-enhanced radiography or by CT. Surgical confirmation was available in 21 patients. Small-bowel obstruction was shown by HASTE MR imaging in 26 (90%) of these 29 patients. HASTE MR images showed the correct level of obstruction in 19 (73%) of the 26 patients and showed the cause of obstruction in 13 (50%) of the 26 patients.

CONCLUSION

With a high degree of accuracy, HASTE MR imaging can show the presence and level of small-bowel obstruction.

The role of computerized tomography in the evaluation of complications after laparoscopic urological surgery

PURPOSE

Radiographic evaluation may be necessary to assess the possible complications of laparoscopic procedures. We undertook a retrospective review to determine the indications for and findings of computerized tomography (CT) in symptomatic patients after urologic laparoscopic surgery.

MATERIALS AND METHODS

Of 400 laparoscopic urological procedures performed between July 1993 and September 1996, 20 patients (5%) had postoperative symptomatology that could not be explained by physical exam or routine clinical studies. An abdominal CT scan was obtained (1 to 120 days after the procedure) to help determine a diagnosis. CT findings were correlated with the indication for the study and clinical followup.

RESULTS

The indications for CT were unexplained pain, fever, leukocytosis or falling hematocrit. Thirteen patients had significant findings related to their surgery that were identified by CT. In 2 cases, we identified pathology unrelated to the surgery. Therefore, CT identified a symptom-related diagnosis in 75% of patients (15 of 20). Each scan for decreasing hematocrit demonstrated a hematoma. In all patients with unexplained fever or leukocytosis, CT revealed the cause. CT evaluation of atypical postoperative pain demonstrated a pathological cause in 58% (7 of 12). Percutaneous or laparoscopic surgical intervention was required in 4 of 20 patients. In 8 patients scanned by postoperative day 6, intraperitoneal or retroperitoneal gas was identified in 3 who had an abdominal incision made for intact specimen removal and in 1 with a perforated ulcer.

CONCLUSIONS

CT after urologic laparoscopy is indicated in patients with significant clinical findings in whom routine examination and tests are not diagnostic. CT can reliably identify postoperative bleeding, urinary leak or obstruction and can also detect nonurinary pathology.

Perirenal MR high signal--a new and sensitive indicator of acute ureteric obstruction

PURPOSE

This study was carried out to determine the incidence of perirenal magnetic resonance (MR) high signal in acute ureteric obstruction as demonstrated by half-Fourier acquisition single shot turbo spin-echo (HASTE) MR. In addition, we evaluated the sensitivity of this perirenal MR high signal as a predictor of acute ureteric obstruction.

MATERIALS AND METHODS

A prospective evaluation of 55 consecutive patients with suspected ureteric obstruction was carried out using the HASTE MR sequence. Images were compared to concurrent IV urography (IVU) or to computed tomography (CT) where these were available. Acute and chronic ureteric obstruction were differentiated by clinical evaluation.

RESULTS

Forty-one patients had obstructed kidneys. HASTE MR accurately predicted the presence of acute ureteric obstruction in 20/23 (87%) based on presence of perirenal MR high signal. None of these showed evidence of contrast medium extravasation on the concurrent i.v. urogram. 15/18 (83%) chronically obstructed kidneys demonstrated no perirenal high signal on HASTE MR, and the remaining three showed only a trace of perirenal high signal. CT showed perirenal stranding in only 2/8 patients with acutely obstructed kidneys.

CONCLUSION

In acute ureteric obstruction, HASTE MR shows perirenal high signal intensity much more commonly than IVU shows extravasation or CT showing perirenal stranding. The origin of this MR signal is uncertain but may represent oedema, lymphatic distension or free fluid from forniceal rupture. HASTE MR can accurately distinguish between acute and chronic ureteric obstruction based on the degree of perirenal high signal.

Comparison of in vivo red cell survival of donations collected by Haemonetics MCS versus conventional collection

The Haemonetics Multicomponents System (MCS) cell separator allows concurrent donation of red cells in addition to platelets and/or plasma, thus increasing the versatility of apheresis donations. In vivo survival of autologous red cells obtained by MCS was compared with red cells collected conventionally. In this cross-over controlled study, five male volunteers donated one unit of red cells by MCS and one unit of whole blood by the conventional manual method, 3 months apart. After storing donations in SAG-M for 35 days under standard conditions, radioactive (51Cr)-labelled autologous red cells were injected into each donor. The post-transfusion recovery (PTR) of red cells at 24 and 48 h did not show any significant difference between red cells obtained manually and by MCS, indicating that processing differences have no detrimental effects on red cell survival.

Choledocholithiasis: evaluation with MR cholangiography

OBJECTIVE

We performed this study to evaluate the usefulness of a new T2-weighted MR sequence using a half-Fourier acquisition single-shot turbo spin-echo (HASTE) technique in the diagnosis of bile duct stones.

SUBJECTS AND METHODS

We prospectively evaluated 23 patients with suspected bile duct calculi using HASTE MR cholangiography and compared that imaging technique with endoscopic retrograde cholangiography and sonography. The study group consisted of 15 women and eight men who were 42-89 years old. Patients were imaged in the axial, coronal, and sagittal planes with a 1.5-T MR scanner using a body coil. Acquisitions of 13 sec each allowed images to be obtained in a single breath-hold. All images were interpreted by two radiologists in a double-blinded fashion. The presence, number, and size of stones were noted, and common bile duct dilatation was assessed.

RESULTS

Fifteen of the 23 patients were proven to have common bile duct stones. Stone size ranged from 3 mm to 35 mm (mean, 11 mm). HASTE MR cholangiography revealed stones in 14 (93%) of 15 patients; sonography revealed stones in nine (60%) of 15 patients. In 12 patients, the common bile duct was dilated, as shown by endoscopic retrograde cholangiography, HASTE MR cholangiography, and sonography. On HASTE MR cholangiograms, we measured the diameter of the bile duct in all patients. The mean diameter was 11 mm, which correlated well (r = .82) with a mean diameter of 13.5 mm as measured on endoscopic retrograde cholangiograms.

CONCLUSION

HASTE MR cholangiography can noninvasively and rapidly reveal the presence of stones in the common bile duct and allows readers to assess the degree of biliary dilatation. The sequence should be considered as an alternative to endoscopic retrograde cholangiography in patients with clinical evidence of bile duct calculi and in those for whom endoscopic retrograde cholangiography is impossible.