A universal biventricular coordinate system incorporating valve annuli: Validation in congenital heart disease

Universal coordinate systems have been proposed to facilitate anatomic registration between three-dimensional images, data and models of the ventricles of the heart. However, current universal ventricular coordinate systems do not account for the outflow tracts and valve annuli where the anatomy is complex. Here we propose an extension to the 'Cobiveco' biventricular coordinate system that also accounts for the intervalvular bridges of the base and provides a tool for anatomically consistent registration between widely varying biventricular shapes. CobivecoX uses a novel algorithm to separate intervalvular bridges and assign new coordinates, including an inflow-outflow coordinate, to describe local positions in these regions uniquely and consistently. Anatomic consistency of registration was validated using curated three-dimensional biventricular shape models derived from cardiac MRI measurements in normal hearts and hearts from patients with congenital heart diseases. This new method allows the advantages of universal cardiac coordinates to be used for three-dimensional ventricular imaging data and models that include the left and right ventricular outflow tracts and valve annuli.

A deep learning approach for fully automated cardiac shape modeling in tetralogy of Fallot

BACKGROUND

Cardiac shape modeling is a useful computational tool that has provided quantitative insights into the mechanisms underlying dysfunction in heart disease. The manual input and time required to make cardiac shape models, however, limits their clinical utility. Here we present an end-to-end pipeline that uses deep learning for automated view classification, slice selection, phase selection, anatomical landmark localization, and myocardial image segmentation for the automated generation of three-dimensional, biventricular shape models. With this approach, we aim to make cardiac shape modeling a more robust and broadly applicable tool that has processing times consistent with clinical workflows.

METHODS

Cardiovascular magnetic resonance (CMR) images from a cohort of 123 patients with repaired tetralogy of Fallot (rTOF) from two internal sites were used to train and validate each step in the automated pipeline. The complete automated pipeline was tested using CMR images from a cohort of 12 rTOF patients from an internal site and 18 rTOF patients from an external site. Manually and automatically generated shape models from the test set were compared using Euclidean projection distances, global ventricular measurements, and atlas-based shape mode scores.

RESULTS

The mean absolute error (MAE) between manually and automatically generated shape models in the test set was similar to the voxel resolution of the original CMR images for end-diastolic models (MAE = 1.9 ± 0.5 mm) and end-systolic models (MAE = 2.1 ± 0.7 mm). Global ventricular measurements computed from automated models were in good agreement with those computed from manual models. The average mean absolute difference in shape mode Z-score between manually and automatically generated models was 0.5 standard deviations for the first 20 modes of a reference statistical shape atlas.

CONCLUSIONS

Using deep learning, accurate three-dimensional, biventricular shape models can be reliably created. This fully automated end-to-end approach dramatically reduces the manual input required to create shape models, thereby enabling the rapid analysis of large-scale datasets and the potential to deploy statistical atlas-based analyses in point-of-care clinical settings. Training data and networks are available from cardiacatlas.org.

Biventricular shape modes discriminate pulmonary valve replacement in tetralogy of Fallot better than imaging indices

Current indications for pulmonary valve replacement (PVR) in repaired tetralogy of Fallot (rTOF) rely on cardiovascular magnetic resonance (CMR) image-based indices but are inconsistently applied, lead to mixed outcomes, and remain debated. This study aimed to test the hypothesis that specific markers of biventricular shape may discriminate differences between rTOF patients who did and did not require subsequent PVR better than standard imaging indices. In this cross-sectional retrospective study, biventricular shape models were customized to CMR images from 84 rTOF patients. A statistical atlas of end-diastolic shape was constructed using principal component analysis. Multivariate regression was used to quantify shape mode and imaging index associations with subsequent intervention status (PVR, n = 48 vs. No-PVR, n = 36), while accounting for confounders. Clustering analysis was used to test the ability of the most significant shape modes and imaging indices to discriminate PVR status as evaluated by a Matthews correlation coefficient (MCC). Geometric strain analysis was also conducted to assess shape mode associations with systolic function. PVR status correlated significantly with shape modes associated with right ventricular (RV) apical dilation and left ventricular (LV) dilation (p < 0.01), RV basal bulging and LV conicity (p < 0.05), and pulmonary valve dilation (p < 0.01). PVR status also correlated significantly with RV ejection fraction (p < 0.05) and correlated marginally with LV end-systolic volume index (p < 0.07). Shape modes discriminated subsequent PVR better than standard imaging indices (MCC = 0.49 and MCC = 0.28, respectively) and were significantly associated with RV and LV radial systolic strain. Biventricular shape modes discriminated differences between patients who did and did not require subsequent PVR better than standard imaging indices in current use. These regional features of cardiac morphology may provide insight into adaptive vs. maladaptive types of structural remodeling and point toward an improved quantitative, patient-specific assessment tool for clinical use.

An Atlas-Based Analysis of Biventricular Mechanics in Tetralogy of Fallot

The current study proposes an efficient strategy for exploiting the statistical power of cardiac atlases to investigate whether clinically significant variations in ventricular shape are sufficient to explain corresponding differences in ventricular wall motion directly, or if they are indirect markers of altered myocardial mechanical properties. This study was conducted in a cohort of patients with repaired tetralogy of Fallot (rTOF) that face long-term right ventricular (RV) and/or left ventricular (LV) dysfunction as a consequence of adverse remodeling. Features of biventricular end-diastolic (ED) shape associated with RV apical dilation, LV dilation, RV basal bulging, and LV conicity correlated with components of systolic wall motion (SWM) that contribute most to differences in global systolic function. A finite element analysis of systolic biventricular mechanics was employed to assess the effect of perturbations in these ED shape modes on corresponding components of SWM. Perturbations to ED shape modes and myocardial contractility explained observed variation in SWM to varying degrees. In some cases, shape markers were partial determinants of systolic function and, in other cases, they were indirect markers for altered myocardial mechanical properties. Patients with rTOF may benefit from an atlas-based analysis of biventricular mechanics to improve prognosis and gain mechanistic insight into underlying myocardial pathophysiology.

Right Ventricular Flow Vorticity Relationships With Biventricular Shape in Adult Tetralogy of Fallot

Remodeling in adults with repaired tetralogy of Fallot (rToF) may occur due to chronic pulmonary regurgitation, but may also be related to altered flow patterns, including vortices. We aimed to correlate and quantify relationships between vorticity and ventricular shape derived from atlas-based analysis of biventricular shape. Adult rToF (n = 12) patients underwent 4D flow and cine MRI imaging. Vorticity in the RV was computed after noise reduction using a neural network. A biventricular shape atlas built from 95 rToF patients was used to derive principal component modes, which were associated with vorticity and pulmonary regurgitant volume (PRV) using univariate and multivariate linear regression. Univariate analysis showed that indexed PRV correlated with 3 modes (r = −0.55,−0.50, and 0.6, all p &lt; 0.05) associated with RV dilatation and an increase in basal bulging, apical bulging and tricuspid annulus tilting with more severe regurgitation, as well as a smaller LV and paradoxical movement of the septum. RV outflow and inflow vorticity were also correlated with these modes. However, total vorticity over the whole RV was correlated with two different modes (r = −0.62,−0.69, both p &lt; 0.05). Higher vorticity was associated with both RV and LV shape changes including longer ventricular length, a larger bulge beside the tricuspid valve, and distinct tricuspid tilting. RV flow vorticity was associated with changes in biventricular geometry, distinct from associations with PRV. Flow vorticity may provide additional mechanistic information in rToF remodeling. Both LV and RV shapes are important in rToF RV flow patterns.

Right-left ventricular shape variations in tetralogy of Fallot: associations with pulmonary regurgitation

BACKGROUND

Relationships between right ventricular (RV) and left ventricular (LV) shape and function may be useful in determining optimal timing for pulmonary valve replacement in patients with repaired tetralogy of Fallot (rTOF). However, these are multivariate and difficult to quantify. We aimed to quantify variations in biventricular shape associated with pulmonary regurgitant volume (PRV) in rTOF using a biventricular atlas.

METHODS

In this cross-sectional retrospective study, a biventricular shape model was customized to cardiovascular magnetic resonance (CMR) images from 88 rTOF patients (median age 16, inter-quartile range 11.8-24.3 years). Morphometric scores quantifying biventricular shape at end-diastole and end-systole were computed using principal component analysis. Multivariate linear regression was used to quantify biventricular shape associations with PRV, corrected for age, sex, height, and weight. Regional associations were confirmed by univariate correlations with distances and angles computed from the models, as well as global systolic strains computed from changes in arc length from end-diastole to end-systole.

RESULTS

PRV was significantly associated with 5 biventricular morphometric scores, independent of covariates, and accounted for 12.3% of total shape variation (p < 0.05). Increasing PRV was associated with RV dilation and basal bulging, in conjunction with decreased LV septal-lateral dimension (LV flattening) and systolic septal motion towards the RV (all p < 0.05). Increased global RV radial, longitudinal, circumferential and LV radial systolic strains were significantly associated with increased PRV (all p < 0.05).

CONCLUSION

A biventricular atlas of rTOF patients quantified multivariate relationships between left-right ventricular morphometry and wall motion with pulmonary regurgitation. Regional RV dilation, LV reduction, LV septal-lateral flattening and increased RV strain were all associated with increased pulmonary regurgitant volume. Morphometric scores provide simple metrics linking mechanisms for structural and functional alteration with important clinical indices.

Atlas-based methods for efficient characterization of patient-specific ventricular activation patterns

AIMS

Ventricular activation patterns can aid clinical decision-making directly by providing spatial information on cardiac electrical activation or indirectly through derived clinical indices. The aim of this work was to derive an atlas of the major modes of variation of ventricular activation from model-predicted 3D bi-ventricular activation time distributions and to relate these modes to corresponding vectorcardiograms (VCGs). We investigated how the resulting dimensionality reduction can improve and accelerate the estimation of activation patterns from surface electrogram measurements.

METHODS AND RESULTS

Atlases of activation time (AT) and VCGs were derived using principal component analysis on a dataset of simulated electrophysiology simulations computed on eight patient-specific bi-ventricular geometries. The atlases provided significant dimensionality reduction, and the modes of variation in the two atlases described similar features. Utility of the atlases was assessed by resolving clinical waveforms against them and the VCG atlas was able to accurately reconstruct the patient VCGs with fewer than 10 modes. A sensitivity analysis between the two atlases was performed by calculating a compact Jacobian. Finally, VCGs generated by varying AT atlas modes were compared with clinical VCGs to estimate patient-specific activation maps, and the resulting errors between the clinical and atlas-based VCGs were less than those from more computationally expensive method.

CONCLUSION

Atlases of activation and VCGs represent a new method of identifying and relating the features of these high-dimensional signals that capture the major sources of variation between patients and may aid in identifying novel clinical indices of arrhythmia risk or therapeutic outcome.

Computational analysis of cardiac structure and function in congenital heart disease: Translating discoveries to clinical strategies

Increased availability and access to medical image data has enabled more quantitative approaches to clinical diagnosis, prognosis, and treatment planning for congenital heart disease. Here we present an overview of long-term clinical management of tetralogy of Fallot (TOF) and its intersection with novel computational and data science approaches to discovering biomarkers of functional and prognostic importance. Efforts in translational medicine that seek to address the clinical challenges associated with cardiovascular diseases using personalized and precision-based approaches are then discussed. The considerations and challenges of translational cardiovascular medicine are reviewed, and examples of digital platforms with collaborative, cloud-based, and scalable design are provided.

Atlas-based measures of left ventricular shape may improve characterization of adverse remodeling in anthracycline-exposed childhood cancer survivors: a cross-sectional imaging study

Background

Adverse cardiac remodeling is an important precursor to anthracycline-related cardiac dysfunction, however conventional remodeling indices are limited. We sought to examine the utility of statistical atlas-derived measures of ventricular shape to improve the identification of adverse anthracycline-related remodeling in childhood cancer survivors.

Methods

We analyzed cardiac magnetic resonance imaging from a cross-sectional cohort of 20 childhood cancer survivors who were treated with low (< 250 mg/m² [N = 10]) or high (≥250 mg/m² [N = 10]) dose anthracyclines, matched 1:1 by sex and age between dose groups. We reconstructed 3D computational models of left ventricular end-diastolic shape for each subject and assessed the ability of conventional remodeling indices (volume, mass, and mass to volume ratio) vs. shape modes derived from a statistical shape atlas of an asymptomatic reference population to stratify anthracycline-related remodeling. We compared conventional parameters and five atlas-based shape modes: 1) between survivors and the reference population (N = 1991) using multivariable linear regression, and 2) within survivors by anthracycline dose (low versus high) using two-sided T-tests, multivariable logistic regression, and receiver operating characteristic curves.

Results

Compared with the reference population, survivors had differences in conventional measures (lower volume and mass) and shape modes (corresponding to lower overall size and lower sphericity; all p < 0.001). Among survivors, differences in a shape mode corresponding to increased basal cavity size and altered mitral annular orientation in the high-dose group were observed (p = 0.039). Collectively, atlas-based shape modes in conjunction with conventional measures discriminated survivors who received low vs. high anthracycline dosage (area under the curve [AUC] 0.930, 95% confidence interval 0.816, 1.00) significantly better than conventional measures alone (AUC 0.710, 95% confidence interval 0.473, 0.947; AUC comparison p = 0.0498).

Conclusions

Compared with a reference population, heart size is smaller in anthracycline-exposed childhood cancer survivors. Atlas-based measures of left ventricular shape may improve the detection of anthracycline dose-related remodeling differences.

'Artery-first' approaches to pancreatoduodenectomy

BACKGROUND

The technique of pancreatoduodenectomy (PD) has evolved. Previously, non-resectability was determined by involvement of the portal vein-superior mesenteric vein. Because venous resection can be achieved safely and with greater awareness of the prognostic significance of the status of the posteromedial resection margin, non-resectability is now determined by involvement of the superior mesenteric artery (SMA). This change, with a need for early determination of resectability before an irreversible step, has promoted the development of an 'artery-first' approach. The aim of this study was to review, and illustrate, this approach.

METHODS

An electronic search was performed on MEDLINE, Embase and PubMed databases from 1960 to 2011 using both medical subject headings and truncated word searches to identify all published articles that related to this topic.

RESULTS

The search revealed six different surgical approaches that can be considered as 'artery first'. These involved approaching the SMA from the retroperitoneum (posterior approach), the uncinate process (medial uncinate approach), the infracolic region medial to the duodenojejunal flexure (inferior infracolic or mesenteric approach), the infracolic retroperitoneum lateral to the duodenojenunal flexure (left posterior approach), the supracolic region (inferior supracolic approach) and through the lesser sac (superior approach).

CONCLUSION

The six approaches described provide a range of options for the early determination of arterial involvement, depending on the location and size of the tumour, and before the 'point of no return'. Whether these approaches will achieve an increase in the proportion of patients with negative margins, improve locoregional control and increase long-term survival has yet to be determined.

Using the ovarian vein to find the ovary

Computed tomograms of 68 adult women who had undergone contrast-enhanced, 5-mm helical computed tomography of the abdomen and pelvis were retrospectively reviewed to determine whether the ovarian vein could be used to locate the ovary. Subjects were 17 to 84 years of age (mean 45 years); 31 scans were normal, and 37 showed pelvic masses. Both ovarian veins were identified at their termination and were followed into the pelvis by scrolling through the set of venous phase images with a manual cine-paging tool. All 68 left ovarian veins and 67 of 68 right ovarian veins were identified. All visualized ovarian veins led to a normal ovary or to an ovarian mass. There were no anatomic variations. In 13 ovaries displaced by pathology in the pelvis, the ovarian vein was correspondingly displaced and indicated the altered ovarian position. In all 14 patients with non-ovarian pelvic masses, ovarian veins led to the normal ovary; the vein and ovary were markedly displaced in three of these patients. On computed tomography, the ovarian vein can be consistently identified. By tracing the vein into the pelvis, the ovarian or non-ovarian nature of a pelvic mass can be determined.

Pancreatico-pericardial fistula: a rare complication of chronic pancreatitis

A 16-year-old boy presented with pericardial effusion, bilateral pleural effusion and mediastinal fluid collection. CT scan of abdomen revealed pancreatic calcification and a fistulous tract from a pseudocyst going along the inferior vena cava wall up to the pericardial cavity. After initial pericardiocentesis and pleurocentesis, lateral pancreatico-jejunostomy with Roux-en-Y loop was performed. The patient is well at 6 months follow up.

Adrenal histoplasmosis: clinical presentation and imaging features in nine cases

BACKGROUND

We describe a retrospective analysis of the clinical presentation and imaging features in nine patients with adrenal histoplasmosis in nonimmunocompromised patients from a nonendemic region.

METHODS

Clinically, a tuberculosis-like presentation in four patients and a tumor-like presentation in five patients were seen. All patients were seronegative for the human immunodeficiency virus. Ultrasound (US) in all patients, computed tomography (CT) in six, and magnetic resonance imaging (MRI) in three showed suprarenal masses. CT-guided (in five) and US-guided (in four) biopsy and fine-needle aspiration cytology established a definite diagnosis. The work-up for malignancy and tuberculosis was negative.

RESULTS

On cross-sectional imaging, eight patients had bilateral adrenal masses and one had a unilateral adrenal mass. Imaging features were variable. All adrenal masses were hypoechoic on US, homogeneous in five, and heterogeneous in four patients. All adrenal masses were hypodense on CT, homogeneous in four, and heterogeneous in two. Heterogeneous enhancement was seen in three, homogeneous enhancement in two, and no enhancement in one patient. MRI in three patients showed that the masses were of variable signal intensity on all pulse sequences.

CONCLUSION

Our case series showed that adrenal histoplasmosis does occur in immunocompetent persons living in areas not endemic for the disease. The imaging features were variable.

Pneumothorax preceding pulmonary blastoma in a child

Serial plain radiographic, ultrasound and CT findings of an unusual case of pulmonary blastoma are described with a review of the literature.

Problem in diagnostic imaging: pancreaticoduodenal arcade in splanchnic arterial stenosis

This paper features a problem in diagnostic imaging in which a pre-transplant abdominal angiogram of a potential liver recipient shows filling of the hepatic artery via the superior mesenteric artery and the pancreaticoduodenal arcade. The routing of this unusual supply to the liver is explained by careful study of abdominal aortic angiograms and a sagittal MRI made through the aorta.

Efficacy of non-breath-hold magnetic resonance cholangiography at midfield strength

The efficacy of non-breath-hold magnetic resonance (MR) cholangiography at mid-field strength (0.5 Tesla) was evaluated for delineating biliary anatomy and the cause and extent of biliary obstruction. We performed 65 MR cholangiograms on a mid-field 0.5 Tesla MR unit and correlated them with contrast cholangiography and/or surgery. MR cholangiography was found to be both sensitive and specific in the detection of biliary obstruction and in the definition of its cause (sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 85.7%, accuracy 98%). MR cholangiography accurately predicted the level of obstruction in 94 per cent of strictures. Normal caliber intra-hepatic biliary radicles were visualised in only 6 per cent of the MR cholangiograms. In contrast, 94 per cent of dilated intrahepatic biliary radicles were demonstrated. The confluence, and right and left hepatic ducts were visualized in 98 per cent; the gall bladder in 65 per cent; the cystic duct in 45 per cent and the cystic duct insertion in 25 per cent. The extrahepatic bile duct was seen in 82.7 per cent. A normal caliber pancreatic duct was seen in 18 per cent while a dilated pancreatic duct was seen in 86 per cent. The pancreatico-biliary junction was visualised in 7 per cent. Non-breath-hold MR cholangiography at midfield strength is a highly accurate method of evaluating the cause and level of biliary obstruction, comparable to high-field MR cholangiography. The spatial resolution however is inadequate for the detection of variations in biliary or pancreatic ductal anatomy when the ducts are of normal caliber.

Value of splenic preservation during distal pancreatectomy for chronic pancreatitis

BACKGROUND

Pain relief after distal pancreatectomy for chronic pancreatitis is reportedly satisfactory in 50-80 per cent of patients. This study attempted to determine clinical and radiological features that might select patients likely to benefit from distal pancreatectomy, and whether splenic preservation influenced the outcome.

METHODS

Thirty-eight patients with chronic pancreatitis, who underwent distal pancreatectomy between 1982 and 1998, were reviewed retrospectively. The outcome of surgery was correlated with the aetiology of pancreatitis and radiological appearance on endoscopic retrograde cholangiopancreatography and computed tomography.

RESULTS

Good results were achieved in 23 of 36 patients for whom follow-up (median 48 months) was available, including all 11 with obstructive pancreatitis. The spleen was preserved in 22 patients. Twelve patients became diabetic after surgery: three of 20 in whom the spleen was preserved and nine of 16 who underwent splenectomy.

CONCLUSION

Non-alcoholic patients with a normal pancreas proximal to a dominant ductal stricture had a consistently good outcome from surgery. Spleen-preserving distal pancreatectomy, although technically demanding, can be performed safely with results equivalent to those of distal pancreatectomy with splenectomy or autotransplantation. Splenic preservation, apart from preventing postsplenectomy sepsis, might also delay the onset of diabetes.

Choledochal cysts: evaluation with MR cholangiography

BACKGROUND

To determine where magnetic resonance (MR) cholangiography can accurately demonstrate the presence, extent, and type of choledochal cysts.

METHODS

Ten patients with sonographically suspected choledochal cysts were evaluated with a non-breath-hold MR cholangiography technique. The presence, extent, and type of choledochal cyst were determined. Visualization of the pancreatobiliary junction was recorded. MR cholangiographic findings were correlated with the gold standard of surgery in six patients, endoscopic retrograde cholangiography in two, and a 99mTc hepatobiliary scintigram in one. Three patients underwent intraoperative cholangiography.

RESULTS

All MR cholangiograms were correlated with findings at surgery, endoscopic retrograde cholangiography, or 99mTc hepatobiliary scintigraphy. There were seven Todani type 1 and two Todani type 5 choledochal cysts (Caroli's disease). The extent of involvement was correctly demonstrated on all MR cholangiograms. The pancreatobiliary junction could not be identified in any of the cases. Calculi and sludge were correctly identified on the MR cross-sectional images in three patients but were not seen on MR cholangiograms in two. In one patient with an initially misinterpreted choledochal cyst, MR sectional images showed the typical appearance of a hydatid cyst, which was confirmed at surgery.

CONCLUSION

MR cholangiography can be used to confirm the diagnosis of choledochal cysts and define the extent of involvement preoperatively. The pancreatobiliary junction, however, is difficult to visualize. Non-biliary cysts such as a hydatid cyst can mimic a choledochal cyst on the MR cholangiogram and should be correlated with the MR cross-sectional images to avoid misinterpretation.

Choledochal cysts in adults

The clinical features and management of 14 adults with choledochal cysts who presented to our hospital are discussed. There were 10 Todani type I, and four type IV cysts. The cysts were fusiform in all but three cases. The pancreatobiliary junction was abnormal in only two patients. Ten patients had cystolithiasis. Six patients had undergone previous biliary surgery, three of whom presented with biliary strictures. We recommend that choledochal cyst be considered as a differential diagnosis in all patients with dilated bile ducts, especially when symptoms persist after biliary surgery. In two patients who had undergone endoscopic sphincterotomy and stone clearance, and in whom the diagnosis was still in doubt after cholangiography, hepatic iminodiacetic acid (HIDA) scan confirmed the diagnosis of choledochal cyst by showing persistent biliary stagnation despite free flow of bile across the sphincter of Oddi. Complete resection of the cyst was achieved in all cases with one postoperative death. A modification of the standard surgical technique is described which makes mobilisation of the cyst easier. The need to demonstrate the pancreatobiliary ductal confluence as an aid to complete excision of the cyst is emphasised.

Transjugular liver biopsy: a comparison of aspiration and trucut techniques

The results of 67 transjugular liver biopsies are described. Two failures were encountered due to inability to pass the needle into acutely angulated hepatic veins. Thirty-four patients underwent a liver aspiration biopsy using a Colapinto needle, while the remainder were biopsied using a trucut needle. The success rate with the Colapinto needle was 68% and with the trucut model, 97%. Capsular perforation occurred in three cases, but without significant morbidity or mortality. It is concluded that the trucut needle biopsy is more reliable than aspiration biopsy, when the transjugular approach is mandated, in obtaining optimal liver tissue for histopathological diagnosis.

Monitoring of antibiotic use in a primary and tertiary care hospital

Prophylactic and curative use of antibiotics was studied prospectively in 87 consecutive medical and surgical cases of a tertiary care hospital and in 98 cases of a primary care hospital. Based on Kunins' criteria, antibiotic prophylaxis was found to be more inappropriate in the primary care hospital (49%) than in the tertiary care hospital (34%). Antibiotic therapy, however, was more appropriate at the primary level; 67% as opposed to 60% at the tertiary level. This resulted in a similar overall level of inappropriate antibiotic use in the two hospitals. Surgical prophylaxis was started postoperatively in 68% of the primary care hospital cases. Though prophylaxis was always perioperative in the tertiary care hospital, the postoperative duration was more than 7 days in one third of the cases. The nosocomial infection rate in those given prolonged prophylaxis was higher than those who received antibiotics for less than 72 hours. Antibiotics were started empirically in 78% of tertiary hospital care cases and 100% of cases in the primary hospital. Though culture sensitivity was done in 80% of the tertiary care cases, more than half the specimens were sent after multiple doses of antibiotics were started. The choice of antibiotic did not always correlate with the sensitivity report. Though cost-effective drugs were chosen in 50% of cases, in more than 20% of cases expensive drugs were started. The study highlights the need for an antibiotic audit and suggests the necessity of having an ongoing peer audit.

Spontaneous regression of pulmonary mucormycosis

A case of pulmonary mucormycosis with spontaneous resolution is presented. The patient had no known underlying predisposing disease.

Colonic sonography: preliminary observations

Transrectal instillation of water is a recently described technique for improved sonological imaging of the lumen and wall of the colon. In order to assess the accuracy of this technique, termed colonic sonography (CS), in the detection of abnormalities of the large bowel, 100 consecutive patients were subjected to colonic sonography and the results were compared with the results of colonoscopy and surgery. The technique showed a sensitivity of 91% for the detection of colonic tuberculosis, 89% for ulcerative colitis and 83% for colonic cancers. Small mucosal ulcers, polyps less than 7 mm in diameter and the changes of non-specific colitis were not detected. Sonography displayed the entire colon more consistently than colonoscopy. The extent and extra-colonic spread of disease were better appreciated. The procedure was not adversely influenced by the presence of faecal material within the colon and was well tolerated. Colonic sonography is a promising new technique for detecting significant colonic pathology and merits further comparison with existing modalities.

Culture appropriate indicators for monitoring growth and development of urban and rural children below 6 years

In this cross sectional study, 2000 apparently normal children aged 0-6 years (1200 urban and 800 rural), were nutritionally and developmentally assessed and their environment scrutinized for possible risk factors. Measurement of mid upper arm circumference (MUAC) using standard techniques revealed malnutrition in 44% of the rural and 24% of the urban children especially in the 2-6 years of age group. Culture appropriate indicators of psycho-social development picked up gross delays in gross motor (GM), vision and fine motor (V&FM) and language skills. Self help, concept hearing (SHCH) skills were recorded as normal while social skills were advanced particularly in the 0-2 years old urban group. By the use of the family protocols, low socio-economic status, malnutrition and 9 other risks factors have been generated for the urban group. No risk factor could be identified for the rural group. Better income emerged as the only real protective factor for the sample showing a direct positive relationship with the 45 skills tested, especially in the 2-6 years age group. Nineteen developmental skills were identified as powerful predictors of development. A prototype home based screening record was constructed for monitoring of growth and development which can be even used by minimally trained primary care worker.

Pedunculated colonic polyp diagnosed by colonic sonography

A solitary hamartomatous polyp of the colon in a four year old boy was diagnosed by colonic sonography while barium enema and colonoscopy were non-diagnostic. Colonic sonography provides an additional simple, relatively non-invasive modality for evaluation of the colon.

Double alkoxides of zirconium with alkaline earth metals

Volatile double isopropoxides M[Zr2(OPri)9]2 and MZr3(OPri)14 of zirconium with alkaline earth metals (M = Mg, Ca, Sr or Ba) are described. Their likely structures are discussed on the basis of alcoholysis studies, molecular weights, i.r. and N.M.R. spectra.