Spiral CT Angiography: Applications in Neurovascular Imaging

Background

The advent of Spiral Computed Tomographic (CT) angiography has provided the patients a non-invasive, accurate and fast modality of imaging the vasculature.

Methods

Spiral CT angiography was performed in 30 patients to evaluate intracranial circulation using standard protocols of data acquisition. The images were processed and reconstructed in 3-dimension to delineate anatomy and pathology accurately.

Results

The study established that CT angiography is an accurate modality for evaluating the intracranial circulation in a variety of abnormalities. It is safe both in terms of being non-invasive and exposure to radiation. It has a distinct advantage over other non-invasive modalities of imaging like MRI in the evaluation of patients with metallic stents and clips.

Conclusion

CT angiography has tremendous potential in imaging the intracranial vasculature. It is unquestionably safer than catheter angiography as it avoids arterial puncture and intra-arterial catheter manipulation. It is fast and capable of producing excellent 3-dimensional images of the intracranial vasculature.Key Words: Neurovascular imaging, Spiral CT, CT Angiography     

Liver specific magnetic resonance imaging contrast medium for evaluation of focal liver lesions – Initial experience at a service hospital

Background

Contrast enhanced MRI is today considered the investigation modality of choice in detection and characterization of focal liver lesions. The conventional MRI contrast media like Gadolinium (Gd) chelates undergo elimination through the urinary pathway and are not selectively concentrated or metabolized in the liver. Gadobenate dimeglumine (Chemical name: Gadolinium-BOPTA) is a promising newer liver specific MRI contrast medium having additional properties of selective uptake and biliary excretion by hepatocytes. Our study was designed as a pilot study to evaluate the utility of Gd-BOPTA in detection and characterization of focal liver lesions.

Methods

Fifty-three consecutive patients with focal liver lesions (excluding only simple hepatic cysts) detected on ultrasonography and CT abdomen, were prospectively subjected to standardized MRI protocol for the liver, using Gd-BOPTA as the intravenous contrast medium. An additional T1W axial scan of the liver was incorporated in the study protocol, at a delay of 2 h post-contrast, in all patients.

Results

In the study population, the combination of USG and contrast enhanced CT abdomen findings were adequate to reach a definitive diagnosis in 70% of the patients. The liver specificity of Gd-BOPTA contributed to improved lesional characterization in 9/50 patients (18%) on the delayed phase images.

Conclusion

The study revealed that the liver specific properties of Gd-BOPTA can be used to obtain additional information to improve characterization of focal hepatic lesions, when delayed phase scans are included in the study protocol.     

Diffusion weighted magnetic resonance imaging for acute stroke: practical and popular

Aim

To evaluate the feasibility and impact of diffusion weighted magnetic resonance imaging (DW MRI) as the first line neuroimaging of stroke at a district general hospital.

Methods

Prospective audit of all in‐patients admitted with clinically suspected acute stroke and referred for imaging over a consecutive 17 week period. The data collected included scan type, time from cerebral event to imaging request, and time from formal radiological request to neuroimaging. Clinicians'' (general physicians, neurologists, and radiologists) perceptions were assessed by a questionnaire.

Results

148 patients had neuroimaging for clinically suspected stroke during this period. Eighty one per cent of patients (120 of 148) had DW MRI as first line. Ninety two per cent of these patients had DW MRI within 24 hours of the formal radiological request. Twenty eight patients did not undergo DW MRI because lack of MRI safety, clinical state, unavailability because of maintenance service or lack of trained staff. Clinicians found the introduction of the DW MRI based service a significant improvement on computed tomography, especially for equivocal cases.

Conclusion

DW based MRI service is both feasible and sustainable in the setting of a district general hospital and most clinicians feel that this is a significant improvement to stroke services.     

Computed tomography and magnetic resonance imaging of multiple focal nodular hyperplasias of the liver with congenital absence of the portal vein in a Chinese girl: case report and review of the literature

Background

Patients with congenital absence of the portal vein (CAPV) often suffer from additional medical complications such as hepatic tumors and cardiac malformations.

Case presentation

Congenital absence of the portal vein (CAPV) is a rare malformation. We present a case of a 16-year-old Chinese girl with CAPV with multiple pathology-proven hepatic focal nodular hyperplasias (FNHs) and ventricular septal defect (VSD). The CT and MRI features of this case are described, and previously reported cases are reviewed.

Conclusions

CAPV is a rare congenital anomaly and in such patients, clarifying the site of portosystemic shunts, liver disease, and other anomalies is critical for appropriate treatment selection and accurate prognosis determination. Close follow-up, including laboratory testing and radiologic imaging, is recommended for all CAPV patients.     

Comparative analysis of changes in MR imaging of pre and post intrauterine progesterone implants in adenomyosis cases

Background

Magnetic Resonance Imaging (MRI) plays an important role in the evaluation and management of adenomyosis. In this study, we first diagnosed the adenomyosis on MRI and then we analyzed the MRI changes in the uterus in pre and post intrauterine progesterone implants cases.

Method

All the patients with clinical diagnosis of menorrhagia or dysmenorrhea were screened by Ultrasonography (USG) of the pelvis. Patients with heterogeneous echo texture of the uterus were then evaluated by the MRI of the pelvis. All patients with MRI findings suggestive of adenomyosis formed the study group.

Result

On MRI study 60 patients were diagnosed as adenomyosis, 68.33% had diffuse adenomyosis and 31.66% had focal adenomyosis. 83% of diagnosed adenomyosis cases had high intensity signal foci which were seen in 75% cases of diffuse adenomyosis and 100% cases of focal adenomyosis. 50 diagnosed adenomyosis cases were then reviewed after 03 months, 06 months and 12 months to see for any change in the MRI findings in the post intrauterine implant cases. On follow up MRI after post progesterone intrauterine implant, 50% of the cases showed reduction in the high intensity signals, 10% of the cases showed mild reduction in the junctional zone thickness with no significant change in the uterine size.

Conclusions

It is inferred that MR imaging is not only helpful in diagnosing but also helpful in monitoring the effects of hormonal therapy in adenomyosis.     

Research and applications: Semantic analysis of SNOMED CT for a post-coordinated database of histopathology findings

Objective

This research investigated the use of SNOMED CT to represent diagnostic tissue morphologies and notable tissue architectures typically found within a pathologist''s microscopic examination report to identify gaps in expressivity of SNOMED CT for use in anatomic pathology.

Methods

24 breast biopsy cases were reviewed by two board certified surgical pathologists who independently described the diagnostically important tissue architectures and diagnostic morphologies observed by microscopic examination. In addition, diagnostic comments and details were extracted from the original diagnostic pathology report. 95 unique clinical statements were extracted from 13 malignant and 11 benign breast needle biopsy cases.

Results

75% of the inventoried diagnostic terms and statements could be represented by valid SNOMED CT expressions. The expressions included one pre-coordinated expression and 73 post-coordinated expressions. No valid SNOMED CT expressions could be identified or developed to unambiguously assert the meaning of 21 statements (ie, 25% of inventoried clinical statements). Evaluation of the findings indicated that SNOMED CT lacked sufficient definitional expressions or the SNOMED CT concept model prohibited use of certain defined concepts needed to describe the numerous, diagnostically important tissue architectures and morphologic changes found within a surgical pathology microscopic examination.

Conclusions

Because information gathered during microscopic histopathology examination provides the basis of pathology diagnoses, additional concept definitions for tissue morphometries and modifications to the SNOMED CT concept model are needed and suggested to represent detailed histopathologic findings in computable fashion for purposes of patient information exchange and research.

Trial registration number

UNMC Institutional Review Board ID# 342-11-EP.     

Three dimensional reconstruction of the pancreas based on the virtual Chinese human--female number 1

Objective

To study the three dimensional (3D) reconstruction and 3D visualisation of the pancreas and create anatomy of the digitalised visual pancreas so as to construct a concrete basis for virtual operation and surgical operation on pancreas.

Methods

The digital imaging data of pancreas, duodenum, common bile duct, arteries, and veins were obtained from the virtual Chinese human—female 1 (VCH‐F1). The image data were investigated and 380 images ascertained of pancreas picked up from images numbers 2617 to 2996. Finally, the images from number 2574 to 3017 were adopted to segment and processed using ACDSee and Photoshop so as to reconstruct 3D pancreas digitally. The data of pancreatic surfaces were transformed into Visualization Toolkit (VTK). The GUI program written with VC+ was used to display this VTK file and realise 3D visualisation of the pancreas.

Results

3D reconstruction and visualisation of the pancreas and the peri‐pancreatic structures (the duodenum, the common bile duct,the inferior vena cava, the portal vein vessels, the aorta, the coeliac trunk vessels) was successful. The 3D and visualised pancreas manifested itself with its complete structure as well as its adjacency to other tissues.

Conclusion

The 3D reconstruction and 3D visualisation of the pancreas based on the digital data of VCH‐F1 produces a digitally visualised pancreas, which promises a novel method for virtual operation on the pancreas, clinical operation on the pancreas, and anatomy of 3D visualised pancreas.     

Evaluation of angiography as the sole imaging study for the proximal aortic neck prior to EVAR

Background

Angiographic assessment is an alternative to computerised tomography (CT) prior to endovascular aneurysm repair (EVAR). We evaluated angiography in aortic neck morphology assessment as an alternative investigation.

Methods

Patients admitted for elective or emergency EVAR were assessed by pre-operative CT and intra-operative angiography. The proximal and distal aortic neck diameters, and neck length were measured. Measurements were expressed as median (95% CI).

Results

35 patients (20 male) were assessed from August 2003 to January 2005 for elective (26) and emergency (9) EVAR. In the overall group, the proximal neck diameter was 22.0mm (21.0–23.0) on CT, and 20.7mm (19.3–22.3) on angiography. The distal neck diameter was 23.0mm (22.0–24.0) on CT, and 22.3mm (20.3–24.6) on angiography, while the neck length was only slightly greater on angiography [23.0mm (17.5–28.4)] relative to CT [23.0mm (20.0–28.0)]. The stent-grafts deployed were oversized by 26.8% (± 14.8%) relative to the CT measurements, and 33.7% (± 15.6%) relative to angiographic measurements. Good correlation was found for all three measurements between CT and angiography.

Conclusions

Angiography alone is inadequate for endovascular aneurysm repair. Although it has timesaving potential, the accuracy achieved is not sufficient to use alone.     

Role of computed tomography before lumbar puncture: a survey of clinical practice

Introduction

It is becoming increasingly common to request computed tomography (CT) to rule out space occupying lesions before lumbar puncture (LP), even in patients with no clinical signs. Imaging trends within a busy district general hospital in Oxfordshire, UK were analysed with results used to clarify when imaging should be considered mandatory.

Method

A retrospective six month sample was obtained comprising all adults considered for LP. Observed frequencies of abnormal examination findings compared with abnormal investigations were used to determine sensitivity, specificity, positive predictive, and negative predictive values to assess the validity of using a normal clinical examination as a basis for excluding CT.

Results

64 patients were considered for LP. In total, 58 patients underwent LP, with a single patient receiving two. After an abnormal CT scan, six patients did not undergo a planned LP. In all six of these cases subarachnoid haemorrhage was detected, and in all cases this was considered a probable diagnosis. In no case was an LP precluded by an unsuspected space occupying lesion. Neurological examination showed a sensitivity of 0.72 (0.52 to 0.93), specificity 0.78 (0.64 to 0.91), positive predictive value 0.61 (0.41 to 0.83), and negative predictive value 0.85 (0.73 to 0.97).

Discussion

The high sensitivity and negative predictive values support normal neurological examination as an effective predictor of normal CT scan. This permits the recommendation in cases where subarachnoid haemorrhage is not suspected, a CT scan can be avoided provided there are no abnormal findings on physical or fundoscopic examination.     

Computed Tomographic Findings in 50 Cases of Gall Bladder Carcinoma

Background

A retrospective assessment of contrast enhanced computed tomography (CECT) scan findings in histopathologically proven cases of carcinoma of the gallbladder (GB) was performed to review its role in diagnosis, staging and assessment of surgical resectability.

Methods

All the patients had been subjected to a standardised abdominal helical computed tomography scan. Orally administered iodinated contrast was used for opacification of bowel and dynamic intravenous injection of non-ionic iodinated contrast for studying the lesional enhancement and vascular structures.

Results

The presence of focal or diffuse mass lesions in the gallbladder fossa, infiltration of a liver and second part of duodenum were the most reliable diagnostic features in carcinoma gallbladder. Regional spread was better delineated on CT scan as compared with ultrasonography.

Conclusion

CT scan is an effective method for evaluating, characterizing and detecting the spread of GB carcinomas.Key Words: Gall Bladder, Carcinoma, Computed Tomography     

Parathyroid Neoplasms: The Army Hospital (Research & Referral) Experience

Background

Neoplasms of the parathyroid are common but parathyroid carcinoma is exceptionally rare. In contrast to most other malignant endocrine tumours that are usually less hormonally active, malignant parathyroid tumours are hyper functional. Malignant parathyroid tumours pose a diagnostic dilemma for the pathologist.

Objective

To study the clinicopathological profile of a case series of parathyroid neoplasms and determine features which facilitate a malignant diagnosis.

Methods

A retrospective analysis of seven cases of surgically treated parathyroid tumours over a three-year period at a single centre was done. Clinical, haematological, biochemical, and radiological data was accrued from medical records. The histopathology slides were reviewed along with the clinicopathological profile in an attempt to delineate markers of malignancy.

Results

Patients ranged from 30 to 58 years of age. Males and females were approximately equal. Weakness and bone pain were the commonest presenting symptoms. Over 50% had significant hypercalcaemia and all had elevated serum parathormone. Clinically apparent mass was seen in only one. All tumours were successfully localised using CT scan and MRI. Thick fibrous capsule and broad septal fibrosis was seen in both the carcinomas; these were thin in the adenomas. Mitotic counts of 1-3 per high power field (HPF), capsular invasion and nodal metastasis were noted in the malignant tumours.

Conclusion

Elevated serum calcium and parathormone values point to a parathyroid neoplasm. Current imaging modalities are successful in localising the tumour preoperatively. Markedly elevated serum calcium, broad fibrous bands, mitotic counts and capsular invasion are indicators of malignancy.Key Words: Parathyroid, Adenoma, Carcinoma     

Osteosarcoma of limb bones: a clinical,radiological and histopathological diagnostic agreement at Black Lion Teaching Hospital,Ethiopia

Objectives

To measure the strength of agreement in clinical, radiological and histopathological diagnosis of osteosarcoma in a 5 year study period.

Setting

Addis Ababa University, Black-Lion (‘Tikur Anbessa’) Hospital-BLH, is the country''s highest tertiary level referral and teaching hospital. The departments involved in this study (Radiology, Pathology and Orthopedics) receive referred patients from all over the country.

Methods

All bone tumor patients, presenting to the three departments at BLH between the study period, December, 2003 – March, 2008 were recruited for the study. 51 patients with radiological diagnosis of osteosarcoma of the extremities were identified and their clinical and histopathological diagnoses reviewed in detail. All patients had a clinical examination, plain radiographs and biopsies of the affected part of the extremity. Radiographs of selected difficult cases were discussed at joint orthopedic & radiologic sessions every week. The radiological and histopathological diagnoses made were categorized separately using WHO classification of bone tumors. Strength of agreement between radiological and histopathological diagnoses was measured using Cohen''s Kappa test.

Results

Of the total of 216 bone tumor patients presented and biopsied in the five year period, fifty one (51) had osteosarcoma of extremity bones. Commonest age affected by osteosarcoma was 16 (7–55years) and sex ratio was 1:1. Osteosarcoma was also the single most common clinical, radiological and histological diagnosis made. Considering all bone tumors presented together, the study indicated that radiological diagnosis was confirmed by similar histological diagnosis in 172 out 205 cases (84 %) and the corresponding Cohen''s Kappa value (0.82) showed excellent level of agreement between radiological and histological diagnoses of all bone tumors. The agreement between radiological and histopathological diagnoses of osteosarcoma of the limbs was 84.5%.

Conclusion

There is an excellent agreement between clinical, radiological and histopathological diagnoses of bone tumors in general and osteosarcoma in particular. In setups where there is limited or no histopathological service, joint clinical and radiological decision could lead to a higher degree of accuracy in diagnosis of bone tumors, especially osteosarcoma. Radiological diagnosis of bone tumors at Black Lion Hospital, Addis Ababa is excellent.     

Clinico-radiological evaluation of juxta articular fractures and diaphyseal fractures of upper limb managed with locking compression plating

Background

Locking compression plate (LCP) fixation of juxta articular and diaphyseal fractures of upper limb is a new modality of operative management.

Methods

Twenty-five consecutive cases of juxta articular and diaphyseal fractures of upper limb were fixed with LCP and results were analyzed.

Results

All fractures healed in good anatomical position in 6–8 weeks with good functional outcome.

Conclusion

LCP is a reliable fixation device for juxta articular and diaphyseal fractures of upper limb.     

Comparison of PET/CT with conventional imaging modalities (USG,CECT) in evaluation of N0 neck in head and neck squamous cell carcinoma

Background

Evaluation of a clinically N0 neck is mandatory in cases of squamous cell carcinoma of head and neck region in order to determine the need to address the neck. The study was designed to compare the accuracy of PET/CT scan with that of USG and CECT Neck in assessing clinically N0 neck in cases of squamous cell carcinoma of upper aerodigestive tract.

Methods

Single center, prospective, study over a 2 year period. All Cases of squamous cell carcinoma of upper aerodigestive tract with no palpable neck lymphadenopathy and who were scheduled for surgery were evaluated with USG, CECT and 18F-FDG PET/CT, of the neck. Post operative histopathology was correlated with pre-operative nodal status. Statistical analysis was done using the chi square test.

Results

In the 49 patients enrolled, 51 neck sides underwent dissections. Sensitivity of USG, CECT and PET-CT was 4.76%, 23.80% and 71.43% respectively while the specificity was 93.33%, 93.33% and 96.67% respectively. The positive predictive value (PPV) calculated for USG, CECT and PET-CT was 33.33%, 71%, 93.5% respectively while the negative predictive value (NPV) 58.33%, 63.63% and 82.85% respectively.

Conclusions

In N0 neck in head and neck squamous cell carcinoma, though FDG-PET-CT is more accurate than either USG or CECT in staging of the neck, it is not accurate enough to alter the current treatment paradigm.     

Twenty-seven years follow-up of a patient with congenital retinocephalofacial vascular malformation syndrome and additional congenital malformations (Bonnet-Dechaume-Blanc syndrome or Wyburn-Mason syndrome)

Purpose

Follow-up of vascular changes in a patient with congenital retinocephalofacial vascular malformation syndrome.

Methods

MRI and cerebral angiography.

Results

In a 36-year-old man, magnetic resonance im aging of the skull and cerebral angiography revealed left intracranial arteriovenous malformations. Follow-up observation of 27 years revealed no essential change of retinal and cerebral arteriovenous malformations. Additional congenital deficits in this patient were described.

Conclusion

Patients with retinal arteriovenous malformations should be early examined with neuroradiological methods.     

Role of single photon emission computerised tomography in evaluating osseointegration of indigenous DRDO implants: An in vivo study

Background

A study of first indigenous titanium dental implant developed by DRDO was undertaken at INMAS, Delhi. The aim was to establish the time taken for osseointegration, along with objectives to define the time of implant loading and compare the osseointegration of indigenous dental implants with already established dental implant systems.

Methods

21 subjects rehabilitated using 39 indigenous dental implants were evaluated by bone SPECT before implantation and at regular intervals towards establishing the aim and objectives.

Results

The rise followed by fall in Osteoblastic activity indicates the postoperative physiologic changes, which peaked at 2 weeks (mean) post-implantation and falls off to pre-implantation levels in 12 weeks (mean) indicating completion of osseointegration, healing and time of loading.

Conclusion

It can be summarized that the Osteoblastic activity of indigenous dental implants completes within three months, which can be taken as the time required for complete healing/osseointegration and loading the implants. On comparison with the available data of already established implants the figures appear similar, indicating indigenous implants to be similar in biologic behaviour.     

A comparative analysis of periimplant bone levels of immediate and conventionally loaded implants

Background

With the trend of shortening the treatment time and reducing patient discomfort/inconveniences immediate loading of implants has emerged as an alternative approach for replacing missing natural teeth. The aim of this study is to evaluate and compare the effectiveness of immediate implant loading protocol over conventional implant loading protocol in partially edentulous mandible.

Methods

Twenty patients were selected from out patients department who needed the replacement of one of the missing mandibular first molar. They were divided into two groups. In Group A patients implants were loaded with immediate implant loading protocol, whereas in Group B they were loaded with conventional loading protocol. Periimplant bone loss and soft tissue health were measured and compared using OPG and IOPA radiographs 06 and 12 months after implant placement.

Results

One implant failed in immediate loading group (Group A), whereas all implants survived in conventional loading group (Group B). The average periimplant bone loss after 6 months and 1 year for Group A were 0.69 mm and 1.09 mm respectively, whereas it was 0.74 mm and 1.13 mm respectively for Group B. The difference in the bone loss between Group A and B was not statistically significant.

Conclusion

Immediate implant loading protocol has a highly acceptable clinical success rate in partially edentulous lower jaw although implant survival rate is slightly inferior to conventional loading protocol.     

Hepato-biliary Scintigraphy in diagnosis of Biliary Atresia

Background

Biliary Atresia and Neonatal Hepatitis are the two major causes of Persistent Neonatal Jaundice. Differentiation is done by biochemical and radiological tests. Radiological investigations use intra-or extra-hepatic biliary dilation for diagnosing biliary atresia but this is not always reliable.

Methods

14 neonates with persistent conjugated hyperbilirubinemia who had undergone hepato-biliary scintigraphy were retrospectively evaluated and those having Extrahepatic Biliary Atresia were analyzed with reference to operative findings.

Results

11 out of 14 had Extrahepatic Biliary Atresia during operation whereas 3 proved to be false positive.

Conclusion

Mebrofenin hepato – biliary scintigraphy is a simple, safe, accurate and cost effective investigation for diagnosis of biliary atresia.Key Words: Biliary Atresia, Neonatal Jaundice, Hepato-biliary scintigraphy     

Information needs of case managers caring for persons living with HIV

Objective

The goals of this study were to explore the information needs of case managers who provide services to persons living with HIV (PLWH) and to assess the applicability of the Information Needs Event Taxonomy in a new population.

Design

The study design was observational with data collection via an online survey.

Measurements

Responses to open-ended survey questions about the information needs of case managers (n=94) related to PLWH of three levels of care complexity were categorized using the Information Needs Event Taxonomy.

Results

The most frequently identified needs were related to patient education resources (33%), patient data (23%), and referral resources (22%) accounting for 79% of all (N=282) information needs.

Limitations

Study limitations include selection bias, recall bias, and a relatively narrow focus of the study on case-manager information needs in the context of caring for PLWH.

Conclusion

The study findings contribute to the evidence base regarding information needs in the context of patient interactions by: (1) supporting the applicability of the Information Needs Event Taxonomy and extending it through addition of a new generic question; (2) providing a foundation for the addition of context-specific links to external information resources within information systems; (3) applying a new approach for elicitation of information needs; and (4) expanding the literature regarding addressing information needs in community-based settings for HIV services.