Atypical Imaging Findings in "Central Nervous System Varicella Zoster Virus Vasculopathy Sine Herpete".

Varicella-zoster virus (VZV) infection is notorious for central nervous system involvement, the spectrum of which encompasses vasculopathic manifestations as well. Central nervous system VZV vasculopathy (CVV) most commonly manifests as ischemic strokes or TIA, even though other less common modes of presentation are also well documented in the literature. The pathophysiological mechanism is primarily attributed to active virus infection in the blood vessels secondary to decline in varicella-specific cell-mediated immunity. More than one-third of those with CVV do not have preceding skin lesions of zoster. Hence, a high index of clinical suspicion should be entertained in the appropriate clinical scenario. We hereby describe the case of a 40-year-old lady with systemic lupus erythematosus on long-term oral steroids who presented with acute ischemic stroke involving the right PCA territory, with asymptomatic chronic infarcts in the left MCA. Further evaluation revealed concentric vessel enhancement involving right PCA on high-resolution MR vessel wall imaging with the "Moya-Moya" phenomenon on the left supraclinoid ICA/MCA segment. CSF showed mononuclear pleocytosis with a hemorrhagic component, along with positive VZV DNA PCR. A diagnosis of "CNS VZV Vasculopathy sine herpete" was made and the patient was initiated on appropriate management.

Assessment of the normal pediatric pineal gland - MR findings of a single centre; A retrospective study.

OBJECTIVE: To analyse the size and morphology of the normal pineal gland in the paediatric age group using magnetic resonance imaging. METHODS: The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised data of patients aged <18 years who had magnetic resonance imaging done between 2007 and 2017. Pineal size was estimated measuring its largest anteroposterior and supero-inferior diameters on sagittal T2-weighted sequences on any slice with maximal diameter. The width of pineal gland was measured on axial or coronal T2 sequences. The volume, morphology and enhancement patterns of the gland were also assessed. Data was analysed using SPSS 21. RESULTS: Of the 200 patients, 116(58%) were males and 84(42%) were females. The overall mean age was 7.8±5.5 years. The mean anteroposterior dimension was 4.85±1.46mm, height 3.31±0.95mm, width 4.16±1.19, and volume 39.54±38.12 mm3. Mean size of cyst was 2.77±1.4mm (range: 1.2-7.5mm). No significant differences in the pattern of enhancement were found in different age groups (p>0.05). CONCLUSIONS: Comprehensive knowledge of the size of the typical pineal organ is useful for radiologists in the identification of pineal gland anomalies and the exclusion of neoplastic lesions.

Clinicoradiological Correlation of Infarct Patterns on Diffusion-weighted Magnetic Resonance Imaging in Stroke.

Diffusion-weighted magnetic resonance imaging (DW-MRI) represents a major advance in the early diagnosis of acute ischemic stroke. It can detect edema due to ischemia in the brain tissue. It not only establishes the presence and location of ischemic brain injury but also a relatively new concept is the determination of infarct patterns seen on diffusion imaging and its clinical correlation. Objective To determine the frequency of various infarct patterns and their relationship with functional outcome of the patient. Materials and methods A total of 108 patients with acute stroke were enrolled by purposive sampling. Magnetic resonance imaging (MRI) was obtained with departmental protocol and diffusion-weighted sequences. The clinical data was collected from medical records and functional outcome was assessed at the time of admission using Barthel Index (BI) which was dichotomized into poor and favorable outcomes. The radiological data was collected and three infarct patterns (cortical, subcortical, and territorial infarcts) were recorded from diffusion-weighted images. Association of other risk factors such as age, gender, diabetes, hypertension (HTN), hyperlipidemia, and smoking were also evaluated. Results Amongst the three infarct patterns, subcortical infarcts were noted with the highest proportion of 62% (67/108). The highest proportion of territorial infarcts (78.6%) was significantly associated with a poor outcome in comparison to cortical and subcortical infarcts. Cortical infarcts (61.5%) were significantly associated with good outcomes followed by subcortical and then territorial infarcts (p-value < 0.002). Amongst the risk factors, HTN was found to be highly prevalent followed by diabetes mellitus (DM). Conclusion Subcortical infarct pattern was the most common, followed by territorial and cortical infarct. The highest proportion of infarct pattern with good outcomes was seen with cortical infarcts followed by subcortical and then territorial infarct pattern. HTN and coronary artery disease (CAD) were the effect modifiers showing significant association with poor outcomes.

Hepatic, Periportal, Retroperitoneal, and Mesenteric Neurofibromatosis in von Recklinghausen's Disease.

We present a rare case of histologically proven neurofibromatosis of the liver, hepatic hilum, retroperitoneum, and mesentery. An adult male who had been diagnosed with neurofibromatosis (NF) type 1 underwent a computed tomography (CT) scan for abdominal pain and vomiting. The CT scan showed a large low-attenuating lesion in the region of porta hepatis which was infiltrating along portal tracts into the liver, encasing the major vessels, and extending into the retroperitoneum and mesentery. Based on the radiological findings, a differential diagnosis of plexiform neurofibroma was given, although sarcomatous transformation could not have been entirely excluded from imaging alone. The tumor was subsequently biopsied, and the histopathological analysis confirmed the diagnosis of neurofibroma. This case highlights the importance and diagnostic dilemmas in the presence of this tumor at atypical locations in this disease spectrum.

Accuracy of Specimen Radiography in Assessing Complete Local Excision with Breast-Conservation Surgery

Objective: The aim of this study was to evaluate the accuracy of "X- ray examination of surgically resected specimen'' in assessing complete local excision (CLE). Materials and Methods: In this retrospective cross sectional study, data were collected for all female breast cancer cases who underwent breast-conserving surgery after needle localization of mammographically visible disease. Males, patients with mammographically invisible disease and cases with benign or inconclusive histopathology, those undergoing modified radical mastectomy and individuals with dense breast parenchyma were excluded. We evaluated radiography of resected specimens to assess margin spiculation, distance of mass/microcalcification from the excised margin, presence of a mass, and presence of any adjacent microcalcification, Other features including mass size, nuclear grade and patient's age were also recorded and all were analyzed for any association with CLE. Results: Absence of adjacent microcalcification and the presence of a mass on radiographs showed significant associations with CLE, but no links were evident with other features. Specimen radiography was found to be a sufficient tool to predict CLE with a positive predictive value of 83.3%, a sensitivity of 80.7% and a specificity of 81%. Conclusion: Specimen radiography is an important and sensitive tool to predict CLE.

Carotid intima media thickness evaluation by ultrasound comparison amongst healthy, diabetic and hypertensive Pakistani patients.

OBJECTIVE: To compare carotid Intima media thickness and atherosclerosis burden amongst healthy, diabetic and hypertensive Pakistani patients. METHODS: A cross-sectional study was carried out at the Department of radiology and family medicine, Aga Khan University Hospital Karachi from April 2014 to July 2015. Bilateral carotid ultrasound was done in 133 healthy adults, 65 hypertensive, 31 type-2 diabetic and 37 hypertensive with type-2 diabetes patients. Normal adults were matched for age and gender. Mean intimal media thickness was measured for common and internal carotid arteries. Presence or absence of atherosclerotic plaque was also identified. Height, weight, ethnicity, socioeconomic status and other risk factors were also assessed. Ultrasound findings were compared between healthy and diseased patients through statistical tests. RESULTS: A total of 266 patients participated (Controls=133, Hypertensive=65, Diabetic=31, and Diabetes with Hypertension=37). There was no significant difference in the baseline characteristics between the four patients' groups for age (p>0.05) and gender (p>0.05). The mean carotid intima media thickenss of right common carotid artery was significantly higher in patients with diabetes along with hypertension as compared to the control group (p=0.03). For (RICA) Right Internal Carotid Artery, (LCCA) Left Common Carotid Artery and (LICA) Left Internal Carotid Artery, there was a significantly higher thickness among patients with hypertension as compared to the control group with p=0.011, p=0.002, and p=0.039 respectively. CONCLUSIONS: Increased CIMT is most likely associated with underlying chronic diseases. Ultrasound is a non-invasive, easily available and useful modality for early detection and prevention of vascular atherosclerosis.

Radiology of renal stone disease.

Nephrolithiasis is a common cause of abdominal pain and will affect approximately 1 in 10 people in their lifetime. In the past two decades, there have been several technological advances that have changed the imaging approach to stone diagnosis and follow-up. We present a review of the current imaging evaluation for renal stone disease, and outline how new technology has helped with diagnosis and management.

Predictive value of pyramidal lobe, percentage thyroid uptake and age for ablation outcome after 15 mCi fixed dose of radioiodine-131 in Graves' disease.

PURPOSE: The purpose was to find out the efficacy of fixed 15 mCi radioactive iodine-131 (RAI) dose and predictive values of various factors for inducing hypothyroidism in Graves' disease (GD). MATERIALS AND METHODS: Retrospective study conducted from January 2012 till August 2014. Patients with GD who had a technetium-99m thyroid scan, thyroid antibodies, received fixed 15 mCi RAI and did follow endocrine clinics for at least 6 months were selected. RAI was considered successful if within 6 months of RAI therapy patients developed hypothyroidism. RESULTS: Of the 370 patients with GD who had RAI during study period, 210 (57%) qualified study criteria. Mean age of patients was 48 ± 15 years with female: male ratio of 69:31, positive thyroid antibodies in 61%, means thyroid uptake of 15.09 ± 11.23%, and presence of pyramidal lobe in 40% of total population. Hypothyroidism was achieved in 161 (77%) patients while 49 (23%) patients failed to achieve it (remained either hyperthyroid or euthyroid on antithyroid medication). Patients who became hypothyroid were significantly younger with higher proportion of presence of thyroid antibodies and pyramidal lobe and lower percentage thyroid uptake than those who failed. Multiple logistic regression analysis revealed that age (odds ratio; OR = 2.074), pyramidal lobe (OR = 3.317), thyroid antibodies (OR = 8.198), and percentage thyroid uptake (OR = 3.043) were found to be significant prognostic risk factors for post-RAI hypothyroidism. Gender was found to have nonsignificant association with the development of hypothyroidism. Receiver operating characteristic analysis revealed age <42 years and thyroid uptake <15% as threshold values for the development of post-RAI hypothyroidism. CONCLUSION: We conclude that fixed (15 mCi) RAI dose is highly effective in rendering hypothyroidism in patients with GD. Age (≤42 years), thyroid uptake (≤15%) and presence of pyramidal lobe are strong predictors of hypothyroidism and must be considered for selecting optimal RAI dose.

CT Pelvis in Children; Should We Routinely Scan Pelvis for Wilms Tumor and Hepatoblastoma? Implications for Imaging Protocol Development.

Wilms tumor and hepatoblastoma are the most common intra-abdominal solid organ childhood tumors. CT examination is one of the routinely performed procedures in hospitals for children with these tumors inspite of high radiation exposure associated with CT scans. Sixty patients (Wilms tumor = 45, hepatoblastoma = 16) were evaluated retrospectively. Higher proportion (44.4%) of metastatic disease was identified at presentation in the Wilms tumor subset as compared to hepatoblastoma (6.3%) [p=0.006]. Metastatic disease was noted in 6 patients having Wilms tumor on follow-up while it was also low in hepatoblastoma which was noted in only 2 patients (p > 0.05). No significant difference was identified in pelvic extension of disease at presentation in both studied population (p > 0.05). Pelvic metastasis was noted in 1 patient only with Wilms tumor on follow-up while no pelvic metastasis was seen in the hepatoblastoma patients (p-value > 0.05).

Evaluation of Common Risk Factors for Breast Carcinoma in Females: a Hospital Based Study in Karachi, Pakistan.

BACKGROUND: Breast malignancies are one of the leading causes of deaths in females worldwide. There are a number of risk factors associated with breast cancer but in Karachi Pakistan there are insufficient data available. MATERIALS AND METHODS: A case control study was conducted on females in age group between 30-80 years. This study was accomplished by retrospective data collection in Aga Khan University Hospital Karachi, Pakistan. A total of 108 females with primary malignancy of breast were included along with 108 matched controls. Relationship of various factors with disease was studied using logistic regression to calculate odds ratios with 95 % confidence intervals. RESULTS: A total of 14 variables were analyzed and based on and 7 were found to be risk factors: old age, family history of breast cancer, family history of other carcinomas, personal history of breast carcinoma, early age of menarche, older age of mother at first delivery and lower number of children. Five factors, parity, breast feeding, history of oral contraceptive pills intake, past history of oophorectomy and hysterectomy showed protective associations. One variable, use of hormonal replacement therapy, showed a controversial link and one other, marital status, was not significant in this study. CONCLUSIONS: It is concluded that most of the well-known risk factors for breast cancer are also associated with the disease in the female population of Karachi, Pakistan. High risk patients should be the focus with the help of this study so that screening can be more effective for early diagnosis before clinically evident breast malignancy.

Study protocol: asymptomatic intracranial atherosclerotic disease in pakistanis.

BACKGROUND: Intracranial atherosclerotic disease (ICAD) is the most frequent subtype of ischemic stroke globally. It is important to describe the determinants of early ICAD as a strategy to prevent strokes from clinically evident and progressive ICAD. Our objective is to report the determinants of asymptomatic ICAD by linking the presence or absence of ICAD on magnetic resonance angiogram (MRA) with detailed risk assessment in asymptomatic adults. METHODS: This is an observational cross-sectional analytical study. We plan to recruit 200 adult participants from the radiology departments of two tertiary care centers of Karachi, Pakistan. The participants will first be screened for the absence of stroke symptoms via the Questionnaire for Verifying Stroke Free Status (QVSFS). QVSFS negative will be participants will be eligible. After written informed consent, participants will undergo detailed medical, sociodemographic, lifestyle, and anthropometric evaluation by a detailed interview. They will, in addition, undergo MRA to study the presence, degree, and distribution of asymptomatic ICAD. All MRA scans will be reviewed centrally by vascular neurologists blinded to clinical information. These images would be reviewed on DICOM Viewer 3.0 used for calculating the degree of stenosis using Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study defined criteria employing electronic calipers. A sample size of 200 will achieve 80% power for detecting a minimum difference of 20% in the prevalence of exposure factors (medical and lifestyle) between asymptomatic ICAD positive and ICAD negative persons. This study will generate regional data on risks for ICAD development and prevention in a high-risk susceptible population. Study ID: NCT02072876.

"Pseudo-thyroid lobe": A diagnostic conundrum caused by ossified anterior longitudinal ligament on bone scan.

Radionuclide bone imaging is one of the most commonly performed nuclear medicine procedure around the world and characterized by its high sensitivity and relatively low specificity. False positive findings on a bone scan are very common; however, dense uptake over unilateral ossified anterior longitudinal ligament appearing as single thyroid lobe on a bone scan has not been described in the literature.

Intratumoral pseudoaneurysms in hepatocellular carcinoma: do they occur de novo without any prior intervention? A tertiary care center experience of 6 years.

BACKGROUND: Intratumoural pseudoaneurysms (ITPA) within hepatocellular carcinomas (HCC) usually arise as postprocedural complications of endovascular therapies or surgical procedures. Their de novo presence in HCC without any prior interventions has not been adequately described in medical literature. PURPOSE: To evaluate and quantify the presence of intratumoural pseudoaneurysms (ITPA) within hepatocellular carcinomas (HCC) prior to any intervention. MATERIAL AND METHODS: Retrospective cross-sectional review of 519 patients with HCC at a tertiary care university hospital with the purpose to evaluate and quantify the presence of ITPA present prior to any therapy. Patients' baseline data along with viral marker status, alpha fetoprotein (AFP) levels, imaging findings, and any prior treatment provided were recorded. Multi-detector computed tomography (MDCT) scans of selected patients were reviewed for presence of any ITPA and their incidence was calculated. RESULTS: ITPAs without any prior therapy were found in 5% (25/519) of patients with HCC. Seventeen of 25 (68%) patients had liver cirrhosis while eight of 25 (32%) patients were non-cirrhotic on imaging. Multiple ITPAs were seen in 44% (11/25) of patients. Eight percent (2/25) of patients had pseudoaneurysm-associated hemorrhage, 20% (5/25) had lung metastasis, 12% (3/25) had portal vein thrombosis, 8% (2/25) had hepatic vein thrombosis, and 16% (4/25) had peritumoral hematoma. The incidence of de novo ITPAs occurring in patients with HCC without any prior therapy or intervention was 0.24%. CONCLUSION: These cases provide a unique insight into an additional feature of HCC and usefulness of recognizing the ITPAs on imaging studies. Although de novo ITPAs in HCC are uncommon, occurring with an incidence rate of 0.24%, their presence in hypervascular hepatic lesion may point towards the diagnosis of HCC. Additionally, they should be accounted for in management planning as they can lead to complications of rupture and hemorrhage.

Clinical, lifestyle, socioeconomic determinants and rate of asymptomatic intracranial atherosclerosis in stroke free Pakistanis.

BACKGROUND: Intracranial Atherosclerotic Disease (ICAD) is the most frequent etiology of stroke with high prevalence among Asians. Despite this, early determinants of ICAD have not been described from this region. METHODS: The study is an analytical prospective cross-sectional study of 200 adults from Radiology Departments of two diagnostic centers in Karachi. Eligible participants confirmed the absence of stroke symptoms via the Questionnaire for Verifying Stroke Free Status (QVSFS) and underwent an interview covering medical, socio demographic, lifestyle and anthropometric evaluation using locally validated and standardized definitions. Magnetic Resonance Images (MRI) were centrally reviewed to detect ICAD using the criterion used in the Warfarin-Aspirin Symptomatic Intracranial Disease study. The risk factors associated with asymptomatic ICAD are reported along with prevalence ratios. RESULTS: Of the 200 participants, ICAD was found in 34.5% (n = 69) of the participants. Mean age was 37.1 (S.D 15.1) years with 62% younger than 45 years. Self-reported hypertension was found in 26.5% subjects, diabetes in 9%, dyslipidemia in 5% and depression in 60%. Smokeless tobacco (Adjusted PR 3.27 (1.07-6.05)), Western diet, high socioeconomic status (Adjusted PR 2.26 (1.99-5.62)) and dyslipidemia (Adjusted PR 1.88 (1.25-2.21)) had significant associations with ICAD after multivariable analysis. Age, gender, diabetes, hypertension, depression and physical activity did not have a significant association. CONCLUSION: ICAD was found on MRI in one in three asymptomatic Pakistanis and was associated with modifiable risks. Initiatives targeting primary prevention may be able to decrease the burden of disease caused by stroke due to ICAD. STUDY REGISTRATION NUMBER: NCT02072876 2/25/2014.

Accuracy of magnetic resonance imaging in pretreatment lymph node assessment for gynecological malignancies.

OBJECTIVE: To determine the accuracy of magnetic resonance imaging (MRI) in detection of metastasis in pelvic and para-aortic lymph nodes from different gynecological malignancies. MATERIALS AND METHODS: This retrospective cross sectional analytic study was conducted at the Department of Diagnostic Radiology, Aga Khan University Hospital Karachi Pakistan from January 2011 to December 2012. A sample of 48 women, age range between 20-79 years, fulfilling inclusion criteria were included. All patients had histopathologically proven gynecological malignancies in the cervix, endometrium or ovary and presented for a pretreatment MRI to our radiology department. RESULTS: MRI was 100% sensitive and had a 100% positive predictive value to detect lymph node metastasis in lymph nodes with spiculated margins and 100% sensitive with a 75% positive predictive value to detect lymph node metastasis in a lymph node with lobulated margins. The sensitivity and positive predictive value of MRI to detect heterogeneous nodal enhancement were 100% and 75% respectively. CONCLUSIONS: Our study results reinforce that MRI should be used as a modality of choice in the pretreatment assessment of lymph nodes in proven gynaecological malignancies in order to determine the line of patient management, distinguishing surgical from non-surgical cases.

5-FU induced acute toxic leukoencephalopathy: early recognition and reversibility on DWI-MRI.

Acute toxic leukoencephalopathy (ATL) is a rare adverse effect of 5-Fluorouracil (5-FU) chemotherapeutic agent. It is imperative for the radiologist to confidently identify the white matter changes caused by this agent in case of toxicity. This will help in early detection and appropriate management of patient, as the condition is reversible both clinically and on imaging. We report a case of a 29 years old gentleman, known case of carcinoma of esophagus who suffered from acute toxic leukoencephalopathy secondary to leukotoxic therapeutic agent 5-FU, and illustrate the reversible imaging findings of this condition on withdrawal of the inciting agent.

Wandering Meckel's diverticulum on 99m technetium-pertechnetate scintigraphy: A diagnostic dilemma?

Meckel's diverticulum (MD) is the most common gastrointestinal anomaly with heterotopic mucosa in 60% of cases. 99m technetium-pertechnetate scintigraphy is a sensitive tool for detection of MD containing heterotopic gastric mucosa. It is usually located in the right lower quadrant or umbilical region and less frequently in other quadrants. A mobile or wandering MD is a rare clinical presentation and may pose a diagnostic dilemma. However, presence of temporal correlation with gastric activity and compactness of focus during wandering period could make this riddle easy.

Whole body simultaneous PET/MRI: one-stop-shop?

Beginning of this century is hallmarked by arrival of hybrid imaging PET/CT (positron emission tomography/computerized tomography) which has become a standard of care primarily in oncology in a short span of time. Continuous research and development by industry and academia for exploiting the excellent soft tissue contrast, spectroscopy and precise measurement of various functional parameters by magnetic resonance imaging (MRI) with PET has resulted in emergence of whole body PET/MRI. It is expected this new hybrid modality would be warmly welcomed due to high magnitude of functional and morphostructural information at molecular level with low radiation dose which is indeed a point of concern for young and paediatric population. This short technical report for nuclear medicine readers will focus upon the various configuration and acquisition sequences of PET/MRI, attenuation correction and clinical applications of whole body simultaneous PET/MRI.

Distribution, Severity and Radiologic Features of Intracranial Stenosis in Asymptomatic Pakistanis.

BACKGROUND: Intracranial atherosclerotic disease (ICAD) is the most common ischemic stroke subtype globally. It accounts for 30-50% of all ischemic strokes in Asians. AIMS: The aim of the study is to report the frequency of asymptomatic ICAD and its associated Magnetic Resonance Imaging (MRI) findings. METHODS: 200 adult participants were recruited from the Radiology Departments of two major diagnostic centers in Karachi. Eligible participants were confirmed for the absence of stroke symptoms via the Questionnaire for Verifying Stroke Free Status (QVSFS). QVSFS negative subjects underwent MRI on a 1.5 Tesla scanner. Images were centrally reviewed on Di com Viewer 3.0 with electronic calipers to calculate the degree of ICAD. RESULTS: Mean age of subjects was 37.1 years (S.D 15.1) with 50.5% men (n=101) and 49.5% women (n=99). Asymptomatic ICAD was found in 34.5% (n=69) subjects. Of the 3800 intracranial arteries studied, 2.2% (n=88) had biological disease. 20.5% (n=18) of these vessels had atherosclerotic irregularities, 43.2% (n=38) had mild stenos is, 11.4% (n=10) had moderate stenos is, 5.7% (n=5) had severe stenos is while 19.3% (n=17) were completely occluded. The posterior cerebral artery (42% of stenosed arteries, n=37) was most affected. 23.5% (n=47) of subjects had peri-ventricular lucencies, 10.5% (n=21) had brain atrophy while 3.5% (n=7) had silent brain infarcts. There was a significant association between asymptomatic ICAD and peri ventricular lucencies (PR 1.59; 95% CI 1.35-1.99). CONCLUSION: Asymptomatic ICAD is common in young Pakistanis, with no gender predilection; it preferentially affects the posterior circulation. Silent infarcts are rare compared to peri ventricular lucencies and atrophy.