Accuracy of 99mTechnetium-labeled RBC Scintigraphy and MDCT With Gastrointestinal Bleed Protocol for Detection and Localization of Source of Acute Lower Gastrointestinal Bleeding.

BACKGROUND: Acute lower gastrointestinal bleeding (LGIB) is a major cause of morbidity and mortality. Multidetector row computed tomography (CT) with gastrointestinal (GI) bleed protocol is a novel diagnostic technique for detecting and localizing LGIB. Being rapid and noninvasive, it may be useful as a first-line modality to investigate cases of acute LGIB. GOALS: To assess and compare diagnostic accuracy of (99M)Technetium (Tc)-labeled red blood cell (RBC) scintigraphy and multidetector row CT with GI bleed protocol for detection and localization of source of acute LGIB. STUDY: Requirement of informed consent was waived for this retrospective study. Seventy-six patients had undergone either RBC scintigraphy, CT with GI bleed protocol, or both, followed by conventional angiography for evaluation of acute persistent LGIB between January 2010 and February 2014 at our institution. Accuracy of both modalities was assessed using conventional angiography as reference standard and compared using the 2-tailed, Fisher exact test. A P-value of <0.05 was considered statistically significant. RESULTS: Fifty-one, 20, and 5 patients had undergone RBC scintigraphy only, CT with GI bleed protocol only, and both modalities, respectively. Fourteen of 25 patients in the CT group had angiographic evidence of active bleeding as compared with 32 of 56 patients in the scintigraphy group. CT with GI bleed protocol had higher accuracy (96%) than (99M)Tc-labeled RBC scintigraphy (55.4%, P<0.001). CONCLUSIONS: CT with GI bleed protocol was more accurate in detecting and localizing the source of acute LGIB as compared with (99M)Tc-labeled RBC scintigraphy.

Comparison between Greulich-Pyle and Girdany-Golden methods for estimating skeletal age of children in Pakistan.

OBJECTIVE: To compare Greulich-Pyle (GP) and Girdany-Golden (GG) methods for estimation of Skeletal Age (SA) in children referred to a tertiary care hospital in Karachi, Pakistan. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: Department of Radiology, The Aga Khan University Hospital, Karachi, Pakistan, from July 2010 to June 2012. METHODOLOGY: Children up to the age of 18 years, who had undergone X-ray for the evaluation of trauma were included. Each X-ray was interpreted using both methods by two consultant paediatric radiologists having at least 10 years experience, who were blinded to the actual Chronologic Age (CA) of children. RESULTS: A total of 283 children were included. No significant difference was noted in mean SA estimated by GP method and mean CA for female children (p=0.695). However, a significant difference was noted between mean CA and mean SA by GG method for females (p=0.011). For males, there was a significant difference between mean CA and mean SA estimated by both GP and GG methods. A stronger correlation was found between CA and SA estimated by GP method (r=0.943 for girls, r=0.915 for boys) as compared to GG method (r=0.909 for girls, r=0.865 for boys) respectively. Bland- Altman analysis also revealed that the two methods cannot be used interchangeably. Excellent correlation was seen between the two readers for both GP and GG methods. CONCLUSION: There was no additional benefit of using GP and GG methods simultaneously over using GP method alone. Moreover, although GP was reliable in estimating SA in girls, it was unable to accurately assess SA in boys. Therefore, it would be ideal to develop indigenous standards of bone age estimation based on a representative sample of healthy native children.

Diagnostic accuracy of ultrasonography in differentiating benign and malignant thyroid nodules using fine needle aspiration cytology as the reference standard.

BACKGROUND: In Pakistan thyroid cancer is responsible for 1.2% cases of all malignant tumors. Ultrasonography (US) is helpful in detecting cancerous thyroid nodules on basis of different features like echogenicity, margins, microcalcifications, size, shape and abnormal neck lymph nodes. We therefore aimed to calculate diagnostic accuracy of ultrasound in detection of carcinoma in thyroid nodules taking fine needle aspiration cytology as the reference standard. MATERIALS AND METHODS: A cross-sectional analytical study was designed to prospectively collect data from December 2010 till December 2012 from the Department of Radiology in Aga Khan University Hospital, Karachi, Pakistan. A total of 100 patients of both genders were enrolled after informed consent via applying non-probability consecutive sampling technique. Patients referred to Radiology department of Aga Khan University to perform thyroid ultrasound followed by fine-needle aspiration cytology of thyroid nodules were included. They were excluded if proven for thyroid malignancy or if their US or FNAC was conducted outside our institution. RESULTS: The subjects comprised 76 (76%) females and 24 males. Mean age was 41.8±SD 12.3 years. Sensitivity and specificity with 95%CI of ultrasound in differentiating malignant thyroid nodule from benign thyroid nodule calculated to be 91.7% (95%CI, 0.72-0.98) and 78.94% (0.68-0.87) respectively. Reported positive predictive value and negative PV were 57.9% (0.41-0.73) and 96.8% (0.88-0.99) and overall accuracy was 82%. Likelihood ratio (LR) positive was computed to be 4.3 and LR negative was 0.1. CONCLUSIONS: Ultrasonography has a high diagnostic accuracy in detecting malignancy in thyroid nodules on the basis of features like echogenicity, margins, micro calcifications and shape.

Endovascular embolisation of visceral artery pseudoaneurysms.

Objective. To evaluate the technical success, safety, and outcome of endovascular embolization procedure in management of visceral artery pseudoaneurysms. Materials and Methods. 46 patients were treated for 53 visceral pseudoaneurysms at our institution. Preliminary diagnostic workup in all cases was performed by contrast enhanced abdominal CT scan and/or duplex ultrasound. In all patients, embolization was performed as per the standard departmental protocol. For data collection, medical records and radiology reports of all patients were retrospectively reviewed. Technical success, safety, and outcome of the procedure were analyzed. Results. Out of 46 patients, 13 were females and 33 were males. Mean patient age was 44.79 ± 13.9 years and mean pseudoaneurysm size was 35 ± 19.5 mm. Technical success rate for endovascular visceral pseudoaneurysm coiling was 93.47% (n = 43). Complication rate was 6.52% (n = 3). Followup was done for a mean duration of 21 ± 1.6 months (0.5-69 months). Complete resolution of symptoms or improvement in clinical condition was seen in 36 patients (80%) out of those 45 in whom procedure was technically successful. Conclusion. Results of embolization of visceral artery pseudoaneurysms with coils at our center showed high success rate and good short term outcome.

Assessment of apparent diffusion coefficient values as predictor of aggressiveness in peripheral zone prostate cancer: comparison with Gleason score.

Purpose. To determine association between apparent diffusion coefficient value on diffusion-weighted imaging and Gleason score in patients with prostate cancer. Methods. This retrospective case series was conducted at Radiology Department of Aga Khan University between June 2009 and June 2011. 28 patients with biopsy-proven prostate cancer were included who underwent ultrasound guided sextant prostate biopsy and MRI. MRI images were analyzed on diagnostic console and regions of interest were drawn. Data were entered and analyzed on SPSS 20.0. ADC values were compared with Gleason score using one-way ANOVA test. Results. In 28 patients, 168 quadrants were biopsied and 106 quadrants were positive for malignancy. 89 lesions with proven malignancy showed diffusion restriction. The mean ADC value for disease with a Gleason score of 6 was 935 mm(2)/s (SD = 248.4 mm(2)/s); Gleason score of 7 was 837 mm(2)/s (SD = 208.5 mm(2)/s); Gleason score of 8 was 614 mm(2)/s (SD = 108 mm(2)/s); and Gleason score of 9 was 571 mm(2)/s (SD = 82 mm(2)/s). Inverse relationship was observed between Gleason score and mean ADC values. Conclusion. DWI and specifically quantitative ADC values may help differentiate between low-risk (Gleason score, 6), intermediate-risk (Gleason score, 7), and high-risk (Gleason score 8 and 9) prostate cancers, indirectly determining the aggressiveness of the disease.

MDCT of Small Bowel Obstruction: How Reliable Are Oblique Reformatted Images in Localizing Point of Transition?

The goal of this study is to prospectively assess the additional value of oblique reformatted images for localizing POT, having surgery as a reference standard. Materials and Methods. 102 consecutive patients with suspected small bowel obstruction (SBO) underwent 64-slice multidetector row CT (MDCT) using surgical findings as reference standard. Two independent GI radiologists reviewed the CT scans to localize the exact POT by evaluating axial images (data set A) followed by axial, coronal, and oblique MPR images. CT findings were compared to surgical findings in terms of diagnostic performance. McNemar's test was used to detect any statistical difference in POT evaluation between datasets A and B. Kappa statistics were applied for measuring agreement between two readers. Results. There was a diagnostic improvement of 9.9% in the case of the less experienced radiologist in localizing POT by using oblique reformatted images. The more experienced radiologist showed diagnostic improvement by 12.9%.

Ovarian masses: is multi-detector computed tomography a reliable imaging modality?

BACKGROUND: Ovarian cancer continues to pose a major challenge to physicians and radiologists. It is the third most common gynecologic malignancy and estimated to be fifth leading cancer cause of death in women, constituting 23% of all gynecological malignancies. Multi-detector computed tomography (MDCT) appears to offer an excellent modality in diagnosing ovarian cancer based on combination of its availability, meticulous technique, efficacy and familiarity of radiologists and physicians. The aim of this study was to compute sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of 64- slice MDCT in classifying ovarian masses; 95% confidence intervals were reported. MATERIALS AND METHODS: We prospectively designed a cross-sectional analytical study to collect data from July 2010 to August 2011 from a tertiary care hospital in Karachi, Pakistan. A sample of 105 women aged between 15-80 years referred for 64-MDCT of abdomen and pelvis with clinical suspicion of malignant ovarian cancer, irrespective of stage of disease, were enrolled by non- probability purposive sampling. All patients who were already known cases of histologically proven ovarian carcinoma and having some contraindication to radiation or iodinated contrast media were excluded. RESULTS: Our prospective study reports sensitivity, specificity; positive and negative predictive values with 95%CI and accuracy were computed. Kappa was calculated to report agreement among the two radiologists. For reader A, MDCT was found to have 92% (0.83, 0.97) sensitivity and 86.7% (0.68, 0.96) specificity, while PPV and NPV were 94.5% (0.86, 0.98) and 86.7% (0.63, 0.92), respectively. Accuracy reported by reader A was 90.5%. For reader B, sensitivity, specificity, PPV and NPV were 94.6% (0.86, 0.98) 90% (0.72, 0.97) 96% (0.88, 0.99) and 87.1% (0.69, 0.95) respectively. Accuracy computed by reader B was 93.3%. Excellent agreement was found between the two radiologists with a significant kappa value of 0.887. CONCLUSION: Based on our study results, we conclude MDCT is a reliable imaging modality in diagnosis of ovarian masses accurately with insignificant interobserver variability.

Asymmetry of lateral lamella of the cribriform plate: a software-based analysis of coronal computed tomography and its clinical relevance in endoscopic sinus surgery.

BACKGROUND: Endoscopic sinus surgery is a known approach for sinonasal pathologies. Due to close proximity of sinuses to orbits and brain, surgeon should be aware of sinonasal anatomy and associated variations. The roof of ethmoid (fovea ethmoidalis) separates the ethmoidal cells from the anterior cranial fossa. Medially the fovea attaches to the lateral lamella of the cribriform plate, which is the thinnest bone of the skull base. Hence, it is at a high risk of getting damaged during surgery. OBJECTIVE: To ascertain the quantitative analysis of height of lateral lamella according to Keros classification in the computed tomographic (CT) images of patients presenting to our clinic. METHODS: It was retrospective review of 77 CT scans using computerized software known as picture archiving and communication system. The height of lateral lamella was examined for both sides and then classified according to Keros classification. Asymmetry between two sides was also reported. RESULTS: Keros type I was seen in 46 sides (29.8%), type II in 75 sides (48.7%) and type III was seen in 33 (21.4%) sides. Keros type I was seen in 38 sides in males and 8 sides in females. Type II was seen in 46 and 29 sides in males and females, respectively. Type III was seen in 18 sides in males and in 15 sides in females. CONCLUSION: Understanding of the anatomy of ethmoid roof with its possible variation is crucial to give the surgeon optimal information about the possible risk that one can face during the surgery. Hence dreadful complications can be avoided.

Comparison of stereotactic core breast biopsy and open surgical biopsy results at a tertiary care hospital in Pakistan.

BACKGROUND: The purpose of this study was to determine the yield of stereotactic core breast biopsy and its cost-saving potential. METHODS: This observational study was conducted at the Department of Radiology at Aga Khan Hospital in Karachi. All female patients (n = 84) undergoing stereotactic core breast biopsy under mammographic guidance from January 2005 to May 2010 were included. Stereotactic core biopsy was performed on a dedicated mammography unit employing a 14-gauge needle with an automated biopsy device. Ten patients with incomplete medical records were excluded. All breast biopsy results were either compared with surgical findings in cases of malignant histopathological findings or with follow-up needle localization in case of benign core biopsy findings. RESULTS: Fifteen of our 74 patients had malignant findings on stereotactic biopsy, confirmed on histopathology of the final surgical mastectomy specimen. The remaining 59 patients had benign results on histopathology; five patients had needle localization of the same area due to either suspicious mammographic findings or clinical suspicion of malignancy. All were proven to be histopathologically benign on open surgical biopsy. Fifty-four patients with benign results had follow-up mammograms, and the follow-up period was 18 months to 5 years. The sensitivity and specificity was 100%. The cost saving per patient was US$253. CONCLUSION: Stereotactic core breast biopsy is a safe and cost-effective method for determining the nature of suspicious mammographic findings.