Is MDCT an accurate tool to differentiate between benign and malignant etiology in diffuse peritoneal disease?

PURPOSE: There is often considerable overlap of imaging findings in benign and malignant peritoneal diseases. We evaluated patients with diffuse peritoneal disease, to assess the diagnostic value of MDCT in predicting benign or malignant etiology in patients with unknown etiology, by analyzing the various patterns of involvement, particularly tuberculosis (TB) vs malignancy. METHODS: One hundred and thirty-six patients with diffuse peritoneal disease who had abdominal CT and subsequently underwent omental biopsies were included in the study. Peritoneal, mesenteric and omental involvement by disease was evaluated on CT using specific parameters. The presence of lymphadenopathy, ascites, scalloping of organs, involvement of liver and spleen, were also compared between benign and malignant conditions using histopathology as the gold standard. RESULTS: In 136 patients, 72 benign and 64 malignant pathologies were classified as per histopathology. Higher age (p < 0.001), increasing omental thickness (mean 25.2 mm, p = 0.004), omental caking (p < 0.001), > 10 mm mesenteric/peritoneal nodules (p < 0.03), visceral scalloping (p = 0.001), free ascites (p = 0.003), serosal involvement (p = 0.004) and bilateral pleural effusion (p = 0.02) were associated with malignant etiology. Mesenteric thickening/stranding (p = 0.02), mesenteric adenopathy (p < 0.001), necrotic nodes (p = 0.02), splenomegaly (p = < 0.001) and higher attenuation (> 20HU) of ascitic fluid (p < 0.001) were associated with benign etiology. The presence of mesenteric thickening or stranding (p = 0.01), splenomegaly (p = 0.02), higher ascitic fluid attenuation > 20HU (p = < 0.01), mesenteric adenopathy (p < 0.01), necrotic nodes (p = 0.03) favored tuberculosis. CT had diagnostic accuracy (79.3, 86.7%), sensitivity (79.2, 74.6%) and specificity (79.4, 97%) for observers 1 and 2, respectively (Kappa 0.713). CONCLUSION: Contrast-enhanced MDCT has good sensitivity, specificity and accuracy in differentiating benign and malignant etiologies of diffuse peritoneal disease. Multiple common parameters can be used to differentiate between tuberculous peritonitis and peritoneal carcinomatosis.

Imaging Manifestations of Accessory Cavitated Uterine Mass-A Rare Mullerian Anomaly.

Context Accessory cavitated uterine mass (ACUM) is an uncommon and under-recognized entity with distinct imaging characteristics and causing significant patient distress. Differentiating it from its other clinical and radiological differentials is therefore extremely important and prevents delay in surgical management which is the treatment of choice. Aims The aim of the study is to describe the MRI appearance of the surgically and pathologically proven ACUM cases from our institution in the last 2 years. Settings and Design This is a retrospective study in a tertiary care hospital in South India. Methods and Material We reviewed the clinical presentations and imaging findings of seven surgically proven cases of ACUM qualifying the proposed diagnostic criteria. Results All patients presented with chronic pelvic pain, dysmenorrhea, and prolonged post-menstrual pain. MRI in all seven cases showed an intramural, noncommunicating, and cavitating lesion near the uterine cornua with internal contents similar to that of endometrioma. Although the cavity was lined by endometrium in all the cases (proven in pathology), it was well appreciable on MRI in only five cases. The rest of the uterine myometrium and main endometrial cavity were normal with no features of adenomyosis. Conclusion MRI is a reliable diagnostic tool for accurate diagnosis of ACUM, and more importantly, in distinguishing it from other causes of chronic pelvic pain like adenomyosis and endometriosis and other imaging differentials like adenomyoma, noncommunicating uterine horn, and degenerating leiomyoma.

Neuroimaging of pediatric infratentorial tumors and the value of diffusion-weighted imaging (DWI) in determining tumor grade.

BACKGROUND: Diffusion-weighted imaging (DWI) provides information about the cellular density of tumors. This feature is useful in grading and identifying different tumor types. PURPOSE: To assess the value of diffusion restriction and apparent diffusion coefficient (ADC) values in differentiating pediatric infratentorial tumors. MATERIAL AND METHODS: This was a retrospective review of the magnetic resonance imaging (MRI) of 82 children (age range 1-16 years) with infratentorial tumors. Histopathological grading after surgical excision/biopsy was categorized as low grade (WHO grades I and II) (n = 31; 29 pilocytic astrocytomas, 2 ependymomas) and high grade (WHO grade III and IV) (n = 51; 40 medulloblastomas, 8 anaplastic ependymomas, 1 anaplastic astrocytoma, 2 atypical rhabdoid teratoid tumors [ATRT]). MRI features and ADC values were compared among tumor types and grades using a two-tailed t test, Mann-Whitney U test for continuous data and Chi-square test for categorical variables. RESULTS: Diffusion restriction and low ADC value was a feature of high-grade tumors (P<0.001). The mean ADC values of the low-grade and high-grade tumors were 1.567 × 10-3mm2/s and 0.661 × 10-3mm2/s, respectively. Using 0.9 × 10-3mm2/s as the cut-off value, the sensitivity, specificity, positive and negative predictive values for differentiating the grades was 87%, 100%, 100%, and 81.8%, respectively. Significant differences were found between the mean ADC values of the individual tumor types (P<0.05), except between medulloblastoma and ATRT. CONCLUSION: ADC values and visual assessment of diffusion restriction are useful in tumor grading. The individual tumor types can be identified by an algorithmic approach, using DWI in conjunction with other described MRI features.

Role of Cross-sectional Imaging (CT/MRI) in Characterization and Distinguishing Benign from Malignant/Potentially Malignant Cystic Lesions of Pancreas.

OBJECTIVES: The aim of the study was to evaluate the accuracy of computed tomography/magnetic resonance imaging (CT/MRI) in characterizing cystic lesions of the pancreas and in differentiating between benign and malignant/potentially malignant lesions. MATERIAL AND METHODS: A retrospective study was performed on patients with pancreatic cystic lesions who underwent pre-operative imaging and surgery between October 2004 and April 2017 at a tertiary care teaching hospital. The images were reviewed for specific characteristics and diagnoses recorded independently by two radiologists who were blinded to the histopathological examination (HPE) report. Radiological diagnostic accuracy was assessed with HPE as reference standard. RESULTS: A total of 80 patients fulfilled the inclusion criteria (M: F = 27:53). The final HPE diagnoses were solid pseudopapillary neoplasm (32.5%), walled off necrosis/pseudocyst (27.5%), mucinous cystadenoma (15%), serous cystadenoma (11.25%), intraductal papillary mucinous neoplasm (8.75%), mucinous cystadenocarcinoma (2.5%), simple epithelial cyst (1.25%), and unspecified benign cystic lesion (1.25%). Observer1 correctly identified the diagnosis in 73.75% of cases while observer 2 did so in 72.5%. Sensitivity for distinguishing benign versus malignant/potentially malignant lesions was 85.1% for observer 1 and 80.9% for observer 2. On multivariate logistic regression analysis: Solid cystic morphology, presence of mural nodule, and female gender were associated with premalignant/malignant lesions. CONCLUSION: Cross-sectional imaging is a valuable tool for characterization of pancreatic cystic lesions within its limitations.

Macrodystrophia Lipomatosa: A Single Large Radiological Study of a Rare Entity.

INTRODUCTION: We present one of the largest case series of Macrodystrophia lipomatosa, a rare congenital disorder of localized gigantism characterized by overgrowth of all the mesenchymal elements, predominantly involving the fibroadipose tissue. AIMS: To detail the radiological features, pattern of distribution, associated conditions and to suggest an appropriate terminology to describe the condition. METHODS AND MATERIAL: It is a retrospective study. Data from PACS server dating from 2000 and 2018 was used. The cases with isolated enlarged limb or digit/digits with or without nerve involvement were included in the study. STATISTICAL ANALYSIS USED: Frequency and percentage were used for analysis of categorical variables. RESULTS: A total of 31 cases was included for the final analysis, out of which 19 were males and 12 were females. Unilateral limb involvement was seen in 30 cases. The most common pattern identified was the 'nerve territory oriented' type in 28 cases confined to the hand or foot, 'diffuse or pure lipomatous' type in one case and mixed type was seen in two cases. The most common nerve territory involved was along the median nerve in the upper limb and along the medial plantar nerve in the lower limb. Neural involvement was seen in 16 cases of the upper limb and 10 cases of the lower limb. Syndactyly was seen in two cases, polydactyly in one case and symphalangism in one case. CONCLUSIONS: A diagnosis of macrodystrophia lipomatosa can be confidently made in cases with congenital isolated limb or digit/digits enlargement with or without fibrolipohamartoma of nerve. Radiographs and ultrasound are sufficient along with clinical examination to make accurate diagnosis. MRI is useful for assessing the extent and for planning surgery.

Best MRI predictors of complete response to neoadjuvant chemoradiation in locally advanced rectal cancer.

OBJECTIVE: To identify the MRI parameters which best predict complete response (CR) to neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (LARC) and to assess their diagnostic performance. METHODS: This was a prospective study of pre- and post-CRT MRI and diffusion-weighted imaging (DWI) of 64 patients with LARC who underwent neoadjuvant CRT and subsequent surgery. Histopathological tumour regression grade was the reference standard. Multivariate regression analysis was performed to identify the best MRI predictors of CR to neoadjuvant CRT, and their diagnostic performance was assessed. RESULTS: The study cohort comprised 48 males and 16 females (n = 64), with mean age of 49.48 ± 14.3 years, range of 23-74 years. 11 patients had pathological complete response. The following factors predicted CR on univariate analysis: low initial (pre-CRT) tumour volume on T2 weighted high-resolution (HR) images and DWI, tumour volume-reduction rate (TVRR) of >95% on DWI and CR on post-CRT DWI (ydwiT0) as assessed by the radiologist. However, the best MRI predictors of CR on multivariate regression analysis were CR on post-CRT DWI (ydwiT0) as assessed by the radiologist and TVRR of >95% on DWI, and these parameters had an area under the curve (95% confidence interval) of 0.881 (0.74-1.0) and 0.843 (0.7-0.98), respectively. The sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of DWI in predicting CR was 81.8%, 94.3%, 75%, 96.1% and 76%; the sensitivity, specificity and accuracy of TVRR of >95% as a predictor of CR was 80%, 84.1% and 64.1%, respectively; however, this difference was not statistically significant. The interobserver agreement was substantial for ydwiT0. CONCLUSION: Visual assessment of CR on post-CRT DWI and TVRR of >95% on DWI were the best predictors of CR after neoadjuvant CRT in patients with LARC, and the former being more practical can be used in daily practice. ADVANCES IN KNOWLEDGE: In rectal cancer, ydwiT0 as assessed by the radiologist was the best and most practical imaging predictor of CR and scores over standard T2W HR images.

Atypical ultrasound features of parathyroid tumours may bear a relationship to their clinical and biochemical presentation.

OBJECTIVES: To describe atypical ultrasound features of parathyroid lesions and correlate them with clinical presentation and histopathology. MATERIALS AND METHODS: Retrospective review of 264 patients with primary hyperparathyroidism who underwent ultrasound imaging prior to parathyroidectomy was performed. Patients with atypical ultrasound findings (n = 26) were identified; imaging findings were correlated with clinical presentation and histopathology. RESULTS: Twenty-one (80 %) lesions were adenomas, two (8 %) were adenomas with cellular atypia, and three (11.5 %) were carcinomas. Seventeen (65 %) lesions showed cystic change; five (19 %) of them had >50 % cystic change. These lesions were adenomas with cystic degeneration. Cystic degeneration had significant positive correlation with the lesion size and PTH level, but cystic adenomas correlated negatively with lesion weight. Six (23 %) lesions were isoechoic and one (4 %) was hyperechoic; histology predominantly revealed haemorrhage, hyalinisation and fibrosis; one lesion showed fat deposition and another had multiple granulomas within the adenoma. Twenty (83 %) lesions had heterogeneous echotexture and showed combinations of acinar dilatation, necrosis, haemorrhage and fibrosis. Heterogeneous lesions tended to be significantly larger and heavier, and they were associated with higher PTH levels. Four (15 %) lesions had calcifications. Scintigraphy was concordant in 22 (96 %), n = 23. One scintigraphy-negative lesion was a cystic parathyroid adenoma. CONCLUSION: Atypical ultrasound features of parathyroid lesions pose a diagnostic challenge. Awareness of these features would help improve lesion detection. TEACHING POINTS: 1. Cystic change is significantly related to the size, weight and measured parathyroid hormone levels. 2. Cystic change in parathyroid tumours indicated a slightly higher risk of malignancy. 3. Heterogeneous parathyroid adenomas are larger in size and heavier, and they have higher PTH levels. 4. Awareness of atypical ultrasound features will improve preoperative clinical prediction.

Causes of discordant or negative ultrasound of parathyroid glands in treatment naïve patients with primary hyperparathyroidism.

OBJECTIVES: To describe causes of discordant or negative parathyroid ultrasound and to assess factors influencing them. MATERIALS AND METHODS: Retrospective review of patients who underwent parathyroidectomy between 2000 and 2012 was done. Imaging findings were compared with operative findings and pathology to identify discrepant (n=60; 32 negative, 28 incorrect) parathyroid ultrasounds. RESULTS: Fifty (83.3%) patients had parathyroid adenoma, of which 10 (16.6%) were ectopic and three were double adenomas; 8 (13.3%) had multigland hyperplasia and two had parathyroid carcinoma. Discrepant reports were due to incorrect localisation in 8 (13.3%); difficulty in differentiating thyroid from parathyroid lesion in 12 (20%); large and small size in two and three patients, respectively; overcall in 5 (8.3%) and satisfaction of search in 7 (11.7%) patients. There was significant correlation between presence of multi-nodular goitre and incorrect reports (χ(2)=4.112, p=0.04). Experience of ultrasound operators performing initial and second look ultrasound was significantly different (p<0.0001). Second look ultrasound was concordant with surgical findings in 39(65%) patients; 21 (66%) patients with initially negative ultrasound and four out of five extra-mediastinal ectopic lesions. Ten patients with negative initial ultrasound had elongated parathyroid lesion. Scintigraphy was concordant in 44 (73.3%) patients and nine were ectopic. CONCLUSION: Second look ultrasound performed by experienced operator for negative or discordant initial ultrasound of parathyroid is a useful strategy which will improve the accuracy of parathyroid ultrasound. Being able to differentiate thyroid from parathyroid lesion is a factor which will influence performance of parathyroid ultrasound.

Giardia duodenalis assemblages associated with diarrhea in children in South India identified by PCR-RFLP.

Giardial diarrhea in a birth cohort of 452 children in an urban slum in South India was characterized. Of the 155 episodes that occurred in 99 children, 73% were acute diarrhea. Children with better educated mothers and a toilet at home had lower odds of acquiring giardial diarrhea, whereas low socioeconomic status and drinking municipal water were associated with greater risk. Children with co-infections tended to have a slightly longer duration of diarrhea (P = 0.061) and showed significantly more wasting after an episode than children with diarrhea resulting from Giardia alone (P = 0.032). Among the 99 cases, 50 diarrheal and 51 asymptomatic Giardia positive samples were genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) at the triose phosphate isomerase gene. Assemblage B was predominant both in giardial diarrhea (80%) and asymptomatic giardiasis (94%). Children with Assemblage A subgroup-II alone or dual infections with both assemblage A and B had diarrhea more frequently (P = 0.07).

Influence of erythrocyte function-enhancing drugs on the bronchoprotective actions of chemokine receptor blockers in mice.

BACKGROUND: CC chemokine receptors are likely to have important roles in the regulation of leukocytes and mast cells. Chemokine receptors are crucial in orchestrating innate and acquired immune responses as well as in allergic inflammation. A disturbance in erythrocyte function can lead to bronchial hyperreactivity and asthma. MATERIAL/METHODS: This study was conducted on Swiss albino mice weighing between 25 to 35 g. The animals were divided into eight groups (n=8). Groups of mice (n=8) were pretreated with the chemokine receptor blockers A122058 (600 microg/kg i.p.) or cyclophosphamide (20 mg/kg i.p.). Other groups received A122058 or cyclophosphamide in combination with either erythropoietin and quercetin. The effects of these drugs on bronchoconstriction and salivation induced by carbachol were evaluated. RESULTS: The results of this study suggest that blockade of chemokine receptors significantly potentiated erythropoietin- and quercetin-induced inhibition of carbachol-induced bronchoconstriction (P<0.05) compared with the control group. However, pentoxifylline did not produce significant bronchoprotection against carbachol-induced bronchoconstriction (P>0.05). CONCLUSIONS: The results of this study suggest that blockade of chemokine receptors and enhancement of the erythrocyte function together potentiate the bronchoprotective effects of these drugs. This combination could be a novel strategy in combating bronchial hyper-responsiveness.