Shivanand Gamanagatti

Diffusion-weighted MRI in renal cell carcinoma: A surrogate marker for predicting nuclear grade and histological subtype:

Background Though previous investigators have attempted to evaluate its utility in characterization of focal renal lesions, diffusion-weighted MR imaging (DW MRI) in renal diseases is still an evolving field and its role in predicting the aggressiveness of renal cell carcinoma (RCC) is yet to be established. Purpose To assess whether apparent diffusion coefficient (ADC) values can be used to determine the nuclear grade and histological subtype of RCCs and to identify the tumor attributes contributing to variation in ADC values. Material and Methods The institutional ethics committee waived the requirement of informed consent for this retrospective study. The study cohort consisted of 33 patients who underwent MRI (with diffusion-weighted imaging at b values of 0 and 500 s/mm2) and were found to have 36 pathologically-proven RCCs. ADC values were determined for solid portions of RCC, cystic/hemorrhagic areas, and normal renal parenchyma. Histological subtype, nuclear grade, and cell count were determined for each lesion. ADC values were compared between different grades and subtypes and correlation with cell count was investigated. Receiver operating characteristic curves were drawn to establish cut-off ADC values. Results There were 23 low grade (grades I and II) and 13 high grade tumors (grades III and IV). There were 32 clear-cell and four non-clear-cell RCCs. A decreasing trend of ADC values was seen with increasing grade and mean ADC of high grade RCC was significantly lower than low grade (1.3145 vs 1.6982 × 10−3 mm2/s) (P = 0.005). Mean ADC for clear-cell RCC was significantly higher than non-clear-cell RCC (1.6245 vs. 1.0412 × 10−3 mm2/s) (P = 0.005). ADC values higher than 1.7960 × 10−3 mm2/s were seen only with low grade and values greater than 1.4904 × 10−3 mm2/s were seen only with clear-cell RCC. Conclusion ADC values provide a non-invasive means to predict the nuclear grade and histological subtype of RCC. Cellularity and morphology are other tumor attributes contributing to the variation in ADC values of RCCs.

Spontaneous Rupture of a Giant Hepatic Hemangioma – Sequential Management with Transcatheter Arterial Embolization and Resection

Hemangioma is the most common benign tumor of liver and is often asymptomatic. Spontaneous rupture is rare but has a catastrophic outcome if not promptly managed. Emergent hepatic resection has been the treatment of choice but has high operative mortality. Preoperative transcatheter arterial embolization (TAE) can significantly improve outcome in such patients. We report a case of spontaneous rupture of giant hepatic hemangioma that presented with abdominal pain and shock due to hemoperitoneum. Patient was successfully managed by TAE, followed by tumor resection. TAE is an effective procedure in symptomatic hemangiomas, and should be considered in such high risk patients prior to surgery.

Clinical Profile, Etiology and Therapeutic Outcome in 324 Hepatocellular Carcinoma Patients at a Tertiary Care Center in India

Objective: To study the profile and outcome of therapy for hepatocellular carcinoma (HCC) in India. Methods: Data analysis of HCC patients enrolled in liver clinic between 1990 and 2005. Results: We registered 324 HCC patients [males 284 (88%), mean age 52.4 ± 13.1 years]. The etiology of HCC was: hepatitis B virus 165 (51%), hepatitis C virus 38 (12%), alcohol 20 (6%), combined 31 (10%) and unknown 70 (21%). Serum α-fetoprotein was >400 ng in 36%, portal vein invasion was seen in 40% and distant metastases in 13%. Therapy was offered to 141 (43.5%) patients, but survival data was available in only 130 (93%) of them. Treatment given and median survival time was as follows: surgical resection, 19 months (n = 14); transarterial chemoembolization, 11 months (n = 23); transarterial rhenium therapy, 26 months (n = 7); radiofrequency ablation, 24 months (n = 4); acetic acid ablation, 13 months (n = 17); oral chemotherapy, 26 months (n = 33), and combination therapy, 26 months (n = 32). Vascular invasion, Okuda staging and therapy were independent factors associated with survival. Treated patients had longer median survival compared to untreated ones (16 months vs. 7 months, p < 0.05). Conclusions: Hepatitis B infection is the predominant cause of HCC in India. Serum α-fetoprotein was diagnostic in only one third of our patients. Most patients present late, when curative therapies are not possible. Treated patients had better survival than untreated ones.

Imaging and interventions in Budd-Chiari syndrome

Budd-Chiari syndrome (BCS) consists of a group of disorders with obstruction of hepatic venous outflow leading to increased hepatic sinusoidal pressure and portal hypertension. Clinically, two forms of disease (acute and chronic) are recognized. Mostly the patients present with ascites, hepatomegaly, and portal hypertension. In acute disease the liver is enlarged with thrombosed hepatic veins (HV) and ascites, whereas in the chronic form of the disease there may be membranous occlusion of HV and/or the inferior vena cava (IVC), or there may be short or long segment fibrotic constriction of HV or the suprahepatic IVC. Due to advances in radiological interventional techniques and hardware, there have been changes in the management protocol of BCS with surgery being offered to patients not suitable for radiological interventions or having acute liver failure requiring liver transplantation. The present article gives an insight into various imaging findings and interventional techniques employed in the management of BCS.

Skeletal dysplasias: A radiographic approach and review of common non-lethal skeletal dysplasias.

Skeletal dysplasias are not uncommon entities and a radiologist is likely to encounter a suspected case of dysplasia in his practice. The correct and early diagnosis of dysplasia is important for management of complications and for future genetic counselling. While there is an exhaustive classification system on dysplasias, it is important to be familiar with the radiological features of common dysplasias. In this article, we enumerate a radiographic approach to skeletal dysplasias, describe the essential as well as differentiating features of common non-lethal skeletal dysplasias and conclude by presenting working algorithms to either definitively diagnose a particular dysplasia or suggest the most likely differential diagnoses to the referring clinician and thus direct further workup of the patient.

Trans-arterial chemoembolization (TACE) in patients with unresectable Hepatocellular carcinoma: Experience from a tertiary care centre in India.

Aims: To evaluate the outcome following transarterial chemoembolization (TACE) and to identify the predictors of survival in patients with unresectable hepatocellular carcinoma (HCC). Material and Methods: HCC patients reporting to our hospital (2001-2007) were subjected to clinical, biochemical, and radiological examination. TACE was performed in those who fulfilled the inclusion criteria. Follow-up assessment was done with multiphase CT scan of the liver at 1, 3, and 6 months. Tumor response and survival rate were estimated. Univariate and multivariate analyses were done for determinants of survival. Results: A total of 73 patients (69 males, 4 females; mean age 49±13.4 years) were subjected to 123 sessions of TACE. The Childs classification was: A – 56 patients and B – 17 patients. Barcelona Clinic staging was: A – 20 patients, B – 38 patients, and C – 15 patients. Tumor size was ≤5cm in 28 (38%) patients, >5–10 cm in 28 (38%) patients, and >10 cm in 17 (23%) patients. Median follow-up was for 12 months (range: 1–77 months). No significant postprocedure complications were encountered. Overall survival rate was 66%, 47%, and 36.4% at 1, 2, and 3 years, respectively. Tumor size emerged as an important predictor of survival. Conclusion: TACE offers a reasonable palliative therapy for HCC. Initial tumor size is an independent predictor of survival.

Traumatic diaphragmatic injury: a review of CT signs and the difference between blunt and penetrating injury.

PURPOSE We aimed to present the frequency of computed tomography (CT) signs of diaphragmatic rupture and the differences between blunt and penetrating trauma. MATERIALS AND METHODS The CT scans of 23 patients with surgically proven diaphragmatic tears (both blunt and penetrating) were retrospectively reviewed for previously described CT signs of diaphragmatic injuries. The overall frequency of CT signs was reported; frequency of signs in right- and left-sided injuries and blunt and penetrating trauma were separately tabulated and statistically compared. RESULTS The discontinuous diaphragm sign was the most common sign, observed in 95.7% of patients, followed by diaphragmatic thickening (69.6%). While the dependent viscera sign and collar sign were exclusively observed in blunt-trauma patients, organ herniation (P = 0.05) and dangling diaphragm (P = 0.0086) signs were observed significantly more often in blunt trauma than in penetrating trauma. Contiguous injury on either side of the diaphragm was observed more often in penetrating trauma (83.3%) than in blunt trauma (17.7%). CONCLUSION Knowledge of the mechanism of injury and familiarity with all CT signs of diaphragmatic injury are necessary to avoid a missed diagnosis because there is variability in the overall occurrence of these signs, with significant differences between blunt and penetrating trauma.

Evaluation of diagnostic utility of multidetector computed tomography and magnetic resonance imaging in blunt pancreatic trauma: a prospective study

Background Blunt pancreatic trauma is an uncommon injury with high morbidity and mortality. Retrospective analyses of computed tomography (CT) performance report CT to have variable sensitivity in diagnosing pancreatic injury. Both a prospective analysis of multidetector CT (MDCT) performance and diagnostic utility of magnetic resonance imaging (MRI) in acute blunt pancreatic injury remain unexplored. Purpose To prospectively evaluate the utility of MDCT with MRI correlation in patients with blunt pancreatic trauma using intraoperative findings as the gold standard for analysis. Material and Methods The contrast-enhanced CT (CECT) scans of patients admitted with blunt abdominal trauma were prospectively evaluated for CT signs of pancreatic injury. Patients detected to have pancreatic injury on CT were assigned a CT grade of injury according to American Association for Surgery of Trauma classification. MRI was performed in patients not undergoing immediate laparotomy and MRI grade independent of CT grade was assigned. Surgical grade was taken as gold standard and accuracy of CT and MRI for grading pancreatic injury and pancreatic ductal injury (PDI) was calculated. A quantitative and qualitative comparison of MRI was also done with CT to determine the performance of MRI in acute pancreatic injury. Results Thirty out of 1198 patients with blunt trauma abdomen were detected to have pancreatic injury on CT, which was surgically confirmed in 24 patients. Seventeen underwent MRI and surgical correlation was available in 14 patients. CT and MRI correctly identified the grade of pancreatic injury in 91.7% (22/24) and 92.86% (13/14) patients, respectively. Both CT and MRI correctly identified PDI in 18/19 and 11/12 patients, respectively, with good inter-modality agreement of 88.9% (kappa value of 0.78). MRI also qualitatively added to the information provided by CT and increased diagnostic confidence in 58.8% of patients. Conclusion MDCT performs well in grading pancreatic injury and evaluating pancreatic ductal injury. MRI is useful in evaluation of acute pancreatic trauma as it can increase diagnostic confidence and provide more qualitative information regarding the extent of injury.

CT in post-traumatic hypoperfusion complex—a pictorial review

Hypoperfusion complex is an uncommon entity found on computed tomography (CT) of blunt trauma. It is more common in children compared to adults. Everyone should be aware of this entity to interact with clinicians to aid in triage and management of patients in view of poor prognosis. It is also important to prevent unnecessary laparotomies by confusing abdominal organ injuries. There are certain visceral and vascular findings described on abdominal CT that would alert the radiologist for this entity. This pictorial review should increase radiologists’ awareness and recognition of the CT manifestations of hypoperfusion complex before an irreversible state of shock occurs in blunt abdominal trauma.

99mTc-Methylene diphosphonate SPECT/CT as the one-stop imaging modality for the diagnosis of osteoid osteoma.

PurposeThe aim of this study was to evaluate the utility of 99mTc-methylene diphosphonate (99mTc-MDP) single-photon emission tomography (SPECT)/computed tomography (CT) for the diagnosis of osteoid osteoma and compare the same with three-phase planar bone scintigraphy (BS) and CT alone. Materials and methodsData of 31 patients (age: 20.6±13.2 years; male: 80.6%) who had undergone 99mTc-MDP BS with SPECT/CT for clinically and/or radiographically suspected osteoid osteoma were retrospectively evaluated. Planar BS images were analyzed by an experienced nuclear medicine physician. CT images were evaluated by an experienced radiologist. SPECT/CT images were evaluated by the nuclear medicine physician and radiologist in consensus. On the basis of the diagnostic confidence the interpreters used a scoring scale of 1–3, in which 1 is negative for osteoid osteoma, 2 is equivocal, and 3 is positive for osteoid osteoma. For the calculation of sensitivity, specificity, and predictive values for planar BS, CT, and SPECT/CT an interpretive score of 2 or higher was taken as positive for osteoid osteoma. Receiver operating characteristic curve analysis was performed and the area under the curve was calculated and compared. Histopathology and microbiology/clinical imaging follow-up was used as the reference standard. ResultsThere were nine equivocal lesions on planar BS and five equivocal lesions on CT, but none on SPECT/CT. The sensitivity, specificity, and accuracy of SPECT/CT were all 100%; those of CT were 77.8, 92.3, and 83.8% and those of planar BS were 100, 38.4, and 74.1%, respectively. On comparison, the area under the curve of SPECT/CT was significantly larger than that of planar BS (1.00 vs. 0.761; P=0.005) and CT (1.00 vs. 0.872; P=0.044). However, no significant difference was seen between planar BS and CT (0.761 vs. 0.872; P=0.236). Conclusion99mTc-MDP SPECT/CT shows excellent diagnostic accuracy for osteoid osteoma and can be used as a one-stop imaging modality for the same. It is superior to planar BS and CT alone for the diagnosis of suspected osteoid osteoma.