Optimal abdominal CT protocol for obese patients

INTRODUCTION

This study investigated the impact of different protocols on radiation dose and image quality for obese patients undergoing abdominal CT examinations.

METHODS

Five abdominal/pelvis CT protocols employed across three scanners from a single manufacturer in a single centre used a variety of parameters (kV: 100/120, reference mAs: 150/190/218/250/300, image reconstruction: filtered back projection (FBP)/iterative (IR)). The routine protocol employed 300 reference mAs and 120 kV. Data sets resulting from obese patient examinations (n = 42) were assessed for image quality using visual grading analysis by three experienced radiologists. Objective assessment (noise, signal/contrast-noise ratios) and radiation dose was compared to determine optimal protocols for prospective testing on a further sample of patients (n = 47) for scanners using FBP and IR techniques.

RESULTS

Compared to the routine protocol, mean radiation dose was reduced by 60% when using 100 kV and SAFIRE technique strength 3 (p = 0.001). Reduction of up to 30% in radiation dose was noted for the FBP protocol: 120 kV and 190 reference mAs (p = 0.008). Subjective and objective image quality for both protocols were comparable to that of the routine protocol (p > 0.05). An overall improvement in image quality with increasing strength of SAFIRE was noted. Upon clinical implementation of the optimal dose protocols, local radiology consensus deemed image quality to be acceptable for the participating obese patient cohort.

CONCLUSION

Radiation dose for obese patients can be optimised whilst maintaining image quality. Where iterative reconstruction is available relatively low kV and quality reference mAs are also viable for imaging obese patients at 30-60% lower radiation doses.

Sofosbuvir-Based Therapy for Genotype 4 HCV Recurrence Post-Liver Transplant Treatment-Experienced Patients

Background and Aim. This is an open label prospective cohort study conducted at a tertiary care hospital. The primary endpoint is SVR12 in patients treated with sofosbuvir-based therapy in post-liver transplant patients with genotype 4 HCV recurrence. Methodology. Thirty-six treatment-experienced liver transplant patients with HCV recurrence received sofosbuvir and ribavirin ± peginterferon. Results. We report here safety and efficacy data on 36 patients who completed the follow-up period. Mean age was 56 years, and the cohort included 24 males and one patient had cirrhosis. Mean baseline HCV RNA was 6.2 log10 IU/mL. The majority of patients had ≥ stage 2 fibrosis. Twenty-eight patients were treated with pegylated interferon plus ribavirin in addition to sofosbuvir for 12 weeks and the remaining were treated with sofosbuvir plus ribavirin only for 24 weeks. By week 4, only four (11.1%) patients had detectable HCV RNA. Of the 36 patients, 2 (5.5%) relapsed and one died (2.75%). Conclusion. Our results suggest that sofosbuvir + ribavirin ± pegylated interferon can be utilized successfully to treat liver transplant patients with HCV recurrence.

Dedifferentiated giant cell tumour of bone in the form of low-grade fibroblastic osteogenic sarcoma: case report of a unique presentation with follow-up

Giant cell tumour (GCT) of bone is a locally aggressive benign tumour. It can, however, undergo dedifferentiation, either de novo or secondarily after local recurrence or radiation. Whether spontaneously occurring or induced by previous irradiation, this malignant transformation is typically defined as a high-grade anaplastic sarcoma devoid of giant cells. Dedifferentiation of GCT into low-grade-appearing sarcoma has not been reported yet. Here, we describe the first case of dedifferentiated GCT in the appearance of low-grade fibroblastic osteogenic sarcoma with distant bone metastases. This disease progression occurred without previous irradiation. We confirm the aggressive behaviour of this tumour despite the deceptively bland appearance of the malignant component. We also alert others to the importance of recognizing this rare histology to avoid underdiagnosis and subsequent undertreatment.

Purification and some properties of low molecular weight crystallins from camel lens (Camelus dromedarius)

1. The use of an Ultrogel AcA 54 gel-filtration column separates camel lens cortex low molecular weight proteins into four peaks containing beta s-, gamma 1-, gamma 2- and gamma 3-crystallins. 2. The molecular weight of beta s-crystallin corresponded to 29 kDa on SDS-PAGE and showed three major bands between pH 5.85 and 8.45 on isoelectric focusing. In addition, as compared to gamma-crystallins it has a lower degree of homology in amino acid composition, a low sulfhydryl content and a blocked N-terminal amino acid. 3. gamma 1-, gamma 2- and gamma 3-crystallins appeared homogenous on SDS-PAGE and their molecular weights were recorded as 23, 22 and 21 kDa. The isoelectric points of the gamma-crystallin fractions ranged from pH 6.55 to 8.60 and they were found to have an unmodified glycine at the N-terminal end. 4. The three camel gamma-crystallin fractions were similar in molecular weight, isoelectric points, amino acid composition, sulfhydryl concentration and N-terminal amino acid.