Resilience of stormwater biofilters following the deposition of wildfire residues: Implication on downstream water quality management in wildfire-prone regions

Stormwater treatment systems such as biofilters could intercept and remove pollutants from contaminated runoff in wildfire-affected areas, ensuring the protection of water quality downstream. However, the deposition of wildfire residues such as ash and black carbon onto biofilters could potentially impair their stormwater treatment functions. Yet, whether and how wildfire residue deposition could affect biofilter functions is unknown. This study examines the impact of wildfire residue deposition on biofilter infiltration and pollutant removal capacities. Exposure to wildfire residues decreased the infiltration capacity based on the amount of wildfire deposited. Wildfire residues accumulated at the top layer of the biofilter, forming a cake layer, but scraping this layer restored the infiltration capacity. While the deposition of wildfire residues slightly changed the pore water geochemistry, it did not significantly alter the removal of metals and E. coli. Although wildfire residues leached some metals into pore water within the simulated root zone, the leached metals were effectively removed by the compost present in the filter media. Collectively, these results indicate that biofilters downstream of wildfire-prone areas could remain resilient or functional and protect downstream water quality if deposited ash is periodically scraped to restore any loss of infiltration capacity following wildfire residue deposition.

Do drinking water treatment residuals underperform in the presence of compost in stormwater media filters?

Drinking water treatment residuals (WTR), a waste-derived product, are often recommended to use as an amendment in stormwater biofilters to enhance their capacity to remove phosphate and microbial pollutants. However, their efficacy has been assumed to remain high in the presence of compost, one of the most common amendments used in biofilters. This study tests the validity of that assumption by comparing the removal capacities of WTR-amended biofilters with and without the presence of compost. Our results show that amending sand with WTR increased E. coli removal by at least 1-log, but the addition of compost in the sand-WTR media lowered the removal capacity by 13 %. Similarly, the addition of WTR to sand improved phosphate removal to nearly 1177 %, but the removal decreased slightly by 8 % when adding compost to the media. The results confirmed that dissolved organic carbon (DOC) leached from the compost could compete for adsorption sites for bacteria and phosphate, thereby lowering WTR's adsorption capacity based on the amount of DOC adsorbed on WTR. Collectively, these results indicate that the stormwater treatment industry should avoid mixing compost with WTR to get the maximum benefits of WTR for bacterial removal and improve the performance lifetime of WTR-amended biofilters.

Supernumerary intrathoracic ribs: imaging features of two cases

Intrathoracic supernumerary ribs are a rare congenital abnormality. The chest radiography and computed tomographic findings (including 3D reconstruction) of two cases are presented with a brief review of the literature.

Role of chest CT in the follow-up of ovarian adenocarcinoma

OBJECTIVE

We describe the prevalence of metastatic chest disease in ovarian adenocarcinoma as seen on CT. We sought to determine whether routine chest CT added any pertinent information to the follow-up examination of patients with ovarian adenocarcinoma.

MATERIALS AND METHODS

Retrospective review of our tumor registry yielded 96 patients with ovarian adenocarcinoma who had only a single primary malignancy and at least one CT scan of the chest, abdomen, and pelvis. CT scans were reviewed to assess the presence of metastatic chest disease in relation to disease activity in the abdomen and pelvis. Chest CT findings were correlated with the physical examination findings and CA-125 levels and were reviewed in consultation with a gynecologic oncologist to select only those patients with chest abnormalities attributable to metastatic disease.

RESULTS

A total of 266 CT scans were obtained. Forty (41.7%) of the 96 patients had abnormalities attributable to metastatic chest disease on one or more scans. In the absence of disease progression in the abdomen and pelvis, chest disease progression was seen in only six (2.7%) of the 226 follow-up CT scans. Five of the six patients had rising CA-125 levels.

CONCLUSION

Correlation of the findings of abdominal and pelvic CT with the physical findings and the CA-125 levels serves as effective follow-up in patients with ovarian adenocarcinoma. The contribution of additional chest CT in these patients is small.

Comparison of tubal ring and corpus luteum echogenicities: a useful differentiating characteristic

The purpose of this report is to compare the echogenicity of the tubal ring of an ectopic pregnancy and the corpus luteum with that of the ovary for improved detection of early ectopic pregnancy. In patients with ectopic pregnancy diagnosed at sonography on the basis of the presence of an adnexal tubal ring, echogenicity of the ring was compared with the echogenicity of the ovarian parenchyma. Twenty-six patients with tubal rings containing either a yolk sac or cardiac activity were included. Twenty-three (88%) of the 26 tubal rings had echogenicity equal to or greater than that of ovarian parenchyma. In 13 patients with ectopic pregnancy diagnosed on the basis of an empty tubal ring, 10 rings (77%) were more echogenic than the ovary. In 45 control patients with intrauterine pregnancy, the corpus luteum was more echogenic than the ovary in only 3 (7%). The tubal ring of an ectopic pregnancy is usually more echogenic than ovarian parenchyma, and the corpus luteum is usually equal to or less echogenic than the ovary. Echogenicity of an adnexal mass may help distinguish the tubal ring of an ectopic pregnancy from a corpus luteum.

CT and ultrasound features of metanephric adenoma in adults with pathologic correlation

PURPOSE

The purpose of this work was to correlate the CT, ultrasound, and pathologic features of metanephric adenoma, a rare benign renal tumor in adults.

METHOD

Retrospective review of medical records (1990-1997) revealed three adult female patients who had both preoperative imaging and nephrectomy with pathologic diagnosis of metanephric adenoma performed at our institution. CT (n = 3) and ultrasound (n = 2) features were reviewed in consensus by two radiologists and correlated with pathologic findings.

RESULTS

In all three cases, the metanephric adenoma was of increased attenuation relative to adjacent renal parenchyma on unenhanced CT scans. No septa or calcifications were seen. Ultrasound images showed both tumors to be hyperechoic with enhanced through-transmission.

CONCLUSION

The CT and ultrasound findings correlate with the pathologic features of a high nuclear-to-cytoplasmic ratio and psammomatous calcifications. In the adult population, it is unlikely that metanephric adenoma can be prospectively differentiated from renal cell carcinoma based on imaging features.

Comparison of contrast detail curves of full field digital with screen film breast phantom images

In this investigation, we imaged a standard breast phantom and compared the contrast detail curves from a prototype full breast digital mammography system with the corresponding curves for a conventional, analog screen-film system. The full breast digital system exhibited superior contrast detail detectability. The results from this study will be used to plan future clinical evaluations comparing full breast digital and screen film mammography.