Hybrid SPECT-CT for characterizing isolated vertebral lesions observed by bone scintigraphy: comparison with planar scintigraphy, SPECT, and CT

PURPOSEWe aimed to assess the role of single photon emission computed tomography-computed tomography (SPECT-CT) for characterizing isolated vertebral lesions observed by bone scintigraphy compared to planar scintigraphy, SPECT, and CT, and to evaluate the impact of SPECT-CT on patient management. MATERIALS AND METHODSData from 99 patients (mean age, 52.4±18.9 years; females, 58.5%) with 108 isolated vertebral lesions visible on planar bone scintigraphy, who had undergone SPECT-CT of a selected volume, were retrospectively analyzed. Planar scintigraphy, SPECT, CT, and SPECT-CT images were independently evaluated in separate sessions to minimize recall bias. A scoring scale of 1 to 5 was used, with 1 being definitely metastatic, 2 most likely metastatic, 3 indeterminate, 4 most likely benign, and 5 definitely benign. Sensitivity, specificity, and predictive values were calculated; a score ≤3 was defined as metastatic. The areas under the receiver operating characteristic curve were calculated and compared. Clinical and imaging followup with or without histopathology were used as a reference standard. RESULTSAmong the 108 lesions, 49 were indeterminate on planar scintigraphy, 16 on SPECT, and one each on SPECT-CT and CT. SPECT-CT was superior to both planar scintigraphy (P < 0.001) and SPECT alone (P = 0.014), but not to CT (P = 0.302). CT was superior to planar scintigraphy (P < 0.001) but only slightly superior to SPECT (P = 0.063). SPECT-CT correctly characterized 96% of the indeterminate lesions observed by planar scintigraphy. SPECT-CT had an impact on the clinical management of 60.6% patients compared to planar scintigraphy and 18.1% compared to SPECT. CONCLUSIONSPECT-CT is better than planar scintigraphy and SPECT alone, but not CT alone, for characterizing equivocal vertebral lesions that are observed by bone scintigraphy, thus SPECT-CT can have a significant impact on patient management

Proteus syndrome: a case report with bone scintigraphy findings

Proteus syndrome is an extremely rare genetic disorder characterized by an asymmetrical overgrowth of skin, bones, muscles, fatty tissues, and blood and lymphatic vessels. We present a case of a six-year-old boy with proteus syndrome who underwent bone scintigraphy for suspected osteomyelitis. Bone scintigraphy ruled out osteomyelitis and suggested cellulitis. In addition, it demonstrated striking characteristic deformities, which need to be emphasized. Knowledge of these findings will avoid misinterpretation of bone scintigraphy in patients with proteus syndrome

New insight into the evolution of India's west coast geothermal province: trace element signature in the thermal waters

Trace element signature in the thermal waters from India's west coast geothermal province brought out distinct circulation regime within the province. The northern group of thermal springs circulate within the Deccan volcanic flows with geothermal gradients and heat flow values contributed by the mantle below the Deccan. The southern group of thermal springs circulate within the Precambrian granites, registering high B content. Thus, the earlier held view that the entire west coast geothermal province host geothermal reservoirs within the Deccan volcanic flows is not valid. The west coast geothermal province thus has two distinct sub-provinces: one controlled the basalt flows and the other controlled by the high heat generating granites

Geothermometry of West Coast Geothermal Province, Maharashtra, India

Around 60 thermal springs emerge at temperatures ranging from 40 to 72°C along the west coast of Maharashtra spanning a linear distance of about 350 km. Silica and cation geothermometers indicate reservoir temperatures of about 120°C, with a few springs showing higher potential. The mineral phase equilibrium plots (Q/K v/s Temperature) yielded higher equilibrium temperatures ranging from 120-170°C. The highest being the Unhavre-Farare and the Tural spings, pointing towards more promising sites with potential for adequate heat generation. Located in an agricultural and coastal area, the province holds great promise for direct heat utilization such as green house, food dehydration and aquaculture

Geochemistry of thermal springs around Lake Abhe, Western Djibouti

The Republic of Djibouti, occupying an area of 23,180 km2, falls within the arid zone of East Africa and is located above the 'Horn of Africa', adjacent to the Red Sea. This country has several thermal springs and fumaroles distributed over three regions - Lake Assal, Lake Hanle and Lake Abhe. The most characteristic feature of Lake Abhe is the presence of several linear chains of travertine chimneys. The thermal waters are typical of the Na-Cl type near neutral waters rich in CO2. These waters show an oxygen shift, indicating reservoir temperatures>200°C. The chemical signature of the thermal springs and the geology of the Lake Abhe region are very similar to the Tendaho geothermal area of Ethiopia. The geology, temperature gradient and its proximity to Damah Ale volcano make the Lake Abhe region a potential site for geothermal power development

Water resource management using geothermal energy: Eritrea

Eritrea is a country with rich gold, silver and base-metal deposits and geothermal energy resources associated with all the fivevolcanoes located within the Danakil graben. Due to low rainfall, the country has to depend on imported food and food importshave crossed > 46% in the recent years. Although the cultivable land is about 16,000 km2, only 5030 km2land is being cultivateddue to insufficient water resources. The per capita water requirement is projected to fall below 1300 m3/year from the present1470 m3/year. The country’s GDP has fallen from 1.3% in 2013 to 0.3% in 2015. Each geothermal province associated with theactive volcanoes can support to generate 445 million m3of desalinated water from the Red Sea. Providing basic needs like waterand energy will boost the country’s economy and lift the socio-economic status of 6 million people in the country