82 years old male,
abdominal aortic aneurysm CT study,
80 ml of contrast medium was administrated with IDR of 1,48 gl/s.
Technical parameters are reported in figure 1.
At 86 keV, ROI in abdominal aorta demonstrates a contrast enhancement of 272 HU (Fig.
At same IDR,
by decreasing KeV,
an initial increased contrast enhancement is
up until 1255 HU of density by choosing very low KeV (40 KeV) to improve imaging quality (Fig.
63 years old female,
oncological history; performed an angiography CT to evaluate inferior epigastric artery perforators to plan breast reconstruction.
At 120 KV, HU (156 HU) was sub-optimal (< 200 HU) for angiographic exam.
As previously mentioned,
contrast enhancement is increased by decreasing KeV,
even in small vessel as inferior epigastric artery (Fig.
Also 1039 HU values are acquired at 40 KeV,
useful to obtain high quality post processing reconstruction imaging and to study also some collateral vessel (Fig.
60 years old male.
Candidate to kidney transplantation for chronic renal disease.
We administered low contrast medium volume (40 ml; 14,8 gr I) because of renal impairment and low flow injection rate (3 ml/s),
because of damaged antecubital veins.
Despite such parameters,
we obtained an optimal opacification of entire aorto-bisiliac axis (Fig.
modifying KeV value (increased KeV),
beam-hardering artifact was reduced and patency of stent was valued (Fig.
85 years old female.
History of renal impairment.
Study of thoracic aortic aneurysm.
We performed CT scan with low contrast medium volume (50 ml) and concentration (320 mg/l) at low injection rate (3 ml/sec).
At 77 KeV,
HU is sub-optimal for angiographic study (175 HU),
but at 40 KeV we reached very high HU value (585 HU) with only 0,95 gl/s IDR,
useful for post-processing reconstruction.
We were able to obtain high quality images even with these parameters keeping the patient safe (Fig.
optimal images also of the abdominal aorta was obtained with only 0,95 gl/s IDR (Fig.
77 years old male.
Acute dorsal pain,
SSCT with 1,48 gl/s IDR is performed to study thoracic aortic aneurysm.
Aortic intramural hematoma is observed (Fig.
The next day,
a control scan is performed with DECT,
after stent application.
A lower amount of contrast medium is administered for the patient's care.
It can be seen that at 55 KeV,
similar HU values are obtained with lower IDR (1,11 gl/s vs 1,48 gl/s).
Two following cases do not concern frail patients but they are helpful to demonstrate as DECT could be also useful to assess wall structure (hemorrhage) and composition (carotid plaque) in some specific exams (as carotid,
76 years old male,
We chose this case in order to show how UH of the plaque change modifying KeV.
This new concept allows introduction of a new chapter in characterizing the plaque (calcific,
fatty or mixed),
as already demonstrated by Saba L,
83 years old female; atypical chest pain.
Post-processing virtual unenhanced imaging allows to obtain UH of intramural hematoma similar to non contrast CT scan (Fig.