Focus Diagnostics

ABDOMEN AND PELVIS


			Neuro Endocrine Lesions in pancreas A, B - Mono energetic image & poor lesion delineation C, D - DE CT Iodine image, Showing better delineation of the lesion

			(a) Axial mixed CT image shows low-attenuation wall thickening in the gastric antrum and pylorus (arrow). (b) Axial virtual nonenhanced CT image was created by subtraction of the calculated iodine content. (c) Axial iodine map image displays the iodine content in color. (d) Axial iodine overlay image superimposes the color iodine map on the gray-scale virtual nonenhanced image. A dualenergy region of interest in the thickened gastric wall (blue circle) shows no iodine content in comparison to an adjacent small bowel loop (yellow circle) with attenuation of 78 HU and calculated iodine density of 1.5 mg/mL. The gastric wall finding is consistent with edema.

			Small bowel lymphoma in a patient with a known history of lymphoma. (a) Axial contrast-enhanced mixed CT image shows an enhancing nodule (arrow). (b) Coronal iodine overlay image shows sma l l b o w e l o b s t r u c t i o n , w i t h imp r o v e d conspicuity of the enhancing nodule at the transition point (arrow).




	Acute appendicitis. (a) Axial contrast-enhanced mixed CT image shows a fiuid-filled appendix with a hyperemic wall (arrow), a finding that represents acute appendicitis. (b) Axial iodine overlay image highlights iodine content in the hyperemic wall of the appendix (arrow).



	Diverticulitis. (a) Axial contrast-enhanced mixed CT image shows localized sigmoid colon wall thickening (arrow) with surrounding fat stranding and fascial thickening. (b) Axial iodine overlay image shows iodine content in the thickened wall (arrow), as well as surrounding inflamed fat.



	Clostridium difficile colitis. (a) Coronal contrast-enhanced mixed CT image shows wall thickening throughout the colon, with enhancing mucosa and prominent vasa recta (arrows) representing C difficile pancolitis. (b) Coronal iodine overlay image highlights increased enhancement in the mucosa and vasa recta (arrows). (14) In a patient with ulcerative colitis, axial contrast-enhanced mixed CT image (a) shows bowel wall thickening and mucosal enhancement (arrow), findings that are more conspicuous on an iodine overlay image (b).


	Image A - Arterio portal phase showing segment 6 mass lesion. Image B - Iodine map shows quantity of iodine and fat fraction. Image C - Contrast washout in the lesion. Image D - Iodine quantication and fat fraction - Hepato cellular carcinoma Post lithotripsy with right DJ Stent. Residual calculus in the kidney and adjacent to the stent in the lower ureter. The demonstration of the stone type

NEUROLOGY


			DECT in a patient presenting with headache demonstrates indeterminate focal hyperdensity in the pons. On Material decomposition maps the hyperdensity was calcium and not hemorrhage. Based on the presence of calcium, this was a cavernous malformation rather than a hypertensive hemorrhage. Although both entities commonly occur in this location, DECT could distinguish the 2 based on energy-dependent attenuation.

DECT in a patient presenting with headache demonstrates indeterminate focal hyperdensity in the pons. On Material decomposition maps the hyperdensity was calcium and not hemorrhage. Based on the presence of calcium, this was a cavernous malformation rather than a hypertensive hemorrhage. Although both entities commonly occur in this location, DECT could distinguish the 2 based on energy-dependent attenuation.


					Routine noncontrast head demonstrates hyperdensity in a right temporo-parietal mass. That could represent hemorrhage (A). DECT performed after administration of contrast demonstrates enhancement around the periphery of the mass on simulated 120-kVp image (B). Material decomposition accurately maps iodinated contrast enhancement onto the iodine overlay image (C), whereas tumoral hemorrhage maps onto the virtual noniodine image (D).

DE CT image demonstrate an intraparenchymal hematoma within the left basal ganglia and insula with active extravasation of iodinated contrast. The iodinated contrast is successfully subtracted on the VNC image (B). In addition, the iodine map can be used as iodine overlay on the weightedaverage dual-energy images (C) to differentiate iodine from dense hemorrhage.



	Brain CT angiography, metallic coil artifact (Image A) The coils are completely removed & improved delineation of the parent artery on DECT Angiogram (Image B)

	Sudden loss of vision in right eye:

	Angiogram findings inconclusive (Image A)

	Iodine uptake images show no iodine in the right optic nerve Sudden loss of vision in right eye:
	------ Central retinal artery occlusion (Image B & C))

ORTHOPEDICS AND RHEUMATOLOGY


	Three-dimensional volume-rendered CT images of gout (green) in a 56-year-old man



Three-dimensional volume-rendered CT images of left Hip Prosthesis. No Artifacts.




	Left hip prosthesis evaluation. No artifacts.



RIB Analysis (360 )

CT Angio C left hip prosthesis. No artifacts


THORAX
SPN. (A) Lung window settings image shows an irregular right upper lobe nodule (arrow). (B) Color-coded Iodine map image shows contrast enhancement (arrow). Biopsy reveled lung adenocarcinoma.

Moderately differentiated lung adenocarcinoma. (A) Lung window settings image shows a wellcircumscribed right middle lobe nodule (arrow). (B) 100/Sn140 kVp image with color-coded iodine map overlay shows iodine uptake (arrow). Lung nodule application software showed 3D-IRA of 34 HU. (C) Fused PET/CT image demonstrates FDG avidity (SUVmax 3.8) (arrow). 3D-IRA is associated with the degree of differentiation in primary lung cancers. Good correlation has been demonstrated between iodine uptake on DECT and metabolic activity on PET/CT

Assessment of response to concurrent chemoradiation therapy in a patient with squamous cell carcinoma. A
persistent right upper lobe paramediastinal soft tissue mass (arrows) raised concern for residual viable tumor.
(A) 100/Sn140 and (B) iodine map overly images show low level of iodine enhancement in the tumor (2.6 HU),
suggesting response to the therapy. (C) PET/CT image shows concordant low FDG uptake (SUV max 3.5,
previously 20.3 before treatment). Biopsy showed absence of viable tumor.


UROLOGY
Post lithotripsy with right DJ Stent. Residual calculus in the kidney and adjacent to the stent in the lower ureter. The demonstration of the stone type.

Soft-tissue mass. (image a & b) Iodine-density image showing heterogenous mass (Image c) Virtual non contrast image showing hyperdense mass. (image d) Color-coded iodine overlay image shows large iodine-containing regions (red pixels) within the lesion, findings suggestive of an enhancing solid mass.

Renal cyst. (a & b) contrast-enhanced dual-energy CT shows a 1.5-cm homogeneous lesion with attenuation of 65 HU (arrow) in the left kidney. (c) On the water-density image the lesion has density higher than that of adjacent renal parenchyma, (d) Color-coded iodine overlay image shows a lack of enhancement (absence of red pixels representing iodine) within the lesion.



	Bladder carcinoma with prostate metastases in a 66-year-old man. (a, b) Contrast-enhanced CT images obtained at the level of the base of the bladder show an enhancing mass involving the bladder wall with possible extension outside the wall. (c & d) Material-specific iodine CT image better shows the mass, which extends beyond the bladder wall (arrow) and prostate gland deposit.

VASCULAR

Varicose veins of the calf with the deep veins and communicating branches.

Extensive Calcific Arteriosclerosis. (Image A)
Calcium removal with demonstration of the
lumen (Image B)

Neck CT angiography, severe calcification degrades luminal delineation of the right internal
carotid artery (Image A). Calcification is removed in image B for luminal delineation

DE CT Angiogram in a patient with left Hip Prosthesis (Image A).
No Artifacts.
Image B Calcium and Prosthetic removal with demonstration of the lumen.

DE CT Angiogram of Femoral Artery demonstrating soft plaque (arrow mark)

Left ventricle Analysis

ABDOMEN AND PELVIS

Neuro Endocrine Lesions in pancreas A, B - Mono energetic image & poor lesion delineation

C, D - DE CT Iodine image, Showing better delineation of the lesion

Acute appendicitis. (a) Axial contrast-enhanced mixed CT image shows a fiuid-filled appendix with a hyperemic wall (arrow), a finding that represents acute appendicitis. (b) Axial iodine overlay image highlights iodine content in the hyperemic wall of the appendix (arrow).

Diverticulitis. (a) Axial contrast-enhanced mixed CT image shows localized sigmoid colon wall thickening (arrow) with surrounding fat stranding and fascial thickening. (b) Axial iodine overlay image shows iodine content in the thickened wall (arrow), as well as surrounding inflamed fat.

NEUROLOGY

Sudden loss of vision in right eye:

Angiogram findings inconclusive (Image A)

Iodine uptake images show no iodine in the right optic nerve Sudden loss of vision in right eye:

------ Central retinal artery occlusion (Image B & C))

ORTHOPEDICS AND RHEUMATOLOGY

THORAX

UROLOGY

VASCULAR