 Good morning, everyone, myself, Dr. Kashesh Garg, along with my co-authors, Dr. Shiva Ranjan, Dr. Mayur Nath Reddy, and Dr. Vasant CJ from Mahatma Gandhi Medical College at Research Institute is presenting a paper on imaging spectrum of rare abdominal pelvic vascular compression syndromes or multi-detector CT. Introduction. Vascular structures in the abdominal pelvis may be compressed by adjacent anatomical structures. Thus, compression of proximal celiac artery, left common iliac vein, and ureter can occur due to their closed-ratmic relationship to ligaments, bones, and other vascular structures. Such compression can result in variety of uncommon syndromes like median-arquate-ligament syndrome, meternal syndrome, and other forms of ureter compression. This heterogeneous group of disorders are referred as vascular compression syndromes. Aim and objective behind this paper is to criminalize imaging of these compression syndromes on MDCT and the added benefit on MPR-multi-planar reformatation in diagnosis. MDCT imaging of these vascular compression syndromes owing to its high spatial and temporal resolution, multi-planar reformatation imaging not just in societal and coronal planes, but in any defined anatomical plane thereby providing a prospective that is customized to the unique anatomy of the patient. Material and methodology. In this paper, we are going to get familiarized with these three compression syndromes and we will discuss in terms of relevant anatomy, usual clinical presentation, metogenesis, imaging findings, with emphasis on findings of MDCT and other treatment options. Median-arquate-ligament syndrome, also known as Dunbar syndrome. Medial-arquate-ligament is an arch-like fibrous band connecting right and left hemidefrimetic cura at the level of aortic hiatus. Compression of the proximal celiac artery may result in celiac artery compression to its ossiflate origin or if the ligament is abnormally low. Patient may be asymptomatic or may present as post-perendial epigastric pain and weight loss. Finding on contrast-enhanced MDCT focal narrowing of the proximal celiac artery with a characteristic hood appearance. This appearance, along with the absence of atheroesthetic changes in the adjacent aorta and proximal celiac segment, helps to distinguish medial-arquate-ligament syndrome from the atheroesthetic narrowing. In few cases, post-genotic dilatation may be present. This is an example of a 28-year-old male with symptoms of chronic upper abdominal pain, post-perendial nausea, loss of appetite, and weight loss. The first image is a midline sagittal reformatted image from an abdominal CT shows a mild indentation of the diaphragmatic cura on the proximal aspect of the celiac artery. The second and third image is a MIP image and a VR image of the same patient in the mid-sagittal section that shows an indentation or a hooked appearance of the proximal celiac artery. In this image, you can see the post-genotic celiac dilatation, distal to the compression. Coming to the second vascular compression syndrome, that is meternal syndrome, which is also known as cockat syndrome, it results due to obstruction of common iliac vein of left side by the right common iliac artery over the lumbar vertebra. Spethogenesis behind this syndrome is because of the eccentric factor causing physical compression of the left common iliac vein between the right common iliac artery and the underlying vertebral body and the intrinsic factors that result from the formation of internal webs or bands. Clinical presentation of the patient will be left lower extremity swelling, varicose or chronic venous stasis ulcers. On contrast-enhanced MDCT shows the extent of iliofemoral vein thrombocytin helps exclude other causes of venous compression such as pelvic masses. This is a contrast-enhanced venogram of a 45-year-old patient who presented with acute left-lowered extremity pain swelling and screen discoloration following a long-distance flight. In the first image, we see an axial CT venogram image of a pelvis shows a severe compression of the left common iliac vein between the right common iliac artery and the underlying vertebral body. Indicated by the yellow arrow in this image, second image of volume rendered image of abdomen pelvis shows the right common iliac artery and that has a compressive effect of the left common iliac vein. Moving to the third syndrome that is retrocavalurator. The compression of ureter may rarely occur if the ureter has a retrovascular cause. Either it could be a retro iliac or retrocaval. Compression can also occur at the point of intersection of the ureter with retro-paintonal vascular structures. Patient may present with minimal or no symptoms or may have a flank pain or hematuria. On CCT, we can see a medial deviation of the obstructed segment resulting in characteristic reverse j-configuration or proximal hydrourator and hydronephrosis. Findings are best depicted on coronal MPR images. This is in contrast enhanced delayed defrogram phase of a 24 years old male patient. We can see the right kidney shows grade 2 HUN and the dilatation of the proximal ureter. There is acute kinking of the ureter with abrupt decrease in caliber. Considered by the red arrow in this volumetric images, you can see there is an abrupt kinking of the ureter and the proximal ureter appears dilated. It is also known as fish-hooked ureter. At this point, the ureter is noted going behind and crosses to the medial side of the IVC. Diagnosis. Abdominal vascular syndromes, although rare, are relevant because they can often represent diagnostic challenge for the attending physicians. Depending on their ideology, they can be characterized as congenital or compressive. Symptoms resulting from such compression can be nonspecific. If unrecognized and untreated, they can be associated with significant morbidity. Contrast enhanced multi-director CT is the imaging modality of choice for the many of these syndromes owing to its high accuracy in identifying the typical imaging findings and other related disorders. Vascular structures in abdominal and pelvis can compress or be compressed by adjacent anatomical structures over surrounding bony structures. Clinically, patient may be asymptomatic or may result in clinical syndromes that manifest with nonspecific and obstructive symptoms, causing delayed diagnosis. MBCT with isotropic data sets allow reconstruction in various ways of these anatomic structures, however controversy remains as to the true anatomic or physiological mechanism that causes such compression, their relationship with symptoms and the treatment with these syndromes. These are the references for today's paper discussion. Thank you.