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Textbook of

RADIOLOGYAbdomen and Pelvis

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Hariqbal Singh MD DMRDDean and Professor (Radiodiagnosis)

Prakash Institute of Medical Sciences and ResearchUrun Islampur, Sangli, Maharashtra, India

Co-Author

Shailendra Savale DNBConsultant

Department of Radiology Shrimati Kashibai Navale Medical College

Pune, Maharashtra, India

New Delhi | London | Panama

The Health Sciences Publisher

Textbook of

RADIOLOGYAbdomen and Pelvis

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Jaypee Brothers Medical Publishers (P) Ltd.

HeadquartersJaypee Brothers Medical Publishers (P) Ltd. 4838/24, Ansari Road, Daryaganj New Delhi 110 002, India Phone: +91-11-43574357 Fax: +91-11-43574314 E-mail: jaypee@jaypeebrothers.com

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© 2017, Jaypee Brothers Medical Publishers

The views and opinions expressed in this book are solely those of the original contributor(s)/author(s) and do not neces-sarily represent those of editor(s) of the book.All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photo copying, recording or otherwise, without the prior permission in writing of the publishers.All brand names and product names used in this book are trade names, service marks, trademarks or registered trade-marks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book.Medical knowledge and practice change constantly. This book is designed to provide accurate, authoritative informa-tion about the subject matter in question. However, readers are advised to check the most current information available on procedures included and check information from the manufacturer of each product to be administered, to verify the recommended dose, formula, method and duration of administration, adverse effects and contra indications. It is the re-sponsibility of the practitioner to take all appropriate safety precautions. Neither the publisher nor the author(s)/editor(s) assume any liability for any injury and/or damage to persons or property arising from or related to use of material in this book.This book is sold on the understanding that the publisher is not engaged in providing professional medical services. If such advice or services are required, the services of a competent medical professional should be sought.Every effort has been made where necessary to contact holders of copyright to obtain permission to reproduce copyright material. If any has been inadvertently overlooked, the publisher will be pleased to make the necessary arrangements at the first opportunity.

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Textbook of Radiology: Abdomen and Pelvis

First Edition: 2017

ISBN: 978-93-86322-65-4

Printed at

Jayp

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The clinicians involved in research and

unwearied, enduring, tolerant, and serene patients,who place themselves in their handsin pursuit to alleviate their suffering

for restoration of their health

SayingThe one who pervades the Universe also dwells in the body;

whoever seeks, conceives and believes, can achieve as the Almighty has equipped the world once for all

to fulfill our dreams

—Hariqbal Singh

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Abhijit Pawar DNB (Radiology) Associate Professor Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Aditi Dongre MD (Radiology) Assistant Professor Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Amol Sasane MD (Radiology) Associate Professor Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Anand Kamat MD (Radiology) Professor Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Hariqbal Singh MD DMRD Dean and Professor (Radiodiagnosis) Prakash Institute of Medical Sciences and Research Urun Islampur, Sangli, Maharashtra, India

Manisha Hadgaonkar DNB (Radiology) Consultant Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Parvez Sheik DMRE Consultant Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Prashant Naik MD (Radiology) Associate Professor Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Santosh Konde MD (Radiology) Associate Professor Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Shailendra Savale DNB (Radiology) Consultant Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Shrikant Nagare DNB (Radiology) Consultant Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Sikandar Sheikh MD (Radiology) DMR Consultant Department of Radiology and PET-CT Apollo Health City Hyderabad, Andhra Pradesh, India

Sushil Kachewar MD (Radiology) Professor Department of Radiology Rural Medical College Loni, Maharashtra, India

Varsha Rangankar MD (Radiology) Professor Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

Yasmeen Khan DMRE Consultant Department of Radiology Shrimati Kashibai Navale Medical College Pune, Maharashtra, India

CONTRIBUTORS

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PREFACE

Textbook of Radiology: Abdomen and Pelvis provides the students with strength, determination, confidence and this is what matters when the postgraduate students prepare to undertake the examination, not only in radiology, but also for other clinical subjects as, today, radiology occupies the center stage in concluding the diagnosis. It also connects you to the best results in most-trusted format.

This book has been developed with dedication for efficient and organized result orientation, acquired through humility and hard work. It will help the students learn to craft, to achieve the targets and goals to come out with the brightest and strongest version; and to bring them out of mediocrity.

It is very useful for all residents and general practitioners. It is also meant for medical colleges, institutional and departmental libraries.

Hariqbal SinghShailendra Savale

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We thank Shri Nishikant Bhosale Patil (Dada), Founder; and Dr Pramod Kulkarni, Director, Prakash Institute of Medical Sciences and Research, Urun Islampur, Maharashtra, India, for their kind acquiescence in this endeavor.

Our special thanks to the consultants Dharmendra Patil, Pooja Shah and Shripad Kamble, who have facilitated it with their inputs in the book.

We profusely extend our gratefulness to the postgraduate residents, Swati Shah, Vikram Shende, Jarvis Pereira, Prasad Patil, Punit Agrawal, Swapnil Raut, Bhole Priya Raman, Amar Sangapwad, and Prajakta Jagtap, for their genuine help in construction of this instructive entity.

Our appreciation for the computed tomography (CT) and magnetic resonance imaging (MRI) technicians Rahul More, Demello Thomas, Musmade Bala and Raghvendra, for their untiring help in retrieving the data.

We offer our gratitude to Anna Bansode and Sachin Babar, for their clerical help.We are grateful to God and mankind, who have allowed us to have this wonderful experience.

ACKNOWLEDGMENTS

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1. ANATOMY OF ABDOMEN AND PELVIS 1Hariqbal Singh

Anatomy on X-ray 1Abdominal Radiograph 1

Anatomy on CT Scan 3Abdomen and Pelvis 3

Anatomy on Magnetic Resonance Imaging 14Liver 14; Gallbladder 14; Biliary Ducts 14; The Portal Vein 18; Pancreas 18; Spleen 18; Stomach 19; Small Bowel 19; Large Bowel 20; Kidneys 22; Ureter 22; Urinary Bladder 22; Adrenal Gland 23; Abdominal Aorta 23; Coeliac Trunk 23; Superior Mesenteric Artery 24; Inferior Mesenteric Artery 24; Renal Artery 24; Inferior Vena Cava 24; The Male Genital System 24; The Female Genital Organs 45; Male and Female Urethra 46

2. PEDIATRIC ABDOMEN 47Shailendra Savale

Gastrointestinal Tract 47Imaging in a Vomiting Infant 47; Right Iliac Fossa Pain in Children 49; Tracheoesophageal Fistula 50; Small Bowel Atresia 50; Congenital Hypertrophic Pyloric Stenosis 52; Epigastric Hernia 52; Gastroschisis 52; Malrotation 53; Intussusception 53; Mesenteric Cyst 55; Hirschsprung’s Disease 55; Anorectal Malformation 55;Roundworms 57; Trichobezoars 57; Meckel’s Diverticulum 58

Hepatobiliary System 59Hemangioma 59; Pediatric Hepatic Masses 60; Choledochal Cyst 60;Budd-Chiari Syndrome 62; Hydatid Cyst 63; Splenunculus 64

Genitourinary Tract 65Renal Development and Renal Anomalies 65; Horseshoe Kidney 66;Pelviureteric Junction Obstruction 67; Wilms Tumor 68; Obstructive Uropathy 68;Duplex Moiety 70; Retrocaval Ureter 71; Ureterocele 71; Vesicoureteric Reflux 72;Bladder Diverticula 73; Bladder Outlet Obstruction 73; Posterior Urethral Valve 73;Adrenal Hemorrhage 74; Undescended Testicle (Cryptorchidism) 74; Hypoplastic Uterus 75; Müllerian Duct Cyst 75

3. ACUTE ABDOMEN 76Shailendra Savale

Causes of Acute Abdomen 76Infection/Inflammation 77

Acute Appendicitis 77; Acute Pancreatitis 79; Acute Cholecystitis 83;Cholelithiasis and Choledocholithiasis 83; Acute Pyelonephritis 86;Liver Abscess 90; Renal Abscess 90; Intra-abdominal Abscess 91;Abdominal Tuberculosis 91; Epiploic Appendagitis 93;

Urinary Calculus 95Bowel Pathology 97

Small Bowel Obstruction 97; Large Bowel Obstruction and Volvulus 99;Bowel Perforation 99

CONTENTS

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xiv v Textbook of Radiology: Abdomen and Pelvis

Trauma 105Splenic Trauma 105; Liver Trauma 105; Renal Trauma 106;Ureteric Trauma 107; Bladder Trauma 107; Urethral Injury 108;Abdominal Polytrauma 109

Vascular 110Aortic Aneurysm 110; Aortic Dissection 110; Bowel Ischemia 111;Omental Infarction 113

Obstetrical 114Ectopic Pregnancy 114

4. GASTROINTESTINAL TRACT 115Varsha Rangankar, Prashant Naik

Esophagus 115Esophageal Webs and Rings 115; Esophageal Stricture 116; Esophageal Diverticulum 118;Achalasia Cardia 118; Tertiary Contractions 119; Carcinoma Esophagus 119

Stomach 123Upper Gastrointestinal Bleeding 123; Gastric Ulcer 125; Gastric Malignancies 125

Duodenum 129Duodenal Ulcer 129

Bowel 130Enteroclysis 130; Internal Hernias 131; Inflammatory Bowel Diseases 134;Malabsorption Syndrome 135; Lower Gastrointestinal Hemorrhage 136;Necrotizing Enterocolitis 137; Superior Mesenteric Artery Syndrome 138;Right Iliac Fossa Mass 139; Gastrointestinal Lymphoma 144;Carcinoid Tumor 146; Colonic Strictures 147

Anal Canal 149Anal Fissure 149

5. HEPATOBILIARY SYSTEM 150Aditi Dongre, Anand Kamat

Investigations 150Role of CT in Hepatobiliary Diseases 150; Difference between MRCP and ERCP 151

Liver Cirrhosis 152Hepatic Cirrhosis and Portal Hypertension 152

Obstructive Jaundice 153Tumors 155

Classification of Liver Tumors 155; Adenoma 155; Hemangioma 155;Focal Nodular Hyperplasia 155; Hepatocellular Carcinoma 156;Fibrolamellar Carcinoma 157; Liver Metastasis 157; Cystic Liver Tumors 158;Cystic Lesions of Liver 159; Cholangiocarcinoma 161

Interventions in Hepatobiliary Scintigraphy (HBS) 163Interventional Angiography in Liver 163; Interventions in Hepatocellular Carcinoma 164;Interventional Radiology in Biliary System 165

Miscellaneous 168Mirizzi Syndrome 168; Portal Vein Thrombosis 168; Calcifications of Liver 168

6. PANCREAS 169Abhijit Pawar, Amol Sasane

Pancreatic Pathology 169Congenital Conditions 169

Trauma 171Trauma Pancreas 171

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Inflammatory Disorders 172Acute Pancreatitis 172; Acute Edematous Pancreatitis 173; Pancreatic Inflammation with Pseudocyst and Psoas Abscess 173; Pancreatic Duct Calcification 174; Chronic Pancreatitis 174

Pancreatic Tumors 176Imaging Appearances of Carcinoma Head of Pancreas 176;Endocrine Tumors of Pancreas 177; Cystic Tumors of the Pancreas 178

Pancreatic Endosonography 179Normal Anatomy of Pancreas on EUS 179

Pancreatic Interventions 181Ultrasound-guided Interventions in Pancreatic Disease 181

7. RENAL SYSTEM 182Santosh Konde

Infections 182Emphysematous Pyelonephritis 182; Renal Tuberculosis 182; Perinephric Abscess 184

Tumors 185Nephroblastomatosis 185; Angiomyolipoma 185; Classification of Renal Tumors 185;Urothelial Tumors/Transitional Cell Carcinoma 187; Bladder Mass 187

Renal Calculi 189Staghorn Calculus 189; Radiolucent Calculi 189;Extracorporeal Shock Wave Lithotripsy 190

Vascular 191Renovascular Hypertension 191

Others 192Renal Transplant 192; Nephrocalcinosis 192; Papillary Necrosis 192Urinoma 193

8. ADRENALS 194Manisha Hadgaonkar, Yasmeen Khan

Anatomy 194; Evaluation Techniques in Adrenal Diseases 195; Adrenal Masses 196

9. RETROPERITONEUM 199Parvez Sheik

Retroperitoneal Spaces 199; Retroperitoneal Lymphadenopathy 200;Retroperitoneal Fibrosis 200; Retroperitoneal Teratoma 200

10. OBSTETRICS 202Shrikant Nagare

Infertility and Assisted Reproduction 202; USG in First Trimester 203;First Trimester Anomaly Scan 205; Mid-trimester Anomaly Scan 209;Intrauterine Growth Retardation 212; Intrauterine Fetal Demise 214;Biophysical Score 215; Fetal Hydrops 216; Antenatal Ultrasound in Alimentary Tract Lesions 217; Imaging of the Placenta 219;PCPNDT Act 221

11. GYNECOLOGY 224Hariqbal Singh, Sushil Kachewar

Evaluation of Female Infertility 224; Uterine Anomalies 227; Hysterosalpingography 229;Uterine Fibroid 231; Uterine Arterial Embolization 233; Endometriosis 234;Pyometra 235; Endometrial Carcinoma 236; Cervical Incompetence 237;Carcinoma Cervix 238; Ovarian Cysts 242; Ovarian Carcinoma 243

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12. MALE REPRODUCTIVE ORGANS 246Sikandar Sheikh

Male Infertility 246; Erectile Dysfunction 248; Testicular Tortion 249;Trauma Testis 251; Hydrocele 251; Seminoma Testis 252; Carcinoma Prostate 255;Carcinoma Penis 258

APPENDIX 261Normal Radiology Measurements 261

GLOSSARY OF CT AND MRI TERMS 267

Index 271

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9RETROPERITONEUM

Parvez Sheik

Retroperitoneal SpacesIt is the portion of abdomen located behind the peritoneal cavity. Superiorly, it extends up to the diaphragm on either side and inferiorly it extends up to the pelvic brim. MRI imaging is a good modality to look for any pathology in the retroperitoneum, especially involving the spine as well. The retroperitoneum for descriptive purposes has been subdivided into- anterior pararenal space, perirenal space and posterior pararenal space (Fig. 1).

The anterior pararenal space is bounded anteriorly by the parietal peritoneum, posteriorly by the anterior renal fascia and laterally by the lateroconal fasica. The contents of the anterior pararenal fascia are pancreas, portions of duodenum, ascending and descending colon.

The perirenal space lies between the anterior renal fascia anteriorly and posterior renal fascia posteriorly. The contents of the perirenal space are the kidneys, adrenals, renal vessels at hilum, retroperitoneal fat and lymph nodes. Medially the perirenal spaces

communicate with each other through a narrow prevertebral space; here the abdominal aorta and inferior vena cava (IVC) are located. The fatty connective tissue found in the perirenal space is interdivided by thin strands of fibrous tissue, this helps in preventing the spread of any pathology to other retroperitoneal spaces.

The posterior pararenal space is located posterior to the posterior renal fascia. Contents of this posterior pararenal space are fatty connective tissue. The posterior pararenal space extends laterally tapering gradually towards the anterior abdomen.

The psoas space is a potential space located just medial to the posterior pararenal space adjacent to the psoas muscle.

The retroperitoneal spaces communicate freely with each other inferiorly at the pelvic brim. Any pathology from the pelvis can track upwards in any of the retroperitoneal spaces.

The Figure 1 illustrates the modified tricompart-ment model of fascial planes and spaces of the retro-peritoneum, the perirenal fascia is laminar and variably fused and there are interfascial connections between the spaces. The retromesenteric plane (RMP), retrorenal space (RRS), and lateroconal space are potential interfascial communications. Perinephric septa run between the renal capsule and the perinephric fascia, allowing subcapsular fluid to communicate with the retrorenal space or retromesenteric plane.

Localization of retroperitoneal fluid within one of the retroperitoneal spaces can sometimes be difficult. On MR the anterior pararenal space, posterior pararenal space and lateroconal fascia as not seen distinctly are different layers but are seen as multilayered structures.

Pericaval fat can be identified on T1WI MR images, closely related to the intrahepatic portion of IVC. MR can easily distinguish between lymph nodes and flowing blood on T1WI and T2WI spin echo technique because flowing blood emits no signal. Normal retroperitoneal lymph nodes show signal intensity slightly lower than the adjacent retroperitoneal fat on T1W images. On T2W images the retroperitoneal lymph nodes show signal intensity almost similar to retroperitoneal fat.

Fig. 1 Diagrammatic illustration of retroperitoneal spaces. 1. Anterior pararenal space, 2. Retromesenteric plane, 3. Perirenal space, 4. Retrorenal space and 5. Posterior pararenal space

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Detection of lymph node metastasis is done by injecting iron oxide contrast agents. Normal retroperitoneal lymph node takes up the iron oxide contrast and shows low signal intensity on T2W images but those retroperitoneal lymph nodes which contain metastasis do not take up the iron oxide contrast and give a heterogeneous signal on T2W images.

Retroperitoneal LymphadenopathyThe retroperitoneal (or lumbar) lymph nodes are the regional lymph nodes for the organs of the retro-peritoneal space, and also for the testes, ovaries, fallopian tubes, and uterus (which are embryologically derived from the retroperitoneum). The retroperitoneal nodes are divided by the aorta and inferior vena cava into three groups: those lying to the left of the aorta (left para-aortic or left lumbar group), those lying between the aorta and inferior vena cava (interaortocaval or intermediate lumbar group), and those lying to the right of the inferior vena cava (right paracaval or right lumbar group). Lymph nodes are abnormal when they are enlarged in size (> 10 mm in diameter in short axis), increased in number, or characterized by aberrant internal architecture. Enlarged retroperitoneal lymph nodes may be seen in the malignancy, neoplasia or inflammatory reaction. CT is the best modality for imaging retroperitoneal lymphadenopathy (Fig. 2). Abnormal nodes must be distinguished from bowel loops, left-sided inferior vena cava, retroaortic or circumaortic renal vein, dilated normal veins, diaphragmatic crus, retroperitoneal hemorrhage and retroperitoneal fibrosis. Oral and intravenous contrast agents are extremely helpful and sometimes vital in diagnosing lymphadenopathy. In areas difficult to image by CT, such as the diaphragmatic region, MR is often of value. Abnormal nodes may occur singly or in clusters. An abnormal number of normal-sized nodes

are seen in patients with lymphoproliferative disease. Lymphadenopathy is usually of soft tissue density. However, attenuation values are variable, including negative values in lipoplastic lymphadenopathy, near fluid density in necrotic lymphadenopathy, or high attenuation (up to 120 Hounsfield units (HU) in patients with Hodgkins disease or metastases from breast or ovarian carcinoma. Calcification occurs following chemotherapy and in nodal metastases from testicular carcinoma. A normal CT scan does not exclude the possibility of lymphadenopathy, as foci of metastatic disease may be present in a normal-sized node. PET-CT is more specific in metastatic lymphadenopathy. MR may provide additional information. Nodes harbouring fibrotic tissue after chemotherapy or radiation are hypointense on T2-weighted images, while those bearing tumor are hyperintense. MR is excellent for distinguishing vessels from nodes, as flow voids are seen in vascular structures. Lymphangiography is more sensitive at depicting abnormalities in internal architecture, but it is performed with decreasing frequency given the patient discomfort it causes. Lymphangiography is also limited in the evaluation of pelvic lymphadenopathy, given the deep drainage patterns of the pelvic nodes.

Retroperitoneal FibrosisRetroperitoneal fibrosis is the proliferation of fibrous tissue in retroperitoneum in midline and para-aortic distribution.

In 70% of cases it is idiopathic. In Ormand’s disease it is associated with fibrous pseudotumor of orbit, Riedel’s thyroiditis, mediastinal fibrosis and sclerosing cholangitis. The other causes include drugs (methysergide), surgery, irradiation, aortic hemorrhage, atherosclerosis, appendicitis, infections like tuberculosis, histoplasmosis, actinomycosis and malignancies.

It is more common in male than female in 40–60 years age group. The clinical features are nonspecific like fever and backache.

The imaging modalities include intravenous urography, ultrasound and CT.

Intravenous urography shows hydronephrosis with tapering of ureters which may be bilateral or unilateral.

Ultrasound shows ill defined, hypoechoic peria-ortic mass.

Infrarenal, para-aortic soft tissue encasing aorta, inferior vena cava and ureter is seen in CT. The soft tissue shows contrast enhancement in early stage while no contrast enhancement is seen in later stage.

Retroperitoneal TeratomaRetroperitoneal cystic masses, arising within the retroperitoneal space but outside the major

Fig. 2 Coronal reconstruction CT shows multiple, enlarged, calcified retroperitoneal lymph nodes (arrow)

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organs within that compartment, are uncommon. Retroperitoneal cystic teratomas are cystic tumors composed of well-differentiated derivations from at least two of the three germ layers (ectoderm, mesoderm, and endoderm). It is more common in females and the tumor is commonly diagnosed in newborns that are usually asymptomatic. A cystic teratoma is likely to be benign, whereas a solid teratoma is likely to be malignant. At CT, a mature teratoma of the retroperitoneum manifests as a complex mass containing a well-circumscribed fluid

component, fatty tissue, and calcification (Figs 3 and 4). The presence of hypo-attenuating fat within the cyst is considered highly suggestive of cystic teratoma and with the presence of calcifications in the cyst wall; cystic teratoma is even more likely.

Cystic lesions of the retroperitoneum can be either neoplastic or non-neoplastic. Neoplastic lesions include cystic lymphangioma, mucinous cyst- adenoma, cystic teratoma, cystic mesothelioma, Müllerian cyst, epidermoid cyst, tailgut cyst, cystic change in solid neoplasms, pseudomyxoma retro-peritonei, and perianal mucinous carcinoma. Non-neoplastic lesions include pancreatic pseudocyst, nonpancreatic pseudocyst, lymphocele, urinoma, and hematoma.

Because the clinical implications of therapeutic strategies for retroperitoneal cystic masses vary depending on the cause, the ability to noninvasively differentiate between masses is important. Although, there is substantial overlap of computed tomographic (CT) findings in various retroperitoneal cysts, some CT features, along with clinical characteristics, may suggest a specific diagnosis. CT may provide important information regarding lesion location, size, and shape; the presence and thickness of a wall; the presence of septa, calcifications, or fat; and involvement of adjacent structures. The most important clinical parameters include patient gender, age, symptoms, and clinical history. Familiarity with the CT and clinical features of various retroperitoneal cystic masses facilitates accurate diagnosis and treatment.

Figs 4A to F (A) Plain CT image shows dense calcification; (B) Plain CT images shows large cystic lesion with fat attenuation component; (C) Contrast-enhanced CT image shows solid component posterior to the spleen; (D) Contrast-enhanced CT image shows cystic lesion with fat component in posterior relation to the spleen which is displaced anteriorly; (E) Contrast-enhanced CT image shows multiple septae within the cystic lesion; (F) Contrast-enhanced CT image shows displacement of the bowel loops anteriorly and to right side

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D

B

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Fig. 3 Scout image showing large mass in left side of the abdomen