16.3 ) CT Used for staging, looking for lymphadenopathy and metastases. Spread is primarily lympha tic to the retroperitoneal aorto-caval nodes, consistent with the embryological origin of t he testis. Mediastinal nodes are seen in more advanced disease. Hematological spread is mos t commonly to the lungs and more rarely to brain, bone, liver, and other abdominal viscera. FDG PET scanning may have a future role in determining residual disease sites to direct th e need for further treatment but it is not used routinely at present. MRI Not used routinely in the diagnosis or staging of testicular cancer but is useful in de tecting cryptorchidism when ultrasound has failed to localize. It offers a wide \201 eld of view from mid abdomen through the inguinal canal into the scrotum. SUBASH KC/NMC-15TH/2014 TESTICULAR CANCER 221 Information for the radiologist Presence of a lump, relevant past history. Fig. 16.3 the testis in a patient with multifocal germ cell tumors. Testicular ultrasound showing multifocal low echogenicity lesion within SUBASH KC/NMC-15TH/2014 222 CHAPTER 16 Genitourinary conditions Prostate cancer \200 2 \200 Risk factors: age > 50 years, genetic predisposition, famil ial/racial nd leading cause of cancer deaths in males in UK. preponderance Afro-Caribbean > Caucasian > Asian. Distinction made between clinical prostate cancer and microscopic, up to 30 % men > 50 years thought to harbor the disease, most of which will never become appar ent. Clinical presentation Symptoms of prostatism, haematuria, urinary obstruction, or metastati c disease; however, an increasing number present with an abnormal digital rectal examinatio n (DRE) or an elevated prostate speci \201 c antigen (PSA). PSA screening is not performed in the UK at present but has gained popu- larity in the USA and some of Europe. TNM staging \200 T1a: on histology only from a TURP malignancy in <5 % of sample. \200 T1b: on histology only from a TURP malignancy in > 5 % of sample. \200 T1c: identi \201 ed on histology from a TRUS biopsy sample. \200 T2a: less than half of one lobe (DRE or i maging). \200 T2b: more than half of one lobe (DRE or imaging). \200 T2c: involves both lobes (DRE or imaging). \200 T3a: extra-capsular extension. \200 T3b: extra-capsular e xtension involves the seminal vesicles. \200 T4: invades local structures other than semi nal vesicles. \200 N1: one or more regional nodes involved. \200 M1a: distant (outside the pelvis) lymph nodes involved. \200 M1b: bone metastases. \200 M1c: non-bone metasta ses. Imaging Plain \201 lm and bone scintigraphy Useful to determine the presence of bone meta stases. Often sclerotic on plain \201 lm. \200\230Hot \200\231 osteoblastic reaction is seen on bone scanning. Request if symptomatic or PSA markedly elevated. Ultrasound: trans-rectal ultrasound guided biopsy (TRUS) The accepted method of obtaining t issue for diagnosis in patients with a raised PSA and suspicion of prostate cancer. Non-tar geted \200\230random \200\231 samples are aimed at the peripheral zone of the gland, due t o the known preponderance of disease here ( > 70 % ). CT Staging CT advised if PSA > 20, T \211 3, Gleason grade suggest metastatic spread. Loo king for upper tract obstruction, lymphad- enopathy, and metastases. \211 8 or symptoms SUBASH KC/NMC-15TH/2014 PROSTATE CANCER 223 MRI (Fig. Used for local staging to predict spread through the prostatic capsule \200\224 important to determine operative or conservative management. It can predict lymph node invo lvement and bone metastases but is limited by the \201 eld of view. Some centers advocate full spinal acquisitions to stage for bone metastases in clinical/biochemically appropriat e cases. 16.4 ) Information for the radiologist PSA level and presence of symptoms suggestive of metastases . Fig. 16.4 the peripheral aspect of the right prostate (arrow). The posterior margin of the prostate is blurred, in keeping with early T3 disease. Axial MRI showing a bulky prostate, with a low signal intensity area within SUBASH KC/NMC-15TH/2014 224 CHAPTER 16 Genitourinary conditions Cervical cancer \200 3 rd most common malignancy worldwide, average age at diagnosis is 50 years. 90 % squamous carcinomas, from squamocolumnar junction; 10 adenocarcinomas/adenosquamous ca rcinomas, arising from glandular elements within the endocervical canal. % Clinical presentation Vaginal bleeding or discharge. Pain suggests more advanced disease. M ay be asymptomatic if screen detected. ) Staging (see Table 16.1 Table 16.1 Staging of cervical cancer FIGO stage MRI features 0: carcinoma in situ Normal IA: microscopic invasive Normal IB1: clinically visible tumor <4cm Intermediate signal tumor on T2-weighted imaging replaces dark cervical stroma. An intact s tromal ring around tumor indicates tumor con \201 ned to cervix IB2: clinically visible tumor > 4cm IIA: invasion of tumor to upper 2/3 vagina, no parametrial invasion Loss of integrity of low signal vaginal wall on T2-weighted sequences IIB: parametrial invasion but not to pelvic side wall Dark cervical stromal ring completely replaced by intermediate signal tumor IIIA: tumor extends to lower 1/3 vagina, not to pelvic side wall Disruption of the vaginal wall extends to the lower 1/3 IIIB: extension to pelvic side wall or hydronephrosis Tumor extends to within 1cm of the pelvic side walls or there is ureteric dilatation due to obstruction from the tumor IVA: bladder or rectal mucosa invaded by tumor Bladder or rectal wall on T2-weighted images is breached IVB: distant metastases Tumor outside the true pelvis Imaging Preoperative staging to determine the size and extent of tumor, lymph node status a nd presence of distant metastases. SUBASH KC/NMC-15TH/2014 CERVICAL CANCER 225 Ultrasound Transrectal transvaginal scanning may determine tumor size and extent. The li mited \201 eld of view reduces assessment of bulky tumors and lymph nodes. CT Useful in advanced disease but not accurate in staging early stage tumors. Assessment of local complications, e.g. hydronephrosis, lymphadenopathy, and detection of distant metast ases. MRI (Fig. Most accurate staging method preoperatively, determining tumor size, volume, exte nt, and nodal status with an overall accuracy of 86 \200\22390 also useful to monitor treat ment response. 16.5 ) % . It is FDG-PET Main advantage is in detection of lymph node metastases in the pelvis and retroperi toneum. It is also useful in the detection of recurrence of cervical tumor. Information for the radiologist Accurate clinical and EUA \201 ndings. Fig. 16.5 a patient with a tumor of the cervix. Sagittal MRI showing exophytic tumor (arrow) arising from the cervix, in SUBASH KC/NMC-15TH/2014 226 CHAPTER 16 Genitourinary conditions Endometrial cancer \200 One of the most common female pelvic malignancies, usually adenocarcinoma. Less common histological types include serous papillary carcinoma, clear ce ll carcinoma and undifferentiated carcinoma, which are more aggressive. Predominantly occurs in postmenopausal women. \200 Risk factors: hypertension, obesity, d iabetes mellitus, late menopause, long-term tamoxifen treatment for breast cancer, a personal or family history of breast or ovarian cancer, and a family history of endometrial or breast cancer, hereditary non-polypo sis colorectal cancer. Clinical presentation Postmenopausal vaginal bleeding or vaginal discharge. Staging (see Table 16.2 ) Table 16.2 Staging of endometrial cancer FIGO stage MRI features IA: con \201 ned to endometrium Junctional zone intact, smooth interface between endometrium and myometrium IB: <50 % invasion into myometrium Tumor signal extends into super \201 cial myometrium. Irregular interface between endometr ium and myometrium IC: > 50 % invasion into myometrum Tumor signal intensity extends into outer half of myometrium. Serosal surface of myometrium maintained IIA: extension into endocervix Tumor signal extends into internal os and widens endocervical canal. Cervical stroma intact IIB: cervical stromal invasion Dark signal of cervical stroma interrupted by hyperintense tumor signal IIIA: spread outside uterus into adnexa Serosal surface disrupted, direct extension into ovaries or discrete ovarian metastases IIIB: vaginal involvement Dark T2-weighted signal of vaginal wall invaded by hyperintense tumor IIIC: lymph node involvement LN metastases suggested if morphological features such as altered signal of LN, irregular m argins, extension outside LN capsule > 1cm in short axis. Also IVA: bladder or rectum involvement Loss of T2-weighted dark signal of walls of bladder and rectum IVB Distant metastases Imaging Ultrasound (Fig. TV ultrasound is the \201 rst-line test. Look for: \200 Endome trial thickness of > 4mm: detects 95 % of endometrial carcinoma 16.6 ) (may be thicker if on hormone replacement therapy/tamoxifen). Abnormal endometrium is heterogeneous, hyperechoic, and irregular. SUBASH KC/NMC-15TH/2014 ENDOMETRIAL CANCER 227 If there is bleeding, a biopsy is required if the endometrial thickness measures > 4mm. Endometrial thickness > 8mm: with or without bleeding requires biopsy. \200 Hysterosonogr aphy is a useful adjunct to conventional TV ultrasound, although not widely available. 5ml saline is introduced into the uterine cavity using a catheter, this helps the TV ultrasound to delineate causes such as submucosal myomas or polyps. CT May demonstrate pelvic disease and para-aortic lymph node involvement. Not good at local staging. MRI Used to locally stage endometrial carcinoma pre-operatively, looking for disruption of normal zonal anatomy and to plan treatment. Information for the radiologist Any salient clinical \201 ndings and tumor grade and hist ology if known. Fig. 16.6 bulky mass arising from the endometrium of the upper uterus. This was found to be endometrial adenocarcinoma at histopathology, following hysterectomy. Sagittal T2-weighted image through the midline of the pelvis, showing a SUBASH KC/NMC-15TH/2014 228 CHAPTER 16 Genitourinary conditions Ovarian masses There is a broad spectrum of masses, ranging from physiological cysts to mal ignant tumors. It is beyond the scope of this chapter to detail every ovarian mass. Instead the broad concepts of imaging and characterization will be described. (See also b Ovarian cancer, p. 230.) Clinical presentation Depends on the underlying pathology. Abdominal pain may be a presenti ng feature if there has been an acute event, such as hemorrhage into a cyst. Ovarian cancer tends to present late with abdominal distention. Imaging \200 Con \201 rm the presence and characteristics of a pelvic mass and determine its organ of origin. In cases of malignant tumors, imaging is used for: Preoperative staging. \200 Assessment of response to treatment. \200 Detection of recur rence in the context of clinical deterioration or worsening tumor markers. Guiding percutaneous biopsies/aspiration of ascites. Ultrasound First-line investigation. There is much overlap between benign and malig- nant t umors, although certain features may suggest a particular tumor type. It may be necessary t o repeat an ultrasound after a 6-week interval to establish whether the ovarian mass identi \201 ed is physiological and potentially will resolve. CT (Fig. May detect incidental ovarian masses, due to the widespread use of this modality. Cysts associated with the ovary that are > 3.5cm should be followed up with ultrasound in 6 weeks to ensure resolution. 16.7 ) MRI Provides excellent tissue contrast and high spatial resolution. MRI may be used if the mass: \200 Is large ( > 10cm). \200 Is complex or indeterminate on ultrasound. MRI can accurately determine malignant from benign features, e.g.: \200 Intralesional fat in keeping with a teratoma. \200 Altered blood in an endometrioma. \200 Fibrous tissue, observed in ovari an \201 bromas or brenners tumors. Information for the radiologist History and examination, tumor markers such as CA-125. SUBASH KC/NMC-15TH/2014 OVARIAN MASSES 229 Fig. 16.7 Axial CT showing a mixed attenuation mass within the left adnexa. This contains f at (dark) and calci \201 ed teeth (arrow) in keeping with a dermoid tumor. SUBASH KC/NMC-15TH/2014 230 CHAPTER 16 Genitourinary conditions Ovarian cancer \200 5 \200 > 90 % epithelial, arising from epithelium ovary/tube. Rarer types include th leading cause of death from cancer in women. germ cell tumor or sex cord/stromal tumors. Risk increases with age and decreases with pregnancy. Associated with BRCA1 and BRCA2 gene mutations. Clinical presentation Often non-speci \201 c symptoms, such as abdominal pain, mass, bloat ing. Late presentations include leg oedema due to pelvic vein pressures from pelvic mass. A ssociated with raised CA-125. Imaging Ultrasound (Fig. First-line investigation to assess the ovaries. Ultrasound \201 ndings suggestive of a malignant tumor: \200 Ovarian cyst > 10cm. \200 Thick internal s epta > 3mm. \200 Solid component in a cystic mass. \200 Color Doppler \202 ow in the solid elements. \200 Presence of ascites. \200 Presence of peritoneal nodules. 16.8a ) CT (Fig. CT features suggestive of a malignant ovarian tumor include: \200 The presence o f bilateral adnexal masses. \200 Mixed solid and cystic components. \200 Enhancement of solid components after IV contrast. \200 Necrosis in a solid tumor. \200 Irregular, th ick septae > 3mm within a cystic mass. \200 Papillary nodules within a cystic mass. \200 Presence of lymphadenopathy. \200 Invasion into other pelvic organs. \200 Ascites. \200 Serosal or peritoneal deposits. 16.8b ) MRI The following MR features are suggestive of malignancy: \200 The presence of solid co mponents that have early strong uptake of gadolinium. Papillary projections: one of the most signi \201 cant indicators of malignancy. \200 Se condary malignant features such as ascites, invasion of pelvic organs, and enlarged lymph nodes. Information for the radiologist History and clinical examination \201 ndings, tumor marke rs. SUBASH KC/NMC-15TH/2014 OVARIAN CANCER 231 (a) (b) Fig. 16.8 CA-125. The cyst contains a mural nodule (arrows) and debris. This was an ovarian cancer. b) Axial CT in a patient with bilateral adnexal masses (not shown). The CT shows a scites, and a thick \200\230cake \200\231 of omental disease (arrow). This was due to adva nced ovarian cancer. a) Ultrasound showing complex ovarian cyst in a patient with raised SUBASH KC/NMC-15TH/2014 232 CHAPTER 16 Genitourinary conditions Adrenal masses \200 Common incidental \201 nding 81 % of abdominal CT exams. \200 Non -functioning lesions are benign or malignant. Benign lesions include adenoma, myelolipoma, and hemorrhage. Malignant lesions may be primary or secondary. Functi oning adrenal tumors may be: \200 Aldosterone secreting tumor. \200 Phaeochromocytoma. \200 Cushing \200\231s syndrome. Clinical presentation Majority asymptomatic. Metastatic lesions may be discovered as part o f a staging scan. Commonest metastasis to the adrenal glands is from lung cancer followed b y breast in women and renal cell carcinoma in men, but even in patients with known cancer, an adrenal lesion found on imaging has only a 26 \200\22337 % chance of malignancy. 1 Phaeochromocytoma presents with headache, sweating, \202 ushing, and palpitations, and are bilateral <10 % cases. Imaging The most important distinction for the radiologist to make is whether the lesion ca n be considered incidental and benign or whether further investigation is needed. Plain \201 lm Adrenal calci \201 cation is a relatively common phenomenon with causes in cluding: carcinoma, adenoma, neuroblastoma, phaeochromocytoma, infection such as TB or prev ious hemorrhage. CT (Fig. Size is a useful indicator. As a general rule lesions > 3cm are more likely to be malignant than those <3cm. Attenuation of the lesion is prob- ably the most useful characte ristic. Low attenuation lesions <10HU are usually benign, lesions following IV contrast are also helpful. 16.9a ) > 10HU are indeterminate. Washout characteristics MRI (Fig. MRI is often used to clarify the nature of an adrenal lesion seen on CT. The majo r distinction is whether or not the lesions contain fat, as this is an indicator of benigni ty. 16.9b ) PET A standardized uptake value (SUV) of > 4 is indicative of metastatic disease. Information for the radiologist Any symptoms or history of malignancy. Reference 1 Boland MA , GW , Goldberg Lee MJ , et al. Indeterminate adrenal mass in patients with cancer: Evaluation at PET with 2-(F-18)- \202 ouro-2 deoxy-D glucose . Radiology \200\223 4 . 1995 ; 194 : 131 SUBASH KC/NMC-15TH/2014 ADRENAL MASSES 233 (a) (b) Fig. 16.9 a) Non-enhanced axial CT showing fat attenuation nodule within the left adrenal g land, in keeping with a lipid-rich adenoma. b) Coronal MRI showing enhancing, solid mass ar ising from the left adrenal gland (arrow) found to be a phaeochromocytoma. SUBASH KC/NMC-15TH/2014 234 CHAPTER 16 Genitourinary conditions Benign renal masses Often an incidental \201 nding. Role of the radiologist is to decide if the lesion is benign, requires follow-up, or is malignant. Clinical presentation Asymptomatic or local symptoms such as \202 ank pain or retroperito neal hemorrhage. Cysts Described using the Bosniak classi \201 cation system. Class I and II cysts are best imaged with ultrasound, CT is to be used as a problem solver, and MRI to follow-up more co mplex cases. \200 Bosniak class 1 cysts: referred to as \200\230simple cysts \200\231: thin wall, near water density. Often multiple, usually of no consequence unless associated with polycystic kidney disease. Bosniak class 2 cysts : this group contains: non-enhancing hyperdense cysts (haemorrhagic) <3cm, cysts with a single thin septation or cysts with a thin layer of calci \201 cation in the wall. They are benign and do not need follow-up. Bosniak class 2F cysts : \200\230F \200\231 for follow-up. Contain > 1 of the features of class 2 cysts or numerous septa, also hyperdense cysts > 3cm. Bosniak class 3 cysts : indeterminate lesions \200\224 cysts with evidence of wall thickening, mild nodularity, coarse calci \201 cation, septal enhancement. Require conside ration for surgical resection. Bosniak class 4 cysts : cystic carcinoma. Enhancing thick wall with soft tissue components. Enhancement generally considered as an increase in attenuation of > 10 H ouns \201 eld (CT density) units after contrast. Managed surgically. Angiomyolipoma (renal hamartoma) Contain fat, blood vessels, and connective tissue. If > 4c m have increased risk of retroperitoneal hemorrhage. Usually appear bright on ultrasound. C an be safely diagnosed on CT (thin slice) and MR scanning (T1 and opposed phase) by demonst rating fat within the lesion. Abscess Can extend into the retroperitoneum. CT gives best demonstration of size and extent . Imaging Start with ultrasound, use cross-sectional imaging (CT) as a problem solver (Fig. 1 6.10 ). Consider radiation dose if lesions are to be followed up. MRI can help in complex c ases and is ideal for following-up patients with multiple lesions at risk of malignant tran sformation such as in Von-Hippel \200\223Lindau syndrome. SUBASH KC/NMC-15TH/2014 BENIGN RENAL MASSES 235 Coronal CT in a patient with right-sided angiomyolipoma (arrows). Fig. 16.10 The CT shows a mass containing fatty (dark) and soft tissue elements (lighter septations). In view of its large size, this was embolized. SUBASH KC/NMC-15TH/2014 236 CHAPTER 16 Genitourinary conditions Pyelonephrosis Any condition affecting the renal pelvis; however, often used interchange- a bly with acute pyelonephritis which is a clinical diagnosis. Chronic pyelonephritis is typi cally atrophic kidneys following repeated infection/ obstruction, usually related to vesico -ureteric re \202 ux. \200 Acute pyelonephritis : de \201 ned as \202 ank pain, bacte riuria, and pyrexia. 85 % caused by ascending UTI. 15 % from haematogenous spread. Risk fac tors include stone disease, diabetes, vesico-ureteric junction re \202 ux, and pregnancy. The role of imaging is to identify obstruction, elucidate causation, and detect complicatio ns such as abscess formation. Emphysematous pyelonephritis : seen with severe infection in diabetics often in an older age group; thankfully rare. There is renal parenchymal gas and destructio n, gas can spread in perinephric space and collecting system. NCCT is advised. Prognosis is poor. Renal tuberculosis : infection via haematogenous route following pulmonary TB, often in immunocompromised. Half will have an abnormal CXR. Presentation is w ith haematuria, \202 ank pain, sterile pyuria (it is dif \201 cult to culture TB, at lea st 3 samples advised). Pathological changes include destruction of the papilla, strictures, intrarenal cavitations, abscess formation, \201 stulas, and calci \201 cation. Disease progression can descend the ureters into the bladder, prostate, and seminal vesicles howeve r this is rare. Imaging is with CT, CTU or IVU. Xanthogranulomatous pyelonephritis : chronic in \202 ammatory reaction following repeated infections usually with Proteus and is associated with stone disease. Ca n be focal or diffuse. Imaging demonstrates low density \201 lling of the pelvicalyceal s ystem and ureters. Papillary necrosis : ischaemic sloughing of the papilla, causes include analgesic NSAID abuse, sickle cell disease, diabetes, and repeated infection. Detached papi lla can be seen as \201 lling defects in the collecting system best demonstrated on IVU o r CT-IVU. Imaging Ultrasound is the initial test to identify obstruction and can show pelvical- yceal pathology/calculi. CT provides extra information regarding causation, extent of disease, a nd extra renal complications (Fig. assess renal function, pelvicalyceal and ureteric pathol ogies demonstrated as \201 lling defects within excreted contrast in the collecting syste ms. 16.11 ). CT-IVU can Information for the radiologist Signs and symptoms and suspected clinical diagnosis. SUBASH KC/NMC-15TH/2014 PYELONEPHROSIS 237 Fig. 16.11 the right kidney in a patient with pyelonephritis. Coronal CT showing ill-de \201 ned area of low attenuation (arrow) within SUBASH KC/NMC-15TH/2014 238 CHAPTER 16 Genitourinary conditions Renal tract calculi \200 Peak incidence 20 \200\22355 years, with a male: female preponde rance of 4:1. \200 Calculi form by crystallization of minerals in urine in the pelvicalyc eal system. The most common are Ca dehydration, UTI, metabolic abnormality, small bowel resecti on, and can be familial. 2 + based. Associations include Clinical presentation \200 Loin pain radiating to the groin, which can cause nausea. \200 Haematuria (often microscopic) UTI. Imaging Plain \201 lm 90 % of stone are visible (Ca \201 lms and IVU are becoming obsol ete with the high sensitivity and avail- ability of CT. 2 + ), (struvate (Mg 2 + based) may not be). Plain Ultrasound Identi \201 es hydronephrosis, indicative of obstruction. Calculi may be seen a s the cause of obstruction. They are characteristic by the fact they cast an \200\230acous tic shadow \200\231; however, small calculi may not do this, and maybe missed. CT (Fig. Gaining popularity is the CT \200\230KUB \200\231 or CT \200\230stone chaser \200\231. This is a non-IV contrast-enhanced CT scan covering the kidneys, ureters, and bla dder. Performed prone with a full bladder. All stones with the exception of those produced by antiretroviral therapy are well seen. Upper tract obstruction may be seen. Alternative d iagnosis may be found, such as appendicitis or diverticulitis. 16.12 ) IVU Performed as a series of \201 lms. The acute protocol involves a control \201 lm an d a \201 lm 10 minutes post-IV contrast, to identify obstruction. Percutaneous nephrolithotomy (PCNL) Performed in theater by urologists with a radiologist. A retrograde ureter- ogram is performed to de \201 ne the anatomy and the renal collecting system is punctured, like in a nephrostomy insertion, using ultrasound. The track is dilat ed and a device is inserted to perform stone removal. Information for the radiologist Clinical signs, i.e. side of pain, haematuria, presence of sepsis. SUBASH KC/NMC-15TH/2014 RENAL TRACT CALCULI 239 Fig. 16.12 within the upper left ureter (arrow). Coronal CT showing left-sided hydronephrosis secondary to calculus SUBASH KC/NMC-15TH/2014 240 CHAPTER 16 Genitourinary conditions Renal transplant dysfunction Since the \201 rst successful renal transplant performed by Joseph Murray in 1954 between identical twins, transplant medicine has come a long way and with the advent of immunosuppressants, transplant surgery has become a hugely successful te chnique. The majority of renal transplants are \200\230heterotopic \200\231 which means that they are transplanted to the patient with the native kidneys still Usually the patients wil l have had chronic renal failure for some time and their native kidneys will be small and s ometimes dif \201 cult to see in detail. The transplant kidney is usually placed in one of the iliac fossae, outside the peritoneum. in situ . Imaging Ultrasound (Fig. Ultrasound is used to assess dilatation of the pelvicalyceal syste m (PCS), interlobar artery \202 ow, to guide biopsy and interventions such as drainage of collections and placement of nephrostomy tubes. Ultrasound is also useful in assessment of postoperative complications including: \200 Obstruction: a small degree of collecting sy stem dilatation can be normal but persisting or worsening dilatation may indicate obstructi on. This may be due to clot or debris within the ureter or as a result of an ischaemic-rela ted stricture at the vesico-ureteric anastomosis. Nephrostomy under ultrasound guidance may be needed to relieve the obstruction in some circumstances. 16.13 ) Vascular occlusion: ultrasound is used to assess the \202 ow in the main renal artery and veins and in the interlobar arteries. This is done using Doppler ultrasound. An absent ren al vein \202 ow may indicate total occlusion whereas a partial occlusion will manifest as reverse end diastolic \202 ow in the arterial Doppler trace. Rejection: non-speci \201 c ultrasound appearances include generalized oedema of the kidne y and prominent pyramids. Clinical correlation is essential, and often biopsy is needed. Information for the radiologist Transplant anatomy, renal function, and signs of sepsis. SUBASH KC/NMC-15TH/2014 RENAL TRANSPLANT DYSFUNCTION 241 Fig. 16.13 Ultrasound showing hydronephrosis in a transplant kidney. SUBASH KC/NMC-15TH/2014 242 CHAPTER 16 Genitourinary conditions Vesico-ureteric re \202 ux \200 Predominantly affects children, with retrograde \202 o w of urine from the bladder into ureters. Primary: majority of cases. Failure of the one-way vesico-ureteric valve. \200 Secondary: to obstruction or poor functioning of the lower tract, e.g. in posterior urethral valves or neurogenic bladder. May lead to renal scarring, hypertension, and chronic renal failure. \200 See Table 16.3 for classi \201 cation. Table 16.3 vesico-ureteric re \202 ux International classi \201 cation of radiographic grading of Grade I Ureter only Grade II Ureter, pelvis , and calyces; no dilatation, normal calyceal fornices Grade III Mild or moderate dilatation and/or tortuosity of the ureter and mild or moderate dilatation of the renal pelvis. None/slight blunting of the fornices Grade IV Moderate dilatation and/or tortuosity of the ureter and moderate dilatation of the renal pelvis and calyces. Complete obliteration of the sharp angle of the fornices but maintenance of the papillary impressions in the majority of calyces Grade V Gross dilatation and tortuosity of the ureter. Gross dilatation of the renal pelvis and calyces. The papillary impressions are no longer v isible in the majority of calyces Clinical presentation Usually diagnosed in investigation of antenatal hydronephrosis and pa e- diatric UTI. Imaging Ultrasound First-line investigation in UTI or suspected re \202 ux, and for follow -up of antenatally diagnosed hydronephrosis. Local protocols vary, most units image childre n under 5 with a history of UTI, boys of any age with UTI, and children of any age with feb rile UTI. Ultrasound features indicating vesico-ureteric re \202 ux (VUR) include hydronep hrosis, dilated distal ureters, small kidneys, renal scarring, and even demonstration of re \202 ux in to the urinary tract during the examination. A normal ultrasound does not excl ude VUR. MCUG (Fig. Considered the gold standard investigation. Usually reserved for children under the age of 1 year due to the invasive nature of the procedure. Contrast is instilled into t he bladder via a catheter and the ureters imaged during voiding for retrograde passage of c ontrast/dilatation. The urethra is also imaged in boys for signs of posterior urethral valv es as a cause of VUR. 16.14 ) SUBASH KC/NMC-15TH/2014 VESICO-URETERIC REFLUX 243 Nuclear medicine Alternative technique to MCUG using 99m-pertechnetate instilled into the b ladder. Advantage is reduced radiation dose but the limitations are lack of visualization o f the urethral anatomy and dif \201 culty in diagnosing minimal re \202 ux as this may be obscured by bladder uptake. Technetium-99m dimer- captosuccinic acid (DMSA) is widely used in the investigation of VUR to diagnose and monitor renal scarring. Information for the radiologist \200 History of proven UTI. \200 Previous imaging resul ts including antenatal ultrasound scans. Fig. 16.14 bladder re \202 uxing up both ureters into the kidneys. Coronal image from micturating cystogram showing contrast from the SUBASH KC/NMC-15TH/2014 244 CHAPTER 16 Genitourinary conditions Ectopic pregnancy \200 Ectopic pregnancy occurs when the fertilized egg implants outside of the endometrium of the uterus. Incidence is 2 % and the mortality rate is around 9 \200\22314 % . \200 Risk factors incl ude previous ectopic pregnancy, pelvic in \202 ammatory disease, tubal surgery and the use of intrauterine devices. Clinical presentation Abdominal pain and vaginal spotting following a period of amenorrhea. Indirect signs of ruptured ectopic are hypovolaemic shock, and shoulder tip pain due to di aphragmatic irritation. Pain may decrease after rupture. Imaging Imaging should only be performed in stable patients. Initial evaluation of ectopic pregnancy should include a TV ultrasound (Fig. tion with a serum BhCG level. If the feature s of a normal pregnancy are not identi \201 ed at a certain pregnancy required (Table 16.15 ) in conjunc- B hCG level, then close scrutiny for an ectopic 16.4 ). Table 16.4 Correlation of BhCG, gestational age, and TVUS \201 ndings BhCG level (mIU/ml) Gestational age (weeks) Gestational sac 2000 4.5 Yolk sac 7000 5 Fetal pole 11000 5 \200\2236 Fetal heart beat 25000 5 \200\2236 Ultrasound 95 % of ectopic pregnancies are tubal. Findings include: \200 An adnexal mass: size of mass, the presence of a gestational sac, a fetal pole, heart beat, and a yolk sac. Pregnancy in a non-speci \201 c adnexal mass. \200 Pelvic \202 uid: look in the pouch of Douglas and right posterior subhepatic space. The endometrium which may be normal or there may be a pseudogestation sac. MRI Problem solving modality to con \201 rm or better de \201 ne suspected ectopic pregna ncy. Looking for: \200 An extrauterine gestational sac. \200 Fresh haematoma. \200 Tu bal wall enhancement post contrast, due to increased vascularity following implantation. SUBASH KC/NMC-15TH/2014 ECTOPIC PREGNANCY 245 Information for the radiologist \200 Salient history and examination \201 ndings. \200 Last menstrual period important. \200 B hCG level if known. Fig. 16.15 calipers) inseparable from the right ovary. This was con \201 rmed at surgery t o be a tubal ectopic pregnancy, and the patient underwent a salpingo-oophorectomy. Image from a TV ultrasound showing a complex mass (indicated by SUBASH KC/NMC-15TH/2014 246 CHAPTER 16 Genitourinary conditions Endometriosis This is the presence of endometrial glands and stroma outside the uterine cav ity and musculature. Ectopic endometrial material responds to hormonal stimuli causing cycl ical hemorrhage. Common sites for endometrial deposits include the ovaries and pelvic perit oneum. Deep endometriosis describes endometriosis that in \201 ltrates the peritoneum > 5m m. These deposits are found in the subperitoneal pelvic space, the uterosacral ligaments, r ectovag- inal septum, and also in the bladder and bowel wall. Clinical presentation Many patients are asymptomatic. It commonly presents with infertility or pelvic pain. Imaging Ultrasound and MRI are the most useful tests. Occasionally the diagnosis may be uns uspected, and suggests following other imaging, such as barium enema showing endometrial se rosal deposits on the bowel wall, typically at the rectosigmoid. Ultrasound \200 Endometriomas ( \200\230chocolate cysts \200\231) appear as complex cysti c ovarian mass with homogeneous low level echoes and a thick wall (Fig. 16.16 ). Hydrosalpinx maybe present. \200 Assessment of super \201 cial peritoneal deposits, ovar ian foci and deep endometriosis is less accurate with ultrasound. MRI \200 Typical MRI features of endometriomas include high signal intensity on T1-weighted sequences due to blood products in the cyst. There may be layering of \202 ui d within the cyst due to blood products of different ages. Features of deep endometriosis depend on whether it is in \201 ltrative small implants, vi sceral implants, or solid deep lesions in the posterior cul-de-sac. Secondary complications of adhesions, such as bowel obstruction may be seen. Information for the radiologist Detailed clinical symptoms and examination \201 ndings wi ll help the radi- ologist identify endometriotic deposits accurately particularly when the deposits are small and subtle. SUBASH KC/NMC-15TH/2014 ENDOMETRIOSIS 247 Fig. 16.16 Ultrasound showing endometrioma within the right ovary. SUBASH KC/NMC-15TH/2014 248 CHAPTER 16 Genitourinary conditions Ovarian torsion \200 The abnormal rotation of the ovary on its vascular pedicle, compromising the venous and arterial blood supply to the ovary. Predisposing factors include: ovarian cyst ( > 5cm) or cystic neoplasm, cystic ovaries associated with ovarian hyperstimulation syndrome and polycystic ovaries. Initially the venous out \202 ow and lymphatic drainage are compromised, with maintenance of arterial in \202 ow. The ovary enlarges and becomes oedematous causing arterial thrombosis, leading to ovarian ischaemia and infarction. Highest prevalence is in women of reproductive age. 17 \200\22320 % of cases occur in pregnant women. Clinical presentation Symptoms may be non-speci \201 c iting associated with tenderness/pe ritonism, be intermittent. \200\224 lower abdominal pain, nausea and vom- a palpable mass. Pain may Imaging Ultrasound First-line investigation. Both TA and TV ultrasound should be performed. \200 A unilateral enlarged ovary \200 Peripheral ovarian follicles ( \200\230string of pearl \200\231 sign) as the follicles are a coexistent ovarian mass. displaced by the oedematous stroma. Free \202 uid in pelvis. \200 Arterial and venous blood \202 ow can be maintained des pite a twisted vascular pedicle; however, absence of blood \202 ow is highly suggestive o f the diagnosis. CT (Fig. May be performed prior to ultrasound, as CT is commonly used as the \201 rst-lin e investigation for non-speci \201 c abdominal and pelvic pain. \200 An adnexal mass whi ch may be displaced to the midline. \200 Ascites or haemoperitoneum. \200 Reduced centr al enhancement of the ovary. \200 Hemorrhage and gas in the ovary if necrotic. \200 Str anding and in \202 ammatory changes in the adjacent fat. 16.17a ) MRI (Fig. May be required when pelvic ultrasound inconclusive. 16.17b ) Information for the radiologist \200 Last menstrual period \200\224 is the patient pregn ant? \200 Is there any relevant gynecological history? \200 Is the woman taking inferti lity drugs? \200 Are there any other symptoms to suggest other diagnoses, e.g. diverticulitis, appendicitis? SUBASH KC/NMC-15TH/2014 OVARIAN TORSION 249 (a) (b) Fig. 16.17 a) CT and b) MRI in a patient with left-sided ovarian torsion. The CT shows a bu lky, high attenuation left ovary, in keeping with hemorrhage. MRI showing enlarged, low sig nal intensity infarcted left ovary (long arrow), showing no enhancement compared to the nor mal right ovary (short arrow). SUBASH KC/NMC-15TH/2014 250 CHAPTER 16 Genitourinary conditions Pelvic in \202 ammatory disease \200 Infection of the upper genital tract, commonly sexu ally transmitted Chlamydia trachomatis or Neisseria gonorrhoeae . Less commonly occurs as a result of second ary infection from appendicitis or diverticulitis. Peak incidence rate is in women aged 20 \200\22324 years. Long-term sequelae include infertility, ectopic pregnancy, and chronic pain if left untreated. Clinical presentation Abdominal pain, raised temperature, vaginal discharge, abdominal tend er- ness, cervical and adnexal tenderness. Imaging Ultrasound (Fig. TA and TV ultrasound are the \201 rst-line investigations, looki ng for: \200 An enlarged and indistinct uterus. Adjacent fat may be in \202 amed and of 16.18 ) increased echogenicity. Free \202 uid in the pouch of Douglas. \200 Evidence of salpingitis which occurs in the early stages of pelvic in \202 ammatory disease (PID). A tubo-ovarian complex/abscess. \200 Perihepatitis: Fitz \200\223Hugh \200\223Curtis synd rome occurs when in \202 ammatory exudates spread to the liver via the right paracolic gutter from the pelvis, causing RUQ pa in. CT This may be the \201 rst investigation if symptoms are non-speci \201 c. Advantages o f CT over US are that \201 rstly, it is easier to appreciate the effects of pelvic in \202 ammation on adjacent structures, e.g. bowel ileus, hydroureter, or appendicitis. Secon dly, subtle signs of in \202 ammation are easier to appreciate on CT, e.g. there may be ha ziness in the pre-sacral fat, thickening of the uterosacral ligaments, peritoneal enhanceme nt or periovarian stranding in adjacent fat. Classic features of PID are also appreciated o n CT such as dilated fallopian tubes, adnexal abscesses, enlarged ovaries, and free \202 uid. MRI MRI has a higher sensitivity and speci \201 city in depicting PID compared with TV ult rasound. However, ultrasound is a relatively low cost and more readily accessible compared to MRI. MRI should only be used in dif \201 cult cases as a problem solver. Information for the radiologist Relevant history and examination \201 ndings. SUBASH KC/NMC-15TH/2014 PELVIC INFLAMMATORY DISEASE 251 Fig. 16.18 is seen to contain debris. Ultrasound showing dilated, \202 uid \201 lled fallopian tube (arrow). The \202 uid SUBASH KC/NMC-15TH/2014 252 CHAPTER 16 Genitourinary conditions Epididymitis May be acute or chronic. Usually acute, secondary to infection, resolving with antibiotic therapy. The role of imaging is to con \201 rm the diagnosis and exclude compl ications.