Table 2.

Differential diagnoses table for adherent placenta

Modality	Adherent Placenta	Submucosal fibroid	Leiomyo sarcoma	Invasive mole	Placental site trophoblastic tumour	Endometrial carcinoma
Ultrasound	Absence of the usual subplacental sonoluscent space Increased placental lacunae “Swiss cheese” appearance	Most frequent Ultrasound appearance is that of a concentric solid, hypoechoeic mass. If the fibroid is small and isoechoeic the only USG sign may be a bulge in the endometrial/uterine contour. Distorsion of uterine cavity with intracavitary extension	Complex mass lesion causing Posterior wall enhancement and acoustic shadowing	Complex multicystic/solid mass filling the uterine cavity and invading myometrium	Heterogenous, hyperechoeic, Solid intramural mass with cystic vascular spaces - Hypervascular type and hypovascular type	Diffuse/focal Echogenicity Increased texture of endometrium Echogenic mass lesion of endometrium extending in to the myometrium
CT	Exophytic bulging vascular mass	Well defined isodense mass lesion distorting the uterine contour	Heterogenous mass lesion with areas of hypodensity	Filling defects in a markedly contrast enhanced lesion probably represent hydatids penetrating the myometrium and should suggest invasive mole.	Prominent enhancement of the focal myometrial wall with vessels	Shows enhancing myometrium peripherally and low-density tumor centrally Sensitivity-83% Specificity-25%
MRIT1	Heterogenous signal intensity within the placenta	Sharply marginated with low to intermediate signal intensity on T1 and T2 weighted.	Iso intense mass lesion	ill-defined, permeative masses with densely enhanced solid components and tiny cystic lesions.	Isodense mass in relation to the myometrium	Intermediate to low signal intensity Sensitivity-92% Specificity-90%
MRI T2	Hypointense intraplacental bands Hyperintense and heterogenous Focal thinning of myometrium and interruption of junctional zone	One third of fibroids have a hyperintense rim on T2 weighted images	Heterogenous hyperintense	Mixed signal intensity or diffuse low signal intensity	Hetergenous intense signal of mass lesion	Low signal intensity
Contrast enhancement MRI	Avid contrast enhancement	Enhancement is homogenous and later than the healthy myometrium Fibroid enhancement can be hypointense (65%), isointense (23%), or hyintense (12%) in relation to that of the myometrium	Centripetal type of enhancement-- T1 low signal intensity suggests extensive necrosis	Marked enhancement indicates viability of the tumour	Marked enhancement Areas of contrast enhancement correlated with changes in S-β-HCG level	High diagnostic accuracy than CT for myometrial invasion
MRI DWI	Clearly defines the border between the placenta and myometrium because only the placenta shows high signal intensity Focal thinning of myometrium caused by the placenta increeta can be visualised well	Cellular leiomyoma – high signal intensity Degenerated leiomyoma-Low signal intensity	High signal intensity. The mean ADC lower than that of normal myometrium & degenerated leiomyomas Overlap with that of cellular leiomyoma and ordinary leiomyomas	Increase in signal on DW 1 Highlights the vascularity	Decrease in signal intensity as water content is less	Enhancement less than that of myometrium Less distinct enhancement on delayed scans
Scintigraphy	Tc-99m MDPused for bone scandoes not cross placenta. Placental scintigraphy with 113m In (Indium) 82% sensitivity for adherent placenta and localisation of placental site	Intense, heterogeneous, and persistent vascular pelvic mass during a Tc-99m RBC scan ‘doughnut sign’	Indium-111 pentetreotide (OctreoScan tm.) for metastatic disease increased uptake in regions of known disease	hCG has proved to be a useful target antigen for immunoscintigraphy Increased uptake		Lymphatic mapping with both labelled colloid and patent blue violet for sentinel lymphode and staging
PET	Blood flow through the areas of high metabolic activity	Focal or varying FDG uptake (Not useful to differentiate from malignancy). Mode-rately intense uptake denotes proliferation of smooth muscle cells	Intense FDG accumulation Ring like accumulation- necrosis Heterogenous accumulation — pathological pleomorphism	High FDG uptake metabolically active tumour and micrometastasis. More sensitive than MRI and CT	Non- hypermetabolic areas suggest PSTT	Estrogen receptor expression imaging fluoroestradiol (F-18 FES)uptake. Poorly differentiated tumors often have increased and abnormal breakdown of glucose, indicated by FDG