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Imaging is a key component of diagnosis and treatment response evaluation of urinary tract tuberculosis (UT TB). Tuberculosis can have a long latency, but if found early, one may have the opportunity to prevent complications such as ureteral strictures, obstructive nephropathy, contracted (thimble) bladder, renal parenchymal destruction/calcification, and renal failure. Imaging can aid in diagnosis and differential diagnoses, evaluate the extent of disease and complications, and guide image-directed biopsy, surgical planning, and evaluation of treatment response. Imaging abnormalities in the renal parenchyma and urinary tract at different stages of the disease, lymphadenopathy, and extra-urinary tract organ involvement are suggestive of UT TB. Recent advances in imaging modalities aid in UT TB diagnosis, follow-up, and guiding treatment., Competing Interests: Declarations. Competing interests: The authors have no relevant financial or non-financial interests to disclose. The authors have no competing interests to declare that are relevant to the content of this article., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: To assess diagnostic accuracy of perfusion CT (pCT) based biomarkers in differentiating clear-cell renal cell carcinoma (ccRCC) from non-ccRCC., Materials and Method: This retrospective study comprised 95 patients with RCCs (70 ccRCCs and 25 non-ccRCCs) who had perfusion CT (pCT) before surgery between January 2017 and December 2022. Two readers independently recorded PCT parameters [blood flow (BF), blood volume (BV), mean transit time (MTT), and time to peak (TTP)] by drawing a circular ROI on the tumor. The open-source program "Labelme" was used to create a polygonal bounding box to outline tumor borders. The intraclass correlation coefficient (ICC) was used to determine interreader agreement. The pCT model was evaluated using multivariable logistic regression analysis with the STATA 18 program to determine the importance of each of these characteristics in predicting the type of tumor., Results: Clear cell RCC had significantly greater MIP and lower TTP values than non-clear cell RCC (p < 0.05). RCCs showed considerably higher TTP, MTT, and lower MIP values than the normal renal cortex (p < 0.05). At a threshold of 129 HU, MIP had an AUC of 0.78, sensitivity and specificity of 80% and 70%, respectively, according to ROC analysis., Conclusions: pCT has a high diagnostic accuracy in distinguishing between ccRCC and non-ccRCC tumors; Clinical relevance: A non-invasive, accurate, reliable, and reproducible imaging biomarker for RCC subtype prediction is possible on pCT, which may be significant for evaluating the response to antiangiogenic therapy., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: To evaluate the performance of intravoxel incoherent motion and diffusion kurtosis imaging (IVIM- DKI) in response assessment of rectosigmoid carcinoma to chemo-radiotherapy (CRT) and compare with 18-FDG PET/CT parameters., Methods: A total of 30 patients of recto-sigmoid cancer on CRT underwent baseline staging and follow-up with IVIM - DKI. Out of this cohort, 20 patients underwent 18-FDG PET/CT. IVIM- DKI MRI and PET/CT parameters were noted from both pre and post-chemoradiotherapy (done at 6 weeks after completion) scans. Quantitative IVIM-DKI parameters, viz. apparent (ADC) and molecular (D) diffusion coefficient, perfusion coefficient (f), and kurtosis (K) were measured from non-necrotic areas and semi-quantitative PET parameters including SUV max, SUV ratio, metabolic tumor volume (MTV), total lesion glycolysis (TLG) were also measured. All these parameters correlated with the patient's response keeping RECIST 1.1 criteria as reference standard., Results: A statistically significant increase in D and ADC with a significant decline in K was noted after therapy in the entire cohort. These changes were observed in both responders as well as non-responders. No significant differences were observed in the percentage changes of these parameters post therapy amongst both groups. Among 20 patients with follow-up PET/CT imaging, a significant decline in all parameters of primary lesion was seen post-therapy. Responders (n = 12) showed a significant decline in MTV and TLG from baseline after therapy, whereas non-responders did not show any such decline. Change in TLG (ɗ TLG), followed by ɗ MTV had the strongest correlation with a positive response. A ɗ TLG value of ≥ 54.19 carried a 79% sensitivity and 83% specificity in differentiating responders from non responders., Conclusion: 18-FDG PET/CT is a more accurate single modality for assessing both response and tumor burden post therapy, while ADC and D from IVIM MRI are useful adjuncts to response assessment., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The purpose is to discuss abdominal tuberculosis mimicking malignancy involving the abdominal viscera. TB of the abdominal viscera is common, especially in countries where tuberculosis is endemic and in pockets of non-endemic countries. Diagnosis is challenging as clinical presentations are often non-specific. Tissue sampling may be necessary for definitive diagnosis. Awareness of the early and late disease imaging appearances of abdominal tuberculosis involving the viscera that can mimic malignancy can aid detecting TB, providing a differential diagnosis, assessing extent of spread, guiding biopsy, and evaluating response., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: The purpose is to discuss abdominal tuberculosis mimicking malignancy involving the lymph nodes, peritoneum, and the GI tract., Conclusion: Awareness of the pathophysiology and imaging appearance on various modalities of abdominal tuberculosis involving the lymph nodes, peritoneum, and the GI tract that may simulate malignancy can aid differentiation, diagnosis, and therapy, particularly in areas where tuberculosis is endemic., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Contrast-enhanced ultrasound (CEUS) is an extension and an enhanced form of ultrasound that allows real-time evaluation of the various structures in different vascular phases. The last decade has witnessed a widespread expansion of CEUS applications beyond the liver. It has shown fair potential in kidneys and its diagnostic efficacy is comparable to CT and MRI. Ultrasound is the well-accepted screening modality for renal pathologies, however, it underperforms in the characterization of the renal masses. CEUS can be beneficial in such cases as it can help in the characterization of such incidental masses in the same sitting. It has an excellent safety profile with no risk of radiation or contract-related nephropathy. It can aid in the correct categorization of renal cysts into one of the Bosniak classes and has proven its worth especially in complex cysts or indeterminate renal masses (especially Bosniak Category IIF and III). Few studies also describe its potential role in solid masses and in differentiating benign from malignant masses. Other areas of interest include infections, infarctions, trauma, follow-up of local ablative procedures, and VUR. Through this review, the readers shall get an insight into the various applications of CEUS in kidneys, with imaging examples., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Kaposi sarcoma (KS) is a form of cancer that primarily appears on the skin but can potentially involve internal organs. There are several types of KS. The purpose of this article is to discuss the manifestations of KS and their appearance on imaging, the differential diagnoses associated with these findings, and molecular markers associated with KS that can aid appropriate diagnosis and therapy., (© 2021. The Author(s).)

Renal fusion anomalies are common congenital anomalies of the urogenital tract and have their genesis in the early embryonic period. They are classified into partial fusion anomalies (e.g., crossed fused ectopia, and horseshoe kidney) and complete fusion anomalies (e.g., fused pelvic kidney). Horseshoe kidney is the most common renal fusion anomaly and is characterized by the presence of two distinct functioning kidneys on either side of the vertebral column, with fusion occurring at the inferior poles in majority of the cases. Crossed fused ectopia is characterized by the presence of an ectopic kidney that crosses the midline and fuses with the orthotopic contralateral kidney, whereas fused pelvic (pancake) kidney is a complete fusion anomaly characterized by extensive medial fusion of both kidneys in the pelvis. Fusion anomalies are often associated with abnormalities of renal rotation, migration, and vascular supply, which predispose the kidneys to a number of complications and create difficulty during retroperitoneal surgeries and interventions. They are also associated with other congenital abnormalities of the urogenital tract, gastrointestinal tract, cardiovascular system, and skeletal system. Hence, a thorough understanding of the etiopathogenesis and radiological features of fusion anomalies is important for directing patient management. This review summarizes the embryological basis, clinical presentation and imaging approach to renal fusion anomalies, followed by detailed anatomical and radiological description of the morphological types, and the complications associated with these anomalies., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Urogenital tuberculosis is the most common form of extrapulmonary tuberculosis. Genital organ involvement occurs as a continuum of urinary tract tuberculosis and often presents a diagnostic challenge due to the non-specific nature of the symptoms. Delay in diagnosis may lead to complications such as infertility and perineoscrotal sinuses. Imaging plays an important role in raising timely suspicion of tuberculosis. In this article, we describe the imaging findings of male genital tuberculosis and the differential diagnosis. High-resolution ultrasonography (HRUS) is the best modality for assessing the epididymis, testis, scrotum and vas deferens, whereas MRI is optimal for evaluating the prostate, seminal vesicles and ejaculatory ducts. Epididymis is the most common site of genital tuberculosis, and presents as a nodular lesion limited to the tail or as diffuse enlargement. The proximal vas deferens is also frequently involved due to anatomical contiguity and shows diffuse or nodular thickening. Advanced cases may show pyocele formation and scrotal wall sinuses. Testicular involvement is almost always secondary to epididymal tuberculosis and presents as single or multiple nodules, diffuse enlargement, or the 'miliary' pattern. Isolated testicular involvement should raise suspicion of malignancy. Tuberculosis of the prostate is often asymptomatic. The most common imaging manifestations are nodules and the diffuse forms, which may later evolve into abscesses. Fibrosis and calcification occur with healing. Seminal vesicle and ejaculatory duct involvement with fibrosis may cause infertility. Awareness of the imaging findings would enable the radiologist to raise timely suspicion, so that prompt treatment is initiated and complications are prevented.

Prostate cancer is the fourth most common cancer and population-based screening programmes are being increasingly adopted worldwide. Screening-positive patients undergo routine transrectal ultrasound (TRUS)-guided systematic biopsy, which is the current diagnostic standard for prostate cancer. However, systematic biopsies suffer from poor sensitivity, especially for the tumors of the anterior prostate and apex as well as in large volume glands. In the past decade, MRI-guided targeted biopsies have come up, which utilize the multiparametric capability of MRI to target lesions for sampling. MRI/TRUS fusion biopsies combine the advantages of MRI-targeting with that of real-time guidance made possible by TRUS. MRI-TRUS fusion biopsies are being increasingly used in men with high clinical suspicion of prostate cancer who have had prior negative systematic biopsies. A large number of fusion biopsy platforms are currently available commercially. Although the basic workflow is similar, there are differences in the operational software, biopsy routes offered, TRUS acquisition technique, type of correction applied at the time of fusion and in the probe tracking hardware. The article describes the current role and indications of MRI-TRUS fusion biopsy followed by a discussion on the workflow, patient preparation, biopsy procedure and complications.

Objective: The article attempts to describe the indications, classification, and surgical anatomy of the commonly performed urinary diversion procedures, followed by the imaging protocol and radiological appearances of the normal postoperative anatomy and complications related to these procedures., Contents: Diversion procedures are used to reroute urine after cystectomy and in patients with refractory neurogenic or outlet obstruction of the urinary bladder. Broadly, these can be classified as continent and incontinent diversions. Patients with urinary diversions frequently undergo radiological investigations for the detection of complications. Commonly, a loopogram or pouchogram is performed few weeks after the surgery to look for leak, whereas CT or MRI is used for long-term follow-up. Postoperative complications can be early (within 30 days of the surgery) or delayed and include leaks, collections, strictures, calculi, parastomal hernia, small bowel obstruction, and oncologic recurrence., Conclusion: A variety of urinary diversion procedures are commonly performed and interpretation of the postsurgical anatomy can be overwhelming for the general radiologist. This article provides a basic understanding of the normal anatomy as well as a thorough discussion on the imaging protocol and radiological appearances of the potential complications associated with these procedures.

Objective: To investigate the effect of number and combination of b values used on the accuracy of estimated Intravoxel Incoherent Motion (IVIM) parameters using simulation and clinical data., Materials and Methods: Simulations with seven combinations of b values were performed for 4, 6, 8, and 13 numbers of b values with six different values of D, D*, and f parameters. Two methodologies were implemented for IVIM analysis: standard biexponential model (BE) and biexponential model with total variation penalty function (BE + TV). Clinical data set of six patients with prostate cancer was retrospectively analyzed using 4, 8, and 13 b values., Results: BE + TV method showed lesser error and lower variability in simulation and clinical data, respectively. 8 and 13 b values showed good agreement in the values of parameters estimated with high correlation coefficient (ρ = 0.83-0.93). Clinical data showed high spurious noise with lower b values [4 b values leading to high coefficient of variation (CV); however, substantially, lower CV was observed with 8 and 13 b values]., Discussion: BE model with TV penalty function is robust to combination of b values used for IVIM analysis. Combination of 8 b values provided a reasonably good accuracy in IVIM parameters.

Purpose: To evaluate the diagnostic performance of stalk morphology on diffusion-weighted imaging (DWI) in comparison with conventional MRI in predicting muscle invasion in urinary bladder cancer., Methods: The study was prospective and approved by the institutional ethics committee. A written informed consent was obtained from all the patients. The study included 56 patients who presented with bladder mass between January 2014 and November 2015. After excluding 16 patients, 40 patients with 92 tumors were assessed. All the 40 patients underwent MRI at 3.0 Tesla (Achieva, Philips) inclusive of DWI (b0, 500, 1000 and 1500). Two radiologists evaluated the images independently, and disparities were resolved through consensus. For predicting muscle invasion on T2-weighted images, tumor morphology (papillary versus non-papillary), distensibility of the underlying bladder wall, and perivesical fat infiltration were evaluated. On DWI, the criterion used in a previous study (Takeuchi et al.) was used along with tumor stalk morphology. Findings were compared with histopathology using Pearson's χ 2 test, and diagnostic performance indices were calculated., Results: All the evaluated features were present with significantly higher frequency in muscle-invasive tumors (p < 0.001). The finding of absent or distorted stalk on DWI had the highest sensitivity (87.5%) and specificity (97.6%). Conventional imaging features of non-papillary stalk morphology, restricted distension of underlying bladder wall, perivesical fat infiltration, as well as the previous DWI criterion were less sensitive (56.3%, 68.8%, 56.3% and 56.3%, respectively) in predicting muscle invasion., Conclusions: Assessment of the morphology of the reactive tumor stalk on DWI has better diagnostic performance in predicting muscle invasion than conventional MRI.